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Gross Morbid Pathology of Selected Avian Species
C. L. Davis Foundation “Gross Morbid Pathology of Animals”
March 23, 2006, A.F.I.P., Bethesda, MD
1.
Rob Porter, D.V.M., Ph.D., Diplomate American College of Veterinary Pathologists,
Diplomate American College of Poultry VeterinariansWisconsin Veterinary Diagnostic
Laboratory and University of Wisconsin School of Veterinary Medicine, Department of
Pathobiological Sciences, 6101 Mineral Point Road, Madison, WI 53705
Tel: (608) 262-5432
Fax: (608) 262-5005
[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
Purdue University, ADDL
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 24-30 weeks (30-45 pounds)
Layer: 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 6 weeks of age (4.5 lbs).
5.
Oultine: systemic, Lymphohematopoietic, Musculoskeletal, Respiratory, Integumentary,
Nervous, Cardiovascular, Digestive, Urogenital, Neoplasia.
Virus Taxonomy, Classification and Nomenclature of Viruses. C.M. Fauquet et al., eds.
Elsevier Press, 2005.
Attendees receive interpretative summaries of significant avian pathology articles from
Avian Diseases (2002-2006), Avian Pathology (2002-2006), Veterinary Pathology (20002006)
__________________________________________________________________________
SYSTEMIC DISEASES
1
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________
6.
7.
8.
9.
10.
11.
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
12.
13.
14.
15.
16.
17.
18.
Eggs, turkey
Shell thinning, wrinkling and depigmentation
Low path AI
DDX: NDV, avian pneumovirus
__________________________________________________________________________
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.
19.
20.
21.
22.
23.
24.
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
Trachea, chicken
Hemorrhagic tracheitis
END
2
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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25.
Head, turkey
Cutaneous infarction
Erysipelas rhusiopathiae
Causes swine erysipelas and erysipeloid of humans. Lesions of sepsis with bacterial emboli,
thrombosis, necrosis and hemorrhage (closely resembles colibacillosis of broiler chickens).
Hemorrhagic hepatitis/myocarditis, Necrohemorrhagic splenitis
26.
27.
28.
29.
30.
DDX: P. multocida, Salmonella, E. coli, HPAI and END.
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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. Sixteen serotypes- 1, 3 and 4 are most
common isolates. Lesions of bacterial embolism, thrombosis, necrosis and disseminated
intravascular coagulation.
31.
32.
33.
34.
DDX: Ornithobacterium, E. coli, chlamydiosis, Staph.aureus
__________________________________________________________________________
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.
35.
36.
37.
38.
DDX: E. coli, chlamydiosis, P. multocida
__________________________________________________________________________
Liver, poult
Mf necrotizing hepatitis
Salmonella pullorum
Heart, broilers
Mf granulomatous myocarditis
Salmonella pullorum
Heart, spleen, chick
Mf necrohemorrhagic splenitis
Salmonella pullorum
Cecum, poult
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
3
degeneration and sepsis in adult birds in contrast to S. pullorum. Nonmotile Salmonella:
possess few flagella.
39.
40.
41.
42.
43.
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, chick
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.
44.
45.
46.
47.
48.
DDX: paratyphoid Salmonella, E. coli, pullorum-typhoid
__________________________________________________________________________
Head, hen
Fibrinoheterophilic cellulitis
Staphylococcus aureus
Tibiotarsus, hen
Fibrinoheterophilic osteomyelitis
Staphylococcus aureus
Leg, turkey
Fibrinoheterophilic arthritis
Staphylococcus aureus
Foot, duck
Plantar pododermatitis
Staphylococcus aureus
Liver, hen
Mf to coalesc. necrotizing hepatitis Staphylococcus aureus
S. aureus requires skin penetration. Coagulase positive strains are the most pathogenic.
DDX: other systemic bacteria, esp. P. multocida and E. coli
__________________________________________________________________________
LYMPHOHEMATOPOIETIC
49.
