Familial aortic aneurysm in Leonberg dogs

A thoracic aortic aneurysm was diagnosed in a 6-month-old male Leonberg dog by use of radiography, transthoracic and transesophageal echocardiography, and magnetic resonance imaging. The aneurysm was associated with a twisted ascending aorta and dilatation of several other thoracic arteries (pulmonary trunk, brachiocephalic trunk, and left subclavian artery). Histologic examination of the aorta revealed cystic medial necrosis, with disruption of the elastic network, collagen fibers, and the muscle glycoprotein fibrillin-1. The dam and sire of the dog and 8 littermates were examined by use of transthoracic echocardiography. The sire and 1 male littermate also had an aneurysm of the ascending aorta. To the authors' knowledge, this is the first report of familial aortic aneurysm in dogs.     

Reproductive performance of camels (Camelus dromedarius) under pastoral management and its influence on herd development

Camels (Camelus dromedarius) produce milk and offspring and provide transport in pastoral husbandry systems in the Afro-Asian dryland belt. The aim of the present study was to investigate the reproductive performance of camels kept under pastoral management in northern Kenya. Using the Progeny History surveying technique, data were collected from 471, 287 and 416 adult Rendille, Gabra and Somali female camels including data on 1506, 789 and 1206 parturitions, respectively. Surveys took place from January to December 1995, but data refer to the 15-year production period preceding the survey. Age at first calving (AFC) was 58.4±1.0 months (LSMeans±S.E.), 63.0±1.1 months and 68.4±1.3 months for the Somali, Rendille and Gabra camels, respectively.The mean calving interval was similar for all three populations with 27.3±0.6 months (LSMeans±S.E.) for Rendille camels, 28.0±0.6 months for Gabra (n=500) and 28.4±0.6 months for Somali camels. The annual calving rate varied between 33% and 46% in the Somali, 19% and 44% in the Gabra and 8% and 86% in the Rendille camel population. Calf mortality rate averaged 25%, 22% and 27% in Rendille, Gabra and Somali camel calves, respectively, and showed highest variation between the years in the Rendille system (5% to 60%).The number of adult breeding females increased by about 20% over a simulation period of 10 years using the status quo reproductive parameters and by about 70% with improved AFC and CI (excluding AFC>78 months and CI>36 months). The results reveal the usual and unusual variation in the reproductive parameters over different years and in the different systems. It is concluded that eliminating unusual variation is a promising way to enhance herd development and reduce risk in the production systems.     

Landscape pattern in topographically complex landscapes: issues and techniques for analysis

Ecological research provides ample evidence that topography can exert a significant influence on the processes shaping broad-scale landscape vegetation patterns. Studies that ignore this influence run the risk of misinterpreting observations and making inappropriate recommendations to the management community. Unfortunately, the standard methods for landscape pattern analysis are not designed to include topography as a pattern-shaping factor. In this paper, we present a set of techniques designed to incorporate the topographic mosaic into analyses of landscape pattern and dynamics. This toolbox includes adjustments to classic landscape indices that account for non-uniform landscape topography, indices that capture associations and directionality in vegetation pattern due to topographic structure, and the application of statistical models to describe relationships between topographic characteristics and vegetation pattern. To illustrate these methods, we draw on examples from our own analysis of landscape pattern dynamics in logged and unlogged forest landscapes in southwestern British Columbia. These examples also serve to illustrate the importance of considering topography in both research and management applications.This revised version was published online in May 2005 with corrections to the Cover Date.     

Meta-analysis of the effect of animal maturity on muscle characteristics in different muscles, breeds, and sexes of cattle

The effect of animal maturity on fiber cross-sectional area, percentage of fiber types, activities of isocitrate dehydrogenase (ICDH) and lactate dehydrogenase (LDH), total and insoluble collagen and lipid concentration was investigated in the longis-simus thoracis (LT), semitendinosus (ST), and triceps brachii (TB) muscles. The analysis considered 2,642 muscle samples from bulls, steers, and cows of Aubrac, Charolais, Limousin, Montbéliard, and Salers breeds. For the bulls, the fiber cross-sectional area, percentage of slow oxidative fibers, and ICDH activity showed a quadratic relationship (P < 0.05), and the percentage of fast oxidative-glycolytic and fast glycolytic fibers and LDH activity showed a cubic relationship (P < 0.05) with increased maturity. A linear relationship was observed for the collagen and lipid muscle characteristics. The response equation coefficients for different muscles indicate that development of muscle characteristics is different for each muscle. Compared with the other muscles, ST muscle had a greater fiber cross-sectional area, proportion of fast glycolytic fibers, LDH activity, and collagen content. The LT muscle had a greater proportion of slow-oxidative fibers and lipid (P < 0.05). Within the ST muscle, all characteristics except lipid concentration showed different development between the breeds. Steers showed greater changes in muscle fiber cross-sectional area, percentage of fast oxidative-glycolytic and fast glycolytic fibers, and total lipid in the muscle with increasing maturity compared with bulls. The mean fiber cross-sectional area and percentage of fast glycolytic fibers was greater and the mean lipid concentration was less in bulls compared with steers (P < 0.05). Data for cows were from more mature animals. Muscle characteristics in cows did not show large changes with increasing degree of maturity. Muscle type accounts for a greater proportion of the variation in the muscle characteristics than breed and sex of the animal.     

Temporary remission of disseminated paecilomycosis in a German shepherd dog treated with ketoconazole

Disseminated mycosis caused by Paecilomyces varioti in a female German shepherd dog presented with chronic forelimb lameness is described. Radiographs of the swollen carpal joint revealed geographic lysis of the radial epiphysis. Diagnosis was based on cytological demonstration of fungal hyphae and chlamydiospores, as well as fungal culture of fluid obtained by arthrocentesis. Temporary remission was characterised by markedly improved clinical signs and laboratory parameters, following treatment with ketoconazole. The dog was euthanased 9 months after the initial diagnosis, following the diagnosis of multifocal discospondylitis. This appears to be the longest described period of temporary remission obtained with treatment in dogs with paecilomycosis. Clinical, clinicopathological and necropsy findings of this disease in another German shepherd dog are briefly described.