Cholangiocarcinoma in a yellow-faced Amazon parrot (Amazona xanthops).

A cholangiocarcinoma in a 3 1/2-year-old yellow-faced Amazon parrot (Amazona xanthops) is reported. The parrot presented with a prolapsed cloaca and died after a 6-week clinical course of progressive weight loss. The tumor replaced much of the normal hepatic architecture but apparently did not metastasize. Cholangiocarcinomas have been reported rarely in several species of domestic and captive wild birds, but this appears to be the first reported case in a large psitticiform bird.

Intestinal adenocarcinoma in a chicken.

An obstructing intestinal stricture 65 cm distal to the pylorus in an aged hen was seen on histologic examination to be caused by a primary intestinal adenocarcinoma.

Pseudomonas pneumonia of mink: pathogenesis, vaccination, and serologic studies.

Fulminating pneumonia was produced in mink by the intratracheal administration of Pseudomonas aeruginosa. The sequence of pulmonary lesions was focal inflammation, focal necrosis, and widespread inflammation and necrosis. Secondary lesions of peracute hemorrhage and necrosis were the result of bacterial spread via the airways. Invasion of vessel walls by P aeruginosa was a terminal event and was secondary to bacillary invasion and necrosis of adjacent tissues. Regional (lymphatic) and systemic spread of bacteria followed the development of pulmonary lesions, but there was little morphologic evidence of tissue damage in other organs. Immunofluorescence studies showed that P aeruginosa antigen was dispersed within pulmonary cells and was free in the lung parenchyma. Mink surviving beyond postinfection hour 60 had a macrophage infiltration into limited pulmonary lesions. A vaccine trial was conducted with P aeruginosa lipopolysaccharides (LPS) used as antigen, and an enzyme-linked immunosorbent assay was used to detect antibody. Antibody was detected in mink after vaccination with LPS or natural exposure. Mink with antibody to LPS, from vaccination or naturally acquired, were resistant to experimental infection.

Pathologic changes in lambs with Ostertagia circumcincta infections associated with decreased infectivity of Haemonchus contortus.

Two experiments were done to examine the severity and type of abomasal lesions induced by moderate infections of Ostertagia circumcincta in young lambs and to examine the differences in pathologic changes in lambs with monospecific and combined infections of O circumcincta and Haemonchus contortus. Observations included descriptions of gross and microscopic changes in the abomasums, as well as quantitative analysis of the thickness of the mucosa, numbers of mucus-containing cells, and inflammatory cell accumulations. Seemingly, the changes in the abomasal mucosa of lambs inoculated with O circumcincta were mild and included dilated glands, focal accumulations of lymphocytes, and significant (P less than 0.05) numerical increases of mucus-containing cells, eosinophils, and globule leukocytes, and increase of mucosal thickness when compared with those in noninoculated controls. These differences were less pronounced in lambs given anthelmintic treatment to remove O circumcincta. When H contortus infections were superimposed upon O circumcincta infection, the changes were essentially the same as those described for O circumcincta plus a small, but significant (P less than 0.05), numerical increase of globule leukocytes. Abomasal mucosa of lambs inoculated only with H contortus was more roughened and hyperemic than that of lambs with combined infections, but contained few dilated glands and globule leukocytes. Our conclusions were that moderate infection with O circumcincta did not cause severe or permanent damage to the abomasal mucosa and that such infection decreased the severity of the gross lesions produced by H contortus.

Efficacy of avermectin B1a for treatment of experimentally induced nematode infections in cattle.

Two formulations of avermectin B1a, C-076 and MK-933, were examined for anthelmintic activity in two trials, each using 20 calves with experimentally produced nematode infections. In one trial, C-076 was given orally, and in the other trial, MK-933 was given by injection at dosages of 50, 100, and 200 micrograms/kg of body weight. Treated calves were held for 7 to 8 days and then, together with nontreated controls, were euthanatized and were examined for nematodes in their gastrointestinal tracts and lungs. Efficacy of C-076 approached 100% for Dictyocaulus viviparus, Ostertagia ostertagi, Trichostrongylus axei, T colubriformis, and Oesophagostomum radiatum at 50 micrograms/kg. A dosage level of 100 micrograms/kg was required to achieve 97% efficacy against Cooperia punctata. Efficacy of MK-933 at 50 micrograms/kg was variable, but at 100 micrograms/kg, it approached 100% for D viviparus, O ostertagi, Haemonchus placei, T axei, and T longispicularis. Activity against C oncophora was less, reaching 80% efficacy at 200 micrograms/kg.

