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Gross Morbid Anatomy of Small Ruminants
C. L. Davis Foundation’s “Gross Morbid Anatomy of Diseases of Animals”
April 15th, 2005, AFIP, Washington, DC.
Fabio Del Piero, DVM, Dipl. ACVP, PhD, Associate Professor of Pathology
Departments of Pathobiology and Clinical Studies New Bolton Center, School of Veterinary Medicine,
University of Pennsylvania
Tel.: ** 610-925-6210; Fax: ** 610-925-8110;
E-mail: [email protected]
Organ, species
Gross morphologic diagnosis
Etiology/Disease
Pathogenesis, comments
LEUKON
Lymph node, giraffe
Hemorrhage
Clostridium spp.
From enteric clostridiosis
Lymph node, ovine
Caseous lymphadenitis
Corynebacterium pseudotuberculosis
High morbidity; Skin, lymph nodes; multisystemic
Lymph node, deer
Abscess
Aerobic, microaerophilic and anaerobic bacteria: C. ovis, C. pseudotuberculosis, A. pyogenes, E. coli,
Salmonella, Rhodococcus, Clostridium.
Thymus, goat
Thymoma (thymic carcinoma), with necrosis
From the thymus epithelial stroma; common in old goats; possible metastasis to lymph nodes, other
viscera; cytokeratin positive polygonal and spindloid cells
Thymus, lamb
Hemorrhage, severe, acute
Anticoagulant toxicity
Chlorophacinone
Chlorophacinone (2-[(p-chlorophenyl)phenylacetyl]-1,3-indandione) inhibits vitamin K 2,3-epxoide
reductase and vitamin K quinone reductase in the liver, which prevents reduction of inactive vitamin K 1
2,3-epoxide to active vitamin K1 (vitamin K quinol). This in turn prevents carboxylation of clotting factors
II, VII, IX and X, which is required for their activity in clot formation. Other anticoagulants: brodifacoum,
bromodiolone (0.02 ppm), coumafuryl, dicoumarol, difenacoum, difethialone, diphacinone, pindone,
valone, warfarin.
Bone marrow, goat
Emaciation
Serous atrophy of fat
1
ABORTION, STILLBIRTH, NEONATAL DEATH, MALFORMATIONS
Chorioallantois (cotyledonar epitheliochorial syncitial placenta)
Normal
Abdominal cavity, sheep
Triplets
Aborted fetus, ovine
Salmonella enterica
Abortion
Zoonosis
Aborted Fetus, ovine
Mummification
Common in small ruminants; various infectious agents
Placenta and fetus, ovine
Necrotizing chorionitis and fetal mummification
DD: Chlamydophila, Toxoplasma, Brucella, Listeria, Campylobacter, Pestivirus (several are zoonotic
agents)
Liver, kid
Multifocal (embolic) suppurative hepatitis
Listeriosis
Listeria monocytogenes
From poorly preserved (high pH) silage and other feedstuffs; Zoonosis; placentitis, fetal and newborn
septicemia, rhomboencephalitis
Chorioallantois and fetus, ovine
Chorionitis (and vasculitis)
Chlamydophila abortus, Chl. pecorum (former genus Chlamydia)
Sometimes no fetal lesions
Chorioallantois, ovine
Necrotizing chorionitis (cotyledonitis)
Toxoplasmosis
Toxoplasma gondii
Necrosis with fusion of villi tips (visible under water) ; cysts may be incidental findings (vertical
transmission); zoonosis
Chorioallantois, ovine
Necrotizing diffuse chorionitis
Coxiellosis
Coxiella burnetii
Chalky exudate involving both cotyledons and intercotyledonary avillous areas; zoonosis
Fetus, liver, ovine
Hepatic necrosis, multifocal
Campylobacteriosis
Campylobacter spp.
Bull eye-like lesions, considered highly suggestive
2
Sheep
Hydrops amnii
Wesselsbron’s disease
Flavivirus
Fetal mummification; anasarca; fetal malformations: brachignatia, agenesis, spina bifida.
