Download Gross Morbid Pathology of Selected Avian Diseases

6/15/2013
Gross Morbid Pathology of
Selected Avian Diseases
AVIAN PATHOLOGY
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C. L. Davis Symposium
St. Paul, MN
July 10, 2013
Rob Porter, D.V.M., Ph.D.
Minnesota Veterinary Diagnostic Lab
UM College of Veterinary Medicine
Dept. Vet Population Medicine
St. Paul, MN
[email protected]
Emphasis on poultry
Broiler, layer, turkey, duck, pheasant
Pet birds
“Not all avian pathology is enlarged liver
and spleens and fibrin-covered air
sacs…only about 40% is!”
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THANK YOU
 John Barnes, North Carolina State University
 John King, Cornell University
 Purdue University, ADDL
 Univ. of Wisc., Dept. of Pathobiological Science
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Aviary System
Enriched Cage
Enriched Cage
Pheasant Pens
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Partridges
23 weeks
Bobwhite Quail
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Outline
• Systemic, Lymphohematopoietic,
Musculoskeletal, Respiratory, Integumentary,
Nervous, Cardiovascular, Digestive, Urogenital,
Neoplasia
• Virus Taxonomy (8th report): Fauquet et al.
(eds.) Elsevier Press, 2005.
ictvonline.org/virusTaxonomy.asp
• CD Poultry Diseases
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Normal pelvic nerve plexus
Marek’s disease
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Normal eye
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Day 4
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Day 35
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Spondylolisthesis
Normal vertebral
column
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Broiler chicken
Turkey
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Normal turkey wing
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Courtesy of Dr. Joel Cline
Auburn University
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Target
lesions
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Thank you!
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Gross Morbid Pathology of Selected Avian Species
July 10, 2008
1.
Rob Porter, D.V.M., Ph.D., Diplomate American College of Veterinary Pathologists,
Diplomate American College of Poultry Veterinarians. Minnesota Veterinary Diagnostic
Laboratory and University of Minnesota College of Veterinary Medicine, Department of
Veterinary Population Medicine, 1333 Gortner Avenue, St. Paul, MN 55108
Tel: (612) 624-7400
Fax: (612) 624-8707
[email protected]
2.
Intro Slide: “Not all avian pathology is enlarged liver and spleens and fibrin-covered air
sacs…only about 40% is!”
3.
Acknowledgements for contribution of photographs.
John Barnes, North Carolina State University
John King, Cornell University
University of Wisconsin, Department of Pathobiological Sciences
4.
Poultry Industry
Broiler: Progeny of broiler breeders, indoor confinement/litter bedding, marketed at 5-7
weeks of age; feed efficiency <2.0.
Turkey: progeny of turkey breeders; poult = young turkey; indoor confinement or range
rearing, hens marketed at 15 weeks and toms at 18-24 weeks (30-45 pounds)
Layer (usu. white leghorn): Mostly cage layers; pullet = immature laying hen; lay for
approximately 40 weeks, then molted at 60+ weeks of age, used for second cycle for another
30 weeks. Hen produces 250+ eggs in a lifetime (2 years).
Duck: White Pekin duck; raised on litter or plastic grating; feed efficiency <2.0, processed
at 38 days of age (6.5 lbs).
5.
Newer variations of layer housing: A. Cageless aviary system- hens access multiple levels,
perches and litter floor, B. Enriched battery cages- hold larger number (40-100) of hens and
provide perches, scratch pad and hiding places.
6.
Game bird production: Pheasants, partridges, grouse and quail. Pheasants and partridges
raised indoors (litter) 8 weeks then placed in flight pens on soil. Ready to market after 20-23
weeks.
7.
Oultine: systemic, Lymphohematopoietic, Musculoskeletal, Respiratory, Integumentary,
Nervous, Cardiovascular, Digestive, Urogenital, Neoplasia.
Virus Taxonomy, Classification and Nomenclature of Viruses.
ictvonline.org/virusTaxonomy.asp
1
__________________________________________________________________________
SYSTEMIC DISEASES
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
8.
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10.
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Head, chicken
Cyanosis/ edema wattle and comb Highly pathogenic avian influenza
(HPAI)
Ventral neck, chicken
Edema
HPAI
Legs, chicken
Mf cutaneous hemorrhage
HPAI
Proventriculus, chicken Mf hemorrhagic proventriculitis
HPAI
Peritoneum, chicken
Mf peritoneal hemorrhage
HPAI
Trachea, chicken
Hemorrhagic tracheitis
HPAI
Family Orthomyxoviridae, Genus Influenzavirus A, Species Influenza A virus:
negative stranded ssRNA virus
AI viruses have total of 15 HA and 9 NA. Pathogenicity determined by chick inoculation or by
amino acid sequence at HA cleavage site. Most HPAI has been H5 or H7. Italy H5N2 and
H7N1. Hong Kong H5N1 = “bird flu” with potential to directly infect humans. Virus replicates
in endothelium, myofibers, renal tubules, pancreatic acinar cells. Lesions of coagulative necrosis
and vascular thrombosis/ischemia.
DDX: END, ILT, IBV, END, bacterial sepsis
14.
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Eggs, turkey
Shell thinning, wrinkling and depigmentation
Low path AI
DDX: NDV, avian metapneumovirus
_____________________________________________________________________________
Yolk sac/heart, chick
Fibrinous pericarditis/yolk sacculitis
Escherichia coli
Heart, chicken
Fibrinous pericarditis
E. coli
Liver, chick
Fibrinous perihepatitis
E. coli
Peritoneum, chicken
Fibrinous peritonitis, “egg yolk”
E coli
Oviduct, hen
Fibrinous salpingitis/peritonitis
E. coli
Liver, intestine, hen
MF granulomatous (coligranuloma)
E. coli
Most common poultry serotypes are O1, O2, O35, O78, and many are untypeable.
21.
22.
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DDX, pericarditis: E coli, Chlamydophila, MG, P. multocida
DDX, granulomas: Mycobacteriosis, LL, Leukosis/sarcoma complex
DDX, egg yolk peritonitis: P. multocida, HPAI, Salmonella
_____________________________________________________________________________
Head, chicken
Facial edema
Exotic Newcastle Disease
Proventriculus, chicken Annular mucosal hemorrhage
END
Ovary, hen
Mf hemorrhagic oophoritis
END
Intestine, chicken
Necrohemorrhagic enterotyphlitis/tonsillar necrosis END
Esophagus, rooster
Mf necrohemorrhagic esophagitis/pharyngitis
END
2
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Trachea, chicken
Hemorrhagic tracheitis
END
Family Paramyxoviridae, Subfam Paramyxovirinae, Genus Avulavirus,
Species Newcastle disease virus, negative stranded ssRNA virus
Exotic (Velogenic) Newcastle disease (END); also lentogenic (mild) and mesogenic (moderate)
pathogenicity. Usu. lentogens in U.S. END usually introduced by birds that are more resistant
to disease.
DDX, tracheitis: HPAI, ILT, IBV
DDX, enteritis: HPAI, erysipelas, DVE, acute FC
DDX, esophagitis: Trichomoniasis, HPAI, DVE
_____________________________________________________________________________
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Head, turkey
Cutaneous infarction
Erysipelas rhusiopathiae
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Liver, spleen, turkey
MF necrotizing hepatitis/splenitis
E. rhusiopathiae
29.
Duodenum, turkey
Acute hemorrhagic enteritis
E. rhusiopathiae
Causes swine erysipelas and erysipeloid of humans. All gallinaceous birds, usually turkeys.
Lesions of sepsis with bacterial emboli, thrombosis, necrosis and hemorrhage (closely resembles
colibacillosis of broiler chickens).
Hemorrhagic hepatitis/myocarditis, Necrohemorrhagic splenitis
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DDX: P. multocida, Salmonella, E. coli, HPAI and END.
______________________________________________________________________________
Oviduct, turkey
Fibrinoheterophilic salpingitis
Pasteurella multocida
Wattle, rooster BB
Fibrinoheterophilic cellulitis
P. multocida
Lung, turkey
Necr. fibrinohet. pleuropneumonia
P. multocida
Spleen air sac, turkey
Fibrinous airsacculitis and necr. splenitis
P. multocida
Heart, turkey
Fibrinoheterophilic pericarditis
P. multocida
“Fowl cholera,” Sepsis of both domestic and wild birds- usually older birds, e.g., turkeys >10
weeks.. Sixteen serotypes- 1, 3 and 4 are most common isolates. Enters through pharynx of bird.
