Nonhuman primate bites.

Nonhuman primate (monkey) bites to researchers and attending animal care staff may present problems in patient management. Such inoculations can transmit serious bacterial and viral infections to the human handlers. Significant local and systemic manifestations can subsequently develop following such an injury. Since Herpesvirus simiae (B virus) is enzootic in Asiatic monkeys of the genus Macaca, and since B virus infection in humans is usually fatal, additional prophylactic and therapeutic measures must be taken when persons are bitten by macaque monkeys. Primate bites require early aggressive intervention.

The identification of Eperythrozoon ovis in anemic sheep.

Eperythrozoon ovis, a rickettsial parasite of erythrocytes, was found in anemic lambs maintained for reproductive endocrinology research. The parasite was identified in the blood films of 13 animals in the flock of 30. The sexes were infected equally (7/16 males versus 6/14 females). The relationship between the severity of the anemia and the presence of organisms in blood was statistically significant. One animal died with severe anemia. Light, scanning electron, and transmission electron microscopy of peripheral erythrocytes revealed an extracellular organism identified as E. ovis. These findings indicate that this parasite can cause disease in sheep and therefore may interfere with biomedical research.

Vitamin E deficiency in goldfish fed a shellfish derived diet.

Six month old, laboratory-raised goldfish (Carassius auratus) used in morphologic studies of retinal development developed progressive fraying and deterioration of the tail and fins that reached epizootic proportions and culminated in fungal infection and death. Diagnostic histopathology showed marked skeletal muscle degeneration in the muscles of the tail and caudal body wall compatible with a vitamin E/selenium deficiency. Ration analysis demonstrated inadequate vitamin E in the commercial shrimp-based diets fed to the goldfish fry. Replacement of shrimp-derived diets by a commercial trout diet containing adequate levels of vitamin E was curative.

An enzyme-linked immunosorbent assay to detect serum IgG to Pasteurella multocida in naturally and experimentally infected rabbits.

An enzyme-linked immunosorbent assay (ELISA) was evaluated for efficacy in detecting serum IgG against Pasteurella multocida in both naturally and experimentally infected rabbits. Blood samples and nasal cultures were taken concurrently from 58 rabbits from four conventional rabbitries. Nine rabbits from a pasteurella-free colony served as negative controls. Fifty-six rabbits were ELISA positive. Of these, 46 were P. multocida culture positive, 10 were culture negative. Two rabbits were ELISA negative, culture negative. There were no ELISA negative, culture positive animals. Serotyping by the gel diffusion precipitin test demonstrated that of the 44 typed P. multocida isolates, 57% were serotype 4, 27% were serotype 12 and 16% were serotype 3. In rabbits experimentally infected intranasally with P. multocida, serum IgG against P. multocida began to rise 21 to 33 days after infection and remained elevated until the animals were euthanized 90 days post infection. Two enzyme-linked immunosorbent assays were compared which used potassium thiocyanate extracts of different serotypes of P. multocida as antigen. The results obtained were similar, suggesting the presence of antigens common to both serotypes.

Protection of rabbits against experimental pasteurellosis by vaccination with a potassium thiocyanate extract of Pasteurella multocida.

Antigens were extracted from a virulent isolate of Pasteurella multocida (serotype 3, 12, 15:D) with potassium thiocyanate, and a vaccine was prepared. Pasteurella-free rabbits were vaccinated intranasally and intraconjuctivally twice with a 2-week interval and challenged intranasally with the homologous P. multocida serotype 2 weeks after the second vaccination. The vaccinated rabbits produced serum immunoglobulin G and nasal mucosal immunoglobulin A against P. multocida. The vaccine protected the challenged rabbits against clinical disease and death; however, otitis media was not prevented, and microscopic inflammatory lesions were occasionally noted in the lungs and nasal turbinates. In contrast, nonvaccinated, challenged rabbits became febrile, dyspnic, depressed, and anorectic, and five of six died within 4 days of challenge with severe lesions including pneumonia, pleuritis, otitis media, and bacteremia. The vaccine prevented death and colonization of challenge organisms in the blood and lung, but did not prevent colonization of the middle ear. The vaccine alone did not cause clinical disease or gross lesions, but did produce microscopic pulmonary inflammatory lesions.