Head, lamb
Holoprosencephaly
Veratrum spp. toxicity
Holoprosencephaly is a complex congenital malformation of the brain and is often associated with a
spectrum of facial anomalies ranging from normocephaly or nondiagnostic changes to cleft lip/palate
(premaxillary dysgenesis), cebocephaly, ethmocephaly, and cyclopia.
Exposure to cyclopamine, a steroid isolated from the desert plant Veratrum californicum, causes
holoprosencephaly in mammalian embryos. Cyclopamine-induced holoprosencephaly may be altered
expression of selected proteins in the prechordal mesenchyme and floor plate with secondary impaired
development of the adjacent neural plate and cranial neural crest. Ingestion at 14 th day of pregnancy causes
holoprosencephaly, ingestion at 28th day of pregnancy causes skeletal abnormalities.
Palate, ovine
Palatoschisis (cleft palate)
Jaw, ovine
Brachygnatism
Lamb
Atresia ani
Sometimes associated with hypospadia
Abdomen, lamb
Dilatation
Atresia ani
Intestine, lamb
Segmental aplasia and aplasia of left diaphragm
Lambs
Hydrocephalus, Hydranencephaly, Anencephaly and Arthrogryposis
DD: Ovine pestivirus (border disease virus), Cache valley bunyavirus, Akabane bunyavirus, Rift valley
fever phlebovirus, Wesselsbron disease flavivirus.
Pathogenesis: CNS necrosis  denervation atrophy  contracted limbs; also muscle necrosis.
Lung, fetus, ovine
Fetal diarrhea with meconium inhalation
Hypoxia in utero  defecation within amniotic cavity and inhalation of meconium  nonseptic histiocytic
pneumonia with multinucleated phagocytic giant cells
Lambs
Demyelination and dysplastic abnormal hair growth (“Hairy shakers”,“fuzzy lambs”)
Border disease
Ovine pestivirus
Thyroid gland, lamb
Goiter
Iodine deficiency responsive disease
May be associated with joint laxity and tendon contraction
3
Cervical column, goat
Vertebral cervical congenital malformation with cervical stenotic myelopathy
Especially goats and camelids
Brain, lamb
Lissencephaly
Swayback (scoliosis)
Copper deficiency
May be related to three different and independent biological functions, a deficiency of cytochrome oxidase
causing anorexia and chromatolysis in the neurons, impaired phospholipid synthesis leading to impaired
myelin synthesis, or a deficiency of dopamine-b-hydroxylase leading to an accumulation of catecholamines
in the central nervous system
Lamb
Retained emphysematous fetus
Ovine fetus
Multiple congenital teratologic defects
FEMALE REPRODUCTIVE SYSTEM
Uterus, sheep
Endometritis and failure of caruncle involution
DD: aerobic and microaerophilic bacteria
Uterus, goat
Suppurative Endometritis
Uterus, sheep
Tear
Uterus, pigmy goat
Cesarean dehiscence
Uterus, sheep
Polypoid (leiomyomatous carcuncles) with melanosis
Salpynx, goat
Epidermoid inclusion cyst
DD: salpyngitis
Pseudohermaphrodite, goat
Testes and female (muellerian) genital tract
Sporadic, more common in goats.
Mammary gland, goat
Supernumerary nipples (duplication)
Mammary gland, goat
Hyperplasia
Mammary gland, sheep
Suppurative mastitis
DD: Escherichia coli, Corynebacterium spp., Mycoplasma, others.
