Essential fatty acids and skin disease

Essential fatty acids (EFAs) are important in the maintenance of epidermal barrier function, as components of cell membranes and as precursors of prostaglandins, leukotrienes, thromboxanes and other substances involved in mediating inflammation. There is increasing evidence that dietary supplementation with certain EFAs, notably gamma-linolenic acid (GLA) and eicosapentanoic acid (EPA), can have anti-inflammatory actions. In man, it has been shown that supplementation with evening primrose oil (EPO), a source of GLA, can ameliorate atopy. Recent studies in the dog indicate that both EPO and cold water marine fish oil (containing EPA) can ameliorate allergic skin disease and improve skin and coat condition. EFA supplementation also promises to be useful in the treatment of seborrhoea and other conditions in the cat.     

Glutathione synthesis in response to captan: A possible mechanism for resistance of Botrytis cinerea to the fungicide

Two Botrytis cinerea isolates, field captan-resistant and normal type, were grown in liquid medium for 4 days prior to captan application. The glutathione (GSH) and oxidized glutathione (GSSG) of their mycelium and medium were analyzed at various times during the fifth day of their growth. Only slight differences in GSH levels between the isolates were observed, but marked differences in mycelial GSH were found in response to captan. Following the application of captan, less GSH was produced and after a longer lag period by the normal type of the fungus compared to the resistant isolate. This increase in the GSH level in the resistant isolate could make more nonvital thiol compound available for detoxifying captan and therefore prevent damage the fungicide could cause to the vital protein thiols of fungal cells.     

Elimination of Staphylococcus intermedins in healthy dogs by topical treatment with fusidic acid

Cutaneous and mucosal carriage of Staphylococcus intermedius was investigated in six healthy beagles before and after application of fusidic acid to mucosal surfaces as 1 per cent viscous eye drops twice daily for seven days. Bacterial populations were determined repeatedly over four weeks using quantitative techniques. The overall cutaneous populations of S intermedius reduced significantly (P<0·01) two days after treatment but returned to pretreatment levels after a further week. The mucosal frequency of S intermedius reduced significantly (P<0·001) two days after treatment and remained reduced (P<0·01) at the end of the study. The mucosal populations were also reduced (P<0·01) two days after treatment and remained lower (P<0·05) after a further week. No such changes occurred in the control group of six beagles. The study indicates the importance of mucosae as carriage sites for S intermedius in dogs. This form of therapy may be useful as an additional tool against canine recurrent pyoderma.     

Dissipation of residues of MCPA and cyanazine in three forage grasses following post-emergence application as a mixture in the establishment year

The dissipation of MCPA and cyanazine in smooth bromebrass (Bromus inermis Leyss.), Russian wild ryegrass (Elymus junceus Ficsch.) and intermediate wheatgrass (Agropyron intermedium) (Host) Beauv.) grown at three sites in western Canada was monitored for an eight-week period following post-emergence application of the herbicides as a mixture at 0.56 + 0.28 kg ha ?1. The grasses were in the two- to six-leaf stage at the time of application. MCPA, as its methyl ester, was detected using electrolytic conductivity detection whereas N-specific alkali-ionization detection was used for cyanazine. Foliar MCPA residues decreased more rapidly than those of cyanazine. At 56 days after application, MCPA residues were non-detectable in all three grass species at all sites. Corresponding residues of cyanazine were of the order of the limit of quantification (0.02 mg kg ?1 or less.     

Tolerance of cattle to increased dietary sulfur and effect of dietary cation-anion balance

The objective of this study was to determine if dietary cation-anion balance (DCAB) affects the concentration of S that can be tolerated by growing and finishing cattle without adversely affecting performance. Angus cross and Bradford steers (n=114; average initial BW=252.8 kg) were blocked by BW and breed, and randomly assigned within a block to treatment. The design was a 3 × 2 factorial arrangement of treatments with S (from NH(4)SO(4)) supplemented at 0, 0.15, or 0.30% of DM, and NaHCO(3) added at 0 or 1.0% of DM. Each treatment consisted of 3 pens containing 5 steers and 1 pen containing 4 steers. Steers were used in an 84-d growing study followed by a finishing study. A corn silage-based diet was fed during the growing study and a corn-based diet was fed during the finishing study. Steers were not randomized between experiments. The analyzed concentrations of S in the growing diets were 0.12, 0.30, and 0.46%, whereas the analyzed concentrations of S in the finishing diets were 0.13, 0.31, and 0.46% for treatments supplemented with 0, 0.15, and 0.30% S, respectively. Increasing DCAB by approximately 15 mEq/100 g of DM, by the addition of NaHCO(3,) did not affect (P > 0.36) performance during the growing or finishing studies. During the growing study DMI was not affected (P=0.29) by dietary S. Steers fed diets containing 0.30% S had greater ADG (P=0.02) and G:F (P=0.01) than those receiving 0.46% S, but similar (P > 0.36) performance to steers fed 0.12% S. During the finishing study, steers fed diets containing 0.46% S had less ADG than steers fed 0.13 (P=0.004) or 0.31% S (P=0.07), whereas ADG did not differ (P=0.18) among steers fed 0.13 and 0.31% S. Steers fed diets containing 0.31 (P=0.01) or 0.46% S (P=0.001) had less DMI than controls, but G:F was not affected (P=0.52) by S during the finishing study. Carcass characteristics did not differ (P > 0.18) among steers fed diets containing 0.13 and 0.31% S. Steers receiving diets containing 0.46% S had decreased HCW (P=0.001), quality (P=0.02), and yield grades (P=0.04) than steers receiving 0.13% S. Plasma Cu concentrations on d 101 of the finishing phase and liver Cu concentrations at slaughter were greater (P ≤ 0.05) in control steers compared with those fed diets containing 0.31 or 0.46% S. This study indicates that steers fed growing diets can tolerate up to 0.46% S with minimum effects on performance. Finishing steers tolerated diets containing 0.31% S without adverse affects on ADG or G:F. However, 0.46% S greatly decreased ADG and DMI, and increasing DCAB did not prevent these depressions.     

