The clinical expression and emergence of porcine circovirus 2

Since its discovery and characterization in western Canada in 1995, the distribution of post-weaning multisystemic wasting syndrome (PMWS) has grown and the syndrome is undoubtedly recognized worldwide. More recently, there is a heightened interest in several potentially related conditions including porcine dermatitis and nephropathy syndrome (PDNS), proliferative and necrotizing pneumonia (PNP), congenital tremors (CT-AII), perinatal myocarditis and reproductive failure. Although the causality of porcine circovirus type 2 (PCV2) has recently been proven [Vet. Pathol. 37 (2000) 254; J. Comp. Pathol. 122 (2000) 9; J. Vet. Diagn. Invest. 13 (2001) 185], PCV2 is present in both diseased and healthy pig populations. Furthermore, recent serologic studies have shown that there are no significant differences in PCV2 specific IgG titres between PMWS clinical and non-clinical herds (Harding et al., in press). Clearly, the transmission, epidemiology, and factors triggering clinical expression are poorly understood. With these uncertainties in mind, the objective of this paper is to review the clinical expression and emergence of PMWS and the potentially associated disease syndromes including PDNS.     

A comparison of traditional and modified inland artisanal aquaculture systems

Traditional artisanal aquaculture systems are commonly assumed to be mainly for subsistence, to use predominantly on-farm inputs, and to have been developed by farmers themselves. Such systems with a long history in South East Asia exist mainly in northern Lao PDR, northern Vietnam and in West Java. In most other areas the traditional fish supply, wild fish, has declined only relatively recently, providing a stimulus for growth of aquaculture over the past few decades. An overview of artisanal aquaculture so defined in the South East Asian region is presented from a systems context considering social and economic aspects (micro- and macro-level perspectives), production technology (rice fields, ponds, cages), and environmental aspects (fitting into the local resource base without adverse environmental impact). Most artisanal aquaculture systems are integrated with crops and livestock but generally resource-poor farms constrain production. Rising expectations mean that productivity must be enhanced by off-farm inputs for aquaculture to contribute significantly to the farm household livelihood system. It is proposed that the term ‘small-scale’ be used rather than ‘artisanal’ because of increasing farmer interest in income rather than subsistence, because of increasing use of off-farm inputs, and because of the increasingly important role of science in the promotion of such systems.     

Evaluation of mechlorethamine,vinblastine, procarbazine,and prednisone for the treatment of resistant multicentric canine lymphoma

Multi-agent chemotherapy successfully induces remission in most naïve, high-grade canine lymphoma patients; however, disease recurrence is common. MOPP (mechlorethamine, vincristine, procarbazine, and prednisone) is an effective rescue protocol used to re-induce remission, but is associated with gastrointestinal toxicity and can be a less desirable option for patients that previously failed vincristine-containing protocols. Therefore, alternative members of the vinca alkaloid family, such as vinblastine, could be potentially advantageous as substitutes for vincristine to reduce gastrointestinal toxicity and chemoresistance. The objective of this study was to report the clinical outcomes and toxicity of 36 dogs with relapsed or refractory multicentric lymphoma treated with a modified MOPP protocol whereby vincristine was replaced with vinblastine (MVPP). The overall response rate to MVPP was 25% with a median progression free survival of 15 days and a median overall survival of 45 days. MVPP at the prescribed doses resulted in modest and transient clinical benefit, but was well tolerated with no treatment delays or hospitalizations secondary to side effects. Given the minimal toxicity, dose intensification could be considered to improve clinical responses.     

Mycobacteriosis in a black-tailed deer (Odocoileus hemionus columbianus) caused by Mycobacterium kansasii.

An eviscerated hunter-harvested female black-tailed deer (Odocoileus hemionus columbianus) was submitted to the Washington Department of Fish and Wildlife. The deer was emaciated, devoid of adipose tissue, and the parietal surface of the thoracic cavity contained multiple granulomas. Acid-fast bacteria were detected histologically from the granulomas and were isolated and identified as Mycobacterium kansasii, a nontuberculous mycobacterium sporadically reported to cause tuberculosis-like disease in a variety of vertebrates. This was the first report of symptomatic disease caused by M. kansasii in free-ranging deer. This case indicates that atypical mycobacteria can cause tuberculosis-like disease in free-ranging deer and illustrates the importance of identifying causative agents of tuberculosis-like disease in wildlife.     

Some enzyme interrelationships in serum and organs of Egyptian camel

In 7 normal healthy Egyptian one-humped camels aged 3-4 years, the relationships were studied between enzyme activities of lactic dehydrogenase (LDH), creatine phosphokinase (CPK), alkaline phosphatase (ALP), acid phosphatase (ACP), and cholonesterase (CHE) of serum and organs as well as between ACP and ALP and between LDH and CPK. Liver, heart, kidney, and spleen tissue samples as well as serum were analysed for total enzyme activity. The following results were obtained: --The heart was the organ with the highest activities of ALP, LDH, and CPK, and it contained high values of CHE, whereas the lowest activities of all enzymes were recorded from serum. The spleen exhibited of the highest activity of ACP. --Each of the serum enzymes ALP, LDH, and CHE were in strong inverse relationship with the corresponding enzymes in the liver. Strong inverse relationships existed also between serum LDH and kidney LDH as well as between CPK in serum and heart. --Direct relationships were remarkable serum LDH and that of spleen and heart as well as between serum ACP and that of liver and heart. --Interrelationships were inverse between ACP and ALP in liver, kidney, and heart, but weak direct interrelationships were characteristic between the 2 enzymes in serum and spleen. --LDH was inversely interrelated with CPK in serum and heart.     

Estimation of genetic parameters among reproductive and growth traits in yearling heifers

Growth and reproductive data were obtained on 779 beef heifers at the San Juan Basin Research Center, Hesperus, Co. Genetic parameters were estimated for age of puberty (AOP), age of first calving (AOC), julian day of first calving (DOC), julian day of second calving (DOSC), birth weight, weaning weight, yearling weight, and average daily gain from weaning to yearling and to cycling weights. The least squares model included birth year, age of dam and breed as fixed effects, sire/breed as a random variable, and day of birth and percent inbreeding as covariates. Day of birth was not included in the analyses of AOC, DOC or DOSC. Paternal half-sib estimates of heritability were: AOP, .10 +/- .17; AOC, .01 +/- .12; DOC, .09 +/- .13 and DOSC, .36 +/- .18. Genetic and phenotypic correlations were generally favorable, but genetic correlations were variable with large standard errors. Inbreeding had a detrimental effect on reproductive traits, and a seasonal effect was present for AOP.