Lesions of bacterial embolism, thrombosis, necrosis and disseminated intravascular coagulation.
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DDX: Ornithobacterium, E. coli, Staph.aureus, Chlamydophila
_____________________________________________________________________________
Spleen, air sac, duckling Fibrinous airsacculitis/necr. splenitis
Riemerella anatipestifer
Brain, duckling
Purulent meningoencephalitis
R. anatipestifer
Heart, liver, duckling
Fibrinous pericarditis/perihepatitis
R. anatipestifer
Oviduct, duckling
Fibrinoheterophilic salpingitis
R. anatipestifer
“New duck disease.” Closely related to Ornithobacterium rhinotracheale. Lesions of septicemia
closely resemble colibacillosis of broiler chickens.
DDX: E. coli (best), chlamydiosis, P. multocida
_____________________________________________________________________________
39.
Liver, poult
Mf necrotizing hepatitis
Salmonella pullorum
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Heart, broilers
Mf granulomatous myocarditis
Salmonella pullorum
41.
Heart, spleen, chick
Mf necrohemorrhagic splenitis
Salmonella pullorum
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Cecum, poult (closed/open)
Fibrinonecrotic typhlitis
Salmonella pullorum
New designation of “Salmonella enterica subspecies enterica serovar Gallinarum-Pullorum”
represents combination of S. pullorum and S. gallinarum. S.gallinarum causes ovarian
degeneration and sepsis in adult birds in contrast to S. pullorum. Nonmotile Salmonella:
possess few flagella.
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DDX: E. coli, Mycoplasma synoviae, viral arthritis-reovirus, paratyphoid salmonellae
_____________________________________________________________________________
Eye, poult
Hypopyon
Salmonella arizona
Brain, poult
Purulent meningoencephalitis
Salmonella arizona
Air sac, poult
Fibrinous airsacculitis
Salmonella arizona
Cecum, poult
Necrohemorrhagic typhlitis
Paratyphoid Sal.
Liver, pigeon
Mf necrotizing hepatitis
Paratyphoid Sal.
Salmonella arizona; biochemically distinct from paratyphoid Salmonella but cause similar
clinical disease and lesions. Paratyphoid salmonellae refers to the motile serotypes
(approximately 2400), and does not include S. pullorum and S. gallinarum.
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DDX: paratyphoid Salmonella, E. coli, pullorum-typhoid
_____________________________________________________________________________
Head, hen
Fibrinoheterophilic cellulitis
Staphylococcus aureus
Tibiotarsus, hen
Necrotizing fibrinohet osteomyelitis Staph aureus
Leg, turkey
Fibrinoheterophilic arthritis
Staph aureus
Foot, duck
Granulom. Plantar pododermatitis Staph aureus
Liver, hen
Mf to coalesc. necrotizing hepatitis Staph aureus
S. aureus requires skin penetration. Coagulase positive strains are the most pathogenic.
DDX: other systemic bacteria, esp. P. multocida and E. coli
_____________________________________________________________________________
LYMPHOHEMATOPOIETIC
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Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
Wing, chick
Necrohemorrhagic dermatitis
Necrotic dermatitis
Bursa of Fabricius, broiler
Cloacal bursal atrophy
Chicken infectious anemia
Thymus, chick
Thymic atrophy
Chicken infectious anemia
Femur, chick
Bone marrow aplasia
Chicken infectious anemia
Family Circoviridae, Genus Gyrovirus, Species Chicken anemia virus, ssDNA virus
Chicken infectious anemia virus: circovirus replicates in hematopoietic cells and T lymphocytes
 anemia and immunosuppression. Circovirus immunosupression promotes Staphylococcus
aureus/Clostridium infection in skin. Had been referred to as “blue wing disease,” but is actually
necrotic dermatitis. DDX: exudative diathesis
DDX: IBDV, trichothecene mycotoxins
4
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____________________________________________________________________________
Cloacal bursa, broiler
Necrohemorrhagic cloacal bursitis Infectious bursal disease
Leg, broiler
Intramuscular hemorrhage
Infectious bursal disease
Family Birnaviridae, Genus Avibirnavirus, Species Infectious bursal disease virus;
dsRNA virus
Replicates in bursa of Fabricius lymphocytes of young chickens, followed by spread to other
lymphoid sites  cytolysis and immunosuppression. Classic serotype 1, variant serotype 1 and
serotype 2 viruses.
DDX: ionophore toxicosis, chicken infectious anemia, trichothecene mycotoxins, exudative
diathesis (vitamin E deficiency)
_____________________________________________________________________________
59.
Liver, bursa, WL hen
Hepatic/bursal lymphoma
Lymphoid leukosis
60.
Liver, WL hen
Mf hepatic lymphoma
Lymphoid leukosis
61.
Liver, WL hen
Diffuse hepatic lymphoma
Lymphoid leukosis
Family Retroviridae, Subfamily Orthoretrovirinae, Genus Alpharetrovirus,
Species Avian leukosis virus; RNA Reverse Transcribing virus  DNA proviral insert
into host cell genome
Retrovirus of leukosis/sarcoma complex. Chicken genome contains endogenous viral loci (ev).
Exogenous virus subgroup A transmitted vertically and horizontally. Exogenous virus induces
neoplastic transformation of B lymphocytes. Subgroups A-D avian leukosis viruses can produce
lymphoid leukosis. ALV Subgroup J produces myelocytomatosis.
_____________________________________________________________________________
62.
Lung, spleen, pheasant Splenomegaly/pulmonary edema
Marble spleen disease
Family Adenoviridae, Genus Siadenovirus, Species Turkey adenovirus A (Marble spleen
disease virus), ds DNA virus
Type II adenovirus (old terminology) related to hemorrhagic enteritis virus of turkeys; pheasants
3 – 12 months, IgM-positive B cells and macrophages are primary viral targets. Death from
pulmonary edema/hemorrhage or secondary infection.
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DDX: Salmonella, erysipelas
_____________________________________________________________________________
Body, pullet
Marek’s disease “range” paralysis Marek’s disease
Pelvic nerves, broiler
Neural lymphoma
Marek’s disease
Liver, spleen
Hepatic/splenic lymphoma
Marek’s disease
Pectoral muscle, broiler
Muscular lymphoma
Marek’s disease
Kidney, pullet
Renal lymphoma
Marek’s disease
Eye, broiler “grey eye”
Ocular/iridial lymphoma
Marek’s disease
Body, processed broiler
Cutaneous lymphoma
Marek’s disease
Family Herpesviridae, Subfamily Alphaherpesvirnae, Genus Mardivirus,
Species Gallid herpesvirus 2 (Marek’s Disease virus type 1)
5
MD serotype 1 (oncogenic) strain. Productive infection (viral replication) in feather follicle
epithelium and transmitted in dander. Neoplastic transforming infection and latent infection in T
lymphocytes. Lesions observed as early as 4 weeks.
DDX: Mycobacteriosis, coligranuloma, lymphoid leukosis in older birds (visceral lesions)
_____________________________________________________________________________
70.
Subcutis, Macaw
Mf subcutaneous hemorrhage
Avian polyomavirus
71.
Heart, liver, Macaw Anemia, epicardial hemorrhage, hepatomegaly Avian polyomavirus
Family Polyomaviridae, Genus Polyomavirus, Species Budgerigar fledgling disease
polyomavirus (Avian polyomavirus), dsDNA virus
Originally identified as budgerigar fledgling disease/French molt. Papovaviridae contains
papillomavirus and polyomavirus families. I have diagnosed in Macaw, Electus parrot,
Budgerigar, Lovebird and Conure. Intranuclear inclusion bodies in spleen, kidney mesangial
cells and liver Kupffer cells.
_____________________________________________________________________________
MUSCULOSKELETAL SYSTEM
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Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
Femur/ tibiortarsus, normal broiler
Rapid growth long bones
Normal
Leg, young pheasant
Angular limb deformity
Metabolic/traction
_____________________________________________________________________________
Foot, parakeet
Articular gout
Leg, rooster
Articular gout
Mostly males, occurs with or without visceral/renal gout; high protein in diet promotes
hyperuricemia, possible genetic predisposition; occurs with or without renal disease or renal
gout. Not as common as visceral gout.
_____________________________________________________________________________
76.
Body, turkey
Nonambulatory poult
Ionophore toxicosis
77.