50.
51.
52.
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 Circovirus, 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
__________________________________________________________________________
53.
Cloacal bursa, broiler
Necrohemorrhagic cloacal bursitis Infectious bursal disease
54.
Leg, broiler
Intramuscular hemorrhage
Infectious bursal disease
4
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)
__________________________________________________________________________
55.
Liver, bursa, WL hen
Hepatic/bursal lymphoma
Lymphoid leukosis
56.
Liver, WL hen
Mf hepatic lymphoma
Lymphoid leukosis
57.
Liver, WL hen
Diffuse hepatic lymphoma
Lymphoid leukosis
Family Retroviridae, Subfamily Orthoretrovirinae, Genus Alpharetrovirus, Species
Avian leukosis virus; DNA/RNA Reverse Transcribing virus
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.
__________________________________________________________________________
58.
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 (uncertain pathogenesis) or secondary infection.
59.
60.
61.
62.
63.
64.
65.
DDX: Salmonella, erysipelas
__________________________________________________________________________
Body, pullet
Marek’s disease 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
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)
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.
5
DDX: Mycobacteriosis, coligranuloma, lymphoid leukosis in older birds
__________________________________________________________________________
66.
Subcutis, Macaw
Mf subcutaneous hemorrhage
Avian polyomavirus
67.
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.
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MUSCULOSKELETAL SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________
68.
Foot, parakeet
Articular gout
69.
Leg, chicken
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.
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70.
Body, turkey
Nonambulatory poult
Ionophore toxicosis
71.
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.
DDX: Infectious bursal disease, chicken infectious anemia, exudative diathesis, injection site
myopathy
__________________________________________________________________________
72.
Hock joint, broiler
Serofibrinous arthritis
Mycoplasma synoviae
73.
Leg, broiler
Tenosynovitis
Mycoplasma synoviae
“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.
DDX: Staph. aureus, viral arthritis, salmonellae
__________________________________________________________________________
74.
Pectoral muscle, turkey Deep pectoral m. infarction
Deep pectoral myopathy
6
“Green muscle disease,” turkeys (esp. breeder hens during artificial insemination) and meattype chickens with vigorous exercise  swelling of deep pectoral muscle within fascial sheath
 ischemic necrosis of muscle. Usually found at processing.
75.
76.
77.
78.
79.
80.
81.
82.
83.
DDX: ionophore toxicosis, injection site myopathy
__________________________________________________________________________
Skull, crested polish chicken
Open fontanelle, skull
Common in
crested polish
Skull, crested polish chicken
Open fontanelle, melanosis
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Vert. column, turkey
Fibrinoheteophilic 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.
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Pectoral muscle, layer breeder 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
Family Reoviridae, Genus Orthoreovirus, Species Avian orthoreovirus, dsRNA virus
Avian 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.
84.
85.
86.
87.
88.
89.
DDX tenosynovitis: Staph.aureus, Mycoplasma synoviae, trauma
__________________________________________________________________________
Leg, WL hen
Acute femoral fracture
Osteomalacia
Keelbone, WL hen
Osteomalacia
Osteomalacia
Thorax, WL hen
Osteomalacia
Osteomalacia
Ribs, chick
Medial deviation ribs, rickets
Rickets
Head, chick
Pliable beak, rickets
Rickets
Ribs, chick
Rib fractures, Rickets
Rickets
Laying hen mobilizes 10% of skeletal calcium into egg shell each day. Deficiencies of calcium,
phosphorus and vitamin D3 (cholecalciferol) can promote osteoclastic resorption of bone without
sufficient osteoblast activity.
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90.
Body, broiler
Spondylolisthesis
Spondylolisthesis
91.
Vertebral column, broiler
Dorsal deviation T6, S/C compression
7
Spondylolisthesis=“kinky back” of 3-6 week broilers. Deviation of T6 vertebral body resulting
in spinal cord compression. Conformation defect (genetic trait) complicated by rapid growth rate
of broiler.
