Rhodococcus equi Infections in Dogs.

Five cases of Rhodococcus equi infection in dogs were identified from 2003 to 2014. Three of the dogs had severe, internal lesions attributable to R. equi that have not been previously described: endophthalmitis, endocarditis, and suppurative pleuropneumonia. Isolates from 4 of the dogs were analyzed by polymerase chain reaction for Rhodococcus virulence-associated plasmid (vap) genes. One isolate was vapA-positive, 2 lacked a virulence plasmid, and 1 carried the novel vapN-associated plasmid (pVAPN) recently characterized in bovine isolates. The pVAPN plasmid has not been described in isolates cultured from companion animals. Four of the dogs either were receiving immunosuppressive drugs or had endocrinopathies. R. equi has the potential to cause significant infections in dogs, and immunocompromised animals should be considered at risk for infection.

Multicentric Benign Epithelial Inclusions in a Free-ranging Risso's Dolphin (Grampus griseus).

This report describes the histological and immunohistochemical features of multicentric, benign, epithelial inclusions (BEIs) in a free-ranging, adult, female Risso's dolphin (Grampus griseus). The differential diagnoses included ectopic hamartomatous epithelial inclusions, non-Müllerian choristoma, Müllerian choristoma and low-grade metastatic carcinoma/mesothelioma. The most likely diagnosis of such BEIs was multicentric, embolic, reactive mesothelium, as suggested by cytomorphological and immunophenotypical features of the BEIs, the occurrence of focal pleural rupture and the immunophenotype of the pleural mesothelium. The former represents a pathological condition not previously reported in a marine mammal species, rarely described in animals, and relatively infrequently recognized in man.

Verminous Arteritis Due to Crassicauda sp. in Cuvier's Beaked Whales (Ziphius Cavirostris).

The vascular system of Cuvier's beaked whales (CBW) (Ziphius cavirostris; family Ziphiidae), an extremely deep, prolonged-diving cetacean, is increasingly receiving anatomic and physiologic study due to possible anthropogenic interactions; however, vascular pathology rarely has been reported in this species. Thirteen CBW stranded in the Canary Islands from June 2008 to June 2014 were autopsied. A careful dissection of the thoracic and abdominal vasculature was performed on these animals. All had moderate to severe and extensive chronic fibrosing arteritis with aneurysms, hemorrhages, and thrombosis primarily involving the mesenteric and gastroepiploic arteries and the thoracic and abdominal aorta. Microscopically, the lesions varied from subacute subintimal hemorrhages and severe neutrophilic, eosinophilic, and histiocytic dissecting arteritis with intralesional nematode larvae to marked, chronic, fibrosing arteritis with thickening and distortion of the vascular wall with calcification and occasional cartilage metaplasia. In addition, adult nematodes in renal arteries and veins, renal parenchyma and/or ureter were identified morphologically as Crassicauda sp. Nucleic acid sequenced from renal nematodes from 2 animals yielded closest nucleotide identity to C. magna The pathogenesis is proposed to involve a host response to larval migration from the intestine to the kidney through the mesenteric arteries, abdominal aorta, and renal arteries. Severe consequences for such lesions are possible and could vary from reduced vascular compliance to chronic renal disease and predisposition to the development of disseminated intravascular coagulation and multiorgan failure. Severe chronic arteritis in CBW is associated with renal parasitism by Crassicauda spp.

Ellis-van Creveld Syndrome in Grey Alpine Cattle: Morphologic, Immunophenotypic, and Molecular Characterization.

