Abstract.A spectrum of proliferative cutaneous lesions occurred in 12 dogs at the injection site of live canine oral papillomavirus (COP) vaccine, suggesting a viral etiology for the masses. Lesions included epidermal hyperplasia, epidermal cysts, squamous papilloma, basal cell epithelioma, and squamous cell carcinoma. Peroxidase-antiperoxidase staining of tumor sections revealed nuclei which stained for group-specific papillomavirus antigen in five of 12 masses. Electron microscopic examination of tumor sections did not reveal virions. In transmission studies, macerated tumor tissue did not produce oral papillomas on the scarified mucosa of puppies; this procedure did protect the puppies from development of lesions when challenged with infectious papilloma material. These findings are evidence that COP can induce hyperplastic and neoplastic lesions in sites other than oral, pharyngeal, and ocular mucosa.
Abstract. Postm or tem examina tion of 1000 commercia lly bred Beagle dog s used in 39 drug-safety eva lua tions showe d a spectrum of co ncurrent lesions of spontaneous, subclinical disea se tha t was used to develop a profile of lesions. Th is profile included the gross obser vations and the histopathologic findi ngs in at least 36 differen t tissues from 647 of these dogs. Th e incidence, sex dist ribution, and etio logic classificatio n of 77 different spo nta neous lesion s and the occu rrence of four species of parasites a re indicated. The profile provides a mean s of differentiating concurr ent , spontaneous lesions from those indu ced by experi menta l proced ures in 'norma l' Beagle dogs .Recogniti on of the lesion s of subclinical spo nta neo us disease in dogs used in t he safety evalu at ion of new dru gs a nd th e differenti at ion of these lesion s from drug-induced alterations is of o bvio us impo rtance. T hese signs of spo nta neo us disease mu st also be con sidered in th e appr aisa l of a wide va riety of othe r experi me nta l proc edu res performed o n lab or at or y a nima ls to avo id the misinterpret ati on of induced effects.Despite th ese con sider ati on s, only a few sur veys of spo nta neo us lesion s in dogs were found in th e literature: cer ta in lesion s in militar y dogs [3,22,43] a nd co ngenita l lesion s in a wide va riety of breeds [10]. Th e incide nce of spo nta neo us t umors [12], a no ma lies [11,48], a nd various indivi dua l lesion s [I , 5, 13, 15, 16, 28, 29, 33, 42, 44, 51, 52] in Beagle dogs have been described . N on e of th e sur veys, however , gave th e spectrum of gross and micr oscopi c lesion s of spo nta neo us subclinical disease in Beagle dogs. Becau se of th e popularity of the Beagle as a n experim ent al a nima l and th e enzootic pr obl em s inherent in th e commercial rearing of lar ge numbers of dogs, a path ologic pr ofile of the gross a nd microscopic lesion s of co nc urren t spo nta neo us subclini cal disease in co mmercially sup plied Beagle dogs sho uld be of interest to many investi gator s.
Abstract. An enzootic lungworm infection caused by a nematode not previously found in the dog, and probably representing a new species in the Filaroides-Metathelazia group, was found during postmortem examination of Beagle dogs purchased from a commercial breeder. Abnormal respiratory signs were not present, and clinicopathologic tests did not aid in the antemortem detection of infected dogs. Lungworms were present only in alveoli and terminal and respiratory bronchioles. In the majority of dogs there was a focal, granulomatous reaction directed against the adult lungworm, but a remarkably broad spectrum of other pulmonary changes was also seen, including some that mimic drug-induced and neoplastic lesions. Preliminary evidence suggests this lungworm may be present in a number of kennels that breed Beagles for use in research.Canine pulmonary filaroidiasis has usually been considered an uncommon disease, even though MILLS and NIELSEN [20] suggested otherwise. Occasionally one or a few small lungworms morphologically similar to Filaroides rnilksi have been observed as incidental findings in the canine lung [17]. This paper describes a 6-year observation of an enzootic lungworm infection in Beagle dogs bred for use in research. The lungworm is a metastrongyloid nematode not previously reported in the dog, but its morphologic appearance is similar enough to F. milksi in tissue sections that it could be easily mistaken for this lungworm. Emphasis has been placed upon the recognition and proper interpretation of the lungworm lesions as spontaneous and preexisting, rather than experimentally produced.
A Mycoplasma, which was a natural pathogen for the bovine mammary gland was added to bull semen prior to processing and freezing in liquid nitrogen. Twelve virgin heifers were inseminated with frozen semen containing live Mycoplasma, and 6 with semen containing heat-killed organisms. Mycoplasma were recovered from cervico-vaginal mucus for up to 8 months after insemination, and also in pure culture from lesions observed at necropsy. Ten of 12 heifers receiving semen containing live Mycoplasma required multiple inseminations, and 4 of the 12 failed to conceive after as many as 5 inseminations. All heifers that received killed organisms conceived. At necropsy, the 4 heifers that failed to conceive had varying degrees of chronic suppurative salpingitis, chronic endometritis, and ovarian adhesions. The Mycoplasma was considered to be the cause of the genital lesions and the resultant infertility.
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