Small Ruminant

Brain Copper Elevation and Neurological Changes in North Ronaldsay Sheep: a Model for NeurodegenerativeDisease? This study in North Ronaldsay (NR) sheep showed that copper was elevated in both the liver and brain of older animals and that the elevation in these two sites was highly correlated. The accumulation of copper in the liver culminated in chronic active hepatitis. Evidence of tissue damage in the brain was equivocal, but the astrocytes showed strong immunoreactivity for metallothionein. The study suggested that the blood brain barrier of NR sheep possesses unusual features in respect of the import of copper into the brain, and that NR sheep may provide a useful animal model for the investigation of brain copper homeostasis.

1) Maedi-Visna: the Meningoencephalitis in Naturally Occurring Case: MVis characterized by a chronic non-purulent interstitial inflammation of the lungs, joints, mammary gland and central nervous system. Gross lesions were seen mostly in thoracic spinal cord. Histologically, non-suppurative encephalomyelitis consisting of perivascular cuffs and inflammatory infiltrate seen mostly in the cerebellar peduncles, corposum callosum and thoracic spinal cord. The other common lesion was malacia, characterized by white matter vacuolation.

Ovine Small Intestinal Adenocarcinomas are NOT associated with Infection by Herpesviruses, Helicobacter species or Mycobacterium avium subspecies paratuberculosis. J. Comp. Path. 2009, Vol. 140, 177e181.  Sheep in New Zealand more frequently develop small intestinal adenocarcinoma (SIA) than sheep in other countries.  These results suggest that the high rates of SIA in New Zealand sheep are not due to frequent infection by herpesviruses, Helicobacter species or MAP.

Pathological Changes in the Respiratory Tract of Goats Infected by Pasteurella multocida B:2. J. Comp. Path. 2009, Vol. 140, 194e197. Experimentally infected goats.  Pulmonary lesions included acute pneumonia, congestion, edema and hydrothorax. Subcutaneous edema of the lower jaw and brisket, typically seen in cattle and buffalo, was absent in goats. Hemorrhagic septicemia (HS) is an acute, highly fatal infection of ruminants (buffalo and cattle) in tropical countries. Goats are more resistant but are naturally infected.

AA Amyloidosis Induced in Sheep Principally Affects the Gastrointestinal Tract.  J. Comp. Path. 2009, Vol. -, 1e9. Sheep experimentally inoculated to cause granulomatous pneumonia.   Beginning 18 dpi amyloid was present from the tongue to the rectum, but was most prominent in the duodenum where the deposits disrupted the normal mucosal architecture. Other body organs had only mild amyloid deposition. Immunohistochemistry confirmed that the deposits were AA amyloid.

Atypical scrapie in a Swiss goat and implications for transmissible spongiform encephalopathy surveillance. J Vet Diagn Invest 19:2–8 (2007).  No difference between the molecular characteristics of PrPsc in this animal and those of atypical scrapie in sheep, differences in the distribution of histopathologic lesions and PrPsc deposition were observed. In particular the cerebellar cortex, a major site of PrPsc deposition in atypical scrapie in sheep, was found to be virtually unaffected in this goat. In contrast, severe lesions and PrPscdeposition were detected in more rostral brain structures, such as thalamus and midbrain.

Abomasal coccidiosis associated with proliferative abomasitis in a sheep. J Vet Diagn Invest 19:118–121 (2007).  The abomasal mucosa was grossly thickened with a nodular surface and focal areas of hemorrhage. Microscopically, the middle to deep abomasal mucosa contained many intact and ruptured giant protozoal schizonts associated with hyperplasia of mucous neck cells, parietal cell atrophy, moderate lymphocytic-plasmacytic inflammation, and fibrosis centered on mineralized remnants of degenerate schizont walls. Sexual tissue stages and oocysts were not present.

Unilateral orchitis and epididymitis caused by Salmonella enterica subspecies diarizonae infection in a ram. J Vet Diagn Invest 19:194–197 (2007).  A case of unilateral suppurative epididymo-orchitis associated with Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7 with fibrous adhesions between testicular layers, coexistence of epididymal abscesses and foci of fibrinous exudate, and testicular atrophy. Microscopically, testicular and epididymal microabscesses and diffuse inflammatory infiltrates with abundant macrophages containing short Gram-negative rods were observed. Superimposed on the chronic lesions were fibrin deposits with clusters of neutrophils, as well as walled-off granulation tissue.  Bacterial colonies were also identified in thrombosed spermatic cord vessels, scrotal lymph nodes, lung, and liver.

Polypoid uterine leiomyosarcomas in a sheep.  J Vet Diagn Invest 19:309–312 (2007) .  Uterine leiomyosarcoma was diagnosed based on cellular morphology and atypia and positive immunohistochemistry for a-SMA.  intraluminal polypoid masses of variable sizes (0.5–4 cm). The masses were red, with white, smooth, and glistening cut surfaces. Histologically they comprised variably dense sheets of moderately pleomorphic, plump spindle cells embedded in richly vascularized stroma.