Leg, turkey
Muscular necrosis/degeneration
Ionophore toxicosis:
Polyether ionophores: Promote movement of mono and divalent cations across cell membrane.
Toxicosis causes cellular loss of K+ and gain of Ca+2 into mitochrondria  cell death.
Myocytolysis with proliferation of satellite and myocyte nuclei (inset photo).
DDX: Infectious bursal disease, chicken infectious anemia, Vit E/Se deficiency, injection site
myopathy
_____________________________________________________________________________
78.
Hock joint/footpad, poult
Tenosynovitis/arthritis(right) Mycoplasma synoviae (MS)
79.
Wing, poult
Tenosynovitis
Mycoplasma synoviae
Exudate clear to serofibrinous
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“Infectious tenosynovitis.” Chicken, turkey and guinea fowl. Usu. colonizes subclinical upper
respiratory tract, but can invade synovial membranes to cause tenosynovitis and sternal bursitis.
Vertical and horizontal transmission. Lameness is primary sign with occasional airsacculitis.
Pure MS infection is usually clear to serofibrinous fluid, not suppurative, but can be altered by
secondary bacteria.
DDX: Staph. aureus, viral arthritis, salmonellae
_____________________________________________________________________________
80.
Pectoral muscle, broiler Deep pectoral m. infarction
Deep pectoral myopathy
“Green muscle disease, deep pectoral myopathy,” turkeys (esp. breeder hens during artificial
insemination) and meat-type chickens with vigorous exercise  swelling of supracoracoideus
muscle within fascial sheath  ischemic necrosis of muscle. Usually found at processing.
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86.
87.
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DDX: ionophore toxicosis, injection site myopathy
_____________________________________________________________________________
Skull, crested polish chicken
Open fontanelle, skull
Common in crested
polish breed
Skull, crested polish chicken
Open fontanelle, melanosis
_____________________________________________________________________________
Vert. column, turkey
Fibrinoheterophilic/caseous osteomyelitis Staph., P. multocida
and E. coli
_____________________________________________________________________________
Leg, rooster
Osteopetrosis/periosteal hyperostosis
Leukosis/sarcoma virus
Leg, rooster
Osteopetrosis
ALV
Retrovirus: many of the avian leukosis viruses causing lymphoid leukosis can also induce
osteopetrosis. Infected osteoblasts proliferate and produce periosteal and some endosteal bone.
Lesions begin in tibiotarsus and tarsometatarsus, but can spread to other long bones, pelvis and
ribs.
_____________________________________________________________________________
Pectoral muscle, layer
Granulomatous myositis/cellulitis Killed vaccine injection
_____________________________________________________________________________
Body, Chicken
Gastroc. Tendon rupture, bilateral
Viral arthritis
Leg, chicken
Gastroc. Tendon rupture with hemorrhage Viral arthritis
Leg, chicken
Gastroc. Tendon rupture with hemorrhage Viral arthritis
Leg, tom turkey
Gastroc. Tendon rupture with hemorrhage Turkey Reo
Family Reoviridae, Genus Orthoreovirus, Species Avian orthoreovirus, dsRNA virus
Chicken reovirus is transmitted both vertically and horizontally. Cause tenosynovitis + rupture
and hemorrhage of gastrocnemius tendon (tendon tensile strength pullet > broiler). Often
associated with heterophilic infiltrates in the myocardium. Turkey reoviral arthritis recently
observed and characterized. Turkey virus is distinct from chicken reo and does not infect
chickens.
DDX tenosynovitis: Staph.aureus, Mycoplasma synoviae, trauma
_____________________________________________________________________________
91.
Leg, white leghorn hen
Acute femoral fracture
Osteoporosis
7
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93.
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Keelbone, WL hen
Ribs, chick
Ribs, chick
Head, chick
Leg, chick
Rickets
Osteoporosis, keelbone deformation
Medial deviation ribs, rickets
Deformed ribs/beaded costocondral jxn
Pliable beak, rickets
Pliable tarsometatarsus, Rickets
Osteoporosis
Rickets
Rickets
Rickets
Rickets
Laying hen mobilizes 2% of skeletal calcium into egg shell each day. Deficiencies or imbalance
of calcium, phosphorus and vitamin D3 (cholecalciferol) can promote osteoclastic resorption of
bone without sufficient osteoblast activity.
_____________________________________________________________________________
97.
Body, broiler
Spondylolisthesis
Spondylolisthesis
98.
Vertebral column, broiler
Dorsal deviation T4, S/C compression
Spondylolisthesis=“kinky back” of 3-6 week broilers. Deviation of T4 vertebral body and
deformation of T5 resulting in spinal cord compression (histo photo). Conformation defect
(genetic trait) complicated by rapid growth rate of broiler.
____________________________________________________________________________
99.
Vertebral column, broiler
Normal (L) and spondylosis/osteomyelitis Enterococcus
100.
Vertebral column, broiler
Necrotizing, fibrinohet osteomyelitis T6
Enterococcus
Most of these lesions in broilers associated with Enterococcus cecorum- affect mostly vertebral
body T6.
DDX: Staph aureus, E. coli
____________________________________________________________________________
101.
Tibia, broiler
Tibial dyschondroplasia
102.
Tibia, turkey
Osteochondrosis/ Tibial dyschondroplasia
Core of avascular cartilage in proximal tibiotarsus (metaphysis) or tarsometatarsus + bowing of
bone and lameness. Failure of blood vessels to invade zone of cartilage hypertrophy in growth
plate. Promoted by genetic line of broiler #1 and marginal deficiency of calcium or a Ca/P
imbalance. Experimentally induced by Fusarium roseum toxin.
_____________________________________________________________________________
103.
Leg, turkey
Curvature of tibiotarsus
Mycoplasma meleagridis
Turkey syndrome 65 chondrodystrophy: inadequate linear bone growth at physis while
appositional growth remains normal; associated with MM infection (impaired vascular invasion)
and genetic predisposition (autosomal recessive inheritance).
DDX: tibial dyschondroplasia, rickets; Chickens, turkeys, ratites: lateral rotation of 90-180
degrees is multifactorial; rapid growth rate with early nutritional deficiency (Ca, P, Vit D3,
protein) complicated by poor traction.
8
_____________________________________________________________________________
RESPIRATORY SYSTEM
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Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
Body, chick
Chick-respiratory distress
Tracheal obstruction
Trachea, chick
Focal granulomatous bronchitis
Aspergillus fumigatus/flavus
Lung, poult
Mf granulomatous pneumonia/airsacculitis
Aspergillosis
Lung, chicken
Granulomatous airsacculitis
Aspergillosis
_____________________________________________________________________________
Spleen, air sac, parrot
Necrotizing splenitis
Chlamydophila psittaci
Genus Chlamydophila includes C. psittaci, C. abortus, C. felis, C. caviae, C. pneumoniae and C.
pecorum. Obligate intracellular parasite. Systemic inflammation characterized by necrosis and
fibrinous exudates, hepatosplenomegaly.
Turkeys, pigeons, ducks and psittacine birds. Eight serovars (A-H): A = psittacine, B/E =
pigeons, B/D = turkey. Obligate intracellular parasite.
DDX: P. multocida, Erysipelothrix, Pacheco’s disease, Staphylococcus, Salmonella
_________________________________________________________________________
109.
Oral cavity, poult
Catarrhal rhinitis/blepharitis
Cryptosporidium baileyi
Cryptosporidium baileyi: chicken, turkey, duck- respiratory epithelium, bursa of Fabricius,
cloaca; C. meleagridis- turkey and quail small intestine. Host specific and do not infect
mammals.
110.
111.
112.
113.
DDX: Bordetella avium
_____________________________________________________________________________
Body, pullet
Respiratory distress
Infectious laryngotracheitis
Trachea, pullet
Fibrinohemorrhagic tracheitis
ILT
Trachea, WL hen
Fibrinonecrotic tracheitis with occlusion
ILT
Trachea, WL hen
Fibrinonecrotic tracheitis with glottis occlusion
ILT
Family Herpesviridae, Subfamily Alphaherpesvirnae, Genus Iltovirus, Species Gallid
herpesvirus 1, (infectious laryngotracheitis virus), dsDNA virus
Propagated on chorioallantoic membrane of embryonated eggs. Cytolytic for respiratory
epithelium of nasal sinus, conjunctiva, air sacs and trachea. No evidence of viremia. Trigeminal
ganglion is site of viral latency.
DDX: fowl pox, infectious bronchitis, END, HPAI
_____________________________________________________________________________
114.
