Naturally occurring tuberculosis in white-tailed deer

OBJECTIVE: To determine the distribution of lesions and extent of tissues infected with Mycobacterium bovis in a captive population of white-tailed deer. DESIGN: Cross-sectional study. ANIMALS: 116 captive white-tailed deer. PROCEDURE: Deer were euthanatized, and postmortem examinations were performed. Tissues with gross lesions suggestive of tuberculosis were collected for microscopic analysis and bacteriologic culture. Tissues from the head, thorax, and abdomen of deer with no gross lesions were pooled for bacteriologic culture. Tonsillar, nasal, oral, and rectal swab specimens, fecal samples, and samples of hay and pelleted feed, soil around feeding sites, and water from 2 natural ponds were collected for bacteriologic culture. RESULTS: Mycobacterium bovis was isolated from 14 of 116 (12%) deer; however, only 9 of 14 had lesions consistent with tuberculosis. Most commonly affected tissues included the medial retropharyngeal lymph node and lung. Five of 14 tuberculous deer had no gross lesions; however, M bovis was isolated from pooled tissue specimens from the heads of each of these deer. Bacteriologic culture of tonsillar swab specimens from 2 of the infected deer yielded M bovis. Mean (+/- SEM) age of tuberculous deer was 2.5 +/- 0.3 years (range, 0.5 to 6 years). Mycobacterium bovis was not isolated from feed, soil, water, or fecal samples. CONCLUSIONS AND CLINICAL RELEVANCE: Examination of hunter-killed white-tailed deer for tuberculosis commonly includes only the lymph nodes of the head. Results of such examinations may underestimate disease prevalence by as much as 57%. Such discrepancy should be considered when estimating disease prevalence.     

Naturally occurring tularemia in a dog

A 4-year-old spayed female Irish Setter was examined because of acute onset of lethargy, anorexia, and weakness. The dog had eaten an adult rabbit 36 hours earlier. Tularemia was suspected because of the rabbit exposure; however, other common diseases characterized by fever, malaise, and lymphadenopathy of acute onset were also considered (ie, ehrlichiosis and Rocky Mountain spotted fever). The dog was treated with doxycycline (5 mg/kg [2.3 mg/lb], PO, q 24 h) for 14 days as well as supportive treatment with a balanced electrolyte solution (lactated Ringer's solution [200 mL, SC]). The diagnosis was first established by results of bacteriologic cultures of fine-needle aspirates obtained from lymph nodes and confirmed by results of ELISA and a polymerase chain reaction assay Successful and timely antemortem diagnosis of tularemia in dogs can be accomplished through lymph node aspiration and bacteriologic culture.     

Naturally occurring cerebrospinal parelaphostronglylosis.

An isolated case and an outbreak of parelaphostrongylosis in goats are described. Signs included tetraparesis, hemiparesis, tetraplegia, spastic gait, scoliosis, vestibular strabismus, blindness, and death. Five cases were necropsied and nematodes were seen in the brain and spinal cord of four of these. Intact adult nematodes from two cases were identified as Parelaphostrongylus tenuis, the meningeal worm of white-tailed deer. Cerebrospinal fluid analysis from affected goats showed a moderately elevated protein content, evidence of hemorrhage, and mononuclear cell and eosinophil pleocytosis. Recoveries are recorded.     

Naturally occurring nasal obstructions in 11 sheep

Eleven adult sheep of various breeds were examined due to inspiratory dyspnea. Fiberoptic examinations conducted in 8 of the sheep revealed masses to be obstructing the nasal passages. Identification of the masses through histopathologic examination showed 7 to be adenocarcinomas, 1 a papillary adenoma, and 4 were cases of glandular hyperplasia with lymphoplasmacytic infiltration (nasal polyps). One ewe had both an adenocarcinoma and a polyp. Surgical removal of the masses was attempted on 6 of the sheep. Four of the 6 surgically-treated sheep have survived between 2 mo. - 2 years without recurrence of the obstruction.     

Naturally occurring Tyzzer's disease in a calf.

Naturally occurring Clostridium piliforme infection (Tyzzer's disease) was found in a calf. Light microscopic examination revealed multifocal coagulative necrosis in the liver, catarrhal gastroenteritis, tracheitis and pneumonia, and thymic atrophy. Warthin-Starry staining clearly showed large filamentous bacilli in bundles or criss-cross patterns within the hepatocytes and epithelium and smooth muscle cells of the ileum and cecum. Immunohistochemistry using anti-C. piliforme RT and MSK strain antisera showed positive reaction against the bacilli. Electron microscopic examination revealed bacilli within the hepatocytes that demonstrated a characteristic vegetative form, with peritrichous flagella, and spores. The polymerase chain reaction (PCR) study using the paraffin-embedded liver sections, the 196-bp DNA fragment specific to 16S ribosomal RNA of C. piliforme was amplified. The characteristics of these bacilli are consistent with those of of C. piliforme. The PCR technique using paraffin-embedded sections should be useful for confirming C. piliforme infection in spontaneous cases.     

Naturally occurring intracytoplasmic inclusions in the canine exocrine pancreas.

Bodies similar to acidophilic intracytoplasmic inclusions were found by light microscopy in the pancreatic acinar cells of 56 of 174 (32%) healthy male and female purebred Beagles and 14 of 97 (14%) of healthy male mongrel dogs. The inclusions were ovoid, acidophilic and often granular with basophilic particulates. Many seemed to be enclosed within halos of various widths. Electron microscopically the inclusions consisted of whorls of rough endoplasmic reticulum, vacuoles, and cytoplasmic organelles in various stages of decomposition. These inclusion bodies were interpreted as evidence of focal intracytoplasmic degradation. They appeared similar to the dense ribosomal autophagic vacuoles, hitherto described only in association with various experimental procedures.     

Naturally occurring xanthine urolithiasis in a domestic shorthair cat

A five year-old neutered male domestic shorthair cat was presented after three episodes of urethral obstruction and anuria requiring relief urethral catheterisation. A double contrast cystogram revealed the presence of multiple small cystollths which were radlolucent on plain radiographs. A perlneal urethrostomy and a cystotomy were performed to relieve the urethral obstruction and to remove the cystoliths. Quantitative analysis revealed the cystoliths to be composed of 100 per cent xanthine. Clinical history suggested the xanthinuria to be naturally occurring. Unfortunately, the cat was killed in a road traffic accident two months after the surgical procedure, preventing further long-term assessment.     

Naturally occurring scrapie-like spongiform encephalopathy in five domestic cats

Naturally occurring transmissible spongiform encephalopathies have been recognised in sheep, man, mink, captive deer and cattle. Recently a similar disease was reported in a domestic cat. This paper describes the clinical and pathological findings in five cats with similar signs, including further observations on the original case. All the cats had a progressive, neurological disease involving locomotor disturbances, abnormal behaviour and, in most cases, altered sensory responses. Histopathological examination of the central nervous system revealed changes pathognomonic of the scrapie-like encephalopathies, including widespread vacuolation of the grey matter neuropil, vacuolation of neuronal perikarya and an astrocytic reaction.