The other branch of medicine: an historiography of veterinary medicine from a Canadian perspective.

Animal (veterinary) medicine, that other branch of medical healing, forms a part of medical history and there are themes in common between human and veterinary medical historiography. Some of these themes include "great docs, great diseases," struggles with professionalization, institutional stories, general chronological overviews, development of medical disciplines, and the role of women. The "patient's view" in veterinary historiography is somewhat different. Veterinary history includes the theme of "great animals" but this is not, in the medical historical sense, a "patient's" view. Much work in this area of Canadian history remains to be accomplished.

A comparison of gross pathology, histopathology, and mycobacterial culture for the diagnosis of tuberculosis in elk (Cervus elaphus).

Using the isolation of Mycobacterium bovis as the reference standard, this study evaluated the sensitivity, specificity and kappa statistic of gross pathology (abattoir postmortem inspection), histopathology, and parallel or series combinations of the two for the diagnosis of tuberculosis in 430 elk and red deer. Two histopathology interpretations were evaluated: histopathology I, where the presence of lesions compatible with tuberculosis was considered positive, and histopathology II, where lesions compatible with tuberculosis or a select group of additional possible diagnoses were considered positive. In the 73 animals from which M. bovis was isolated, gross lesions of tuberculosis were most often in the lung (48), the retropharyngeal lymph nodes (36), the mesenteric lymph node (35), and the mediastinal lymph nodes (16). Other mycobacterial isolates included: 11 M. paratuberculosis, 11 M. avium, and 28 rapidly growing species or M. terrae complex. The sensitivity estimates of gross pathology and histopathology I were 93% (95% confidence limits [CL] 84.97%) and 88% [CL 77.94%], respectively, and the specificity of both was 89% [CL 85.92%]). The sensitivity and specificity of histopathology II were 89% (CL 79.95%) and 77% (CL 72.81%), respectively. The highest sensitivity estimates (93-95% [CL 84.98%]) were obtained by interpreting gross pathology and histopathology in parallel (where an animal had to be positive on at least one of the two, to be classified as combination positive). The highest specificity estimates (94-95% [CL 91-97%] were generated when the two tests were interpreted in series (an animal had to be positive on both tests to be classified as combination positive). The presence of gross or microscopic lesions showed moderate to good agreement with the isolation of M. bovis (Kappa = 65-69%). The results showed that post-mortem inspection, histopathology and culture do not necessarily recognize the same infected animals and that the spectra of animals identified by the tests overlaps.

Classification of 1,198 cases of bovine lymphoma using the National Cancer Institute Working Formulation for human non-Hodgkin's lymphomas.

A retrospective histologic study was made of 1,198 cases of bovine lymphoma using the National Cancer Institute Working Formulation for human non-Hodgkin's lymphoma. This classification scheme was found to be readily applicable to bovine lymphoma. Most of the cell types described in the National Cancer Institute Working Formulation occurred in this series of bovine lymphomas, but the distribution of cell types varied markedly compared to that of human beings. Eighty-nine percent (1,067/1,198) of bovine lymphomas were high-grade tumors. The diffuse large cell type and its cleaved variant comprised 65.9% of all bovine lymphomas. Similar to the dog, but in marked contrast to human beings where at least 34% of non-Hodgkin's lymphomas were follicular, follicular tumors were found to be extremely rare in cattle (0.3% or 4/1,198). The prevalence of cell types varied significantly between the enzootic and sporadic lymphomas. The cleaved variant of the diffuse large cell type constituted 38% (406/1,072) of enzootic lymphomas versus 14% (18/126) of sporadic lymphomas. The mitotic index (100 x oil immersion field, 175 microns in diameter) of enzootic lymphomas (3.72 +/- 0.06, mean +/- standard error) was significantly greater than the mitotic index of sporadic lymphomas (2.82 +/- 0.17). We concluded that the cleaved variant of the diffuse large cell type with high mitotic index is characteristic of enzootic lymphoma. This characteristic high-grade cell type may be a consequence of the viral etiology of the enzootic form of bovine lymphoma.

Paratuberculosis in saiga antelope (Saiga tatarica) and experimental transmission to domestic sheep.

Mycobacterium paratuberculosis was isolated in low numbers from the small intestine and associated mesenteric lymph nodes of a saiga antelope (Saiga tatarica) using routine culture techniques in spite of histologic evidence of high numbers of acid-fast bacteria in these tissues. Two newborn domestic sheep were fed the ground intestinal tissue containing acid-fast bacteria and the progression of the experimental disease was followed by fecal culture, immunodiffusion (AGID) and lymphocyte stimulation (LST) tests. One experimentally infected sheep developed progressive clinical illness 1 yr postinoculation. Few M. paratuberculosis were isolated from feces or tissues although an extensive granulomatous mycobacterial enteritis, lymphadenitis and lymphangitis were observed containing large numbers of typical acid-fast organisms. No clinical illness was observed in the second inoculated sheep after 18 mo of observation, although infection was demonstrated at necropsy. Both sheep developed AGID and LST reactions indicative of paratuberculosis. This study demonstrated that a difficult to culture isolate of M. paratuberculosis was responsible for paratuberculosis in captive wild ruminants and was transmissible to domestic sheep. Diagnosis of paratuberculosis in four of eight of the imported saiga antelope and in eleven of their 18 offspring indicates the importance of this disease in management of captive wild ruminants and the ease with which this organism can be transmitted.

A hundred years of importation: The first animal quarantine station in North America; Lévis, Québec, 1876-1982.