Air sac, chick
Serous airsacculitis
Infectious bronchitis
115.
Kidney, broiler
Urolithiasis/hydroureter
IB, nephrotropic strain
Family Coronaviridae, Genus Coronavirus, Species Infectious bronchitis virus (Group 3
species), Positive sense ssRNA virus
9
Coronavirus of chickens that causes respiratory signs, decreased egg production and wrinkled
egg shells in layers. Nephrotropic strains can cause urolithiasis and visceral gout.
DDX for airsacculitis: NDV, MG
_____________________________________________________________________________
116.
Head, WL hen
Marked caseous sinusitis/conjunctivitis
Avibacterium paragallinarum
“Infectious coryza,” Chickens are the natural hosts of A. paragallinarum. Usually begins as
catarrhal infection with facial edema later complicated by other bacteria  fibrinous to caseous
inflammation.
DDX: P.multocida, E. coli, Staph. aureus, vitamin A deficiency, pox.
_____________________________________________________________________________
117.
Head, turkey
Serous/catarrhal infraorbital sinusitis
Avian pneumovirus
Family Paramyxoviridae, Genus Metapneumovirus, Species Avian Metapneumovirus,
negative sense ssRNA virus
Can also cause malformation of oviduct with misshapen eggs/poor shell quality. Associated with
“swollen head syndrome” in chickens- fibrinpurulent exudates in subcutis of head, neck and
wattles.
118.
119.
120.
121.
DDX: Mycoplasma gallisepticum, respiratory cryptosporidiosis (C. baileyi).
_____________________________________________________________________________
Head, turkey
Infraorbital sinusitis
Mycoplasma gallisepticum
Head, turkey
Serous/catarrhal infraorbital sinusitis
MG
Air sac, poult
Mild acute serofibrinous airsacculitis
MG
Lung, liver, chicken
Fibrinous pericarditis and perihepatitis
MG/E. coli
“Chronic respiratory disease of chickens” and “infectious sinusitis of turkeys” Can cause
decreased egg production in adults. MG occurs naturally in galliformes, especially chicken and
turkey, but also isolated from gamebirds. Transmitted both vertically and horizontally. Infected
birds remain carriers. Mycoplasma is extracellular parasite that causes degeneration of epithelial
cells.
DDX: Cryptosporidiosis, avian metapneumovirus
_____________________________________________________________________________
122.
Air sac, poult
Mild, acute serofibrinous airsacculitis
Mycoplasma meleagridis
Specific pathogen of turkeys in which primary lesion is airsacculitis of 1-4-week-old poults.
Referred to as veneral disease of Tom turkeys.
DDX: Mycoplasma synoviae, gallisepticum or iowae, Newcastle disease.
_____________________________________________________________________________
123.
Air sac; poult
Serous airsacculitis
Newcastle disease (lentogen).
124.
Infraorbital sinus poults Caseous infraorbital sinusitis
NDV plus bacteria
DDX: acute MG, MM, ORT, pneumovirus, Bordetella avium complicated by E. coli
10
125.
_____________________________________________________________________________
Lung, heart, turkey Necrofibrinohet. pericarditis/pleuropneumonia Ornithobacterium
rhinotracheale
Affects turkeys, chickens and many other galliformes. Airsacculitis and unilateral pneumonia in
chickens; pneumonia/hepatosplenomegaly in turkeys. Fibrinopurulent arthritis and osteomyelitis
in older turkeys and chickens.
DDX: P. multocida #1 and E. coli.
_____________________________________________________________________________
126.
Lung, pheasant Acute, diffuse hemorrhagic pneumonia
Avian paramyxovirus-3
Family Paramyxoviridae, Genus Avulavirus, Species Avian Paramyxovirus 3,
negative sense ssRNA virus
Avian paramyxovirus-3; AMPV-1, 2, 3, 6 and 7 are known to cause disease in poultry. APMV-2
and 3 cause mild respiratory signs and decreased egg production in turkey breeders. APMV-3 is
subclinical or causes neurologic signs in psittacine birds. NDV is an APMV-1.
DDX: Any bacterial sepsis
_____________________________________________________________________________
127.
Trachea, bobwhite quail
Fibrinonecrotic tracheitis
Quail bronchitis
Family Adenoviridae, Genus Aviadenovirus, Species Quail bronchitis virus, dsDNA virus
Type 1 adenovirus causes high mortality in young bobwhite quail. Also causes multifocal
necrotizing hepatitis, splenitis and pancreatitis.
DDX: Aspergillosis, Salmonella, E. coli
_____________________________________________________________________________
128.
Trachea, chicken
Tracheal nematodiasis
Syngamus trachea
129.
Trachea, peahen Mf granulomatous tracheitis with nematodes
Syngamus trachea
Direct or indirect (earthworms) life cycle. Affects most galliformes. Form granulomas at site of
attachment to tracheal mucosa.
DDX, tracheal nodules: granulomatous nodules can resemble Marek’s disease lymphoma, ALVinduced myelocytoma or aspergillosis.
_____________________________________________________________________________
130.
Air sac, chicken
Air sac acariasis
Cytodites nudus
Cytodites nudus = air sac mite of galliformes; lives in bronchi, lungs, air sac, and bone cavities
Sternostoma tracheacolum = tracheal mite of passerines-finches, canaries
_____________________________________________________________________________
131.
Body, poult
Serous blepharitis, submand. edema
Bordetella avium (acute)
132.
Trachea, turkey Tracheitis w/chrondrolysis/ luminal collapse
B. avium
“Turkey coryza,” 2 to 6-week-old poults (and occasionally broilers) causing blepharitis and
submandibular edema. Usually concomitant infections that create conjunctival exudate.
11
Colonizes apices of respiratory epithelium and produces cytotoxin that causes chondrolysis of
tracheal rings.
DDX: Respiratory cryptosporidiosis, mycoplasmosis, chlamydiosis, NDV can mimic or
complicate infection.
_____________________________________________________________________________
INTEGUMENTARY SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
133.
Head, Mollucan Cockatoo
Feather alopecia and dystrophy
Beak and Feather Dis
134.
Body, Mollucan Cockatoo
Feather alopecia
Beak and Feather Dis
135.
136.
137.
138.
Family: Circoviridae, Genus: Circovirus, Species: Beak and feather disease virus
Circovirus causing feather dystrophy and immunosuppression. Necrosis, fracture, bending or
hemorrhage, or dystrophic feathers that emerge from follicle and cease growing after each
successive molt. Flank contour feathers in most feather tracts  primary and secondary
feathers of wings, tail and crest. Occasionally see progressive distortion of beak. Death caused
by secondary infections.
_____________________________________________________________________________
Beak, chicken
Normal beak amputation
Beak normal
Beak, chicken
Exuberant granulation tissue
Beak inadequate trim
_____________________________________________________________________________
Body, turkey
Chronic,, hemorrhagic sternal bursitis
“Breast blister “
Body, turkey
Sternal bursitis
Most common in heavy tom turkeys: Conformation and pressure effects; no cutaneous pterylae
over sternal bursa  friction of bursa against litter bursal edema and hemorrhage  fibrosis
and occasional rupture.
139.
Sternal keel, processed turkey
Multifocal ulcerative dermatitis
“Breast button”
Contact dermatitis; contact/friction of sternal skin (keel) with coarse, moist, contaminated litter.
Breast buttons and breast blisters do not necessarily occur together.
_____________________________________________________________________________
140.
Foot, chicken
Chronic, granulomatous plantar pododermatitis
Staph. aureus
Usually. moist environment or constant pressure on foot.
_____________________________________________________________________________
141.
Body, layer
Necrohemorrhagic dermatitis/alopecia
Cannibalism
142.
Cloaca, layer
Multifocal ulcerative cloacitis
Prolapse/cannibalism
_____________________________________________________________________________
143.
Body, processed broiler Fibrinoheterophilic cellulitis
E. coli cellulitis
Referred to as “inflammatory process” at processing plant. Usu. caseous to fibrinous exudate in
subcutis of abomen or flank initiated by skin trauma. Usu. found at processing to cause carcass
12
downgrade. Management problem- incidence increased by poor feather coverage, crowding,
coarse, most litter, aggressive strains of birds.
______________________________________________________________________________
144.
Body, pullet chick
Hemorrhagic omphalitis
Bacterial infection of navel often
progresses to yolk sac infection.
DDX: Salmonella, E. coli, Pseudomonas, Enterococcus, Staph aureus
_____________________________________________________________________________
145.
