Amitraz intoxications in the horse: cases and backgrounds

Since the only registrated anti-ectoparasiticum for horses (foxim) is no longer available in The Netherlands, some cases of amitraz intoxication of the horse have occurred. In this article the literature concerning amitraz intoxications and experiments will be discussed and some cases will be described.     

Correlations of fatty acid supplementation, aeroallergens, shampoo, and ear cleanser with multiple parameters in pruritic dogs

Seventy-two pruritic dogs were fed one of four diets controlled for n-6:n-3 fatty acid ratios and total dietary intake of fatty acids. Multiple parameters were evaluated, including clinical and cytological findings, aeroallergen testing, microbial sampling techniques, and effects of an anti-fungal/antibacterial shampoo and ear cleanser. Significant correlations were observed between many clinical parameters, anatomical sampling sites, and microbial counts when data from the diet groups was combined. There were no statistically significant differences between individual diets for any of the clinical parameters. The importance of total clinical management in the control of pruritus was demonstrated.     

The effect of blood sampling method on indicators of physiological stress in reindeer (Rangifer tarandus tarandus)

The effects of manual blood sampling and remote blood sampling using automatic blood sampling equipment (ABSE) on plasma cortisol and catecholamine concentrations were studied on eight adult female reindeer (Rangifer tarandus tarandus). Contemporary body temperatures and heart rates were also recorded to determine their utility as other possible stress indicators. The animals were blood sampled once every hour with ABSE on 9-10 May and then by manual blood sampling on 13-14 May. Animals were also fitted with equipment to record heart rate and body temperature. Heart rate and body temperature were also recorded continuously without blood sampling on 17-18 May in undisturbed control conditions. Plasma cortisol concentrations were five-to-six fold greater during manual blood sampling compared to sampling with ABSE (F(1,3) = 13.34, P < 0.05). Plasma noradrenaline concentrations were significantly higher (F(1,3) = 22.98, P < 0.05) during manual blood sampling compared to sampling with ABSE, whereas plasma adrenaline concentrations did not differ. Heart rate was higher during manual blood sampling compared to control values. Body temperature was significantly higher during manual sampling compared to values recorded without blood sampling (F(1,4)= 31.65, P < 0.01). In conclusion, plasma cortisol concentration provides an excellent indicator of handling stress in reindeer. The use of ABSE for blood sampling enables measurements of plasma cortisol levels close to basal concentrations that may be used for reference values in studies where indicators of physiological stress are required.     

Urodynamic effects of a percutaneously controlled static hydraulic urethral sphincter in canine cadavers

OBJECTIVE: To describe a percutaneously controlled static hydraulic urethral sphincter (SHUS) and evaluate urodynamic effects of the SHUS in canine cadavers. SAMPLE POPULATION: Cadavers of 6 adult female dogs. PROCEDURE: Cadavers were obtained immediately after dogs were euthanatized. Baseline maximal urethral closure pressure (MUCP) and cystourethral leak point pressure (CLPP) were measured by use of a urethral pressure profilometer. An SHUS system was constructed by use of a silicone vascular occluder and subcutaneous infusion port. The SHUS system was then placed around the pelvic urethra in each cadaver. Measurements of MUCP and CLPP were repeated after varying occlusion of the SHUS (0%, 25%, and 50% occlusion). Baseline MUCP and CLPP values were compared with values obtained at 0%, 25%, and 50% occlusion of the SHUS by use of repeated-measures ANOVA. RESULTS: Mean +/- SD MUCP for canine cadavers was 7 +/- 1.3 cm H2O at baseline, which increased to 127 +/- 53 cm H2O after 50% occlusion of the SHUS. Mean CLPP was 11 +/- 8.6 cm H2O at baseline, which increased to 73 +/- 38 cm H2O after 50% occlusion of the SHUS. Mean MUCP and CLPP were significantly associated with the amount of occlusion. CONCLUSIONS AND CLINICAL RELEVANCE: The SHUS had positive effects on MUCP and CLPP in canine cadavers. Therefore, additional evaluation of the SHUS in live dogs is warranted.     