Note: if due to ovine and caprine lentiviruses is fibrosing and lymphocytic
4
Mammary gland, goat
Chronic mastitis (fibrosing, lymphocytic)
Caprine retrovirus (CAE virus)
Mammary gland, sheep
Galactoliths
MALE REPRODUCTIVE SYSTEM
Spermatic cord, ram
Varicocele
Testis, ram
Sperm granuloma
Testis, ram
Mineralization
Epididymis, ram
Suppurative epididymitis
Brucella spp
DD: Actinobacillus seminis
Glans penis and prepuce, ram
Balanoposthitis, ulceration and perforation
Can occur in small epidemics, etiology unknown
Penis, ram
Urethral process obstruction
Calculi
ALIMENTARY SYSTEM
Palate, lamb
Palatoschysis (cleft palate)
Inhalation pneumonia is a frequent complication
Oral cavity, goat
Papular stomatitis
Contagious ecthyma (Orf)
Parapox virus
Zoonotic dermatitis, painful papules with necrosis and hemorrhage
Oral cavity, fawn
Gangrenous stomatitis and periodontal osteomyelitis
Necrobacillosis
Fusobacterium necrophorum
Oral cavity, sheep
Stomatitis and lingual passive hyperemia (cyanosis)
Erosive stomatitis and cheilitis
Bluetongue (ovine catarrhal fever)
Orbivirus
5
Systemic vasculitis; necrosis papillary muscles; pulmonary artery hemorrhage. Numerous (24) serotypes
with mild crossreactivity; vector: Culicoides spp.
Oral cavity and pharynx, goat
Fibrinous and necrotizing (diphtheritic) stomatitis and pharyngitis
Peste des petite ruminants Morbillivirus
Pharynx, goat
Necrotizing pharyngitis (coagulative necrosis)
Necrobacillosis
Fusobacterium necrophorum
Esophagus, lungs
Esophageal perforation with mediastinitis and inhalation pneumonia
Esophagus, sheep
Sarcocystosis
Sarcocystis tenella
Rumen, sheep
Ruminal impaction
Abomasum, sheep
Abomasal impaction
Abomasum, Suffolk sheep
Abomasal dilatation with necrohemorrhagic abomasitis
Primary emptying abomasal defect with secondary mycotic and yeast infection
Suffolk sheep and other breeds. Smooth muscle hypertrophy, fibrosis, edema and perhaps mild rarefaction
of autonomic fibers and ganglia.
Rumen, sheep
Foamy bloat
Secondary to dysmotility and, perhaps, saponine containing feedstuffs
Rumen, goat
Lithobezoar
Rumen, goat
“Plastobezoar” 
Common in goats
Abomasum, sheep
Abomasal hemorrhage
Haemonchosis
Haemonchus contortus, placei
Severe anemia and hypoproteinemia, pale mucosae and viscera, abdominal effusion and dependent edema;
sudden death
Conjunctiva, sheep
Anemic pallor
Hemonchosis
Haemonchus contortus, placei
6
Abomasum, sheep
Severe hemorrhage with melena
Rift Valley Fever Phlebovirus
Abomasum, calf
Gangrenous (necrohemorrhagic with edema) abomasitis
Braxy
Clostridium spp., Gram negative bacteria, Sarcina spp., Candida spp., Mucor spp. (combinations of the
above).
Abomasum, goat
Abomasal severe chronic pyloric ulcer
Chronic blood loss
Small intestine, goat
Intussusception
Small intestine, ovine
Catarrhal enteritis (with diffuse hyperemia)
Serous atrophy of fat
DD: E. coli, Salmonella spp. Clostridium spp.
Small intestine, fawn
Necrohemorrhagic enteritis
DD: E. coli, Salmonella spp. Clostridium spp.