Feet, pullet chicks
Cutaneous dehydration
Dehydration/water deprivation
DDX: Frostbite, contact dermatitis with disinfectant (quat, cresol, phenol)
_____________________________________________________________________________
146.
Cloaca, layer
Cloaca normal
147.
Cloaca, layer
Cloaca after egg lay
148.
Cloaca, layer
Necrohemorrhagic cloacitis with prolapse
Cloacal prolapse complicated by trauma/cannibalism. DDX: HPAI, END
_____________________________________________________________________________
149.
Head, chick
Serous blepharitis with edema
Conjunctivitis vaccine rxn
DDX: field challenge with respiratory virus- ILT, IBV, NDV, ammonia toxicosis
_____________________________________________________________________________
150.
Head, chick
Granulomatous/hemorrhagic cellulitis
Contaminated MD vaccine
151.
Head, poult
Necrotizing cervical myositis
Contaminated NDVvaccine
_____________________________________________________________________________
152.
Head, turkey
Serous blepharitis
Cryptosporidium baileyi
153.
154.
155.
156.
157.
DDX: avian metapneumovirus, NDV, acute Bordetella infection.
_____________________________________________________________________________
Foot, turkey poult/hen
Digit amputation turkey
Normal microwave process
Beak, poult
Normal (L) and locally extensive thermal necrosis (R)
Microwave
_____________________________________________________________________________
Feet, broiler (L) and turkey (R) MF necro. plantar pododermatitis
Contact dermatitis
_____________________________________________________________________________
Body, cockatiel nestling
Emphysema
Secondary to primary respiratory disease
_____________________________________________________________________________
Wing, Broiler chick
Hemorrhagic dermatitis
Vitamin E deficiency
Exudative diathesis = vitamin E and selenium-responsive dermal hemorrhage; oxidative damage
to endothelial cells extravasation of blood and edema fluid through capillaries
DDX: necrotic dermatitis
_____________________________________________________________________________
158.
Head, WL hen
Chronic blepharitis with cleft formation
Eyelid notch syndrome
Probably primary eyelid trauma or bacterial infection with ulceration of lid and cleft formation.
_____________________________________________________________________________
159.
Head, chicken
Proliferative dermatitis (dermatophytosis)
Favus
13
Microsporum gallinae; chicken, turkey, duck, quail, canary
_____________________________________________________________________________
160.
Vent, chicken
Cutaneous acariasis
Ornithonyssus sylviarum
Inset- higher mag. of mites
161.
Vent feathers
Cutaneous acariasis
Ornithonyssus sylviarum
Covered with mites, mite excreta (no eggs/nits at base of shaft)
Ornithonyssus sylviarum = northern fowl mite; entire life cycle spent on chicken
Dermanyssus gallinae = red chicken mite; feed on chickens at night and reside in litter, nests,
crevices during the day
_____________________________________________________________________________
162.
Head, pullet/hen
Proliferative blepharitis and dermatitis
Fowl pox
163.
Uropygial gland, poult Proliferative dermatitis/adenitis of uropygial gland Fowl pox
Family Poxviridae, Subfamily Chordopoxvirinae, Genus Avipoxvirus, Species Fowl pox
virus, dsDNA virus
Avian poxviruses are antigenically and immunologically distinguishable from one another: fowl,
turkey, pigeon, canary, junco, mynah, psittacine, quail, sparrow, crow, peacock, penguin, alala,
apapane, condor, starling. Mechanical transmission through injured skin; can be spread by
mites and mosquitoes to skin, conjunctiva and mouth.
DDX: Pecking trauma/cannibalism, squamous cell carcinoma, bacterial/fungal conjunctivitis
_____________________________________________________________________________
164.
Head, budgerigar
Proliferative dermatitis
Knemidocoptes pilae
165.
Feet, chicken
Proliferative pododermatitis
Knemidocoptes mutans
Scaley-leg mite, inhabits nonfeathered sites- beak, legs. DDX: Vitamin B6, Zn deficiency, biotin
deficiency
166.
Body, chicken
Cutaneous pediculosis
Various chewing lice- Order Mallophaga
Note egs/nits near base of feather shaft
Chicken: Cuclogaster (head louse), Goniocotes (fluff louse), Menacanthus (body louse)
Turkey: Menacanthus, Chelopistes, Oxylipeurus
Duck and goose: Anaticola, Trinoton
Pigeon: Columbicola, Campanulotes
_____________________________________________________________________________
167.
Body, broiler
Fibrinous sternal bursitis
Staph. aureus, Mycoplasma synoviae
_____________________________________________________________________________
168.
Body, broiler
Necrohemorrhagic dermatitis
Necrotic dermatitis
169.
Body, processed broiler Locally extensive necrohemorrhagic dermatitis
Usu. sudden death in 4-8-week-old broilers, but also turkeys. Caused by Clostridium
perfringens type A, Clostridium septicum and Staphylococcus aureus, often complicated by
immunosuppression from infectious bursal disease, chicken infectious anemia,
reticuloendotheliosis virus. Associated with edema, hemorrhage and gas-production in subcutis
of breast, wings, flank.
DDX: Cutaneous aspergillosis, candidiasis, E. coli cellulitis (inflammatory process).
14
_____________________________________________________________________________
Wing, tom turkey
Normal wing
Wing,thigh tom turkey Hemorrhagic cellulitis with emphysema
Turk clostr cellulitis
Body, tom turkey (3)
Hemorrhagic cellulitis with emphysema
Turk clostr cellulitis
Turkey clostridial dermatitis/cellulitis- associated with subcutaneous overgrowth of Clostridium
septicum and Clostridium perfringens. Assoc. with wet litter and large body size.
_____________________________________________________________________________
173.
Body, chicken
Xanthomatosis
Idiopathic
170.
171.
172.
Yellow, subcutaneous nodules (granulomatous inflammation of fat) in galliformes and psittacine
birds. Sometimes associated with obesity and lipomas. Classic poultry lesion described in
1950’s.
_____________________________________________________________________________
NERVOUS SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
174.
Eye, chicken
Ulcerative keratitis
Ammonia toxicosis
175.
Eyes, chicken
Ulcerative keratitis
Ammonia toxicosis
Wet litter conditions/poor air movement  aerosolized NH3 above 25ppm impairs ciliary
apparatus of trachea/sinus and direct toxic effect on corneal epithelium (simple diffusion).
_____________________________________________________________________________
176.
Body, chicks
Ataxia
Avian encephalomyelitis
177.
Proventriculus, chick
Mf lymphocytic proventriculitis
AE
178.
Eye, chicken
Cataract
AE
Family Picornaviridae, Genus Hepatovirus, Species Avian encephalomyelitis(-like) virus,
Positive sense ssRNA virus
Infects chicken, turkey, quail, pheasant; enterotropic virus with both horizontal and vertical
transmission. Sudden decrease in egg production in adults. Fine head tremors in young birds.
DDX, proventricular lesion: Marek’s disease, vitamin E deficiency
DDX, cataracts: congenital cataracts, nutritional deficiency, induced by artificial light, old age.
_____________________________________________________________________________
179.
Body, mallard duck
Flaccid paralysis
Clostridium botulinum type C toxin
Prevents release of acetylcholine from neuronal presynaptic vesicles  “limberneck.” = flaccid
paralysis of wings, neck, legs and eyelids. Wide variety of birds affected.
DDX: organophosphate, lead toxicosis
_____________________________________________________________________________
180.
Eye, poult
Hypopyon
Ochroconis gallopava
181.
Brain, poult
Necrotizing/granulomatous encephalitis
O. gallopava
Formerly Dactylaria. Contaminant in hard wood shavings; translucent to grey lesions in
tissue compared to Aspergillus. Dematiaceous fungus with hyphae observed in H&E.
15
Neurologic disease is most common clinical sign in chicks and poults. Lesions in eye, brain,
lung and air sac.
DDX: Aspergillus, coliforms, Salmonella (hypopyon), Vitamin E deficiency (brain lesion)
_____________________________________________________________________________
182.
Eye, chick
Fibrinous panophthalmitis
E. coli (puncture)
DDX: Aspergillus, Staph. aureus
_____________________________________________________________________________
183.
Brain, Black australorp
Melanosis
Increased melanin accumulation in
variety of tissues is a breed trait.
_____________________________________________________________________________
184.