Toxic hepatopathy in sheep associated with the ingestion of the legume Tephrosia cinerea.  J Vet Diagn Invest 19:690–694 (2007).   A disease known as water belly (barriga d’a´gua), characterized by chronic progressive ascites,

affects sheep in the semiarid region of northeastern Brazil. Only sheep grazing for long periods in pastures where Tephrosia cinerea

represents 80% to 100% of the available forage are affected.  At necropsy, large amounts of liquid were found in the abdominal cavity, and the liver was hard, with an irregular surface. On histology examination, the main liver lesion was chronic periportal and

subcapsular fibrosis with bridging. Seeds and leaves of the plant were negative for pyrrolizidine alkaloids.

Transmission of bovine viral diarrhea virus to adult goats from persistently infected cattle.  J Vet Diagn Invest 19:545–548 (2007).  The transmission of bovine viral diarrhea virus (BVDV) from persistently infected (PI) heifers to adult seronegative goats was examined in this study. Ten seronegative adult goats were exposed to 4 PI heifers. None of the goats developed any clinical signs but all goats seroconverted by 42 days after exposure to the PI cattle. Results indicate that goats are susceptible to BVDV infection when housed with PI cattle.

Osteocartilaginous metaplasia in the right atrial myocardium of healthy adult sheep.  J Vet Diagn Invest 19:518–524 (2007).  3.49%  had palpable evidence of osteocartilaginous foci. An additional 8% prevalence was estimated based on radiographs of hearts that contained #1 mm foci of nonpalpable, radiographically dense bone. Microscopically, the nodules in the atria were characterized by mature lamellar bone enclosing adipose tissue, with occasional new bone formation by endochondral ossification. No degenerative changes were evident in the affected atrial myocardium, suggesting that these lesions were clinically insignificant background changes.

Diagnosis of Clostridium perfringens intestinal infections in sheep and goats. J Vet Diagn Invest 20:253–265 (2008). The most accepted criterion in establishing a definitive diagnosis of enterotoxemia is detection of C. perfringens toxins in intestinal contents. Also, histopathological examination of brain is very useful for diagnosis of type D disease, as lesions produced by epsilon toxin in the brains of sheep and goats are pathognomonic for type D enterotoxemia.

Acute phase protein response in goats.  J Vet Diagn Invest 20:580–584 (2008). Hp and SAA could be

considered as major APPs.

Ulcerative enterocolitis in two goats associated with enterotoxin- and beta2 toxin–positive Clostridium perfringens type D.  J Vet Diagn Invest 20:668–672 (2008). Enterotoxemia caused by Clostridium perfringens type D in sheep is believed to result from the

action of epsilon toxin (ETX). However, the sole role of ETX in the intestinal changes of the acute and chronic forms of enterotoxemia in goats remains controversial, and the synergistic action of other C. perfringens toxins has been suggested previously.  Histologically, there were multifocal fibrinonecrotic and ulcerative ileitis and colitis, edema of the colonic serosa, and proteinaceous interstitial edema of the lungs. Clostridium perfringens type D carrying the genes for enterotoxin (CPE) and beta2 toxin (CPB2).  These findings indicate that CPB2 may have contributed to the necrotic changes observed in the intestine, possibly assisting ETX transit across the intestinal mucosa.

Bilateral perirenal hemorrhage in two Stone’s sheep (Ovis dalli stonei ): a possible manifestation of malignant catarrhal fever.  J Vet Diagn Invest 20:676–678 (2008). Malignant catarrhal fever (MCF)-like disease was diagnosed at postmortem in 2 Stone’s

sheep (Ovis dalli stonei). On gross examination, the predominant abnormality in both sheep was severe perirenal hemorrhage and multiple renal infarcts. Microscopically, there was severe, multisystemic lymphocytic arteritis. Both sheep were positive for Ovine herpesvirus 2 (OvHV-2).

Hepatic encephalopathy in two goat kids with common paternity.  J Vet Diagn Invest 20:807–811 (2008). Microscopic examination, however, demonstrated hepatocellular atrophy and anomalies in the hepatic microvasculature, including duplication of hepatic arteries, small-to-indistinct portal veins, and oval cell hyperplasia. In addition, spongiform change was microscopically identified throughout the parenchyma of the brain, most notably within the white matter and along the junction of gray and white matter. The diagnosis of congenital portal vein hypoperfusion (suggestive of a portosystemic shunt) with resultant hepatic encephalopathy was proposed in each case based on the characteristic microscopic lesions in conjunction with the signalment and history of the goats.

Mimosa tenuiflora as a Cause of Malformations in Ruminants in the Northeastern Brazilian Semiarid  Rangelands. Vet Pathol 44:928–931 (2007).  Craniofacial anomalies, eye malformations, and permanent flexures of the forelimbs.  abnormalities similar to those observed in field cases, including cleft lip, unilateral corneal opacity, ocular bilateral dermoids, buphthalmos with a cloudy brownish appearance of the anterior chamber due to an iridal cyst, and segmental stenosis of the colon. Malformations induced experimentally by M. tenuiflora were similar to those observed in field cases.

