Evaluation of a canine C6 ELISA Lyme disease test for the determination of the infection status of cats naturally exposed to Borrelia burgdorferi

The efficacy of a commercially available in-office kit (SNAP 3Dx, IDEXX Laboratories) for detection of antibodies directed against an invariable region (IR6) of the B. burgdorferi surface protein VlsE (Vmp-like sequence, Expressed), a surface antigen of the spirochete recognized during active infection has been evaluated in dogs. The present study was conducted to determine whether this in-office test could be useful for detection of antibodies to B. burgdorferi in cats. Cats owned by clients of a veterinary hospital located in an area hyperendemic for Lyme disease were included in the study. When possible, cats with an outdoor lifestyle, bite wounds, or current tick infestation were recruited for the study to help ensure that animals with a likelihood of exposure to natural infection by B. burgdorferi would be included in the test group. Of the 24 cats tested, 17 samples were positive for antibodies to B. burgdorferi by the C6 ELISA kit. For all 17 of these samples, a duplicate sample tested by immunofluorescent assay (IFA) was in agreement with the ELISA. Five samples were negative by both assays. Two samples that were negative by the C6 ELISA test had low IFA titers (1:100). One of these two discrepant samples was negative and one was positive for antibodies to B. burgdorferi by the Western blot test. It was concluded that the C6 ELISA test performed with good agreement with the IFA and Western blot tests for detection of antibody to B. burgdorferi in the majority of cats tested. The test offers the advantages of producing a result rapidly (approximately 8 minutes), and it requires only two drops of serum, plasma, or whole blood.     

Transmissible spongiform encephalopathies in ruminants.

Transmissible spongiform encephalopathies (TSEs) have been observed in North American sheep, cervidae, and cattle. The causative agent of TSEs seems to be proteins that induce a conformational change in normal host proteins. Common clinical signs ofTSEs include chronic weight loss and deteriorating neurologic function. Mechanisms of TSE transmission vary among host species.The diagnostic approach for TSEs of ruminants is presented,and the history and justification of regulatory programs to control and eradicate TSEs are outlined.     

A Markov model of land-use change dynamics in the Niagara Region,Ontario, Canada

Regional Niagara is the site of an intense three-way land-use conflict among urban, agricultural and natural uses. Large scale spatial and temporal land-use data were used to investigate the dynamics of land-use change in this area. A first order Markov chain was used as a stochastic model to make quantitative comparisons of the land-use changes between discrete time periods extending from 1935 to 1981. The Markov model allowed for two main conclusions about the historic dynamics of land-use change in the Regional Municipality of Niagara.

1. The urbanization of agricultural land was the predominant land-use change.
2. A continuing ‘exchange’ of land area occurs between wooded and agricultural land-use categories that has little effect on the net amount of wooded land but which could undermine the long-term ecological value of remaining natural areas in Niagara.

     

Evaluation of secondary protein nutrients as a substitute for soybean meal in diets for beef steers and meat goats

Finding appropriate disposal techniques for waste products is one of many challenges facing the poultry-processing industry. One waste generated in significant quantities is dissolved air floatation sludge, a product of wastewater treatment. Converting dissolved air floatation sludge into a dry feed product (meal) for incorporation into livestock feed appears to be a viable solution. This meal, called secondary protein nutrients (SPN), is high in protein (45% CP), fat (28% crude fat), and minerals. The protein consists of 85% B(2) and B(3) fractions, which are moderately to slowly degradable in the rumen, and therefore may potentially escape ruminal degradation and be available for digestion in the lower gastrointestinal tract. The goal of this research was to evaluate SPN as an alternative to traditional protein sources for ruminants by substituting it on an equivalent N basis for soybean meal in cattle and meat goat diets (0, 25, 50, 75, and 100% for cattle; 0, 20, and 40% for goats). When included in corn silage-based steer diets, increasing SPN resulted in linear and quadratic declines in both DMI and ADG (P < 0.001). Dry matter intake diminished with inclusion rates above 50%, and ADG were reduced after inclusion of SPN reached 25% of added N. Feed efficiency (the reciprocal of the efficiency of gain, which is represented by G:F) declined linearly (P < 0.001) with each incremental increase in SPN. Addition of up to 40% added N as SPN in goat diets caused no change in DMI, digestibility of DM or fiber, or N retention. Ruminal VFA concentrations showed little variation in either species. Increasing the proportion of SPN in the feed caused linear declines in ruminal NH(3) in steers (P < 0.001). Increasing SPN in goat diets, however, resulted in only a trend toward reductions of this parameter (P = 0.14). The decreases observed may have resulted from decreasing ruminal protein degradability or increasing fat caused by increasing the proportion of SPN in the feed. Urinary urea N as a percentage of urinary N showed significant declines in cattle, but not in goats, over the ranges of SPN offered. These results indicate that SPN can be included in diets for ruminants to supply up to 40% of supplemental N with little negative impact on animal performance.     

Comparative effects of proligestone and megestrol acetate on basal plasma glucose concentrations and cortisol responses to exogenous adrenocorticotrophic hormone in cats

Cats were given megestrol acetate (MA, 5 mg once daily for 14 days), subcutaneous proligestone (PRG, 100 mg on two occasions one week apart) or subcutaneous saline (1 ml as for PRG). In cats given saline (n = 6) basal cortical concentrations, cortisol concentrations after adrenocorticotrophic hormone (ACTH) administration and fasting blood glucose concentrations did not change significantly during the following seven weeks. Cats given MA (n = 7) developed suppression of basal and ACTH-stimulated cortisol concentrations and fasting hyperglycaemia during treatment. Effects on cortisol persisted for two weeks after MA dosage ceased. In cats given PRG (n = 7), basal cortisol concentrations were reduced overall, but only three cats had persistently suppressed post-ACTH cortisol concentrations. Adrenal suppression continued for 14 weeks in one of these and for at least 22 weeks in two cats. Fasting blood glucose concentrations were unchanged in PRG-treated cats.     

Putative immunoglobulin VH genes of the goldfish, Carassius auratus, detected by heterologous cross-hybridization with a murine VH probe

By using a defined cDNA probe for the VH region of a murine phosphocholine-binding myeloma protein (S107) we have defined a family of distinct cross-hybridizing DNA sequences in genomic DNA of the goldfish. The estimated number of the goldfish putative VH family detectable by the S107 probe is about 36. By using two putative goldfish VH probes to analyze, by hybridization, the relationships among seven of the goldfish genomic clones, we have determined that the putative goldfish VH genes recognized by the S107 probe comprise at least several distinct families that are not closely related.