Quarantine, as a means of preventing disease importation, has been used for people and animals since the mid-19th century in Canada. The first animal quarantine facility in North America was established at Lévis, Québec in 1876. This quarantine station existed at Lévis until 1982 when it was closed and the function moved to Mirabel, Québec, near the International Airport. Veterinarians were in charge during the life of the Lévis Quarantine Station and some were also in charge of the Port of Quebec or a nearby District Office prior to the 1950's. In 1884 and 1886 the value of such a facility was illustrated in preventing the entry into Canada of contagious bovine pleuropneumonia and a vesicular disease. It was described in 1933 as "undoubtedly our most important quarantine station" and a year's operating costs as "trifling in comparison to losses which could occur if a foreign plague invaded this country". This facility's history also illustrated the close veterinary and human medical cooperation during the early days of organized veterinary medicine in Canada. The station was an example for the establishment of other such facilities in North America.

An abattoir survey of urinary bladder lesions in cattle.

Postmortem examination of 21,340 cattle at an Ontario abattoir over a one-year period revealed macroscopic lesions in urinary bladders of 2,296 animals (10.8%). Chronic cystitis, the most frequent finding, was observed in 2,209 cases (10.4%); uroliths were found in 994 (4.7%) of the cattle with chronic cystitis. Other types of urinary bladder lesions included acute cystitis, developmental abnormalities, hyperplasia, neoplasia, emphysema, and a parasitic cystitis.

Protein G-based enzyme-linked immunosorbent assay for anti-MPB70 antibodies in bovine tuberculosis.

MPB70 is a highly species specific protein which is secreted from Mycobacterium bovis during culture. To investigate whether antibodies against MPB70 can be used as an indicator of infection with M. bovis, an enzyme-linked immunosorbent assay was developed, based on the use of biotinylated protein G, to provide a common indicator for antibody formation in different species. During experimental infection with M. bovis in cattle, a characteristic pattern of anti-MPB70 antibody production was observed with an initial flat plateau followed by a marked rise 18 to 20 weeks after infection. Skin testing with bovine tuberculin purified protein derivative (PPD), which was shown to contain antibody-reactive MPB70, was a potent stimulator of antibody production in infected animals. In experimentally infected cattle, we observed an inverse relationship between antibody activity and delayed-type hypersensitivity skin test reactions. In natural M. bovis infections, skin testing with PPD was also a potent stimulator of anti-MPB70 formation. Comparison between the enzyme-linked immunosorbent assay for antibodies to MPB70 and that for antibodies to the widely cross-reacting M. bovis BCG antigen 85B in animals with M. bovis, Mycobacterium avium, Mycobacterium paratuberculosis, and Corynebacterium pseudotuberculosis infections showed that formation of antibody to MPB70 was highly specific for infection with M. bovis. The use of an MPB70-containing PPD preparation for skin testing followed by this anti-MPB70 assay is a highly specific indicator of M. bovis infection. Adjustment of the test conditions is expected to provide an increased sensitivity of the procedure for the diagnosis of natural M. bovis infections.

Lymphoreticular lesions in beef cattle at an ontario abattoir.

During the period April 1983 to March 1986, lymphoreticular lesions in cattle were surveyed at an Ontario abattoir. Postmortem examination of 171,157 cattle revealed macroscopic lesions in 696 animals (0.4%). The most frequent finding was abscessation of a single lymph node, a finding that was observed in 353 cases (50.7% of animals with lesions/0.2% of total slaughter). Actinobacillary granulomas were present in 252 lymph nodes (36.2%/0.1%). Other specific lesions included mycobacteriosis and mycotic or parasitic lymphadenitis. Cases of nonspecific chronic lymphadenitis or granulomas in lymph nodes, pigmentations, malformations, hyperplasia, and neoplasia were also seen. Abscesses were the most common splenic lesions. One animal had localized lymphangiectasia of the epicardium.

Experimental peste des petits ruminants (goat plague) in goats and sheep.

In order to study the pathomorphology and immunohistochemistry of peste des petits ruminants, four goats and two sheep were inoculated intranasally with the Malig-Yemen strain of peste des petits ruminants virus. The animals developed fever, nasal discharge, oral erosions, cough and diarrhea. One goat and one sheep died and one moribund goat was killed. Three animals survived the infection. At necropsy, erosive stomatitis, pneumonia and gastroenteritis were found. Histopathologically the pneumonocytes and epithelial cells of the ileum had eosinophilic cytoplasmic and nuclear inclusions. By an indirect immunoperoxidase method, the nuclei and cytoplasm of the ileal epithelial cells of one goat contained positively (brown) stained antigen, which corresponded to viral nucleocapsids by electron microscopy. Virus appeared to be released through the microvilli of the epithelial cells. We also confirmed the formation of giant cells due to peste des petits ruminants virus.

Mycotic lymphadenitis in cattle and Swine.

Lymph nodes with granulomatous mycotic lesions from 100 cattle and 9 pigs were examined. More than 90% of cases of mycotic lymphadenitis in cattle occurred in the mesenteric nodes, whereas in swine lesions occurred at multiple sites. All observed mycotic infections were caused by zygomycetes. Histologically the granulomas were characterized by necrosis, mineralization, and fibrosis with infiltration of eosinophils, neutrophils, lymphocytes, and giant cells. Mucoraceous-type hyphae were identified in most of the lesions, and Absidia corymbifera, Rhizopus rhizopodiformis, and R. oryzae were isolated. Within the lesions, chlamydospores were produced by R. rhizopodiformis. Mycelia in a few lesions were suggestive of infections with fungi of the Mortierellaceae and Entomophthoraceae.