Spontaneous and Experimental Glycoprotein Storage Disease of goats Induced by Ipomoea carnea subsp fistulosa  onvolvulaceae).  Vet Pathol 44:170–184 (2007). swainsonine-containing and calystegine- containing plant Ipomoea carnea subsp fistulosa.  Muscle atrophy.  cytoplasmic vacuolation in neurons of the central and the autonomous nervous system, pancreatic acinar cells, hepatocytes, Kupffer cells, follicular epithelial cells of the thyroid gland, and macrophages of the lymphatic tissues. Neuronal necrosis, axonal spheroids formation, and astrogliosis were additionally observed in the brain.  inhibition of the lysosomal a-mannosidase by the alkaloid swainsonine.

Conidiobolomycosis in Sheep in Brazil. Vet Pathol 44:314–319 (2007). Mucohemorrhagic nasal discharge, and cranium-facial asymmetry from exophthalmos of 1 eye, generally with increased volume of the eyeball, keratitis, and corneal ulceration. Friable masses were observed in the posterior region of the nasal cavity, often destroying the ethmoturbinate bones. Frequently, the lesions invaded the nasal sinuses, cribiform plate, orbit, and brain. In all lesions, negatively stained structures representing hyphae were surrounded by Splendore-Hoeppli material. Coagulative necrosis, thrombosis, and vasculitis were also observed. Grocott methenamine silver stain showed 8–30-mm-thick hyphae, rarely septate or ramified, irregular in shape, and with black contoured wall, sometimes with bulbous dilatation in the extremities.

Natural Peste des Petits Ruminants Virus Infection: Novel Pathologic Findings Resembling Other Morbillivirus Infections. Vet Pathol 44:479–486 (2007).  Pathologic findings included erosiveulcerative

stomatitis, fibrino-necrotic tracheitis, bronchointerstitial pneumonia, multifocal coagulation necroses in the liver, and severe lymphocytolysis in lymphoid tissues. Syncytial cells were conspicuous, especially in the oral mucosa, pulmonary alveoli, liver, and lymphoid tissues.  these previously unreported pathologic findings in natural peste des petits ruminants virus infection establish a basis for resemblance to other morbillivirus infections, such as canine distemper and distemper of sea mammals.

Myocarditis Associated with Foot-and-Mouth Disease Virus Type O in Lambs. Vet Pathol 44:589–599 (2007).  Inflammatory infiltration, hyaline degeneration, and necrosis of sheets of myocytes were observed. The cellular infiltrates were mononuclear cells, including many lymphocytes, macrophages, a few plasma cells, and neutrophils. Major histocompatibility complex Class II+ dendritic and mononuclear cells, cd T cells, CD172A+ and CD14+ macrophages and monocytes, and IgM+ B cells were detected mainly in the infected hearts. Inducible nitric oxide synthetase (iNOS) was seen mostly in areas of inflammation infiltrated by large numbers of cells. These findings suggest that the iNOS expressed by inflammatory cells in lesions may have a deleterious effect on cardiac myocytes in these lesions.

Bronchioloalveolar Carcinoma Not Related to Jaagsiekte Sheep Retrovirus in a Goat. Vet Pathol 44:710–712 (2007).  A lung tumor with the characteristics of bronchioloalveolar carcinoma was detected during histopathologic examination. The tumor cells were positive for surfactant proteins C and B, confirming that alveolar type II cells were the origin of the neoplasia. Tumor samples were tested by polymerase chain reaction, immunoblotting, and immunohistochemistry for the presence of Jaagsiekte sheep retrovirus (JSRV) and enzootic nasal tumor virus (ENTV), another retrovirus very closely related to JSRV, but all tests were negative. Therefore, this is the first reported case of spontaneous bronchioloalveolar carcinoma not related to JSRV or ENTV infection in a goat.

Cerebral Segmental Polyarteritis of Unknown Aetiology in Sheep. J. Comp. Path. 2009, Vol. 140, 283e287. Vasculitis affecting the meningeal elastic arteries consisted of intimal proliferation, thickening of the tunica media, perivascular accumulation of lymphocytes and plasma cells within the tunica adventitia.  There was no evidence for pestivirus antigen associated with the lesions in these sheep. OHV-2 DNA by PCR was not found, although this may have been due to technical problems and fresh material was not available for confirmatory studies. In addition, the interpretation of any positive result would be difficult since many healthy sheep carry this virus. Other ddx: Visna, polyarteritis, immune complex deposition.