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92.
Tibia, broiler
Tibial dyschondroplasia
93.
Tibia, turkey
Osteochondrosis/ Tibial dyschondroplasia
Core of avascular cartilage in proximal tibiotarsus (metaphysic) 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 and marginal deficiency of calcium or a Ca/P
imbalance. Experimentally induced by Fusarium roseum toxin.
94.
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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.
__________________________________________________________________________
RESPIRATORY SYSTEM
95.
96.
97.
98.
99.
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________
Body, chick
Chick-respiratory distress
Tracheal obstruction
Trachea, chick
Focal granulomatous bronchitisAspergillus 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
8
100.
_________________________________________________________________________
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.
DDX: Bordetella avium
__________________________________________________________________________
101.
Lung, poult
Mf granulomatous pneumonia
Dactylaria gallopava;
102.
Air sac, poult
Focal granulomatous airsacculitis
Dactylaria gallopava
Contaminant in hard wood shavings; translucent to grey lesions in tissue compared to
Aspergillus. Dematiaceous fungus with hyphae observed in H&E. Neurologic disease is most
common clinical sign in chicks and poults. Lesions in eye, brain, lung and air sac.
103.
104.
105.
106.
DDX: Aspergillosis
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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
__________________________________________________________________________
107.
Air sac, chick
Serous airsacculitis
Infectious bronchitis
108.
Kidney, broiler
Urolithiasis/hydroureter
IB, nephrotropic strain
Family Coronaviridae, Genus Coronavirus, Species Infectious bronchitis virus (Group 3
species), Positive sense ssRNA virus
Coronavirus of chickens that causes respiratory signs, decreased egg production and wrinkled
egg shells in layers. Nephrotropic strains can cause urolithiasis and visceral gout.
__________________________________________________________________________
109.
Head, WL hen Marked exudative sinusitis/conjunctivitis Haemophilus paragallinarum
“Infectious coryza,” Chickens are the natural hosts of H. 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.
__________________________________________________________________________
9
110.
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.
111.
112.
113.
114.
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;” usually young
birds. 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 pneumovirus
__________________________________________________________________________
115.
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.
__________________________________________________________________________
116.
Air sac; poult
Serous airsacculitis
Newcastle disease (lentogen).
DDX: acute MG, MM, ORT, pneumovirus
__________________________________________________________________________
117.
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 and E. coli.
__________________________________________________________________________
118.
Lung, pheasant Acute, diffuse hemorrhagic pneumonia
Avian paramyxovirus-3
Family Paramyxoviridae, Genus Avulavirus, Species Avian Paramyxovirus 3,
negative sense ssRNA virus
10
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.
__________________________________________________________________________
119.
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
__________________________________________________________________________
120.
Trachea, chicken
Tracheal nematodiasis
Syngamus trachea
121.
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.
__________________________________________________________________________
122.
Air sac, chicken
Air sac acariasis
Cytodites nudus
Cytodites nudus = air sac mite of galliformes; lives in bronchi, lungs, air sac, and bone cavities
Stenostoma tracheacolum: tracheal mite of passerines-finches, canaries
__________________________________________________________________________
123.
Head, poult
Serous blepharitis, submand. edema
Bordetella avium (acute)
124.
Body, poult
Fibrinous blepharitis
B. avium (subacute)
125.
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. Often concomitant infections. Colonizes apices of repiratory epithelium
and produces cytotoxin that causes chondrolysis of tracheal rings.
DDX: Respiratory cryptosporidiosis, mycoplasmosis, chlamydiosis can mimic or complicate
infection.
__________________________________________________________________________
INTEGUMENTARY SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________
126.
Head, Mollucan CockatooFeather alopecia and dystrophy
Beak and Feather Dis
127.