Ellis-van Creveld (EvC) syndrome is a human autosomal recessive disorder caused by a mutation in either the EVC or EVC2 gene, and presents with short limbs, polydactyly, and ectodermal and heart defects. The aim of this study was to understand the pathologic basis by which deletions in the EVC2 gene lead to chondrodysplastic dwarfism and to describe the morphologic, immunohistochemical, and molecular hallmarks of EvC syndrome in cattle. Five Grey Alpine calves, with a known mutation in the EVC2 gene, were autopsied. Immunohistochemistry was performed on bone using antibodies to collagen II, collagen X, sonic hedgehog, fibroblast growth factor 2, and Ki67. Reverse transcription polymerase chain reaction was performed to analyze EVC1 and EVC2 gene expression. Autopsy revealed long bones that were severely reduced in length, as well as genital and heart defects. Collagen II was detected in control calves in the resting, proliferative, and hypertrophic zones and in the primary and secondary spongiosa, with a loss of labeling in the resting zone of 2 dwarfs. Collagen X was expressed in hypertrophic zone in the controls but was absent in the EvC cases. In affected calves and controls, sonic hedgehog labeled hypertrophic chondrocytes and primary and secondary spongiosa similarly. FGF2 was expressed in chondrocytes of all growth plate zones in the control calves but was lost in most EvC cases. The Ki67 index was lower in cases compared with controls. EVC and EVC2 transcripts were detected. Our data suggest that EvC syndrome of Grey Alpine cattle is a disorder of chondrocyte differentiation, with accelerated differentiation and premature hypertrophy of chondrocytes, and could be a spontaneous model for the equivalent human disease.

Uterine Leiomyoma and Prolapse in a Live-stranded Atlantic Spotted Dolphin (Stenella frontalis).

A uterine prolapse associated with a leiomyoma (fibroid) was observed in a live-stranded Atlantic spotted dolphin (Stenella frontalis). A 7 cm segment of the reproductive tract including the cervix, uterine neck and caudal uterine body had intussuscepted and prolapsed into the cranial vaginal vault. In the leading edge of the intussuscepted/prolapsed uterine wall was a 6 × 3 × 3.5 cm leiomyoma expanding the myometrium. The leiomyoma and prolapse were associated with necrotizing exposure endometritis. This is the first report of a uterine prolapse associated with a leiomyoma in a cetacean. This lesion was believed to be the underlying cause of the live stranding.

Heterobilharzia americana infection and congestive heart failure in a llama (Lama glama).

The schistosome Heterobilharzia americana infects several mammalian species in the southeastern United States, including horses, but infections have not been reported in camelids. This is a report of H. americana infection in a 6-year-old llama with extensive cardiac pathology and congestive heart failure. Parasite-induced granulomas were widely disseminated and included overwhelming involvement of the lungs and liver. Microscopic lesions in the heart included myofiber degeneration and necrosis, with extensive replacement fibrosis. Polymerase chain reaction amplification and sequencing confirmed the presence of H. americana in the lungs.

Timpanismo ruminal crônico secundário à hipoplasia de pregas de omaso em dois bovinos / Chronic ruminal bloat secondary to omasal laminae hypoplasia in two cattle

Um novilho normando e outro charolês apresentando distensão abdominal, diarreia intermitente e timpanismo ruminal crônico, que iniciaram após desmame, foram enviados para necropsia. Observou-se ausência de pregas omasais associada à hipoplasia do órgão, assim como redução de tamanho das papilas ruminais e reticulares. Com base nas lesões e histórico, conclui-se que o timpanismo ruminal foi ocasionado pela falha no desenvolvimento do omaso...

Two emaciated juvenile steers, one Normande and one Charolaise breed with abdominal distension, intermittent diarrhea and chronic ruminal bloat that had begun at weaning were necropsied. Absence of the omasal laminae with omasal hypoplasia were found together with loss of ruminal papillae and reticular folds. Based on the lesions and history we concluded that the ruminal bloat was due to a development failure of the omasum...

Adrenal cortex carcinomas with distant metastases in beef cattle at slaughter.

Ten cases of adrenal cortex carcinomas with distant metastases were collected as subclinical lesions at slaughter of approximately 14,000 adult cattle. The primary lesion in the adrenal gland and the distant metastases, to either the lung or liver, were characterized by light microscopy and immunohistochemistry. Carcinomas were usually detected by noting metastases in the lungs as polypoid, soft, red or red and yellow masses. All adrenal tumours were unilateral and none were seen in bulls. In six of 10 carcinomas there was gross evidence of invasion of the vena cava via the adrenal vein. Normal bovine adrenal cortex labelled positively with S100, calretinin, α inhibin and melan-A; however, adenomas and seven of 10 carcinomas were labelled best by melan-A and α inhibin. Three carcinomas, grossly identical to the other seven, had numerous calcific granules and a slightly different microscopical appearance. In addition to melan-A and α-inhibin, these variant carcinomas labelled with S100. This variant may be derived from a different layer of the adrenal cortex. Because of the similarity of the bovine and human adrenal cortices, cultures of spontaneously arising bovine adrenal tumours may be a useful resource for study of human neoplasia.