Clostridiosis: agents and conditions
•Clostridium chauvoei: black leg and malignant edema
•Clostridium novyi: black disease, black leg, braxy, malignant edema
•Clostridium septicum: blackleg, braxy, malignant edema
•Clostridium sordellii: malignant edema
•Clostridium tetani: tetanus
Clostridiosis: lesions
•Clostridium toxins  coagulative necrosis
•Predisposing factors: trauma, ischemia
•Abomasum necrosis and hemorrhages (Braxy)
•Intestinal necrosis and hemorrhages
•Hepatic necrosis
•Skeletal muscle necrosis and hemorrhages
•Pulpy kidney (precocious autolysis)
•Encephalomalacia
Clostridium perfringens
•Type A: yellow lamb disease
•Type B: lamb dysentery
•Type C: hemorrhagic enterotoxaemia
•Type D:
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–Enterotoxaemia of suckling lambs
–Focal symmetrical encephalomalacia
Small intestine, sheep
Peyer’s patch necrosis
Mycotic infection
DD: ovine pestivirus, PPR morbillivirus
Intestine, sheep
Granulomatous enterotyphlocolitis (with lymphangitis and lymphadenitis)
Serous atrophy of fat
Paratuberculosis (Johne’s disease)
Mycobacterium avium paratuberculosis
Chronic progressively debilitating. Ileocecal area  proximal and distal progression and to lymph nodes 
liver  lung (rarely)
Small ruminants spread large numbers of bacilli in the environment
Abdominal cavity, goat
Serous atrophy of fat with liver atrophy
Serous atrophy of fat (very severe)
DD: stomatitis, glossitis, dental anomalies, gastroenteritis, parasites, pneumonia, encephalitis, myelitis, any
condition limiting the food intake, malnutrition, starvation  all leading to emaciation characterized by
serous atrophy of fat, liver atrophy, hypoproteinemia, anemia, edema.
Small intestine, goat
Multifocal proliferative – hyperplastic enteritis (enteropathy)
Caprine coccidiosis
Eimeria spp.
Small intestine, goat
Catarrhal enteritis with intraluminal tapeworms
Monietia spp. cestodiasis
Small intestine, sheep
Adenocarcinoma, schirrous with stenosis (“napkin ring” carcinoma)
Pancreas, goat
Adenocarcinoma with liver metastasis
Liver, sheep
Lipidosis
Pregnancy toxemia
Metabolic disease of pregnant ewes
Hypoglycemia, ketonemia, ketonuria, weakness and blindness; rapid grow of twin or triplet fetuses,
declining nutrition and stress; hepatic lipidosis and fat necrosis
Liver, sheep
Copper toxicity
Excessive copper in the diet  liver copper storage  hepatocyte necrosis and copper release  red cell
membrane damage  hemolysis  hemoglobinuria with renal tubular necrosis
Rhodanine stain to identify copper in tissue sections
8
Liver, goat
Abscess
Aerobic, microaerophilic and anaerobic bacteria
Liver, goat
Systemic passive congestion
Passive hyperemia, chronic
Heart failure
Liver, goat
Biliary cysts
Liver, sheep
Necrosis and gall bladder dilatation
Acute – subacute hepatotoxicity
Liver, sheep
Postenecrotic macronodular regeneration
Chronic hepatotoxicity
Hepatotoxicity in small ruminants (and cattle) [summary]
Acute hepatotoxicity:
- Blue-green algae (Cyanobacteria: Oscillatoria [Oscar], Anabena [Annie], Microcystis [Mike],
Aphanizomenon [Fanny]), disarray of hepatocellular cytoskeleton  disarray of hepatocellular cords.
- Cycadales (Zamiaceae): metylazoxymetanol, also neurotoxic; also chronic toxicity
- Solanaceae, Cestrum (inkberry plant)
- Compositae, Xantium (cochlebur): carboxyatractyloside. Also Helichrysium, Asaemia, Athanasia,
Lasiospermum (Africa).
- Ulmaceae, Trema (poison peach, Australia): trematoxin.
- Myoporaceae: furanosesquiterpenoid oils (ngaione). Liver necrosis, hemorrhage and infarcts.
- Carbon tetrachloride: membranous lipoperoxidation.
- Cresols (not described in sheep)
- Phosphorus
- Sawfly larvae (Lophyrotoma, Arge): octapeptide
Chronic hepatotoxicity
- Aflatoxins (Aspergillus, Penicillium) B1, B2, G1, G2: binding to nucleic acids and nucleoproteins with
mioci inhibition and immunosuppression, carcinogenesis, teratogenesis
- Phomopsis (fungus on Lupinus) phomopsins A, B
- Sporidesmin toxin of Phytomyces chartarum on dead ryegrass (Lolium perenne): facial eczema.