Body, Mollucan Cockatoo
Feather alopecia
Beak and Feather Dis
Circovirus causing feather dystrophy and immunosuppression. Necrosis, fracture, bending or
hemorrhage, or dystrophic feathers that emerge from follicle and cease growing after each
11
128.
129.
130.
131.
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, processed turkey
Sternal bursitis with hemorrhage
“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.
132.
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.
__________________________________________________________________________
133.
Foot, chicken
Chronic, granulomatous plantar pododermatitis
Staph. aureus
Usually. moist environment or constant pressure on foot.
__________________________________________________________________________
134.
Body, broiler
Necrohemorrhagic dermatitis/alopecia
Cannibalism
135.
Cloaca, Layer
Multifocal ulcerative cloacitis
Prolapse/cannibalism
__________________________________________________________________________
136.
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
downgrade. Management problem- incidence increased by poor feather coverage, crowding,
coarse, most litter, aggressive strains of birds.
__________________________________________________________________________
137.
Body, pullet chick
Hemorrhagic omphalitis
Bacterial infection of navel often
progresses to yolk sac infection.
DDX: Salmonella, E. coli, Pseudomonas, Enterococcus
__________________________________________________________________________
138.
Feet, pullet chicks
Cutaneous dehydration
Dehydration/water deprivation
DDX: Frostbite, contact dermatitis with disinfectant (quat, cresol, phenol)
__________________________________________________________________________
139.
Cloaca, layer
Cloaca normal
140.
Cloaca, layer
Cloaca after egg lay
141.
Cloaca, layer
Necrohemorrhagic cloacitis with prolapse
Cloacal prolapse complicated by trauma/cannibalism. DDX: HPAI, END
__________________________________________________________________________
142.
Head, chick
Serous blepharitis with edema
Conjunctivitis vaccine rxn
12
DDX: field challenge with respiratory virus- ILT, IBV, NDV, ammonia toxicosis
__________________________________________________________________________
143.
Head, chick
Granulomatous cellulitis
Contaminated MD vaccine
__________________________________________________________________________
144.
Head, turkey
Serous blepharitis
Cryptosporidium baileyi
DDX: avian pneumovirus, NDV, acute Bordetella infection.
__________________________________________________________________________
145.
Foot, turkey hen
Digit amputation turkey
Normal in turkey hens
__________________________________________________________________________
146.
Body, cockatiel nestling
Emphysema
Secondary to primary respiratory disease
__________________________________________________________________________
147.
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
__________________________________________________________________________
148.
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.
__________________________________________________________________________
149.
Head, chicken
Proliferative dermatitis (dermatophytosis)
Favus
Microsporum gallinae; chicken, turkey, duck, quail, canary
__________________________________________________________________________
150.
Vent, chicken
Cutaneous acariasis
Ornithonyssus sylviarium
Ornithonyssus sylviarium = 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
__________________________________________________________________________
151.
Head, pullet
Proliferative blepharitis and dermatitis
Fowl pox
152.
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
__________________________________________________________________________
153.
Head, budgerigar
Proliferative dermatitis
Knemidocoptes pilae
154.
Feet, chicken
Proliferative pododermatitis
Knemidocoptes mutans
13
Scaley-leg mite, inhabits nonfeathered sites- beak, legs. DDX: Vitamin B6, Zn deficiency, biotin
deficiency
155.
Body, chicken
Cutaneous pediculosis
Various chewing lice- Order Mallophaga
Chicken: Cuclogaster (head louse), Goniocotes (fluff louse), Menacanthus (body louse)
Turkey: Menacanthus, Chelopistes, Oxylipeurus
Duck and goose: Anaticola, Trinoton
Pigeon: Columbicola, Campanulotes
__________________________________________________________________________
156.
Body, broiler
Fibrinous sternal bursitis
Staph. aureus, Mycoplasma synoviae
__________________________________________________________________________
157.
Body, broiler
Necrohemorrhagic dermatitis
Necrotic dermatitis
158.
Body, processed broiler Focally 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).
__________________________________________________________________________
159.