Histopathological and Immunohistochemical Findings in the Lungs of Pigs Infected Experimentally with Mycoplasma hyopneumoniae

Histopathological changes consisted of exudates in airways and alveolar lumina, peribronchial and peribronchiolar lymphoid hyperplasia, and enlargement of alveolar septa. These changes coincided with significant increases in the expression of cytokines (IL-1a, IL-1b, IL-8, TNF-a and INF-g) and lymphoid markers (CD4+, CD8+, muramidase, IgG+, IgA+).

Ovine Small Intestinal Adenocarcinomas are not associated with Infection by Herpesviruses, Helicobacter species or Mycobacterium avium subspecies paratuberculosis. J. Comp. Path. 2009, Vol. 140, 177e181

Newzealand sheep develop small intestinal adenocarcinomas 8 times more frequently than sheep elsewhere in the world.

There are no apparent causes identified that causes adenocarcinoma.

Pathological Changes in the Respiratory Tract of Goats Infected by Pasteurella multocida B:2 J. Comp. Path. 2009, Vol. 140, 194e197

Lesions: Acute pneumonia, congestion, edema and hydrothorax without no signs of brisket and jaw edema.

Mismatch Repair Protein Expression in Ovine Intestinal Adenocarcinomas Vet Path 2008 Jan: defect in mismatch repair gene (MMR) causes hereditary non polyposis colorectal cancer in humans. Sheep in New Zealand develop SI adenocarcinomas more frequently, but NO defect in MMR was found.

Toxicity of the Lichen Secondary Metabolite (+)-Usnic Acid in Domestic Sheep Vet Path 2008 Jan: skeletal muscle necrosis was seen. UA is hepatotoxic in monogastric animals. UA is present in lichen xanthoparmelia chlorochora. Toxicity with this lichen caused death of 400-500 Elks in wyomig in 2004, cl signs were red urine, ataxia and muscular weekness.

Bilateral Leydig Cell Tumor in a Six-Year-Old Intersex Goat Affected by Polled Intersex Syndrome Vet Path 2008 Jan: Polled Intersex Syndrome (PIS) is a cause of intersexuality in goats. Affected does show abnormal horn development and intersexuality, resulting in sterility. The PIS gene regulates the transcription of 2 genes involved in gonadal development: PIS-regulated transcript 1 (PISRT1) and forkhead transcription factor gene (FOXL2). This regulatory function is lost when a 11.7-kb deletion occurs in the PIS gene in homozygosis. As a result, XX embryos affected by PIS are masculinized.

Concurrent Peste des Petits Ruminants Virus and Pestivirus Infection in Stillborn Twin Lambs Vet Path 2008 Mar: Peste des petits ruminants (PPR) is a contagious viral disease of small ruminants that is characterized by pseudomembranous oral lesions, bronchointerstitial pneumonia, and enteritis. Epidermal syncytial cells and necrotizing bronchitis/bronchiolitis prompted testing for PPRV infection. Macroscopic anomalies that were typical of border disease included scoliosis, brachygnathism, prognathism, arthrogryposis, hydranencephaly,cerebellar hypoplasia, and hairy fleece; pestiviral antigen was detected by IHC in the brain, liver, lungs, and kidneys.

Experimental Reproduction of Severe Bluetongue in Sheep Vet Path 2008 May: Sheep inoculated with a virulent South African strain of bluetongue (BT) virus serotype 4 developed  lesions  characteristic  of  fulminant  BT,  including coronitis, hemorrhage and ulceration of the mucosal lining of the oral cavity and forestomaches, hemorrhage in the wall of the pulmonary artery, and focally extensive necrosis of skeletal muscle, especially of the neck, pulmonary  edema, edema of the subcutaneous tissues and fascial planes of the head and neck, and pleural and pericardial effusion of varying severity.

Staphylococcus-associated Abortions in Ewes with Long-term Central Venous Catheterization.  Vet Pathol 45:881–888 (2008). Histologically, suppurative placentitis with necrosisand pulmonary aspiration of meconium and amniotic debris often with suppurative bronchopneumonia were  observed  in  abortuses.

A Histopathologic and Immunohistochemical Review of Archived UK Caprine Scrapie Cases.  Vet Pathol 45:443–454 (2008). The vacuolar change observed in the goats was characteristic of transmissible spongiform encephalopathies in general. PrP Sc immunohistochemical morphologic forms described in scrapie and experimental BSE infections of sheep were demonstrable in the goats, but these were generally more extensive and variable in PrP Sc accumulation. None of the cases examined showed a PrP Sc immunohistochemical pattern indicative of BSE

Cutaneous and Nasal Protothecosis in a Goa Vet Path 2008 May t:  Dermatitis with prominent ulcerated nodules up to 3 cm in diameter was observed in the muzzle at the mucocutaneous junctions of nasal and lip skin, and in the border of the pinna.  Histologic lesions were necrotizing pyogranulomatous dermatitis and rhinitis with myriads of walled sporangia, characteristic of Prototheca wickerhamii.