Capture myopathy in live-stranded cetaceans.

A group of 51 cetaceans that had been stranded alive on the coasts of the Canary Islands, experienced human capture/rescue interactions and then died, were necropsied over a 12-year period. Of these cetaceans, 25 had haemodynamic lesions indicative of multiorganic vascular shock, degenerative muscle lesions affecting both skeletal and cardiac muscles and myoglobinuric nephrosis typical of capture myopathy (CM). Because macroscopic lesions in muscles and kidneys were not always obvious, a standard protocol was developed where the longissimus dorsi muscle was examined histologically for segmental hypercontraction, contraction band necrosis and segmental muscular degeneration and cardiomyocytes studied for hypereosinophilic wavy fibres, sarcolemmal and perinuclear vacuolation and contraction band necrosis. Light microscopic skeletal and cardiac muscle lesions in all CM animals were confirmed as ante mortem by immunohistochemical assay for myoglobin loss from and fibrinogen entry into affected myofibres. All animals had tubular nephrosis with casts and tubular myoglobin. The oxidative stress-related marker HSP70 was demonstrated immunohistochemically in tubular epithelium. Although the syndrome related to death of live-stranded cetaceans is multifactorial, this study documents that a clinicopathological syndrome comparable to CM of terrestrial wildlife has a role in stranding outcomes.

Natural Heterobilharzia americana infection in horses in Texas.

The schistosome Heterobilharzia americana infects dogs, raccoons, and other mammals in the southeastern United States. Migration of eggs into the liver results in parasitic granulomas with varying degrees of fibrosis and inflammation. Recently, hepatic parasitic granulomas in horses were shown to be caused by H. americana infection. In the present study, samples of liver from 11 of 12 horses with hepatic granulomas identified at necropsy (n = 11) or surgical biopsy (n = 1) were used for DNA extraction, polymerase chain reaction amplification and sequencing using primers specific for a portion of the H. americana small subunit ribosomal RNA gene. A polymerase chain reaction amplicon of the correct size was produced from the extracted DNA in 8 of the 11 horses. Amplicons from 5 of the 8 positive horses were sequenced and had 100% identity with H. americana. In all but 2 of the 12 horses, Heterobilharzia was not responsible for the primary clinical disease, and the hepatic granulomas were considered an incidental finding.

Effects of repeated transvaginal aspiration of immature follicles on mare health and ovarian status.

REASONS FOR PERFORMING STUDY: Transvaginal ultrasound-guided follicle aspiration (TVA) is performed clinically but there is little information available on complications associated with this procedure. OBJECTIVES: It is possible that TVA is associated with damage to the ovary and may induce peritonitis or peritoneal adhesions. This study was conducted to determine the effect of repeated TVA on mare health and ovarian status. METHODS: Thirty-two mares were used for oocyte recovery via repeated TVA over a 3 year period; different mares were used each year. In Year 1, ovarian status was monitored in 11 mares by transrectal palpation and ultrasonography. In Year 2, 6 of 11 mares underwent abdominocentesis and were examined by laparoscopy after one TVA and again after multiple TVAs. In Year 3, 10 mares underwent multiple TVAs with either a 15 or a 12 gauge needle and the ovaries were removed for examination. RESULTS: Four hundred and twenty-seven aspiration sessions (390 via TVA and 37 via needle placement through the flank) and 3202 follicle punctures (3161 TVA and 41 flank) were performed. One mare developed an ovarian abscess. Transient rectal bleeding was evident after 16% of TVA sessions. No adhesions were found on laparoscopic or gross examination of ovaries and there were minimal changes on histological evaluation. CONCLUSIONS: Follicle aspiration carries a small possibility (< 0.5%) of ovarian abscess formation. There is a possibility of rectal abrasion or puncture but little gross or histological damage to the ovary. POTENTIAL RELEVANCE: These results provide a basis for using prophylactic administration of antibiotics after TVA and for advising mare owners of the rare but potential complications associated with the procedure.