Sporidesmin with Tribulus terrestris produces “” similar but differet from facial eczema
- Pyrrolizidine alkaloids from Senecio, Crotalaria, Heliotropium, Cynoglossum, Amsinckia, Echium,
Trichodesma: alkilating agents causing mitosis inhibition  megalocytosis, fibrosis (mild in sheep);
synergistic effect on copper poisoning
- Lantana camara, lantadene A, B: increase rough endoplasmic reticulum  cell swelling  cholestasis;
also renal tubular necrosis
- Tribulus terrestris (tribulosis,”geeldikkop”), but also Agave, Narthecium, Nolena, Brachiaria, Panicum
(P. coloratum): crystal associated cholangiopathy
- Digitaria, Cooperia, Nidorella, Chloris, Medicago, Trifolium, Avena: unexpected hepatopathy with
photosensitization
- Nitrosamines: alkilating agents
- Indospicine from legume Indigofera
- Alsike clover (Trypholium hybridum)
- Copper: hepatocellular accumulation  lysosome damage  hemolysis  renal tubular necrosis
9
Liver, sheep
Necrotizing hepatitis
Infectious Necrotic Hepatitis (Black disease)
Clostridium novy, type B
Predisposed by immature fluke migration
Liver, sheep
Necrotizing hepatitis
Rift Valley fever
Phlebovirus
Mosquito carriers (Culex, Aedes)
Insidious and fatal zoonotic disease epidemiologically associated to rain fall related mosquito activity. Fetal
abnormalities, abortion, neonatal death, hemorrhagic diathesis, hepatic necrosis (with intranuclear
hepatocellular inclusion bodies), icterus; encephalitis in calves (experimental).
Liver, sheep
Necrotizing hepatitis
Wesselsbron’s disease
Flavivirus
Mosquito carrier (Aedes)
Similar to RVF.
Liver, bovine
Hydatidosis (Echinococcosis)
Echinococcus granulosus (dogs)
Echinococcus multilocularis (wild canids)
Carnivore definitive hosts
Hydatid cysts in liver, lung and other viscera of herbivores and omnivores
Zoonosis
E. multilocularis: progressive continuous multilocular growth (tumor-like behavior)
Liver, sheep
Distomatosis (fascioliasis)
Flukes
Dicrocoelium dendriticum
Fasciola hepatica
Fascioloides magna
Predisposing Clostridium hepatic necrosis (black disease)
Liver, Deer
Hepatic tramatodiasis (fascioliasis)
Fascioloides magna
Bile duct cystic dilatation
F. magna is fatal in sheep: larval stages keep migrating with progressive liver necrosis.
Liver, sheep
Cysticercosis
Cysticercus tenuicollis of Taenia hydatigena
Liver, sheep
Lymphoma
In BLV-infected but healthy sheep, BLV integrates both CD5- B and CD5+ B cells. In lymphoma,
however, BLV provirus is detected only in CD5- B cells but not in CD5+ B cells. This is in contrast to the
BLV-induced lymphoma in cattle which shows CD5+ phenotype.
10
Liver, goat
Cholangiocarcinoma
Large focal growth
Liver, sheep
Cholangiocarcinoma
Multifocal, with metastasis to bronchial lymph nodes and lungs
Omentum, sheep
Carcinomatosis
From duodenal schirrhous adenocarcinoma
Napkin ring stenosis from desmoplasia
DD: undifferentiated sarcoma
Omentum, sheep
Cysticercosis
Cysticercus tenuicollis
Taenia hydatigena
Serosa, sheep
Granulomas
Oesophagostomiasis
Oesophagostomum spp.
Mesenteric lymph nodes, sheep
Lymphadenomegaly
Lymphadenitis and hyperplasia
DD: various infectious agents; Chlamydophila in this case.