Body, pigeon
Ataxia
Avian paramyxovirus-1
Family Paramyxoviridae, Genus Avulavirus, Species Avian Paramyxovirus-1, negative
sense ssRNA virus. APMV-1 virtually identical to Newcastle disease virus; primarily
nonsuppurative encephalitis in pigeons. There are no diagnostic gross lesions.
DDX: head trauma, lead toxicosis, vitamin E deficiency.
_____________________________________________________________________________
185.
Body, broiler
Ataxia
Vitamin E deficiency
186.
Brain, Turkey
Encephalomalacia and hemorrhage
Vitamin E deficiency
Brain lesions are not responsive to selenium supplementation, unlike muscle and skin lesions.
DDX: aspergillosis, ochraconosis, avian encephalomyelitis (body position)
_____________________________________________________________________________
CARDIOVASCULAR SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
187.
Heart, parrot
Aortic atherosclerosis
Most often observed in aged blue-front Amazon, African grey parrots and macaws.
Accumulation of lipid/macrophages/fibrous connective tissue in media of aorta  subclinical or
decreased blood supply to brain and pectoral muscle  death
_____________________________________________________________________________
188.
Head, turkey
Hematochezia
Aortic rupture
189.
Abdominal cavity, turkey
Hemoperitoneum
Aortic rupture
190.
Abdominal cavity, turkey
Aortic rupture
12-16 weeks, M>F, rupture near
cranial mesenteric (celiac) artery
191.
Peritoneum, turkey
Perirenal hemorrhage
DDX: trauma, cannibalism, anticoagulant rodenticides
16
Males, 8-14 weeks, probably
a variant of aortic rupture of turkeys
192.
193.
194.
195.
196.
_____________________________________________________________________________
Body, broiler
Ascites
Peritoneum, broiler
Ascites
Peritoneum, broiler
Ascites
Heart, broiler
Right ventricular dilatation
Heart, broiler
Left atrioventricular endocardiosis
Ascites syndrome of broilers and ducklings: right-sided congestive heart failure promoted by
rapid growth rate hypoxemia  polycythemia, increased blood viscosity, decreased
erythrocyte deformability  pulmonary hypertension, increased cardiac workload  right-sided
cardiac failure and ascites.
DDX: Cardiomyopathy, salt toxicosis, liver disease
_____________________________________________________________________________
197.
Heart, broiler
Vegetative valvular endocarditis, RV
E. coli
DDX: Erysipelothrix, Enterococcus, Salmonella, Staphylococcus aureus
_____________________________________________________________________________
198.
Heart, Macaw
Anemia, Mf myocardial hemorrhage
Avian polyomavirus
199.
Heart, parrot
Hydropericardium
Avian polyomavirus
DDX, hydropericardium: salt toxicosis, avian viral serositis; EEE, West Nile virus
_____________________________________________________________________________
200.
Heart, poult
Cardiomegaly
Dilated cardiomyopathy
201.
Heart, turkey
Left and right ventricular dilatation Dilated cardiomyopathy
Dilated cardiomyopathy (Round heart disease), poults 2-3 weeks old, cause unknown, but
possible genetic predisposition complicated by hypoxia in incubator with pathogenesis similar to
ascites syndrome of broilers.
DDX: salt/sodium toxicosis if ascites present
_____________________________________________________________________________
DIGESTIVE SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
202.
Intestine, chicken
Intestinal ascariasis
203.
204.
205.
206.
Ascaridia galli (chicken, turkey); A. dissimilis (turkey); A. columbae (pigeon)
_____________________________________________________________________________
Crop, pullet
Beak trim injury
Crop, pullet
Choanal and ingluvial hemorrhage Beak trim injury- hemorrhage
_____________________________________________________________________________
Crop, turkey poult
Proliferative ingluvitis
Candida albicans
Oral cavity, chicken
Proliferative stomatitis
Candida albicans
17
Candida albicans = crop mycosis; ubiquitous yeast colonizes mucosal surfaces when normal
bacterial microflora is altered by or antibiotics or other diseases.
DDX: capilliariasis, poxvirus, trichomoniasis
____________________________________________________________________________
207.
Crop, Bobwhite quail
Prolif ingluvitis with intralesion nematodes Capillariasis
Capillaria contorta (direct), C. annulata (earthworm intermediate host). Eggs shed in feces and
larvae develop in 10-15 days, consumed by bird or earthworm. Larvae hatch and burrow into
wall of crop and upper esophagus. Mature after additional 15-25 days.
Capillaria obsignata (direct life cycle) resides in small intestine of birds and can cause decreased
egg production in layer and broiler breeders.
DDX: candidiasis, vitamin A deficiency, trichomoniasis
_____________________________________________________________________________
208.
Yolk sac, chick
Chick normal yolk sac
209.
Yolk sac, chick
Hemorrhagic yolk sacculitis
210.
Peritoneum, chick
Fibrinous peritonitis
Coliforms, Salmonella, Enterococcus. Peritonitis often secondary to yolk sac infection and
rupture
_____________________________________________________________________________
211.
Liver, chick
Gall bladder distension
Inanition,
212.
Gizzard, poult
Foreign body- litter impaction
Litter impaction
213.
214.
215.
216.
Gall bladder enlarges with inanition (“starve out”). Litter consumption indicative of discomfort
of digestive tract (e.g., viral enteritis) or poor adaptation to brooder.
_____________________________________________________________________________
Duodenum, broiler
Mf necrotizing enteritis
Eimeria acervulina: schizogony and
gametogony in prox. small intestine
Jejunum, broiler
Mf necrotizing enteritis
E necatrix: schizogony in intestine
and gametogony in cecum
Cecum, chicken
Necrohemorrhagic typhlitis E. tenella: schizogony and
gametogony in cecum
Cecum, chicken
Fibrinonecr. Typhlitis
E. tenella
217.
Ileum, broiler
Necrotizing enteritis
218.
Cecum, turkey
Catarrhal typhlitis/coccidiosis
Eimeria brunetti: schizogony in
prox. small intestine and
gametogony in distal small intestine
Eimeria adenoeides
Turkey: Eimeria adenoeides-cecum, E. dispersa-small intestine, E. gallopavonis- ileum and
colon; E. meleagrimitis- duodenum/jejunum
DDX for E. tenella is Salmonella
_____________________________________________________________________________
219.
Cecum, pheasant
Fibrinonecrotic typhlitis
Eimeria cholchici
18
Coccidia in pheasants are Eimeria colchici (cecal cores); E. duodenalis and E. phasiani.
DDX: Salmonella
____________________________________________________________________________
220.
Intestine, duck
Necrohemorrhagic enteritis
Duck viral enteritis (DVE)
221.
Esophagus, duck
Fibrinonecrotic esophagitis
Duck viral enteritis
Family Herpesviridae, Subfamily Alphaherpesvirus, Species Anatid herpesvirus 1 (duck
plague herpesvirus), dsDNA virus
DVE =“Duck plague.” Susceptibility limited to family anatidae-ducks, geese and swans.
Transmitted by secretions/direct contact with rapid, high mortality. Probable carrier state in wild
ducks. Lesions of vasculitis and necrosis: petechial hemorrhage and multifocal necrosis of
heart, liver, pancreas, kidney. Intestines and gizzard filled with blood. Necrohemorrhagic to
fibrinonecrotic membranes in esophagus
DDX: END, P. multocida, necrotic enteritis
_____________________________________________________________________________
222.
Liver, WL hen (2 views)
Hepatic lipidosis/hemorrhage
Fatty liver disease
Most common in caged layers due to high calorie rations and minimal exercise. Also occurs in
turkey breeder hens early in egg production.
223.
Liver, cockatiel
Hepatic lipidosis
Fat diet, e.g. sunflower/safflower
Fatty liver DDX: bacterial sepsis, Pacheco’s disease, chlamydiosis
_____________________________________________________________________________
224.
Gizzard, duckling
Ventricular (gizzard) myodegeneration
Vitamin E deficiency
Vitamin E is natural antioxidant in alcoholic form. Selenium (co-factor for glutathione
peroxidase) supplementation can reduce lesions in duck, turkey and chicken. Breast muscle
similarly affected. Muscle lesions of Vit E deficiency are partially selenium responsive.
DDX: furazolidone toxicosis, lymphoma
_____________________________________________________________________________
225.
Liver, Mynah bird
Hepatic hemochromatosis and pulmonary edema
Excessive iron storage is disease of mynahs, toucans, birds of paradise. Hemochromatosis;
enhanced intestinal iron absorption compared to other birds and mammals, with inability to
down-regulate iron absorption when fed iron rich ration. Ascites often occurs from hepatic
disease or heart failure. Hepatomegaly, golden brown with scattered dark foci (Kupffer cells
packed with hemosiderin).