Bilateral ovulation fossa inclusion cysts in Miranda jennets.

Multiple cysts ranging from 2-111 mm were noted bilaterally in the ovulation fossa of 11 mature Miranda jennets. These ovulation fossa inclusion cysts (OFICs) were lined by a simple low to columnar epithelium that included many ciliated cells. Although most cases were incidental findings, two of the jennets were presented with reduced fertility. Extensive cyst formation could have been responsible for the reproductive problems because they replaced most of the ovarian parenchyma. Due to their close proximity to the ovulation fossa, the OFICs may have mechanically interfered with passage of eggs into the oviduct. OFICs are histologically common in equids, but are reported uncommonly as gross lesions in either mares or jennets. Ovarian inclusion cysts are associated with neoplasia in women; however, these OFICs showed no evidence of epithelial hyperplasia or cellular atypia and no evidence of independent growth, therefore they were considered to be non-neoplastic. The bilateral occurrence and high incidence of OFICs in Miranda jennets, a breed with limited genetic variability, suggests that the lesion has a genetic causation.

Rhabdomyosarcoma in 8 horses.

This multi-institutional report describes 8 cases of rhabdomyosarcoma in horses. Four neoplasms were in the tongue and other areas of the mouth or head, 2 were in the abdominal wall, and 1 each was in right shoulder muscles and heart. Four rhabdomyosarcomas that were less than 10 cm in diameter were treated by surgical excision or radiation with no recurrence. Two neoplasms greater than 10 cm in diameter in the abdominal wall and the right shoulder were considered inoperable and led to decisions to euthanize the horses. Two neoplasms were incidental findings at necropsy. All the neoplasms were classified as embryonal except for 1 pleomorphic rhabdomyosarcoma. These 8 cases were evaluated with 9 published case reports of equine rhabdomyosarcoma. For all cases, the most common sites were limb muscles (5/17) and tongue (4/17). Metastasis was reported in 4 of the previously published cases; none was found in this study.

Congenital biventricular cardiac diverticula in a dog.

Multiple diverticula of the right and left cardiac ventricular walls were incidental findings at necropsy in a juvenile, male, mixed-breed dog with no clinical history of heart disease. Each saccular diverticulum had a narrow communication into the corresponding ventricular chamber. Histologically, the diverticular walls consisted mainly of collagen without elastin fibers and atrophic cardiomyocytes. No inflammation or other lesions were associated with the diverticula or the rest of the myocardium. Based on the history and pathologic findings, a diagnosis of congenital biventricular fibrous diverticula was made.

Pathology of GM2 gangliosidosis in Jacob sheep.

The G(M2) gangliosidoses are a group of lysosomal storage diseases caused by defects in the genes coding for the enzyme hexosaminidase or the G(M2) activator protein. Four Jacob sheep from the same farm were examined over a 3-year period for a progressive neurologic disease. Two lambs were 6-month-old intact males and 2 were 8-month-old females. Clinical findings included ataxia in all 4 limbs, proprioceptive deficits, and cortical blindness. At necropsy, the nervous system appeared grossly normal. Histologically, most neurons within the brain, spinal cord, and peripheral ganglia were enlarged, and the cytoplasm was distended by foamy to granular material that stained positively with Luxol fast blue and Sudan black B stains. Other neuropathologic findings included widespread astrocytosis, microgliosis, and scattered spheroids. Electron microscopy revealed membranous cytoplasmic bodies within the cytoplasm of neurons. Biochemical and molecular genetic studies confirmed the diagnosis of G(M2) gangliosidosis. This form of G(M2) gangliosidosis in Jacob sheep is very similar to human Tay-Sachs disease and is potentially a useful animal model.

Hypomyelination associated with bovine viral diarrhea virus type 2 infection in a longhorn calf.

A newborn Longhorn heifer calf presented with generalized tremors, muscle fasciculations, ataxia, and nystagmus. At necropsy, no gross central nervous system lesions were observed. Histologically, the brain and spinal cord had mild to moderate diffuse microgliosis and astrocytosis, minimal nonsuppurative encephalitis, and decreased myelin staining. Ultrastructural examination revealed thinning and absence of myelin sheaths. Various cell types were immunohistochemically positive for bovine viral diarrhea virus (BVDV). Noncytopathogenic BVDV was isolated from the brain and identified as BVDV type 2 by phylogenetic analysis. BVDV-induced hypomyelination is rare and analogous to lesions in neonates infected with border disease and classical swine fever viruses. This is the first documented case of hypomyelination in a calf specifically attributed to BVDV type 2 and the first description of the ultrastructural appearance of BVDV-induced hypomyelination.