Cover illustration: Experimental Transmission of US Scrapie Agent by Nasal, Peritoneal, and Conjunctival Routes to Genetically Susceptible Sheep Vet Path 2008 Jan: susceptibility to scarpie in sheep is partially dependent on polymorphism in prion protein at codon, 136, 154, and 171. Intracerebral inoculation is the fastest route to get infection. Intralingual is fastest non invasive route. This paper suggested upper respiratory tract, esp the pharyngeal tonsil may serve as portal of entry for prion protein.

Aquaporin-4 in Acute Cerebral Edema Produced by Clostridium perfringens Type D Epsilon Toxin Vet Path 2008 May: Lambs, with high circulating levels of Clostridium perfringenstype D epsilon toxin develop severe neurologic signs and microscopically there is microvascular endothelial injury and diffuse vasogenic edema. In rats given epsilon toxin, generalized cerebral edema chr. by marked albumin extravasation; there was increased expression o f AQP-4 in astrocytes, suggesting that AQP-4 plays in role in attempting to resolve edema by astrocyte uptake

Systemic toxoplasmosis and Gram-negative sepsis in a southern chamois (Rupicapra pyrenaica) from the Pyrenees in northeast Spain. J Vet Diagn Invest 21:244–247 (2009). Histopathologic examination revealed systemic toxoplasmosis and acute Gram-negative septicemia. The protozoan organisms were identified as Toxoplasma gondii based on immunohistochemistry. An indirect fluorescent antibody test was performed, and the animal was positive with an antibody titer of 1:50.

Pituitary acidophil macroadenoma in a pygmy goat (Capra hircus hircus).  J Vet Diagn Invest 21:262–266 (2009). This report describes a pituitary acidophil macroadenoma in a goat. Antemortem clinical findings included hypothermia and rumen stasis. Clinicopathologic findings included refractory hypoglycemia, low total thyroxin and insulin concentrations, elevated bile acid concentration, and hyposthenuria. In addition to the pituitary macroadenoma, bilateral atrophy of the zona reticularis of the adrenal glands was observed histologically.

Actinomyces hyovaginalis–associated lymphadenitis in a Nubian goat.  J Vet Diagn Invest 21:380–384 (2009). Fibrinopurulent necrotizing lymphadenitis of a tracheobronchial lymph node, with an appearance similar to that reported in  cases  of  caseous  lymphadenitis.  Actinomyces hyovaginalis  was  isolated  together  with  Staphylococcus  spp.  and  Streptococcus  spp.  from  the  lesion.

Copper toxicosis with hemolysis and hemoglobinuric nephrosis in three adult Boer goats.  J Vet Diagn Invest 21:395–400 (2009). Defects  in  hepatic  metabolism  and  altered  biliary  and urinary  excretion  of  copper  (frequently  related  to  high dietary  intake  of  copper)  and/or  nutritional  imbalances between copper and other trace elements can all result in massive hepatic stores of copper over time and lead to what has been referred to as chronic copper toxicosis, based on the suspected duration of copper exposure.  Hepatic accumulation  of  copper  eventually  causes  hepatocellular damage  during  the  prehemolytic  stage  of  chronic  copper toxicosis.  The  prehemolytic  stage,  which  is  frequently subclinical, is followed by what often appears to be a sudden onset  of  acute  hepatocellular  degeneration  and  necrosis associated with copper-induced oxidative damage. the prehemolytic stage of chronic  copper  toxicosis  often  presents  clinically  as  a hepatopathy8,13,25,26  and,  especially  in  the  case  of  sheep, remains  subclinical  in  the  prehemolytic  stage  until  large quantities  of  copper  are  suddenly  released  from  hepatic stores. A stressful event, such as transportation, pregnancy, lactation,  strenuous  exercise  and/or  handling,  or  disease and malnutrition, can apparently trigger the breakdown of copper-containing lysosomes, resulting in severe hepatocellular disease and release of copper from the liver. As  can  happen  in  acute  copper  toxicosis,  the  sudden increase in blood copper concentrations causes formation of  methemoglobin  and  Heinz  bodies  as  well  as  lipid peroxidation of erythrocyte membranes and intravascular hemolysis of damaged erythrocytes7,17 Severe, acute anemia with   subsequent   hemoglobinuric   nephrosis   frequently develops.

Isolation of Helcococcus ovis from sheep with pleuritis and bronchopneumonia.  J Vet Diagn Invest 21:164–166 (2009). Pathologic examination revealed severe, focally extensive, chronic necrotizing pleuritis with intralesional coccobacilli and mild, multifocal, subacute mucopurulent bronchopneumonia, indicating a bacterial etiology. A Gram-positive bacterium was isolated in heavy growth from the lung tissue.

Frequency and Distribution of Nerves in Scrapie-affected and Unaffected Peyer’s Patches and Lymph Nodes: Nerves within lymph nodes and germinal centers of Peyer’s patches do not play a primary role in transport of infectivity to the central nervous system. Natural infection is by oral route. Initial site of PrP accumulation after oral infection is dorsal motor nucleus of vagus nerve and intermediolateral tract of SC.

