Forty cases of equine penile disease were screened with polymerase chain reaction for the presence of papillomaviral DNA. Cases consisted of 20 squamous cell carcinomas (average age of horse, 23.9 years) and 20 non-squamous cell carcinoma diseases (average age of horse, 13.3 years). All horses but one originated from the Northeastern United States. Breeds were not recorded. As based on MY09/MY11 consensus primers, DNA sequences from equine papillomavirus type 2 were amplified from 9 of 20 horses (45%) with penile squamous cell carcinoma and only 1 of 20 horses (5%) with non-squamous cell carcinoma penile disease. Equine papillomavirus type 2 DNA was the only papillomaviral DNA amplified from any of the 40 horses. Tissues from the 10 horses in which papillomaviral DNA was detected by polymerase chain reaction were also screened with in situ hybridization and immunohistochemistry. The presence of papillomavirus was demonstrated in a subset of these by in situ hybridization (6 of 10) and immunohistochemistry (1 of 10). This report describes a possible association between equine penile squamous cell carcinomas and equine papillomavirus type 2. This study is also the first report of equine papillomavirus type 2 infection in North American horses.Keywords genital, horse, equine papillomavirus type 2, polymerase chain reaction, in situ hybridization, immunohistochemistry, squamous cell carcinoma Squamous cell carcinomas (SCCs) constitute approximately 18% of all equine cutaneous neoplasms. 23 Of these, 45% are reported to involve the male external genitalia, 22 and SCCs are the most common neoplasm in this location. 24 Equine penile SCCs (PSCCs) commonly recur after treatment, and the long-term prognosis is poor. 5,12 Whereas ultraviolet light is an accepted cause of SCC in sun-exposed skin in some species, ultraviolet overexposure may be a less likely cause of equine PSCCs because of the ventral location of the male genitalia. Although equine PSCCs have been associated with chronic inflammation and smegma accumulation, the role of these factors in neoplasm development is unclear. 8,25 Approximately 5% of all human cancers and 50% of human PSCCs are caused by papillomavirus (PV) infection.2,16 The aim of this study is to investigate whether equine PSCCs are also associated with PV infection. The rate of detection of PVs in equine PSCCs is compared with the rate of detection in non-SCC equine penile lesions. If PVs are detected more frequently in PSCC than non-SCC lesions, this will provide evidence of a possible association between equine PSCC and PV infection. Materials and MethodsCases of equine penile disease were located by searching the archives of the Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, New York. Histologic diagnoses were confirmed for this study by one of the authors (J.P.). Ages were recorded, where available. Standard tests for normality were conducted using SAS 9.1. Differentiation between samples from geldings and stallions was not possible,...

An eight-year-old, female spayed, domestic shorthair cat presented with a three-week history of progressive general proprioceptive ataxia and upper motor neuron paresis of the hindlimbs. Computed tomography revealed a mediastinal mass invading the vertebral canal with the T1 spinal nerve and roots, causing extramedullary compression of the cranial thoracic spinal cord. Histopathological and immunohistochemical studies of the mass during postmortem examination disclosed a neoplasm, later determined to be a poorly differentiated histiocytic sarcoma. Feline histiocytic tumours are rare, with only two prior reports existing in the veterinary literature. This report details a case work-up and reviews the literature on feline histiocytic diseases and tumours affecting the feline spinal

An immunohistochemical (IHC) method was used to test brain tissues from 17 elk in a captive herd in which chronic wasting disease (CWD) had previously occurred. The IHC technique detects the protease-resistant prion protein (PrP-res), which is considered a disease-specific marker for transmissible spongiform encephalopathies (TSE), regardless of the species affected. Of the 17 elk tested, 10 were positive by IHC. Only 2 of these 10 animals had shown clinical signs and histologic lesions of CWD, and an additional animal had histologic lesions only. The most consistently IHC-positive tissue was medulla oblongata, especially the obex. These results show that the PrP-res IHC test on brain tissue, specifically medulla oblongata at the obex, should be considered an essential component of any surveillance study intended to determine the incidence of CWD in captive or free-ranging cervids.