Early postmortem biochemical factors influence tenderness and water-holding capacity of three porcine muscles

The objective of this study was to determine whether differences in pork tenderness and water-holding capacity could be explained by factors influencing calpain activity and proteolysis. Halothane-negative (HAL-1843 normal) Duroc pigs (n = 16) were slaughtered, and temperature and pH of the longissimus dorsi (LD), semimembranosus (SM), and psoas major (PM) were measured at 30 and 45 min and 1, 6, 12, and 24 h postmortem. Calpastatin activity; mu-calpain activity; and autolysis and proteolysis of titin, nebulin, desmin, and troponin-T were determined on muscle samples from the LD, SM, and PM at early times postmortem. Myofibrils from each muscle were purified to assess myofibril-bound (mu-calpain. Percentage drip loss was determined, and Warner-Bratzler shear (WBS) force was analyzed. Myosin heavy-chain (MHC) isoforms were examined using SDS-PAGE. The pH of PM was lower (P < 0.01) than the pH of LD and SM at 30 and 45 min and 1 h postmortem. The PM had a higher (P < 0.01) percentage of the MHC type IIa/IIx isoforms than the LD. The-LD had the greatest proportion of (P < 0.01) MHC IIb isoforms of any of the muscles. The PM had the lowest (P < 0.01) percentage of MHC IIb isoforms and a greater (P < 0.05) percentage of type I MHC isoforms than the LD and SM. The PM had less (P < 0.01) drip loss after 96 h of storage than the SM and LD. The PM had more desmin degradation (P < 0.01) than the LD and SM at 45 min and 6 h postmortem. Degradation of titin occurred earlier in the PM than the LD and SM. At 45 min postmortem, the PM consistently had some autolysis of mu-calpain, whereas the LD and SM did not. At 6 h postmortem, some autolysis of mu-calpain (80-kDa subunit) was observed in all three muscles. The rapid pH decline and increased rate of autolysis in the PM paralleled an earlier appearance of myofibril-bound mu-calpain. The SM had higher calpastatin activity (P < 0.05) at 45 min, 6 h, and 24 h and had higher WBS values at 48 h (P < 0.01) and 120 h (P < 0.05) postmortem than the LD. At 48 and 120 h postmortem, more degradation of desmin, titin, and nebulin were observed in the LD than in the SM. These results show that mu-calpain activity, mu-calpain autolysis, and protein degradation are associated with differences in pork tenderness and water-holding capacity observed in different muscles.     

Experimental airborne transmission of PRRS virus

A series of three experiments, differing primarily in airflow volume, were performed to evaluate the likelihood of airborne transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) from infected to non-infected pigs. Pigs were housed in two units (unit A and unit B) located 1m apart and connected by pipes. The air pressure and diameter of the pipes, depending on experiments, were strictly controlled to allow desired airflow volumes from unit A to unit B. Either 25 (experiment 1 and experiment 3) or 26 (experiment 2) pigs infected recently with PRRSV, and either 25 (experiment 1 and experiment 3) or 17 (experiment 2) pigs from a PRRSV-free herd, were housed in unit A. Either 50 pigs (experiment 1 and experiment 3) or 43 pigs (experiment 2) from a PRRSV-free herd were housed in unit B. The amount of air transmitted from unit A to unit B, expressed as a percentage of ventilation intake, was approximately 70, 10, and 1% for experiment 1, experiment 2 and experiment 3, respectively. Blood samples were collected from all pigs once per week and analyzed for antibodies against PRRSV. Based on these methods, airborne transmission of PRRSV from infected to non-infected pigs was confirmed in each of the three experiments.     

Recombinant bovine interferon-gamma enhances expression of class I and class II bovine lymphocyte antigens

Recombinant bovine interferon-gamma augments expression of class I and class II histocompatibility antigens on the surface membrane of bovine lymphocytes. Immunofluorescence techniques using a series of monoclonal anti-HLA antibodies demonstrate that this enhancement is detectable as early as 24 h after incubation with rBoIFN, while maximum surface expression is obtained within 3-5 days. A concentration as low as 10 units of rBoIFN is effective. Such results may be useful for characterizing the BoLA gene products.     

A selective procedure for the field isolation of pathogenic Streptococcus spp. of rainbow trout (Salmo gairdneri)

A procedure established for the selective isolation of the species of Streptococcus responsible for rainbow trout streptococcosis in South Africa, consisted of the inoculation of samples into nutrient broth which had been supplemented with 100 micrograms/ml of nalidixic acid, 160 micrograms/ml of oxolinic acid or 200 micrograms/ml of sodium azide. After incubation, the sample was plated onto tetrazolium agar on which the rainbow trout pathogenic Streptococcus species grew as a red colony. The colonies were isolated from the tetrazolium agar and identified as rainbow trout pathogenic isolates by biochemical and serological tests. In the laboratory the selective procedure is capable of detecting about 2 bacteria per ml. This procedure was used in the field and biochemically identical Streptococcus species were found in the mud and a freshwater crab from the water source of a site with a history of streptococcosis.