Septicemia in a neonatal calf associated with Chromobacterium violaceum.

Chromobacterium violaceum infections are highly fatal and rarely reported in domestic animals. This report describes a fatal case of C. violaceum septicemia in a 7-day-old female beef calf. The calf had necrosuppurative omphalophlebitis, necrotizing interstitial pneumonia, necrosuppurative hepatitis and splenitis, anterior uveitis with hypopyon, suppurative polyarthritis, and disseminated hemorrhagic meningitis with multifocal necrotizing encephalitis. Histologically, clusters of gram-negative bacilli were found in many of the lesions. C. violaceum was isolated in high numbers from the lungs, liver, spleen, carpus, and in pure culture from the cerebrospinal fluid. To our knowledge, this is the first case report of chromobacteriosis in a calf.

Hypoxic/ischemic encephalopathy associated with placental insufficiency in a cloned foal.

Hypoxic/ischemic encephalopathy in a cloned American Quarter horse foal was initially associated with placental insufficiency and exacerbated by protracted hypotension during anesthesia for a surgical procedure. The foal, born at the Texas A&M Veterinary Medical Center, was diagnosed at birth with neonatal maladjustment syndrome that was accompanied by dysmaturity, muscle contracture of the front limbs, and a blood clot within the lumen of the urinary bladder. Seizures that developed after anesthesia were attributed to hypoxia/ischemia during anesthesia and culminated in death. Macroscopically, the cerebrum had flattened cerebral gyri with shallow sulci, yellowish cortical discoloration, and apple-green autofluorescence (under 365-nm ultraviolet light) at the cortical/white matter junction. Microscopically, there was laminar cortical necrosis with prominent diffuse ischemic change of neuronal cell bodies. The white matter had prominent rarefaction with focal axonal and myelin degeneration and focal macrophage (gitter cell) accumulation. Additionally, there was astrocytic hypertrophy with gemistocyte formation. The chorioallantois was diffusely thickened in the area corresponding to the uterine horns. Histologically, microcotyledons were markedly attenuated with absence of chorionic villi.

Staphylococcus-associated abortions in ewes with long-term central venous catheterization.

Forty-two ewes had an intravenous catheter sewn in place in a prepared area over the jugular vein and beginning at 60 days of gestation received an infusion 3 times daily. The infusion consisted of sterile saline or sterile saline containing arginine. Twenty-six ewes in both control and treatment groups aborted between 81 days of gestation and term. Fetuses from 16 ewes that aborted were examined. Most were autolyzed or had early mummification. Macroscopic placentitis and noncollapsing lungs were noted. Large numbers of coagulase-positive Staphylococcus were isolated from fetal abomasal content, lungs, brains, or placentas. Histologically, suppurative placentitis with necrosis and pulmonary aspiration of meconium and amniotic debris often with suppurative bronchopneumonia were observed in abortuses. Four ewes euthanized and examined after abortion had suppurative endometritis. Three ewes had severe, chronic, jugular thrombophlebitis from which coagulase-positive Staphylococcus was isolated. The fourth ewe had mild phlebitis, and Staphylococcus aureus was isolated from both the catheter and the blood. Catheter-associated staphylococcal abortion was diagnosed.

Massive pulmonary thromboembolism in six horses.

This report involves 6 cases in which medical records and post mortem findings were reviewed leading to the diagnosis of massive pulmonary thromboembolism (MPTE). All horses were mature and MPTE has not been recognised previously as a sequel to generalised systemic illness in mature horses. The clinical data and pathological findings of the cases are reported and the authors conclude that MPTE is an uncommon but important complication of medical and surgical disorders in mature horses. In 3 of the cases, the condition was nonfatal suggesting that some horses having developed PTE survive and the condition may not be recognised in such cases. The incidence of the condition might be higher than supposed.