Effect of long-term heat exposure on peripheral concentrations of heat shock protein 70 (Hsp70) and hormones in laying hens with different genotypes

1. The effect of long-term, moderate heat stress (30 to 32 degrees C) on heat shock protein 70 (Hsp70) concentration in mononuclear blood cells and plasma concentrations of 3,5,3'-triiodothyronine (T3) and corticosterone in laying hens was investigated. 2. Three groups of 48 hens each (Ethopian line [Angete Melata, Na], New Hampshire [NH], F1 cross [Na x NH]) were divided into an experimental group (24 each) and a control group (24 each, ambient temperature 18 to 20 degrees C), respectively. All hens were kept in individual cages up to an age of 68 weeks and performance data were recorded. 3. Blood samples were taken from the wing vein of 12 hens from each group at weeks 22, 38, 51 and 65 (12 hens x 3 lines x 2 treatments). Mononuclear blood cells were isolated and Hsp70 concentrations were determined by Western Blot analysis with a monoclonal anti-Hsp70 antibody. T3 and corticosterone were measured with commercially available ELISA and RIA kits, respectively. 4. The moderate heat stress caused significantly increased Hsp70 levels compared with the control groups in weeks 51 and 65. However, the responses of the lines were not uniform at different ages. 5. In contrast, T3 levels were significantly decreased in stressed birds regardless of line and age. There was no effect of treatment and line on corticosterone levels during the experimental period. 6. Our results indicate that Hsp70 and T3 levels are affected by mild heat stress applied over a long period but are both involved in independent mechanisms of acquisition of thermotolerance. Further investigations are necessary to clarify whether the observed differences in Hsp70 response between the genotypes are indicators for differences in thermotolerance.     

The eradication of BSE: a touch stone for the veterinary services

The eradication of BSE is proving to be a lengthy task. Undisputedly, it has become one of the highest priority tasks of the Veterinary Services in Europe since the disease first occurred in the mid eighties. However, the effects of the ongoing eradication effort also impair important economic agricultural sectors. Risk analysis has never before been such a critical tool in the decision-making processes for eradication of animal diseases, despite the problem that many risk analyses are being conducted in the face of incomplete knowledge about BSE. In the focus are the measures minimizing the risk for humans (such as the ban on specified risk material) and the measures implemented to prevent the spread of the disease in animals with the ban on feeding meat and bone meal to ruminants. Due to the long incubation period, implementation of insufficient measures may not be noticed for many years. Implementation of drastic measures is needed, if the eradication of the disease is to be pursued purposefully.     

The efficacy of topical prophylactic antiglaucoma therapy in primary closed angle glaucoma in dogs: a multicenter clinical trial

The ability of either 0.5% betaxolol (1 drop topically, bid; n=31) or a combination of 0.25% demecarium bromide and a topical corticosteroid (gentamicin/betamethasone) (DB/GB; 1 drop of each topically, sid; n=55) to prevent glaucoma in the fellow eye of dogs with unilateral, primary closed angle glaucoma (PCAG) was investigated in a multicenter, open-label, clinical trial. Untreated control dogs (n=20) developed glaucoma significantly sooner (median, eight mos; p less than 0.001) than dogs treated either with DB/GB (median, 31 mos) or betaxolol (median, 30.7 mos). Although DB/GB and betaxolol equally delayed or prevented the onset of glaucoma in the second eye, a less frequent dosing schedule for DB/GB suggests demecarium bromide in combination with a topical corticosteroid may be preferable to betaxolol in preventing PCAG in dogs.     

Sex determination of bovine embryos based on embryonic cleavage rates

Bovine embryos (n = 64) collected at day-6 from 10 superovulated and inseminated donors were evaluated upon recovery and again after incubation for approx. 12 hrs. According to cleavage rate they could be divided into a fast, an intermediate and a slow developing group, respectively. This grouping was correlated to embryonic sex determined by karyotyping (n = 29). From the fast developing group we found 7 males and 2 females (male ratios 78%), from the intermediate group 3 males and 8 females (male ratio 27%) and from the slow group 1 male and 8 females (male ratio 11%). From this preliminary study it is concluded that the rate of embryonic development may be used as a sex discriminator.     

Toxoplasma pneumonia in a cat with incongruous serological test results

A 12-year-old neutered male domestic short-haired cat was presented for rapid breathing, lethargy of two weeks duration and chronic weight loss. A diagnosis of toxoplasma-induced pneumonia was made based on clinical signs, laboratory data, radiology, immunoglobulin M (IgM) serology and isolation of the organism from a lung aspirate. A passive haemagglutination test to measure immunoglobulin G (IgG) levels against toxoplasma was negative. The reliability of agglutination tests, to accurately diagnose an acute toxoplasma infection is questioned. In acute infections the use of an enzyme-linked immunosorbent assay for IgM may be more specific.     

The congenital portosystemic shunt in dogs and cats. I

An overview of the circulation of the liver and of the pathogenesis of hepatic encephalopathy as a result of portal vascular anomalies is given. Clinical signs associated with portal systemic shunts are described on the basis of 16 cases, 14 dogs and 2 cats. These animals ranged in age at the time of presentation from 4 months to 7 years. The predominant abnormality observed were central nervous signs, which differed in severity. 15 animals showed a reduction in liver size. The different techniques of contrast angiography allowing demonstration of a portal systemic shunt are presented along with a discussion of the pros and cons of each. Additionally the significance of making portal venous pressure measurements prior to each angiography is also explained. In most cases mesenteric portography was chosen. Based on their location the anomalies could be categorized as intrahepatic (4 dogs) or extrahepatic (10 dogs, 2 cats). In both groups breeds of various size are represented. The extrahepatic shunts could be further described as portal-caval (n = 5), portal-phrenic (n = 4) and portal-azygos (n = 3). In five of the older animals angiography showed in addition some hepatic perfusion by the portal vein. Laboratory evaluation revealed increased resting blood ammonia concentrations (greater than 200-912 micrograms/100 ml) in all animals. Seven dogs had definitely subnormal BUN concentrations (less than 10 mg%) and ten dogs low total plasmaprotein levels (less than 5.4 g%). Free amino acids (24) were determined in four dogs and a lowered hepatic encephalopathy index (less than 1.64) was found. Medical palliative therapy to control the clinical signs is discussed. The only effective long term therapy is, however, surgery. The shunt vessel is narrowed so that a greater volume of portal blood reaches the liver. Experience gained from the surgical therapy of 14 animals is presented. Ten of these survived well without requiring further therapy at a later time. Finally the etiology, prognosis, and differential diagnosis are summarized.