Efficacy of albendazole for treatment of naturally acquired nematode infections in Washington cattle.

Albendazole, methyl 5-propylthio-1H-benzimidazol-2-yl carbamate, was given as a bolus (7.68 to 8.18 mg/kg of body weight) to cattle naturally infected with gastrointestinal nematodes and lungworms in a controlled trial. Over 99% of adult Ostertagia ostertagi, Trichostrongylus longispicularis, Cooperia oncophora, Nematodirus helvetianus, and Dictyocaulus viviparus were removed by the treatment. Efficacy against immature O ostertagi, early fourth-stage O ostertagi, and Oesophagostomum radiatum was 95.2%, 86.6%, and 96.7%, respectively. In a field trial, the same compound administered in a paste formulation (at approximately 7.5 mg/kg) eliminated over 99% of strongylin and Moniezia eggs from feces of treated cattle.

Pathogenesis of experimental bovine respiratory syncytial virus infection in sheep.

Conventionally reared lambs, seronegative to bovine respiratory syncytial virus (RSV), were inoculated with bovine RSV by an aerosol route. A mild clinical response, characterized by transient fever at postinoculation day (PID) 4, occurred and was accompanied by serous oculonasal secretions in less than 50% of the infected lambs. A decrease in total WBC was observed on PID 6 and 11, with a reduction in the total numbers of lymphocytes. Bovine RSV was recovered from nasal secretions of inoculated lambs from PID 2 to 6. The lambs were euthanatized, and at necropsy, the virus was only isolated from lambs killed between PID 2 and 4. Serum neutralizing antibodies were noticed as early as PID 6 and peaked at PID 13 to 15. Neutralizing antibodies were also detected at low concentration in pulmonary washings. Viral antigen was mainly located in alveolar walls and occasionally in bronchiolar epithelium and alveolar macrophages in lambs killed between PID 2 to 4. Later, specific fluorescence was only present in alveolar walls and was not observed in tissue from lambs killed after PID 22. Budding and free virus-like particles were observed by electron microscopy in type I and type II alveolar epithelial cells. Outstanding macroscopic lesions were not seen. Histologically, mild bronchiolitis and alveolitis were observed.

Cervical vertebral interbody fusion in the horse: a comparative study of bovine xenografts and autografts supported by stainless steel baskets.

A modified form of the Cloward technique for anterior cervical fusion in human beings was used in the application of different grafts for evaluation of their effectiveness in stabilizing equine cervical vertebrae. Results of bovine xenograft implants in 8 horses were compared with results of stainless steel baskets (SSB) packed with cancellous autogenous bone in 8 horses. Graft material was incorporated in all cases. Evidence of graft rejection was not present. Both forms of implants decreased the mobility of the intervertebral space in which they were implanted. A fibrous connective tissue union was prevalent after xenograft implantation. Osseous union was prevalent after implantation of the SSB. Reduction in range of motion was greatest at those sites with the SSB.

Clinical and pathologic features of endometrial hyperplasia, pyometra, and endometritis in cats: 79 cases (1980-1985).