Serial Passage of Sheep Scrapie Inoculum in Suffolk Sheep: US scrapie agent (No. 13-7) appears to have been stabilized in susceptible (171 QQ) Suffolk sheep and may be considered a specific isolate of sheep scrapie agent in the USA. Spongiform lesions present brainstem (obex), colliculi, cerebellum and cereberum.

Pulmonary Myxoma in a Sheep: Myxoma is a rare tumor with a few reports of its occurrence in the jaws of horses and cattle, the heart and synovia of dogs, the heart of a cat, and bronchi of a mare

The Pathology and Pathogenesis of Bluetongue. J. Comp. Path. 2009, Vol. 141, 1e16. Virus-genus Orbivirus, family Reoviridae.  Transmission- Arthropod vectors (Culicoides), transplacental transmission is dependent on strain. Susceptible- Sheep mostly, but serotype 8 can cause disease in Cattle, goats,  and camelids. Replication- macrophage/monocyte, endothelial cells, lymphocytes. Pathogenesis- Injury to small blood vessels in target tissues (lung, skin) leading to thrombosis and infarction.  Direct viral induced cytolysis is also a factor. GROSS lesions- SHEEP- coronitis; subintimal hemorrhage in the pulmonary artery; edema of the lungs, subcutis, muscles of the neck and abdominal wall; and pericardial, pleural and abdominal effusions; haemorrhage and ulcers in the oral cavity and upper gastrointestinal tract; necrosis of skeletal and cardiac muscle, Fetal lesions- cavitation in the CNS, hydranencephaly,  if they survive early infection.  Immunocompetence occurs in mid-gestation.   : CATTLE: Ulceration of muzzle, oral mucosa, teats, interdigital necrosis, rhinitis, conjunctivitis: WTD- DIC and hemorrhage: CAMELIDS- pulmonary edema, hydrothorax and pericardial effusion. Carnoivores- Pulmonary edema, abortion. Comparative- Orbiviruses: Horse- African Horse Sickness; WTD- Epizootic Hemorrhagic Disease virus 1 ans 2 (very similar to BTV). DDX: Hemorrhagic dz in WTD – EHDV, BTV, Ibaraki virus,  and Adenovirus Hemorrhagic Disease.

Brain Copper Elevation and Neurological Changes in North Ronaldsay Sheep: a Model for NeurodegenerativeDisease? This study in North Ronaldsay (NR) sheep showed that copper was elevated in both the liver and brain of older animals and that the elevation in these two sites was highly correlated. The accumulation of copper in the liver culminated in chronic active hepatitis. Evidence of tissue damage in the brain was equivocal, but the astrocytes showed strongimmunoreactivity for metallothionein. The study suggested that the blood brain barrier of NR sheep possesses unusual features in respect of the import of copper into the brain, and that NR sheep may provide a useful animal model for the investigation of brain copper homeostasis

Nor98 scrapie identified in the United States.  J Vet Diagn Invest 21:454–463 (2009). A distinct strain of scrapie identified in sheep of Norway in 1998 has since been identified in numerous countries throughout Europe. Sheep  that  have  genotypes  associated  with  resistance  to  classic scrapie are not spared from Nor98 disease.  Diagnosis of Nor98 scrapie is based on immunohistochemical (IHC) identification of PrPSc  in regions of the brain including the cerebellum and spinal nucleus of  the  trigeminal  nerve  while  sparing  the  motor nucleus  of  the  vagus  nerve  and  lymphoid  tissues, which are  areas  typically  affected in classic  scrapie.   In addition, the Western blot pattern for classic scrapie after deglycosylation with PNGase has a distinct change from 3 protein bands to 1 band at approximately 20 kDa, which corresponds to a single unglycosylated fragment. This change in the Western blot  pattern  does  not  occur  when  Nor98  scrapie  is treated with PNGase.

Axonal degeneration in sheep caused by the ingestion of Halimium brasiliense. J Vet Diagn Invest 21:478–486 (2009).  Transient seizures occurred mainly when sheep were disturbed or frightened.  The main histologic lesion was vacuolation of the brain and spinal cord, with rare axonal spheroid  formation.  Transmission  electron  microscopy  revealed  segmental  axonal  swelling  with degeneration  and  disappearance  of  the  axonal  organelles  and  vacuolation  of  the  axoplasm.  A  pigment identified as ceroid was also present in neurons, astrocytes, and macrophages.