CIRCULATORY SYSTEM
Heart, ovine
Congenital malformations
Intervetricular septal defect; valvular dysplasia
Heart, ovine
Necrosis (with mineralization)
White muscle disease
Vitamin E and selenium responsive
Heart and pericardium, lamb
Fibrinous pericarditis
Secondary to sepsis in young animals
Heart, lamb
Cysticercosis
Cysticercus ovis
Taenia ovis
Pulmonary artery, sheep
Rupture and hemorrhage
Thinning of the vessel wall with uneven distribution of elastic fibers
11
Pulmonary artery, sheep
Hemorrhage
Bluetongue orbivirus
Highly suggestive lesion but sporadic
Heart, sheep
Necrosis of papillary muscles
Bluetongue orbivirus
Highly suggestive and constantly present
Aorta, goat
Mineralization
DD: Paratuberculosis, incidental, hypervitaminosis D (Cestrum spp., Solanum spp., Trisetum spp.)
RESPIRATORY SYSTEM
Conjunctiva, sheep
Edema
Heart water
Cowdria ruminantium
DD: Chlamydia, Moraxella, PPR morbillivirus, MCF
Conjunctiva and eye, bovine
Catarrhal conjunctivitis and corneal opacity
Malignant catarrhal fever herpesvirus
Ovine herpesvirus 2
Ethmoid and nasal turbinate mucosa, sheep
Adenocarcinoma
Enzootic carcinoma
Retrovirus type D
Frontal sinus, sheep
Sinus larval myasis
Oestrus ovis
Catarrhal rhinitis
Pharynx, sheep
Pasteurella spp.
Necrotizing laryngitis
DD: other bacteria, including Fusobacterium necrophorum
Pharynx, goat
Necrotizing pharyngitis (coagulative necrosis)
Necrobacillosis
Fusobacterium necrophorum
Lung, sheep
Hyperemia and hemorrhage
Bluetongue orbivirus
DD: sepsis, systemic passive congestion
Lung, sheep
Bronchointerstitial pneumonia
PPR morbillivirus
12
Conjunctivitis, diphtheritic enterotyphlocolitis with Peyer’s patch necrosis, pneumonia; intranuclear and
intracytoplasmic IB and syncytia
Lung, ovine
Cranioventral bronchopneumonia
Enzootic pneumonia
Pasteurella spp., Mannheimia spp.
Lung, ovine
Cranioventral and dorsal bronchopneumonia with bronchiectasis
Enzootic pneumonia
Pasteurella spp., Mannheimia spp., Mycoplasma spp.
(BRSV, PI3 described with bronchointerstitial pneumonia)
Lung, sheep
Pseudotuberculosis, Caseous lymphadenitis
Corynebacterium pseudotuberculosis
Cranioventral bronchopneumonia with caseous necrosis
Caseous necrosis and abscess with airway obstruction
Lymphadenitis, abscesses in multiple organs
Lung, lamb
Septicemia and polyserositis
Acute embolic pneumonia and cranioventral bronchopneumonia
Escherichia coli
Lung, kid
Caudal pneumonia
Necrosuppurative caudal pneumonia with vasculitis
Inhalation pneumonia and Salmonella spp.
Lung. goat
Multifocal necrohemorrhagic pneumonia
Gram negative bacteria
DD: mycotic
Complication from skin dog bite (gangrenous dermatitis): sepsis with embolic bacterial pneumonia
Lungs, lambs
Acute embolic pneumonia with fibrin
Lung, Deer
Abscess with wall mineralization
Lung, sheep
Proliferative pneumonia
Ovine progressive pneumonia
Ovine lentivirus (OvLV, Retroviridae)
1) Progressive interstitial pneumonia; 2) Mastitis; 3) Arthritis; 4) Encephalitis
OvLV  mature macrophages  slowly progressing inflammatory lesions containing B and T lymphocytes
Histology: pneumocyte hypertrophy and hyperplasia (lung “fetalization”), alveolar proteinosis,
lymphocytic infiltrate.