_____________________________________________________________________________
226.
Body, turkey
Cloacal hemorrhage
HE of turkeys
227.
Intestine, spleen, turkey Hemorrhagic enteritis/necrotizing splenitis HE of turkeys
Family Adenoviridae, Genus Siadenovirus, Species Turkey adenovirus 3 (Turkey
hemorrhagic enteritis virus), dsDNA virus
19
Hemorrhagic enteritis of turkeys = subgroup II adenovirus infecting turkeys 4 weeks of age or
older; causes immunosuppression of turkeys by cytopathic effects on IgM-positive B cells and
macrophages. Serologically related to marble spleen disease virus of pheasants and avian
adenovirus splenomegaly virus of broiler breeders.
DDX: Cannibalism; END, HPAI
_____________________________________________________________________________
228.
Cecum, chicken (2 views)
Cecal nematodiasis
Heterakis gallinarum
H. gallinarum infects variety of galliformes. Severe infections can form granulomas in cecal
wall. Paratenic host (ova) for Histomonas meleagridis protozoa.
_____________________________________________________________________________
229.
Cecum, liver, turkey Mf necr. hepatitis/fibrinonecr. typhlitis
Histomonas meleagridis
Inset: cytology of cecum  amoebae of Histomonas
DDX: Salmonella
_____________________________________________________________________________
230.
Oral cavity, WL hen
Focal ulcerative stomatitis
DDX: Idiopathic, trichothecene mycotoxin, disinfectant contact necrosis
_____________________________________________________________________________
231.
Esophagus, goose
Focal esophageal dilatation/impaction
Lead toxicosis
232.
Gizzard, vulture
Erosive ventriculitis with bile staining
Lead toxicosis
Chickens and turkeys more resistant than waterfowl. Acid-fast intranuclear inclusions in renal
tubule epithelium, basophilic stippling of erythrocytes and myonecrosis of heart.
_____________________________________________________________________________
233.
Body, chicken
Pectoral muscle atrophy, emaciation
Mycobacteriosis
234.
Viscera, chicken Mf granulomatous enteritis, hepatitis and splenitis Mycobacteriosis
Mycobacterium avium subspecies avium, serovars 1, 2, 3. Observed most often in psittacine
birds rather than galliformes, usually adult poultry.
DDX: Coligranuloma; Marek’s disease, lymphoid leukosis, carcinomatosis
_____________________________________________________________________________
235.
Intestine, broiler
Fibinonecrotic enteritis
Necrotic enteritis
236.
Intestine, broiler
Fibinonecrotic enteritis
Necrotic enteritis
Clostridium perfringens toxin types A and C. Overgrowth often preceded by coccidiosis or
ascariasis, immunosuppression (IBD), wheat products in ration.
DDX: coccidiosis, ulcerative enteritis (C. colinum)
_____________________________________________________________________________
237.
Peritoneum, parrot
Splenomegaly and mesenteric edema
Pacheco’s herpesvirus
238.
Liver, parrot
Necrotizing hepatitis
Pacheco’s herpesvirus
20
Family Herpesviridae, Subfamily Alphaherpesvirinae, Unassigned Genus, Species Psittacid
herpesvirus 1, (Parrot herpesvirus), dsDNA virus
DDX: Chlamydiosis, polyomavirus; Salmonella
_____________________________________________________________________________
239.
Cloaca, parrot
Cloacal papilloma
Idiopathic
No virus consistently isolated. Can be associated with hepatic or biliary carcinoma.
____________________________________________________________________________
240.
Proventriculus, Af. Grey
Normal
241.
Proventriculus, Af. Grey
Proventricular dilatation disease
Bornavirus
Myenteric ganglioneuritis, Macaw wasting disease. Diagnosis: lymphoplasmacytic
inflammation of myenteric plexus of tunica muscularis of ventriculus and proventriculus, as well
as small intestine and crop. Nonsuppurative encephalitis present in some instances. Bornavirus
infection or exposure identified in recent reports
DDX: Gastric foreign body or other obstruction
_____________________________________________________________________________
242.
Body, poult
Marked abdominal distension
Viral enteritis
243.
Intestine, cecum, poult Catarrhal enterotyphlitis
Viral enteritis
“Poult enteritis/mortality syndrome (PEMS)” Multifactorial transmissible disease 1-3 week-old
poults with diarrhea, growth depression or death. Complex of enteric viruses (astrovirus,
reovirus, rotavirus, coronavirus), Cryptosporidium meleagridis and bacteria (enteropathogenic E.
coli).
_____________________________________________________________________________
244.
Body, poult/tom (2 views)
Crop dilatation/Pendulous crop
Cause uncertain in turkey and chicken; genetic predisposition, often rapid water consumption in
hot weather, other dietary influences such as high fat or starch in ration
DDX: Impaction, foreign body
_____________________________________________________________________________
245.
Oral cavity, WL hen
Fibrinonecrotic stomatitis
Quaternary ammonium
Quaternary ammonium disinfectants: direct toxic insult to mucosa
DDX: pox, vitamin A deficiency, trichothecene mycotoxins
_____________________________________________________________________________
246.
Abdomen, poult (2 views)
Ascites
Sodium toxicosis
247.
Abdomen, subcutis, poult (2 views)
Ascites, anasarca
Sodium toxicosis
Greater than 2% sodium in ration or 4g/kg body weight  visceral hemorrhages and ascites
DDX: dilated cardiomyopathy
_____________________________________________________________________________
21
248.
Cecum, rhea
Fibrinonecrotic typhlitis
Intestinal spirochetosis
Brachyspira hyodysenteriae: Four pathotypes; inhabit the cecum, ileum and rectum or rheas.
Spirochetes not identified in ostrich and emu. Necrotizing typhlitis with high mortality in
rheas.
Brachyspira intermedia: chickens- typhlitis and diarrhea, no mortality; Brachyspira alvinipulli:
chickens-typhlitis, reduced growth rate and reduced egg production; Brachyspira pilosicoli:
chickens- diarrhea and decreased egg production.
_____________________________________________________________________________
249.
Intestine, chicken
Intestinal cestodiasis
Chicken: Genus: Raillietina, Davainea, Amoebotania, Choanotaenia and Hymenolepsis;
Turkey: Raillietina, Metroliasthes; Ducks/geese: Hymenolepsis, Fimbrairia
_____________________________________________________________________________
250.
Proventriculus, pigeon Proventricular parasitism
Tetrameres americana
T. americana, a proventricular nematode, has grasshopper/cockroach intermediate host. Adult
female embeds in proventricular glands. Often subclinical, but can lead to emaciation and
anemia.
T. crami- wild and domestic ducks
T. fissispina- wild and domestic ducks
_____________________________________________________________________________
251.
Macaw chick
Fibrinous cellulitis
Trauma: crop tube injury
DDX: esophageal thermal burn, injection granuloma
_____________________________________________________________________________
252.
Oral cavity, dove
Fibrinonecrotic stomatitis
Trichomonas gallinae
253.
Esophagus, pigeon
Fibrinonecrotic esophagitis
Trichomonas gallinae
Pigeons (canker), falcons (frounce), flagellated protozoan that colonizes upper digestive tract
mucosa to form multifocal to coalescing, punctate fibronecrotic lesions. Lesions can extend to
crop/proventriculus and flagellates can occasionally invade liver (multifocal necrosis).
DDX: vitamin A deficiency, candidiasis, poxvirus
_____________________________________________________________________________
254.
Oral cavity, broiler
Mf ulcerative stomatitis and glossitis
Trichothecene
mycotoxicosis
Fusarium mold toxins: T-2, diacetoxyscirpenol (DAS) and deoxynivalenol (DON, vomitoxin),
and nivalenol. Promote feed refusal and necrosis of oral mucosa and skin in contact with mold
toxins, rapid necrosis/depletion of lymphoid and hematopoietic tissues.
DDX: quaternary ammonium exposure, wet pox, trichomoniasis.
22
255.
_____________________________________________________________________________
Liver, duodenum, poult Mf necrotizing hepatitis and pancreatitis
Turkey viral hepatitis
(TVH)
Virus causing TVH has not yet been identified, suspect picornavirus. Affects only turkeys;
under 6 weeks; usu. sudden death with causing multifocal hepatic and pancreatic necrosis.