Body, Macaw
Acute, Mf subcutaneous hemorrhage
Polyomavirus
DDX: bacterial sepsis, disseminated intravascular coagulation, coagulopathy secondary to liver
disease, anticoagulant rodenticides
__________________________________________________________________________
160.
Body, chicken
Xanthomatosis
Idiopathic
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
__________________________________________________________________________
161.
Eye, BB hen
Ulcerative keratitis
Ammonia toxicosis
Aerosolized ammonia above 25ppm impairs ciliary apparatus of trachea/sinus and direct toxic
effect on corneal epithelium.
__________________________________________________________________________
162.
Body, chicks
Ataxia
Avian encephalomyelitis
163.
Proventriculus, chick
Mf lymphocytic proventriculitis
AE
164.
Eye, chicken
Cataract
AE
14
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.
DDX, proventricular lesion: Marek’s disease, vitamin E deficiency
DDX, cataracts: congenital cataracts, nutritional deficiency, induced by artificial light, old age.
__________________________________________________________________________
165.
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
__________________________________________________________________________
166.
Eye, poult
Hypopyon
Dactylaria gallopava
167.
Brain, poult
Necrotizing encephalitis
Dactylaria gallopava
DDX: Aspergillus, coliforms, Salmonella, Vitamin E deficiency (brain lesion)
__________________________________________________________________________
168.
Eye, chick
Fibrinous panophthalmitis
E. coli
DDX: Aspergillus, Staph. aureus
__________________________________________________________________________
169.
Brain, Black australorp
Melanosis
Increased melanin accumulation in
variety of tissues is a breed trait.
__________________________________________________________________________
170.
Body, pigeon
Ataxia
Avian paramyxovirus-1
Family Paramyxoviridae, Genus Avulavirus, Species Avian Paramyxovirus-1/Newcastle
disease virus, 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.
__________________________________________________________________________
171.
Body, broiler
Ataxia
Vitamin E deficiency
172.
Brain, Turkey
Encephalomalacia and hemorrhage
Vitamin E deficiency
Brain lesions are not responsive to selenium supplementation, unlike muscle and skin lesions.
DDX: aspergillosis, dactylariosis, avian encephalomyelitis (body position)
__________________________________________________________________________
CARDIOVASCULAR SYSTEM
15
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________
173.
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
__________________________________________________________________________
174.
Head, turkey
Hematochezia
Aortic rupture
175.
Peritoneal cavity, turkey
Hemoperitoneum
Aortic rupture
176.
Peritoneal cavity, turkey Aortic rupture: 12-16 weeks, M>F, rupture between external iliac
and ischiatic arteries
177.
178.
179.
180.
181.
182.
Peritoneum, turkey Perirenal hemorrhage
Males, 8-14 weeks, probably
a variant of aortic rupture of turkeys
DDX: trauma, cannibalism, anticoagulant rodenticides
__________________________________________________________________________
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
__________________________________________________________________________
183.
Heart, broiler
Vegetative valvular endocarditis, RV
Enterococcus
DDX: Erysipelothrix, E. coli, Salmonella, Staphylococcus aureus
__________________________________________________________________________
184.
Heart, Macaw
Anemia, Mf myocardial hemorrhage
Avian polyomavirus
185.
Heart, parrot
Hydropericardium
Avian polyomavirus
DDX, hydropericardium: salt toxicosis, avian viral serositis; EEE, West Nile virus
__________________________________________________________________________
186.
Heart, poult
Cardiomegaly
Dilated cardiomyopathy
187.
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
16
__________________________________________________________________________
DIGESTIVE SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________
188.
Intestine, chicken
Intestinal ascariasis
189.
190.
191.
192.
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
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
__________________________________________________________________________
193.
Crop, Bobwhite quail
Proliferative ingluvitis
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
__________________________________________________________________________
194.
Yolk sac, chick
Chick normal yolk sac
195.