Lung, sheep
Multifocal necrotizing pneumonia
Sheep-poxvirus
DD: lungworms
13
Lung, sheep
Dorsal multifocal to coalescing (lymphocytic and eosinophilic) pneumonia
Pulmonary nematodiasis
Muellerius capillaris
DD: Dictiocaulus filaria induces catarrhal bronchiolitis, bronchitis and tracheitis; D. larvae have alae.
Lung, ovine
Contagious bronchioloalveolar carcinoma of sheep (adenomatosis)
Jaagsiekte sheep retrovirus (JSRV)
URINARY SYSTEM
Kidneys, ovine
Hydronephrosis
Calculi, congenital
Kidney, ovine
Hydronephrosis and glomerulonephritis
Kidney, ovine
Pulpy kidney
Precocious autolysis associated with clostridiosis
Kidney, ovine
Copper toxicity
Hemoglobinuria and renal tubular necrosis
Kidney, ovine
Tubular necrosis (nephrosis)
Numerous toxic causes: plants, antimicrobials
Kidney, ovine
Renal tubular necrosis with hemoglobinuria
Leptospirosis
Leptospira interrogans
Kidney, Finnish lamb, newborn
Glomerulonephritis, mesangiocapillary
Complement C3 deficiency: C’3, IgM and IgA accumulate in capillary walls
Kidney, goat
Nephropathy [“Cloisonné kidney”] (with pigmented thickening of the basement membranes of proximal
convoluted renal tubules)
Male goats
Kidney, deer
Bacterial embolic nephritis
E. coli, A. pyogenes, others
Kidney, ovine
Abscesses
Corynebacterium ovis
14
Kidney, ovine
Infarcts (septic)
Kidney, goat
Amyloidosis
Serum producing goats
Systemic amyloidosis
Kidney, sheep
Interstitial nephritis
Chlamydia (Chlamydophila)
Kidney, camelid
Multifocal suppurative (pyogranulomatous) nephritis
Blastomycosis
Blastomyces dermatitidis
DD: other pathogenic yeasts; pyogenic bacteria
Kidney, sheep
Lymphoma
Urinary bladder, goat
Hemorrhage and necrosis
Secondary to obstruction or paralysis due to lumbosacral spinal lesions; idiopathic
Urethra, goat
Obstructive urolithiasis
NERVOUS SYSTEM
Brain, ovine
Meningeal melanosis
Common in small ruminants and camelids
Skull, pygmy goat
Horn puncture wound
Brain, camelid
Abscess
A. pyogenes, E. coli, others
Brain, reindeer
Cerebral abscess
Arcanobacterium pyogenes
Brain, fawn
Encephalic edema with cerebellar foramen magnum herniation
Brain abscess
DD: encephalic infections
Brain, sheep
Polioencephalomalacia (cerebral cortical necrosis)
Thiamine deficiency
Bacillus thiaminolyticus  inactivation
Excessive sulfur in diet
15
Excessive rumen sulfide production
Autofluorescence identified with UV lamp
Brain, goat
Unilateral encephalomalacia secondary to infarct
Skull, meninges, deer
Meningeal nematodiasis
Paraelaphostrongylus tenuis
Deer final host
Sheep, goats, llamas and alpacas are susceptible to meningoencephalitis due to parasitic migration,
characterized by intraspinal tracts with malacia and eosinophils.
