Mesotheliomas and proliferative lesions of the testicular mesothelium produced in Fischer, Sprague-Dawley and Buffalo rats by methyl(acetoxymethyl)nitrosamine (DMN-OAc).

A single intraperitoneal dose of methyl(acetoxymethyl)nitrosamine (13 mg/kg body weight) given to 78 5-week-old male rats induced 25 mesotheliomas; two mesotheliomas were found in 67 control rats. All mesotheliomas arose from the peritesticular mesothelium and had a typical microscopic appearance of branching papillary fronds with a collagenous core covered by one or many layers of plump tumor cells. Cytoplasm of tumor cells contained material that reacted positively to a colloidal iron stain and was labile to hyaluronidase. In addition to frank mesotheliomas, 16 lesions, which we called atypical mesothelial proliferations, were found. These consisted of a single focus of plump mesothelial cells overlying an area of thick stroma. Often these foci included short, non-branched papillary projections above the surface of adjacent normal mesothelium. Twelve of the 16 lesions occurred in methyl(acetoxymethyl)nitrosamine-treated rats.     

Comparative histopathological study of the canine thyroid gland in London and Munich

The thyroid glands of two series of ninety-nine unselected dogs from consecutive autopsies in London and in Munich were examined histologically. The prevalence of goitre and of neoplasia was distinctly higher in dogs in the Munich series.
Résumé. On a examiné de façon histologiyue les glandes thyroïdes de deux séries de quatrevingt-dix-neufs chiens d'après des autopsies consécutives à Londres et à Munich. La prédominance de goîtres et de néoplasie était nettement plus élevée chez les chien de la série de Munich
Zusammenfassung. Die Schilddrüsen von zwei Serien von 99 Hunden Wurden von darauf-folgenden Autopsien in London und München histologisch untersucht. Das Vorkommenwon Kropf und Neoplasia war entschieden höher in den Hunden der Munchener Serie.     

The relation of fasting and resting metabolic rates to heat tolerance in the domestic fowl

1. Resting metabolic rate (RMR) and fasting metabolic rate (FMR) were periodically determined, using an open air circuit master system, from January to September in 10 White Leghorn, 10 Plymouth Rock and 20 New Hampshire × White Leghorn mature laying birds fed ad libitum.

2. The relationship of metabolic rate (l.O2/hr.) to body weight (kg.) in the pooled data followed the 0.795 W0.61 equation for the fasting level, and 0.916 W0.59 for the resting level. The expression of metabolic rates as litres oxygen per kg. body weight can lead to serious errors if birds of differing body weights are compared.

3. Heat increments of feeding (estimated by RMR‐FMR) gradually increased with rising environmental temperature, with only slight initial change in the FMR, followed by marked reductions in both the FMR and the RMR at the higher temperatures. It is suggested that a decrease in the FMR may allow for a reduction in the RMR in the hotter season, without this necessarily being linked with a depression in the heat increment of feeding and productivity.

4. In the lower temperature range the three breeds had similar metabolic rates. At the highest temperatures the White Leghorns and New Hampshire x White Leghorn had lower FMR than the Plymouth Rocks, thereby maintaining similar heat increments, but at lower RMR. It is suggested that this may be the basis for their better heat tolerance.     

Effect of diurnal or nocturnal heat stress on egg formation.

1. Mature laying hens were subjected to ambient temperatures sufficient to maintain body temperature of 43 degrees C for periods of 6 to 7 h during the day (eight periods) or the night (five periods). This did not reduce total daily food consumption. 2. The effect of heat stress during the day was mostly on egg-shell quality, being adverse and significant. During the night heat stress caused a significant decrease in egg production, its effect during the day was less marked in this respect. 3. Heat stress thus seems mostly to affect the early stages of shell formation, while its effect on egg production seems to depend on the time at which it occurs in relation to ovulation. 4. These results suggest that egg production is directly affected by heat stress; prolonged heat stress probably also acts indirectly, by suppression of food intake.     

Canine Dal blood type: A red cell antigen lacking in some Dalmatians

BACKGROUND: Based upon alloantibodies produced after sensitizing dogs with transfused blood, more than a dozen blood group systems have been recognized thus far, and some have been classified as dog erythrocyte antigens (DEA). HYPOTHESIS: A new canine red cell antigen was suspected, based on the development of specific alloantibodies in a Dalmatian previously sensitized by blood transfusions. ANIMALS: Twenty-six Dalmatians (including 1 Dalmatian in need of blood compatibility studies); 55 canine blood donors. METHODS: Serologic tests, including blood typing, crossmatching, and direct Coombs' test were performed by standard tube techniques and a novel gel column technology adapted from human blood banking. RESULTS: By day 40 after transfusion of an anemic Dalmatian, all major crossmatch tests to 55 non-Dalmatian dogs were incompatible. The 2 initial donors, who were compatible before transfusion, were also now incompatible, suggesting the development of an alloantibody to a common red cell antigen. No siblings were available, but 4 of 25 unrelated Dalmatians were crossmatch compatible, suggesting that they were missing the same red cell antigen. The patient was blood typed DEA 1.1, 3, 4, and 5 positive, but DEA 7 negative. Further blood typing and crossmatching results did not support an association to any of these known blood types. The alloantibodies produced were determined to be of the immunoglobulin G class. CONCLUSIONS AND CLINICAL IMPORTANCE: Based upon the identification of an acquired alloantibody in a Dalmatian, a presumably new common blood type named Dal was identified. Dalmatians lacking the Dal antigen are likely at risk of delayed and acute hemolytic transfusion reactions.     

Severe eosinophilic cholangiohepatitis due to fluke infestation in a pony in Scotland

Fasciola hepatica infestation is reported as a cause of severe eosinophilic cholangiohepatitis in a 28‐year‐old Warmblood cross pony gelding. The gelding presented initially for investigation of acute laminitis found to be secondary to pars pituitary intermedia dysfunction (PPID). Six weeks of treatment including administration of pergolide achieved good control of the laminitis but there was a marked general clinical deterioration over this period with notable weight loss, tachycardia, anorexia and ventral oedema. Hepatobiliary enzymes were increased significantly and there was mild elevation of plasma bile acid concentration. An eosinophilia in both blood and peritoneal fluid specimens and histopathological confirmation of an eosinophilic cholangiohepatitis on examination of liver biopsies supported a primary parasitic aetiology. The pony was treated for Fasciola hepatica with triclabendazole 12 mg/kg bwt but clinical signs continued to progress. Due to poor clinical response the pony was subjected to euthanasia and post mortem examination revealed an overwhelming infestation of the biliary tracts with Fasciola hepatica and a secondary chronic and severe cholangiohepatitis with marked fibrosis. To the authors' knowledge this is the first equine report demonstrating the relationship between the clinical disease syndrome, eosinophilic cholangiohepatitis and hepatic fluke infestation. Depending on geographical location, fasciolosis should be considered as a differential diagnosis for equine hepatopathies and can result in severe disease.     

Clade 2.3.4.4 avian influenza A (H5N8) outbreak in commercial poultry,Iran, 2016: the first report and update data

Tropical Animal Health and Production - In 2010, H5N8 highly pathogenic avian influenza (HPAI) viruses of the A/Goose/Guangdong/1/1996 lineage dramatically affected poultry and wild birds in Asia,...