_____________________________________________________________________________
256.
Int, Liver, Bobwhite quail
Mf fibrinonecr enteritis, necr. hepatitis Ulcerative enteritis
UE = “Quail disease.” Clostridium colinum: acute infection resulting in sudden death; quail
most susceptible, but also turkey, chicken, pheasant, grouse, partridge, pigeon. Bird ingests
feces, litter, water or feed contaminated with spores multifocal fibrinonecrotic enteritis +
peritonitis and pale, necrotic foci in liver. Splenomegaly and hemorrhage also observed.
DDX: necrotic enteritis, coccidiosis, histomoniasis
_____________________________________________________________________________
257.
Esophagus, chicken
Proliferative esophagitis (hyperkeratosis)
Vitamin A deficiency
Vitamin A maintains epithelial structure/function and mucus production . Deficiency: decreased
egg production, ocular discharge with eyelid pasting, hyperkeratosis caused by squamous
metaplasia of mucous glands; renal tubular degeneration results in visceral gout. Affects a wide
variety of birds.
DDX: candidiasis, wet pox, trichomoniasis, capillariasis
_____________________________________________________________________________
UROGENITAL SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
258.
Egg, chicken
Egg membrane (air cell) mycosis, Aspergillosis
Aspergillus fumigatus
Common contaminant of ducts, vents of incubators.
_____________________________________________________________________________
259.
Body, pullet chick
Ureteral/cloacal urate accumulation
Dehydration
260.
Kidney, pullet chick
Visceral gout
Dehydration
DDX: high calcium or vitamin D3 in ration, avian nephritis virus (astrovirus in Japan; affects
only chicks).
_____________________________________________________________________________
261.
Eggs, WL chicken
Soft shell and shell-less eggs
Egg drop syndrome
Family Adenoviridae, Genus Atadenovirus, Species Duck adenovirus A
(Duck adenovirus 1 = egg drop syndrome virus)
Subgroup III adenovirus (old terminology); not documented in U.S., but in Europe an Asia
causes egg production losses in otherwise healthy laying hens. Histology: Lymphoplasmacytic
inflammation of shell gland of oviduct.
23
262.
263.
264.
265.
266.
DDX: low calcium in ration, NDV, IBV, incomplete molt
_____________________________________________________________________________
Oviduct, Bantam hen
Egg-impacted oviduct
Most common in small breeds
_____________________________________________________________________________
Kidney, WL hen Renal/visceral gout
Water deprivation
Peritoneum, WL hen
Visceral gout
Liver, heart, WL hen
Visceral gout
Kidney, chicken Urolithiasis with hydroureter and contralateral renomegaly IBV
DDX: Water deprivation, primary renal disease, nephrotropic IBV, high Ca or Vit D3 in ration,
citrinin/ochratoxin/oosporein mycotoxins; vitamin A deficiency
_____________________________________________________________________________
267.
Egg, WL chicken
Malformed/wrinkled egg shells
Infectious bronchitis
(coronavirus)
DDX: Newcastle disease virus, abnormal calcium/phosphorus in ration
_____________________________________________________________________________
268.
Egg,
WL chicken Thinning of thin albumen layer
Infectious bronchitis
DDX: Newcastle disease, nicarbazine (anticoccidial)
_____________________________________________________________________________
269.
Peritoneum, WL hen
Internal oviposition
Oviduct obstruction/tumor /infection
Often idiopathic and may not affect long term productivity of hen unless extreme
_____________________________________________________________________________
270.
Oviduct, WL hen
Cystic right oviduct
Persistence of right Mullerian duct
_____________________________________________________________________________
271.
Oviduct, chicken
Fibrinoheterophilic salpingitis
E. coli #1
DDX: P. multocida, Riemerella anatipestifer (duck)
_____________________________________________________________________________
NEOPLASIA
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
_____________________________________________________________________________
Chicken neoplasms associated with infection by the leukosis/sarcoma group of retroviruses:
Lymphoid leukosis, erythroblastosis, myeloblastosis, myelocytomatosis, fibrosarcoma,
myxosarcoma, histiocytic sarcoma, chondroma, osteosarcoma, nephroblastoma, renal carcinoma,
ovarian carcinoma, hepatic carcinoma, pancreatic adenocarcinoma, hemangiosarcoma,
mesothelioma, meningioma, glioma and benign counterparts.
Family Retroviridae, Subfamily Orthoretrovirinae, Genus Alpharetrovirus, Species
Avian leukosis virus; RNA Reverse Transcribing virus  DNA provirus
24
272.
273.
274.
275.
276.
277.
278.
279.
280.
281.
Retrovirus of leukosis/sarcoma complex. Chicken genome contains endogenous viral loci (ev).
Exogenous virus subgroup A transmitted vertically and horizontally. Exogenous virus induces
neoplastic transformation of B lymphocytes. Subgroups A-D avian leukosis viruses can produce
lymphoid leukosis. ALV Subgroup J produces myelocytomatosis.
_____________________________________________________________________________
Pancreas, chicken
Pancreatic adenocarcinoma
_____________________________________________________________________________
Ovary, WL hen
Ovarian adenocarcinoma
_____________________________________________________________________________
Peritoneum, WL hen
Metastatic carcinoma (Carcinomatosis)
_____________________________________________________________________________
Peritoneum, BB hen
Metastatic carcinoma (Carcinomatosis)
_____________________________________________________________________________
Kidney, rooster
Embryonal nephroma
_____________________________________________________________________________
Lung, chicken
Hemangiosarcoma
_____________________________________________________________________________
Peritoneum, rooster
Mesothelioma
_____________________________________________________________________________
Head, chicken
Cranial myelocytoma
ALV-J virus
Liver, spine, chicken
Hepatic/vertebral myelocytomas
ALV-J virus
Liver, chicken
Mf hepatic myelocytomas
ALV-J virus
Myelocytoma (myelocytic myeloid leukosis) develops from periosteum on flat bones of skull,
ribs, pelvis, trachea, sternum
____________________________________________________________________________
282.
Body, processed broiler
Squamous cell carcinoma
Usu. seen at processing and histologically resemble keratoacanthoma rather than carcinoma.
Arise in feather follicle epithelium and can regress.
_____________________________________________________________________________
283.
Liver, turkey
Mf hepatic lymphoma
Reticuloendotheliosis
Retrovirus structurally distinct from leukosis/sarcoma complex. Natural hosts are turkey,
chicken, ducks, geese, pheasants, quail, peafowl. Both vertical and horizontal transmission.
_____________________________________________________________________________
284.
Wing, lovebird
Cutaneous fibroma
285.
286.
287.
288.
DDX: feather follicle cyst, poxvirus, squamous cell carcinoma
_____________________________________________________________________________
Kidney, budgerigar
Renal adenocarcinoma
_____________________________________________________________________________
Beak, budgerigar
Hemangiosarcoma
_____________________________________________________________________________
Subcutis, cockatiel
Lipoma, subcutis
_____________________________________________________________________________
Liver, parrot
Biliary carcinoma
25
REFERENCES
1. Diseases of Poultry. M. Saif (ed.) 12 edition; Blackwell Publishing, 2008
2. Poultry Production (13th Edition). R. Austic and C. Neshem, Lea & Febiger Publishers, 1990
3. Avian Disease Manual (6th Edition). C. Whiteman and A. Bickford (eds.), Kendall Hunt
Publishing, 1990
4. Isolation and Identification of Avian Pathogens, 5th Edition. Swayne et al. (eds). American
Association of Avian Pathologists, 2004.
5. Commercial Chicken Meat and Egg Production, 5th Edition. D. Bell and W.D. Weaver, Jr.
(eds.), Kluwer Academic Publishers, 2002.
6. Avian Histopathology, 2nd Edition. C. Riddell (ed). American Association of Avian
Pathologists, 1996.
7. Pathology of Pet and Aviary Birds. R.E. Schmidt, et al. (eds.), Iowa State Press, 2003.
8. Pigeon Health and Disease. D. C. Tudor. Iowa State University Press, 1991.
9. Ratite Management, Medicine and Surgery. T.N. Tully and S.M. Shane (eds.). Krieger
Publishing Company, 1996.
10. Poultry Metabolic Disorders and Mycotoxins. S. Leeson, G. Diaz and J.D. Summers.
University Books, 1998.
11. Color Atlas of Avian Histopathology. C. Randall and R. L. Reece. Mosby-Wolfe Publishers,
1996.
26