Yolk sac, chick
Hemorrhagic yolk sacculitis
196.
Peritoneum, chick
Fibrinous peritonitis
Coliforms, Salmonella, Enterococcus. Peritonitis often secondary to yolk sac infection and
rupture
__________________________________________________________________________
197.
Liver, chick
Gall bladder distension
Inanition,
198.
Gizzard, poult
Foreign body- litter impaction
Litter impaction
Gall bladder enlarges with inanition (“starve out”). Litter consumption indicative of discomfort
of digestive tract (e.g., viral enteritis) or poor adaptation to brooder.
__________________________________________________________________________
199.
Duodenum, broiler
Mf necrotizing enteritis
Eimeria acervulina: schizogony and
gametogony in prox. small intestine
200.
Jejunum, broiler
Mf necrotizing enteritis
E necatrix: schizogony in intestine
17
201.
Cecum, chicken
202.
Ileum, broiler
203.
Cecum, turkey
and gametogony in cecum
Necrohemorrhagic typhlitis E. tenella: schizogony and
gametogony in cecum
Necrotizing enteritis
Eimeria brunetti: schizogony in
prox. small intestine and
gametogony in distal S.I.
Catarrhal typhlitis/coccidiosis
Eimeria adenoeides
Turkey: Eimeria adenoeides-cecum, E. dispersa-small intestine, E. gallopavonis- ileum and
colon; E. meleagrimitis- duodenum/jejunum
__________________________________________________________________________
204.
Cecum, pheasant
Fibrinonecrotic typhlitis
Eimeria cholchici
Coccidia in pheasants are Eimeria colchici (cecal cores); E. duodenalis and E. phasiani.
DDX: Salmonella
_________________________________________________________________________
205.
Intestine, duck
Necrohemorrhagic enteritis
Duck viral enteritis (DVE)
206.
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
__________________________________________________________________________
207.
Liver, WL hen
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.
208.
Liver, cockatiel
Hepatic lipidosis
Fatty liver DDX: bacterial sepsis, Pacheco’s disease, chlamydiosis
__________________________________________________________________________
209.
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
__________________________________________________________________________
18
210.
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).
__________________________________________________________________________
211.
Body, turkey
Cloacal hemorrhage
HE of turkeys
212.
Intestine, spleen, turkey Hemorrhagic enteritis/necrotizing splenitis HE of turkeys
Family Adenoviridae, Genus Siadenovirus, Species Turkey adenovirus 3 (Turkey
hemorrhagic enteritis virus), dsDNA virus
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
__________________________________________________________________________
213.
Cecum, pheasant
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.
__________________________________________________________________________
214.
Cecum, liver, turkey Mf necr. hepatitis/fibrinonecr. typhlitis
Histomonas
meleagridis
DDX: Salmonella
__________________________________________________________________________
215.
Oral cavity, WL hen
Focal ulcerative stomatitis
DDX: Idiopathic, trichothecene mycotoxin, disinfectant contact necrosis
216.
Oral cavity, chicken
Granulomatous stomatitis/cellulitis with impacted feed
__________________________________________________________________________
217.
Liver, chicken
Multifocal necrohemorrhagic hepatitis
Inclusion body hepatitis
Described in a variety of birds and often associated with adenovirus infection. Generic term for
necrotizing hepatitis with basophilic to eosinophilic intranuclear inclusions in hepatocytes;
occurs with every serotype of adenovirus and infection often predisposed by immunosuppression
from infectious bursal disease or chicken infectious anemia. Aplastic anemia may also be
present.
__________________________________________________________________________
218.
Esophagus, goose
Focal esophageal dilatation/impaction
Lead toxicosis
219.
Gizzard, vulture
Erosive ventriculitis with bile staining
Lead toxicosis
19
Chickens and turkeys more resistant than waterfowl. Acid-fast intranuclear inclusions in renal
tubule epithelium, basophilic stippling of erythrocytes and myonecrosis of heart.