Records of 79 cats determined to have endometrial hyperplasia (EH) with or without pyometra or endometritis were studied. Forty-eight cats (61%) were spayed or died because of complications relating to reproductive tract disease. All other cats were free of clinical signs of disease, and lesions were found incidentally during routine ovariohysterectomy or at necropsy. Prevalence of uterine lesions was greater in cats greater than or equal to 5 years old. Breeding, age at first breeding, and queening could not be correlated with clinical or pathologic signs of disease. Seventy-one percent (34/48) of cats with clinical signs referable to the reproductive tract had histologic evidence of pyometra or endometritis, whereas only 19% (6/31) of cats without clinical signs had histologic evidence of either disease. Only 23% (9/39) of cats without pyometra or endometritis had corpora lutea (CL) in at least one ovary, whereas 40% (16/40) of cats with either pyometra or endometritis had CL. We concluded that the prevalence of EH in cats increases with age in sexually intact female cats, and that most cases of pyometra or endometritis, but not EH, in cats are associated with retained CL.

Bacillus piliformis infection (Tyzzer's disease) in foals in northwestern United States: a retrospective study of 21 cases.

From Jan 1, 1967 through June 1980, 21 cases of Bacillus piliformis infection (Tyzzer's disease) in foals were diagnosed at the Washington Animal Disease Diagnostic Laboratory. Affected foals died between 7 and 35 days of age. Of 4 Arabian foals with the disease, 2 also had combined immunodeficiency.

Contagious ecthyma in Alaskan musk-oxen and Dall sheep.

In 1976 and 1977, a disease resembling contagious ecthyma was seen in captive musk-oxen (Ovibos moschatus) in Alaska. A similar disease occurred in 1977 in captive Dall sheep (Ovis dalli). Paravaccinia viruses were detected by electron microscopy and isolated in cell cultures from both species. Experimental inoculation in susceptible and immune domestic sheep (Ovis aries) plus fluorescent antibody tests with ecthyma-immune conjugate indicated that the isolate was contagious ecthyma virus.

Ataxia and weakness associated with fourth ventricle vascular anomalies in two horses.

Two adult horses with progressive neurologic signs were examined clinically and at necropsy. Both horses had signs of progressive ataxia and weakness, clinically diagnosed as spinal cord in origin. Differential diagnoses for cervical spinal ataxia in horses included cervical vertebral malformation, equine degenerative myeloencephalopathy, equine herpes-virus-I myeloencephalopathy, and equine protozoal myeloencephalopathy. Necropsy findings in both horses were similar and consisted of a large hematoma in the fourth ventricle, with upward compression of the cerebellum and downward compression of the pons and rostral portion of the medulla.

Cystic lymphangioma in a colt.

A 6-month-old Morgan colt was examined because of preputial edema and multiple nodular masses in the left inguinal region. A tentative diagnosis of lymphatic hamartoma was made on the basis of initial biopsy findings. The prognosis for surgical excision was poor due to the progressive expansile growth of the tumor. Secondary infectious complications developed, and the colt was euthanatized at the owner's request. An abdominal and retroperitoneal mass was seen at postmortem examination. The mass was adherent to the left lumbar musculature, the craniodorsal aspect of the pelvic inlet, the midjejunum, the left testicle, and the left kidney. The mass extended through the left inguinal and femoral canals into the deep intermuscular fascia of the hindlimb. Histologic examination of the mass indicated that it was a cystic lymphangioma.

Epidemiologic survey of diarrhea in foals.

Epidemiologic and etiologic data about diarrhea in foals were collected under a planned prospective recording and monitoring study. The survey and monitoring procedures included a survey to obtain an overview of current horse management practices on participating farms, a daily health record survey to obtain information on mares and their foals, and collection of feces from 19 of 144 diarrheic foals and 10 age-matched nondiarrheic foals for electron microscopy, ELISA for rotavirus, and bacteriologic culture. Coronavirus was detected in the feces of diarrheic as well as clinically normal foals. Rotavirus was detected in the feces of diarrheic foals only. With regard to agents found in the feces, there was no significant (P less than 0.05) difference between diarrheic and nondiarrheic foals. Half of the 297 foals on which data were available developed diarrhea. Most foals that developed diarrhea lacked other clinical manifestations of disease. Basic cleanliness at foaling was associated with a lower percentage of foals developing diarrhea. Prophylactic use of antibiotics and vitamins in newborn foals was associated with a higher percentage of foals developing diarrhea. A higher percentage of foals born to visiting mares developed diarrhea, compared with foals born to resident mares.