Brainstem (histology)
Scrapie (ovine TSE)
Transmissible spongiform encephalopathy (TSE) with brainstem neuron and neuropil vacuolization and
gliosis (histologic diagnosis)
Progressive accumulation of prion protein (Ppr), heat and protease resistant
Reportable disease
Chronic Wasting Disease of mule deer  brainstem lesions  Inhalation pneumonia and emaciation
Malignant catarrhal fever, deer
Ovine herpesvirus 2 (OvHV-2)
Sheep, deer, cattle
Systemic vasculitis  thrombi  infarcts; (Rete mirabilis vasculitis); Meningoencephalitis, Keratitis,
Dermatitis
DD: rabies, rinderpest, bluetongue
Brainstem, sheep
Rhomboencephalitis
Listeriosis
Listeria monocytogenes
Rhombo-encephalitis, perivascular lymphocytic and plasmacytic cuffs with microabscesses and malacia
From upper digestive tract, from bad silage with high pH (butirric acid)
Zoonosis
Pituitary gland, ram
Abscess
Sporadic, only lesions causing (low heart rate) and sudden death
Brain, sheep
Cenurosis
Cerebral larval teniasis
Multiceps multiceps, M. serialis
Vertebra and spinal cord, sheep
Caseous abscess with spinal cord compression and deviation and spinal cord
Caseous lymphadenitis
Corynebacterium pseudotuberculosis
Brain, sheep
Lymphoma and hematoma
16
MUSCULAR and SKELETAL SYSTEMS
Skeletal muscle, sheep
Striated muscle necrosis (and mineralization)
White muscle disease
Vitamin E and selenium responsive myopathy
DD: Cassia spp. toxicity; Trisetum flavescens, Solanum malacoxilon, Cestrum diurnum phytohormones:
hypervitaminosis D toxicity.
Skeletal muscle, sheep
Sarcocystosis
Sarcocystis tenella (esophagus, grossly visible)
Sarcocystis ovicanis
Lesions if present in large quantities
Abortion, myositis. Dalmeny disease: epizootic of severe Sarcocystis spp. myopathy and abortion
Skeletal muscle and cardiac muscle, lamb
Cysticercosis
Cysticercus ovis,Taenia ovis
Joints, carpal and occipital, goat
Chronic arthritis (arthrosynovitis)
Caprine arthritis and encephalitis virus (CAEV)
1. encephalomyelitis in young goats 2. arthritis, 3. mastitis, 4. pneumonia
DD: infectious arthritis (arthrosynovitis): Erysipelothrix rhusiopathiae,Escherichia coli, Salmonella spp.,
Ovine lentivirus (OvLV)
Joints, hip and knee, goat
Degenerative arthropathy (DJD)
Bone, deer
Pathologic fracture
Bone marrow serous atrophy of fat (emaciation)
Thorax, lamb
Rib fractures
Parturition or post partum trauma. Torsion of the newborn body during parturition (previously, size of the
newborn and position of the elbows were considered).
INTEGUMENTARY SYSTEM
Subcutis and body fat, sheep
Icterus
Copper poisoning
Hemolysis
DD: Pyroplasmosis; Clostridium haemolyticum; onion poisoning
Skin, head
Photosensitization
Severe diffuse edema
Primary: photosensitizer in the skin, Hypericum perforatum ( St. John’s worth)
Secondary: aberrant metabolites, porphyrin accumulation (uroporphyrinogen cosynthetase deficiency)
Tertiary, hepatogenous: toxic hepatopathy  phylloerythrin (chlorophyll catabolite) in the skin
17
Skin, foot, goat
Hygroma
DD: interdigital biflexus sinus dermatitis
Skin, coronary band
Bluetongue orbivirus
Coronary dermatitis
DD: FMD, MCF
Skin and cranium, kid
Dehorning injury
Necrotizing dermatitis and osteomyelitis
Skin, perineum
Sheep-pox virus
Papular and pustular dermatitis
Rubeola  papule  pustule  crust  ulcer  scar
Skin, goat
Pediculosis
Trichodectes spp.
Skin, leg, goat
Chronic focally extensive ulcerative deep dermatitis
Myasis (fly strike)
Skin
Large wounds with gangrenous dermatitis
Dog bite
Complication: sepsis with embolic bacterial pneumonia
Hindlimb
Gangrenous pododermatitis
Footrot
Fusobacterium nodosum
Ear, goat
Fibroma
18