Evaluating the economic and noneconomic impacts of the veterinary medical profession in Michigan

This study reaffirms the diversity and breadth of the veterinary profession. As it turns out, some of the furthest-reaching impacts of the veterinary medical profession were largely non-quantifiable. The veterinary medical profession had a substantial direct economic impact in Michigan during 1995. The total economic contribution of the veterinary medical profession to Michigan during 1995 that was attributable to expenditures on salaries, supplies, services, and their multiplier effect was approximately $500 million. In addition, the profession was associated with nearly 8,500 jobs (combined professional and lay positions). The veterinary medical profession was also considered to have an impact on the prosperity of the live-stock, equine, and pet food industries in Michigan, even though the economic contribution in these areas could not be directly quantified. Economic well-being of the individual businesses in these industries is directly related to the health and productivity of the associated animals, and improvements in output or productivity that accompany improved animal health likely carry substantial economic benefits in these sectors. In addition, progressive animal health management provides a crucial method of managing risk in the animal industries. Similarly, although the economic contribution could not be quantified, the veterinary medical profession enhances the safety and quality of human food through research, regulation, and quality assurance programs in livestock production, minimizing the risk of drug residues and microbial contamination. During 1995, approximately 5.3 million Michigan residents benefitted from the physical, psychological, and emotional well-being that accompanies companion animal ownership. By preserving the health and longevity of companion animals, veterinarians sustain and enhance these aspects of the human-animal bond. As Michigan enters a new century, it is likely that the state's veterinary medical profession will continue to make a highly valued societal contribution. Pets, equines, and food animals will continue to have prominent roles in Michigan for the foreseeable future, as will the human-animal bond, food safety, and medical research. Clearly, for economic and noneconomic reasons, it will be in the interest of the people of Michigan to seek opportunities to maintain and enhance the vitality of the state's veterinary medical profession. It was our hope that results of this study would provide university administrators, legislators, MVMA executives, and others with information needed to justify the ongoing provision of public support for the veterinary medical profession. In addition, we expect that the results will supply useful material for public relations and marketing campaigns by the MVMA and the Michigan State University College of Veterinary Medicine and will provide the media with public interest stories to promote the veterinary profession. Although this study considered the economic and noneconomic impacts of the veterinary medical profession only in Michigan, the results can provide an important reference point for educators, policy markers, and legislators in other states. In addition, this study could serve as a methodologic model for veterinary organizations in other states, or at the national level, to emulate.     

Immunologic and hematologic responses in ponies with experimentally induced Strongylus vulgaris infection

Immunologic and hematologic responses were examined in 4 ponies with experimentally induced Strongylus vulgaris infection and in 5 helminth-free ponies. Two ponies were inoculated with 200 larvae and 2 were inoculated with 700 larvae of S vulgaris and then were reinoculated with the same numbers of larvae 34 weeks later. Initial response of the ponies inoculated with S vulgaris was S vulgaris antigen-induced lymphocyte response that developed 1.5 to 3 weeks after inoculation and did not persist. Development of antigen-reactive lymphocytes was followed sequentially by a biphasic complement-fixing antibody response, then biphasic eosinophilia. Antibody titer to S vulgaris antigen was higher in ponies inoculated with 700 larvae, compared with that in ponies given 200 larvae of S vulgaris. Also, the second peak in antibody titer and in absolute number of eosinophils was observed earlier in ponies inoculated with 700 larvae, compared with ponies inoculated with 200 S vulgaris larvae, and subsided before or from about 24 weeks after inoculation. The prepatent period for S vulgaris infection was 24 to 25 weeks. After reinoculation with S vulgaris, a degree of increased lymphocyte responsiveness was apparent but, by 17 weeks after reinoculation, only the primary peak in the absolute number of eosinophils indicated an anamnestic response. Essentially, antibody was not detectable after reinoculation.