Secondary amyloidosis in rhesus monkeys with chronic indwelling venous catheters.

Secondary amyloidosis was diagnosed in five Rhesus monkeys with chronic indwelling venous catheters. Diagnostic enzymology demonstrated normal serum alanine aminotransferase concentration and consistently elevated serum alkaline phosphatase. Serum protein electrophoresis on all five animals showed a typical pattern of decreased albumin and increased gamma globulin. Necropsy or biopsy specimens verified the presence of amyloid deposits in all animals. The diagnostic usefulness of clinical enzymology, serum protein electrophoresis and liver biopsy were demonstrated and the importance of considering amyloidosis as a differential diagnosis in monkeys with indwelling vascular catheters is emphasized.

Activated coagulation time for rhesus monkeys (Macaca mulatta).

The activated coagulation time test provided a rapid yet accurate measurement of the intrinsic clotting system in rhesus monkey (Macaca mulatta) whole blood. Other advantages of this test included reproducibility, no requirement for control samples, low cost and commercial availability. The mean activated coagulation time value for 60 normal rhesus monkeys was 96 seconds with a range of 77 to 125 seconds. There were no significant differences due to sex, venipuncture site and time of blood collection.

Pneumatocele in a pig-tailed macaque (Macaca nemestrina).

Radiographic examination of a pig-tailed macaque (Macaca nemestrina) with pneumonia revealed a large pneumatocele. The pneumatocele, a thin-walled, partially fluid filled radiolucent area, occupied approximately one-third of the left thorax. Rapid resolution of the pneumatocele accompanied antimicrobial treatment of the pneumonia and coincided with clinical improvement. Severe pulmonary acariasis was found at postmortem 15 months later.

Pathogenicity of a serotype 12:A Pasteurella multocida in hydrocortisone treated and nontreated rabbits.

A Pasteurella multocida isolate of 12:A serotype from a rabbit caused typical pulmonary pasteurellosis and death in pasteurella-free rabbits by intranasal exposure. Rabbits stressed with hydrocortisone and inoculated with 12:A Pasteurella multocida organisms developed a higher prevalence of pneumonia than rabbits not treated with hydrocortisone. Typical 12:A Pasteurella multocida was isolated from nasal cavity, trachea, and lungs and was most prevalent in nasal cavities. Surviving rabbits developed serum agar gel precipitating antibody beginning 15 days post-inoculation. The data showed that the 12:A Pasteurella multocida isolate was pathogenic, caused mortality, colonized the respiratory tract, and stimulated systemic immune response by producing serum agar gel precipitating antibody.

Cimetidine prophylaxis for gastric ulcers in laboratory swine.

Bleeding gastric ulcers were a major cause of morbidity and mortality in young swine subjected to surgery, chronic catheterization, and daily experimental manipulation. Some of the animals died suddenly due to exsanguination into the gastrointestinal tract, while others survived for several days following the onset of clinical signs. These signs included dark, tarry stools, lethargy, pale mucous membranes, decreased appetite, and dyspnea. Abnormal clinical laboratory findings included decreased hematocrit, hemoglobin and erythrocyte counts indicative of chronic blood loss anemia. On postmortem examination, single or multiple ulcers of variable sizes were found in the nonglandular cardiac portion of the stomach, and the gastrointestinal tract often contained blood. Histologically, the ulcers had a base of granulation tissue with surface suppuration. Prophylactic treatment of these ulcers was initiated using cimetidine, a histamine II blocker. The drug was administered via the drinking water at 15 mg/kg body weight/day. Fourteen of 62 (22.5%) pigs that did not receive cimetidine developed bleeding ulcers. Of 45 animals given daily prophylactic doses of cimetidine, none manifested clinical signs indicative of a bleeding ulcer. These results indicated that cimetidine was effective in preventing morbidity and mortality due to bleeding gastric ulcers in young swine used in chronic laboratory experiments.

Pasteurella associated rhinitis of rabbits: efficacy of penicillin therapy.