__________________________________________________________________________
220.
Body, chicken
Pectoral muscle atrophy, emaciation
Mycobacteriosis
221.
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
__________________________________________________________________________
222.
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)
223.
224.
__________________________________________________________________________
Peritoneum, parrot
Splenomegaly and mesenteric edema
Pacheco’s herpesvirus
Liver, parrot
Necrotizing hepatitis
Pacheco’s herpesvirus
Family Herpesviridae, Subfamily Alphaherpesvirinae, Unassigned Genus, Species Psittacid
herpesvirus 1, (Parrot herpesvirus), dsDNA virus
DDX: Chlamydiosis, polyomavirus; Salmonella
__________________________________________________________________________
225.
Cloaca, parrot
Cloacal papilloma
Idiopathic
No virus consistently isolated. Can be associated with hepatic or biliary carcinoma.
__________________________________________________________________________
226.
Proventriculus, Af. Grey
Normal
227.
Proventriculus, Af. Grey
Proventricular dilatation disease
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. Viral
particles associated with the disease (Gough RE, et al., Vet Rec, 139:24, 1996), but remain
unidentified.
DDX: Gastric foreign body or other obstruction
__________________________________________________________________________
228.
Intestine, cecum, poult Poult enteritis/mortality syndrome (PEMS)
229.
Intestine, poult
Peritoneal distension, intestinal dilatation
PEMS
Multifactorial transmissible disease 1-3 week-old poults with diarrhea, growth depression or
death. Complex of enteric viruses (astrovirus, coronavirus), Cryptosporidium meleagridis and
bacteria (enteropathogenic E. coli).
__________________________________________________________________________
20
230.
Body, poult
Crop dilatation/Pendulous crop
Cause uncertain in turkey and chicken; often rapid water consumption in hot weather, other
dietary influences such as high fat or starch in ration
DDX: Impaction, foreign body
__________________________________________________________________________
231.
Oral cavity, WL hen
Fibrinonecrotic stomatitis
Quaternary ammonium
Quaternary ammonium disinfectants: direct toxic insult to mucosa
DDX: pox, vitamin A deficiency, trichothecene mycotoxins
232.
233.
__________________________________________________________________________
Peritoneum, poult
Ascites
Salt toxicosis: Greater than 2%
sodium in ration or 4g/kg body
weight  visceral hemorrhages and
ascites
__________________________________________________________________________
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.
__________________________________________________________________________
234.
Intestine, chicken
Intestinal cestodiasis
Chicken: Genus: Raillietina, Davainea, Amoebotania, Choanotaenia and Hymenolepsis;
Turkey: Raillietina, Metroliasthes; Ducks/geese: Hymenolepsis, Fimbrairia
__________________________________________________________________________
235.
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
__________________________________________________________________________
236.
Macaw chick
Fibrinous cellulitis
Trauma: crop tube injury
DDX: esophageal thermal burn, injection granuloma
__________________________________________________________________________
237.
Oral cavity, dove
Fibrinonecrotic stomatitis
Trichomonas gallinae
21
238.
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
__________________________________________________________________________
239.
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.
__________________________________________________________________________
240.
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.
__________________________________________________________________________
241.
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 hemorrhagic to fibrinonecrotic enteritis +
peritonitis and pale, necrotic foci in liver. Splenomegaly and hemorrhage also observed.
DDX: necrotic enteritis, coccidiosis, histomoniasis
__________________________________________________________________________
242.
Esophagus, chicken
Proliferative esophagitis (hyperkeratosis)
Vitamin A deficiency
Vitamin 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. Signs in wide
variety of birds.
DDX: candiasis, wet pox, trichomoniasis, capillariasis
__________________________________________________________________________
UROGENITAL SYSTEM
Tissue/bird
Morphologic/Etiologic Diagnosis
Etiology/Disease
__________________________________________________________________________Egg,
chicken
Egg membrane mycosis, Aspergillosis
Aspergillus fumigatus
22
Common contaminant of ducts, vents of incubators.
