Gastric Neoplasia in Horses

Background: Gastric neoplasia of horses is incompletely described.
Objective: Provide history, clinical signs, and clinicopathological and pathological findings associated with gastric neoplasia in horses.
Animals: Twenty-four horses with gastric neoplasia.
Methods: Retrospective study. History, clinical signs, and clinicopathological and pathologic findings in horses diagnosed histologically with gastric neoplasia were reviewed.
Results: Horses ranged in age from 9 to 25 years (median 18 years at presentation). There was no apparent breed or sex predisposition. The most common presenting complaints were inappetance (17/24), weight loss (14/24), lethargy (7/24), hypersalivation (7/24), colic (5/24), and fever (5/24). The most consistent clinical signs were tachypnea (10/19), decreased borborygmi (8/19), and low body weight (7/17). Useful diagnostic tests included rectal examination, routine blood analysis, gastroscopy, abdominocentesis, and transabdominal ultrasound examination. Anemia was the most common hematologic abnormality encountered (7/19), and hypercalcemia of malignancy was seen in 4/16 horses. Squamous cell carcinoma was the most common tumor identified (19/24), and was most often (14/19) found as a single ulcerated, necrotic mass in the nonglandular portion of the stomach. Other gastric neoplasms encountered were leiomyoma (n=2), mesothelioma (n=1), adenocarcinoma (n=1), and lymphoma (n=1). Metastatic neoplasia was found in 18/23 horses. The median time from onset of clinical signs to death was 4 weeks, and all horses died or were euthanized because of gastric neoplasia.
Conclusions: Squamous cell carcinoma is the most common primary gastric neoplasia in horses. The survival time after diagnosis of gastric neoplasia in horses is short.     

Isolation of antigenic proteins from erythrocytes parasitised with Babesia divergens and a comparison of their immunising potential

Soluble proteins present in the supernatant prepared from a sonicated lysate of concentrated erythrocytes infected with Babesia divergens were separated by isoelectric focussing into acidic and non acidic fractions. The acidic fraction was further separated by passage through Concanavalin A Sepharose (Con A) into two fractions, the first (Fraction 2) consisting of proteins plus one glycoprotein which did not bind to Con A, the second of glycoproteins (Fraction 1) which were eluted after binding to Con A. One group of six cows was treated with three injections of Fraction 2 with incomplete Freunds adjuvant (IFA); two other groups received the same number of injections of Fraction 1, one with IFA, the other with glucan as adjuvant. These cows plus an untreated control group were infected with 10(5) erythrocytes infected with a heterologous isolate of B. divergens. Only the group treated with Fraction 2 (Group 1) resisted lethal multiplication of the parasite. There were significant differences in magnitude of parasitaemia, reduction of packed cell volume and antibody titres between Group 1 and the other groups.     

Disease patterns in the Detroit Zoo: a study of reptilian and amphibian populations from 1973 through 1983

A retrospective study was conducted to determine disease patterns in reptilian and amphibian populations at the Detroit Zoo from 1973 through 1983. In the reptilian population (mean +/- SD = 285.2 +/- 28), overall annual mortality rates were 1% to 40%. Mortality rates were highest in the fall months (20%) and lowest in the winter months (6%). The most frequently affected reptiles were iguana (Iguana iguana), reticulated python (Python reticulatus), rattlesnakes (Crotalus spp), common boa (Constrictor constrictor), and lizards (various genera of suborder Lacertilia). Of the 1,300 reptilian deaths from 1973 through 1983, 36.6% were caused by microbial agents, 12% by parasites, 11.6% by trauma, and 9.3% by nutritional deficiencies. The main microbial organisms that caused death were Aeromonas spp, Salmonella spp, Pseudomonas spp, Proteus spp, and Edwardsiella spp. The main parasites that caused death were Entamoeba spp and lungworms. Among amphibians, frogs and toads were the most frequently affected, and starvation and trauma were the most frequent causes of death.     

Disease patterns in the Detroit Zoo: a study of the mammalian population from 1973 through 1983

A retrospective study was conducted to evaluate disease patterns in the mammals at the Detroit Zoo from 1973 through 1983. The reindeer (Rangifer tarandus), common eland (Taurotragus oryx), rednecked Wallaby (Protemnodon rufogrisea), sitatunga (Tragelaphus spekii), and kangaroo (Macropus spp)- were the most frequently affected mammalian species. Parasitic agents (80% of which were internal parasites) caused morbidity in 60.2% of the mammals evaluated (n = 2,475) and microbial agents caused morbidity in 20.8% of the animals. Strongyloides spp, Trichostrongylus spp, coccidian species, Diphyllobothrium spp, and Trichuris spp were the internal parasites most frequently found. Overall annual mortality rate was 14% to 34%, with microbiological agents causing the highest mortality (26.5%). Pasteurella spp, beta-hemolytic Streptococcus spp, pathogenic Escherichia coli, Corynebacterium spp, and Klebsiella pneumoniae were the most frequent microbial causes of death. Cause of mortality could not be determined in 21.5% of the animals evaluated. The percentage of animals successfully treated increased from 1973 through 1983. Generally, however, the percentage of successfully treated animals was low (21% to 39%).     

Losses over a 2-year period associated with fetal infection with the bovine viral diarrhea virus in a beef cow-calf herd in Saskatchewan.

In 1992, significant calf losses occurred between birth and weaning in a 650-cow Saskatchewan beef herd. These losses occurred subsequent to ill-thrift and disease, and every calf necropsied was found to be persistently infected with bovine viral diarrhea virus (BVDV). The objectives of this study were to describe the losses associated with fetal infection with BVDV in this herd and to determine why they occurred. For investigative purposes, blood samples were collected from the entire cow herd and the surviving calves at pregnancy testing in 1992, and tested by virus isolation for BVDV. Between 51 and 71 persistently infected calves were born in 1992. Bovine viral diarrhea virus was only isolated from calves. The only confirmed fetal infections with BVDV were recorded as the birth of persistently infected calves. However, abortions, reduced pregnancy rates, and delayed calvings were also recorded in the cow herd and may have been the result of fetal infections. The herd was monitored again in 1993. Fetal infections with BVDV were recorded as the birth of stunted, deformed, and persistently infected calves. The greatest losses due to fetal infection with BVDV in the 2 years of this study occurred in cows that were 3-years-old at calving (second calves). Bovine viral diarrhea virus appears to have remained endemic in this herd by transmission from persistently infected calves on young 3- and 4-year-old cows to naive calved 2-year-old cows that were mingled with them annually for rebreeding. Significant numbers of the 2-year-old cows remained naive to BVDV, because they were segregated from persistently infected calves at weaning, preventing cross-infection with BVDV.     

Transmission of capripoxvirus

The transmission of capripoxvirus to sheep, using an aerosol suspension of a Yemen isolate of the virus, was demonstrated. Capripoxvirus was also transmitted by contact to sheep and goats kept with animals infected with virus isolates from the Yemen, Sudan, India and Nigeria. The incubation period for capripoxvirus infection in sheep and goats was approximately eight to 12 days. Animals that had well developed clinical signs transmitted capripoxvirus more rapidly than animals which died of peracute disease or animals that had only mild clinical signs.