Thirty adult New Zealand white rabbits with chronic rhinitis were obtained from a commercial breeding colony. Penicillin sensitive strains of Pasteurella multocida were isolated from the upper respiratory tract of 28 (93%) of these rabbits. The diseased rabbits were treated with either intramuscular penicillin or penicillin nasal spray for 10 days and monitored for clinical signs of rhinitis and for the presence of Pasteurella multocida in the nasal passages. Rabbits receiving penicillin therapy by either route showed significant remission of the clinical signs of rhinitis during the study period; however, following treatment there was not significant difference in the prevalence of rhinitis between the treated groups and the untreated group. This was due in part to the considerable but non-significant improvement shown by the untreated group. This improvement which was not due to penicillin therapy may have been due to stabilization of environmental factors. The prevalence of Pasteurella multocida in the upper respiratory tracts of either the treated or untreated rabbits did not change significantly during the study period.

Age-associated pathological changes in male rats.

The selection of rats for aging research and the interpretation of experimental results require knowledge of spontaneous age-associated lesions in specific stocks and strains. We have compared selected age-associated pathological changes, as determined by postmortem examination of 113 outbred Crl:CD(SD)BR male retired breeder rats 12--39 months old, with those reported by others in a group of 122 virgin male 12- to 33-month-old F344 rats, an inbred strain from the same commercial source as the outbred rats. Numerous degenerative, inflammatory, and neoplastic lesions occurred in both groups. The wide prevalence and severity of many of the lesions suggest that they could be the source of significant variability in the results of specific aging studies, by their direct and indirect effect(s) on target organs. The prevalence of spontaneous lesions should be defined for each stock or strain intended for use in aging research by postmortem examination of representative groups of animals at various ages. Antemortem diagnostic screening of old rats may also be useful in culling animals bearing lesions that could add to the variability of experimental results, or in selecting for specific lesions that are of research interest themselves.

Characterization of Pasteurella multocida isolates from the nares of healthy rabbits with pneumonia.

Pasteurella multocida was isolated from 42 of the 135 (31%) deep nasal swabs from clinically healthy conventional rabbits supplied by two vendors. The prevalences were significantly different among sex, age, and sources. The females and adults had higher prevalences when compared to males and juveniles, respectively. One vendor's rabbits had a prevalence of 41% while the other had 20%. Biochemically, only 24% of the 42 isolates decarboxylated L-ornithine, and 55% produced indol. All isolates were sensitive in vitro to several of the commonly used antibiotics, but most isolates were resistant to lincomycin, streptomycin, and sulfonamides. Typing with a hyaluronidase inhibition test revealed that 28 of the 42 (67%) isolates were type A. Type A was the major type isolate, whether the samples came from healthy rabbits or from rabbits with pyogenic lesions. The acriflavine flocculation test showed that two of the 42 (5%) isolates were type D. Although none of the 42 isolates were positive to both hyalurondase and acriflavine tests, 12 of the 42 (29%) isolates were negative to both tests, indicating that these isolates were not typeable by these two methods. The demonstration of more than one capsular type of Pasteurella multocida in rabbits indicates the need for more extensive studies on this important rabbit pathogen.

Clindamycin-induced enterocolitis in hamsters.

A lethal enterocolitis was induced in hamsters by oral or parenteral administration of clindamycin in amounts comparable to those used in treatment of humans. The intestinal lesions were characterized histologically as an acute inflammatory reaction with pseudomembrane formation and resembled the lesions seen in humans with antibiotic-induced colitis. Results of quantitative stool cultures showed the numbers of Peptostreptococcus and Corynebacterium decreased in animals with colitis after challenge with 100 mg of clindamycin/kg, while numbers of Escherichia coli, Streptococcus faecalis, and clindamycin-resistant Clostridium sordellii and Clostridium difficile increased. Bacteria were not seen within the intestinal lesions. Viruses were not isolated from hamsters with colitis. Although the pathogenesis of this syndrome is not completely established, the evidence is consistent with the hypothesis that the disease is caused by clostridial toxins and that the production of these toxins by organisms within the intestines is enhanced by the effects of clindamycin upon the bowel flora.