__________________________________________________________________________
243.
Body, pullet chick
Ureteral/cloacal urate accumulation
Dehydration
244.
Kidney, pullet chick
Visceral gout
Dehydration
DDX: high calcium or vitamin D3 in ration, avian nephritis virus (astrovirus in Japan; affects
only chicks).
__________________________________________________________________________
245.
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 laying hens. Histology: Lymphoplasmacytic
inflammation of shell gland of oviduct.
246.
247.
248.
249.
250.
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
__________________________________________________________________________
251.
Egg, WL chicken
Malformed/wrinkled egg shells
Infectious bronchitis
(coronavirus)
DDX: Newcastle disease virus, abnormal calcium/phosphorus in ration
__________________________________________________________________________
252.
Egg,
WL chicken Thinning of thin albumen layer
Infectious bronchitis
DDX: Newcastle disease, nicarbazine (anticoccidial)
__________________________________________________________________________
253.
Peritoneum, WL hen
Internal oviposition
Oviduct obstruction/tumor /infection
Often idiopathic and may not affect long term productivity of hen
__________________________________________________________________________
254.
Oviduct, WL hen
Cystic right oviduct
Persistence of right Mullerian duct
__________________________________________________________________________
255.
Oviduct, chicken
Fibrinoheterophilic salpingitis
DDX: E. coli, P. multocida, Riemerella anatipestifer (duck)
23
__________________________________________________________________________
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; DNA/RNA Reverse Transcribing virus
256.
257.
258.
259.
260.
261.
262.
263.
264.
265.
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
__________________________________________________________________________
266.
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.
__________________________________________________________________________
267.
Liver, turkey
Mf hepatic lymphoma
Reticuloendotheliosis
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Retrovirus structurally distinct from leukosis/sarcoma complex. Natural hosts are turkey,
chicken, ducks, geese, pheasants, quail, peafowl. Both vertical and horizontal transmission.
__________________________________________________________________________
268.
Wing, lovebird
Cutaneous fibroma
269.
270.
271.
272.
DDX: feather follicle cyst, poxvirus, squamous cell carcinoma
__________________________________________________________________________
Kidney, budgerigar
Renal adenocarcinoma
__________________________________________________________________________
Beak, budgerigar
Hemangiosarcoma
__________________________________________________________________________
Subcutis, cockatiel
Lipoma, subcutis
__________________________________________________________________________
Liver, parrot
Biliary carcinoma
REFERENCES
1. Diseases of Poultry. M. Saif (ed.); Iowa State University Press, 2003
2. Poultry Production (13th Edition). R. Austic and C. Neshem, Lea & Febiger Publishers, 1990
Avian Disease Manual (4th Edition). C. Whiteman and A. Bickford (eds.), Kendall Hunt
Publishing, 1990
3. Isolation and Identification of Avian Pathogens, 4th Edition. Swayne et al. (eds). American
Association of Avian Pathologists, 1998.
4. Commercial Chicken Meat and Egg Production, 5th Edition. D. Bell and W.D. Weaver, Jr.
(eds.), Kluwer Academic Publishers, 2002.
5. Avian Histopathology, 2nd Edition. C. Riddell (ed). American Association of Avian
Pathologists, 1996.
6. Pathology of Pet and Aviary Birds. R.E. Schmidt, et al. (eds.), Iowa State Press, 2003.
7. Pigeon Health and Disease. D. C. Tudor. Iowa State University Press, 1991.
8. Ratite Management, Medicine and Surgery. T.N. Tully and S.M. Shane (eds.). Krieger
Publishing Company, 1996.
9. Poultry Metabolic Disorders and Mycotoxins. S. Leeson, G. Diaz and J.D. Summers.
University Books, 1998.
10. Color Atlas of Avian Histopathology. C. Randall and R. L. Reece. Mosby-Wolfe Publishers,
1996.
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