Large Animal/Small Ruminant

IHC evaluation of inflammatory infiltrate in the skin & lung of lambs naturally infected w/sheeppox virus. pp67-75. Jan 2006 NW (Turkey)

-  Response to sheeppox virus (SPV) may be complex and involve mainly CD4+, CD8+ and gs+ Tcells, IgM+ B cells,

and CD 21+ monocytes/ macrophages

- Cell-mediated immune response is predominant

-  Vasculitis – Arthus reaction secondary to antibody-antigen complexes (IgM)

-  SPV caused a down-regulation of MHC I and II express in both skin and lung

-  Sheep pox cells (SPCs), which contain viral antigen:

- Monocyte and macrophages (CD14+ and CD172A+)

- Degenerative epithelial cells or fibroblasts (CD14- and CD172A-)

Chronic copper toxicosis in sheep following the use of copper sulfate as a fungicide on fruit trees.  J Vet Diagn Invest 21:540–543 (2009). hematuria,  icterus,  incoordination,  and  ptyalism. Postmortem findings included generalized icterus; yellow, friable livers; distended gallbladders with dense,  dark bile; and dark, hypertrophic kidneys with hemorrhage.  High Cu concentrations were present in the livers, kidneys, and sera of dead sheep, as well as in the vegetation and soil samples from the field. Chronic Cu toxicosis was confirmed as the cause of death attributed primarily to the use of copper sulfate as a fungicide for fruit trees.

Persistent truncus arteriosus with dissecting aneurysm and subsequent cardiac tamponade in a lamb.  J Vet Diagn Invest 21:543–546 (2009). presence of a common arterial trunk arising from the right ventricle and overriding a ventricular septal defect. The pulmonary arteries originated from a short common trunk from this PTA, which subsequently continued as the thoracic aorta. The death of the lamb was attributed to a rupture of the PTA with subsequent cardiac tamponade. Histologically, a dissecting aneurysm with elastic fiber fragmentation in the wall of the PTA was identified as the underlying pathologic condition.

Oculoglandular Syndrome Caused by Yersinia pseudotuberculosis in a Dairy Goat: J Comp Path 141 vol 2-3: An outbreak of ocular disease in a herd of housed dairy goats was characterized by severe granulomatous conjunctivitis and ipsilateral parotid and submandibular lymphadenopathy. Y. pseudotuberculosis was isolated from both the conjunctiva and submandibular LN. Histo: severe chronic active suppurative and lymphoplasmacytic conjunctivitis; necrosuppurativelymphadenitis associated with yersinia. Similar pathological changes occur in Parinaud’s oculoglandular syndrome in man due to infection with Y. pseudotuberculosis.

Pathology of Inherited Rickets in Corriedale Sheep. J. Comp. Path. 2009, Vol. 141, 147e155. A skeletal disease with features of rickets and osteomalacia and simple autosomal recessive inheritance.  Gross lesions include segmental thickening of physes, growth arrest lines, collapse of subchondral bone of the humeral head, thickened cortices and enthesiophytes around distal limb joints. Microscopically, there is persistence of hypertrophic chondrocytes at sites of endochondral ossification, inappropriate and excessive osteoclastic resorption, microfractures and wide, unmineralized osteoid seams lining trabeculae and filling secondary osteons.  Different from inherited forms of rickets described to date in man and animals.

Pulmonary Myxoma in a Sheep. J. Comp. Path. 2009, Vol. 141, 187e189. Well demarcated, multilobulated, soft in consistency and white in colour.  Microscopically, the tumour comprised a hypocellular myxomatous matrix, rich in acid mucopolysaccharides, with scattered spindle-shaped or stellate cells. These cells had uniform, oval-shaped nuclei without visible nucleoli and expressed vimentin and S100 on im- munohistochemical examination.

Diagnosis of placental pathogens in small ruminants by immunohistochemistry and PCR on paraffin-embedded samples. VETERINARY RECORD |164, 2009 175-178 35 abortions in sheep (from 25 flocks) and 23 abortions in goats (from 21 flocks). All the animals had been vaccinated with a live vaccine against B melitensis, and 26 animals from 18 of the flocks had been vaccinated with combined killed vaccines against C abortus and SAbortusovis. The results of this study indicate that the commercially available killed vaccines provide little protection against C abortus. Severe necrotizing placentitis with an abundant inflammatory infiltrate composed mainly of neutrophils was associated with C burnetii. The basophilic material found in the cytoplasm of the swollen trophoblast cells in all the cases with suppurative placentitis was confirmed by IHC to be composed of C burnetiimicroorganisms. However, several cases that tested positive for C burnetii showed ‘non-classical’ C burnetii lesions, such as mild changes or necrotizing placentitis with a poor inflammatory infiltrate.

Meningoencephalitis associated with Brucella species in a live-stranded striped dolphin (Stenella coeruleoalba) in south-west England.VETERINARY RECORD | 164, 2009 86-89 Amplification of an IS711 element downstream of the bp26 gene by PCR confirmed that the isolate possessed this unique feature, specific to marine mammal strains of Brucella species. Non-suppurative meningoencephalitis and choroiditis lesions involving the brainstem, cerebrum, cerebellum, midbrain and choroid plexus, is consistent with what has been described in other striped dolphins with Brucellaspecies infection.

Mapping PrPSc Propagation in Experimental and Natural Scrapie in Sheep with Different PrP Genotypes: In sheep, susceptibility to this disease is highly dependent on polymorphism in the PrP gene. Homozygous VRQ are regarded as the most susceptible to the disease. The VRQ/ARR sheep are less susceptible to scrapie. ARR/ARR sheep are the most resistant to the disease.VRQ)/VRQ sheep had a greater accumulation of the pathologic form of prion protein (PrPSc) in peripheral tissues, as compared with VRQ/ARQ. All inoculated VRQ/VRQ sheep, but only one of eight inoculated VRQ/ARQ animals, were PrPSc-positive in the CNS. Thus, the propagation of PrPSc seemed slower and more limited in VRQ/ARQ animals. PrPSc- protein spread by lymphatics, periaxonal transportation (satellite cells as early targets)and hematogenous dissemination.

Abortion and Neonatal Mortality in Sheep Poisoned with Tetrapterys multiglandulosa.  Vet Pathol 46:960–965 (2009). Tetrapterys spp. have been reported as a cause of cardiac fibrosis, status spongiosus of the nervous system, and abortion.  Seven fetuses had anasarca. Seven lambs from groups 1 and 4 were weak and died or were euthanatized. The other 2 were born weak with mild nervous signs but recovered. Cardiac fibrosis and status spongiosus of the nervous system were observed in newborn lambs and fetuses.

Outbreak of tuberculosis caused by Mycobacterium bovis in golden Guernsey goats in Great Britain

Veterinary Record (2009) 165, 335-342

Several herds with interconnected histories. Multiple positive single intradermal comparative

cervical tuberculin (SICCT) tests.

GROSS: Chronic necrotizing pneumonia. 2 to 5 cm in diameter with larger cavitated lesions containing yellow pus. Thoracic lymphadenitis. Mesenteric lymphadenitis. Multifocal hepatitis was observed in five animals.

HISTO: Granulomatous inflammation, with central caseous necrosis and mineralisation surrounded by a mantle of macrophage and Langhans-type multinucleate giant cells, with variable numbers of lymphocytes and plasma cells surrounded by a partial or complete fibrous capsule. Acid-fast bacilli varying in numbers from sparse to numerous were usually detected in macrophages and giant cells or free within the coagulum.

Bovine Viral Diarrhea Virus Abortion in Goats Housed with Persistently Infected Cattle: goats experimentally comingled with heifers persistently infected with BVD type 2a. 12 out of 24 aborted. Grossly: placentitis, mummification, facial deformities; Histo: placentitis, myocarditis, thymic depletion, choroid plexitis, encephalitis. Development of PI kid is less likely.

Distribution of Bovine Viral Diarrhea Virus Antigen in Aborted Fetal and Neonatal Goats by IHC: placenta, heart, brain, thymus are most reliable for BVDV antigen detection

Characterization of a US Sheep Scrapie Isolate with Short Incubation Time.  Vet Pathol 46:1205–1212 (2009). This indicates that inoculum No. x124 appears to  induce  scrapie  in  shorter  time  than  inoculum  No. 13-7,  especially  in  sheep  homozygous  or heterozygous for valine at codon 136.

Lung Tumor Development and Spontaneous Regression in Lambs Coinfected With Jaagsiekte Sheep Retrovirus and Ovine Lentivirus. Veterinary Pathology 47(1) 148-162. Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring and experimentally inducible lung cancer of sheep caused by Jaagsiekte sheep retrovirus (JSRV). However, not only was OPA disease progression observed, but the apparent spontaneous regression of OPA was witnessed.

Purulent nasomaxillary and mandibular osteomyelitis in sheep caused by Pseudomonas aeruginosa

A. Benito-Peña, B. Peris, G. Aduriz, J. Martinez, J. M. Corpa Veterinary Record (2010) 166, 115-116: According to the farmer, the mandibular and maxillary bones of almost 12 per cent of the ewes, irrespective of age, became severely deformed over a nine-month period. Initially anorexia, depression, recumbencyand fever. Next a swelling of the nasomaxillary and mandibular area, with purulent nasal discharge. Cachexia, hair loss, and death within two months. GROSS: Gingival ulcers to necrotizing abscess inside the alveolar tooth cavity, which caused a deformed bone structure HISTO: Gross lesions corresponded to extensive necrosis within the trabecular bone, accompanied by a mixed population of inflammatory cells consisting of neutrophils, macrophages, lymphocytes and plasma cells. The swelling lesions were also due to exuberant fibrous tissue surrounding necrotic foci. Mandibular and maxillary osteomyelitis has been documented in four red kangaroos from which a mixed population of bacteria was cultured, but Pseudomonas species predominated in all of the isolates.

Obstructive Jaundice and Photosensitization in a Lamb Secondary to Diaphragmatic Hernia. J. Comp. Path. 2010, Vol. 142, 228e234: Obstructive jaundice and photosensitization occurred in a 9-month-old lamb as a sequela to a diaphragmatic hernia. A loop of proximal duodenum was displaced, resulting in occlusion of the common bile duct, cholecystitis and necrotizing hepatitis.

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