Field study of the efficacy of three types of nose net for the treatment of headshaking in horses

Thirty-six owners of seasonally headshaking horses took part in a trial to compare the effectiveness of three types of nose net, a traditional cylindrical net (full net) and two forms of larger mesh nets which cover only the nostrils and dorsorostral muzzle (half nets). Baseline data relating to the overall severity of the problem and 18 specific behaviours describing the nature of the problem were recorded on a check sheet by the owners. A within-subjects repeated measures design experiment, with each net used for a week before reassessment, was then used to assess the effect of the nets on the headshaking problem. Approximately 75 per cent of owners reported some overall improvement with each net; around 60 per cent recorded a 50 per cent or greater improvement and 30 per cent a 70 per cent or greater improvement. The nets significantly reduced the overall headshaking score and the following specific behaviours: up-and-down headshaking, nose flipping, acting as if a bee had flown up the nose, shaking at exercise, shaking when excited, shaking in bright sunlight or in windy conditions (P < 0.0001), striking at the face, shaking at night, rubbing the nose when moving, rubbing the nose on objects, sneezing, shaking in the rain and shaking indoors (P < 0.05). There was no evidence of a significant effect on side-to-side headshaking, shaking at rest or rubbing the nose when stationary, but the effect on snorting was uncertain. There were few significant differences between the nets, but the half nets were reported to be significantly better at controlling 'bee up the nose' behaviour. Horses more than 10 years old were reportedly less likely to show a 50 per cent or greater improvement in 'nose flipping' and 'headshaking at exercise.     

Postoperative integrity of veterinary surgical gloves

A multicenter, prospective study was performed to document the incidence of defective gloves postoperatively in veterinary surgery and to correlate defects with a variety of influencing factors. Gloves were collected after surgical procedures performed by the small animal clinical services at two veterinary teaching hospitals and one institution's student surgery laboratories. Gloves were evaluated for defects using electrical resistance testing. The overall incidence of glove defects was 23.3%. Significantly more defects occurred in gloves used for nonsoft-tissue procedures and in gloves worn on the nondominant hand. Eighty-four percent of all defects occurred in procedures lasting >60 minutes. No differences were detected in the brands of gloves used nor among surgeons of different experience levels. The individuals performing the surgery were not able to accurately predict the presence of a defect in their gloves. Surgeons should remain alert for possible glove defects and consider measures such as changing gloves every 60 minutes or double-gloving to minimize potential complications.     

Evaluation of the effects of short-chain fatty acids and extracellular pH on bovine neutrophil function in vitro

OBJECTIVE: To investigate the effects of short-chain fatty acids (SCFAs) and pH on neutrophil oxidative burst, phagocytosis, and morphology after exposure to acetate, propionate, butyrate, or succinate at pH 5.5 and 6.7. SAMPLE POPULATION: Neutrophils isolated from bovine blood samples and Porphyromonas levii, Prevotella spp, and Bacteroides fragilis isolated from lesions of cattle with acute interdigital phlegmon (foot rot). PROCEDURES: Bacteria were cultured in strictly anaerobic conditions. Bacterial SCFA production was measured with high-performance liquid chromatography. Neutrophils were isolated, stimulated with phorbol 12-myristate 13-acetate (PMA) or opsonized zymosan (OZ), and incubated with dihydroethidium or dichlorofluorescein diacetate to measure production of O(2)and H(2)O(2), respectively. Phagocytosis was assessed after exposure to serum-opsonized bacteria. Cellular morphology was assessed with differential staining. RESULTS: All bacteria produced at least 3 of the 4 SCFAs. Production of both O(2) and H(2)O(2) was markedly curtailed in PMA-stimulated neutrophils exposed to SCFA at pH 5.5, compared with production at pH 6.7. Succinate caused a significant dose-dependent decrease in O(2) production at pH 6.7 in OZ-stimulated neutrophils. Monoprotic SCFAs elicited a significant increase in H(2)O(2) production in OZ-stimulated neutrophils at pH 6.7 but a significant decrease at pH 5.5. Monoprotic SCFAs significantly increased phagocytosis at pH 6.7 but decreased phagocytic activity at pH 5.5. Cellular necrosis was observed in cells exposed to SCFAs at pH 5.5. CONCLUSIONS AND CLINICAL RELEVANCE: Establishment and persistence of anaerobic bacteria in cattle with foot rot infection may result in part from neutrophil dysfunction secondary to the effects of bacterially secreted SCFA in acidotic microenvironments.     

Comparison of hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of anesthesia with isoflurane and halothane in horses undergoing arthroscopic surgery

OBJECTIVE: To compare hemodynamic, clinicopathologic, and gastrointestinal motility effects and recovery characteristics of halothane and isoflurane in horses undergoing arthroscopic surgery. ANIMALS: 8 healthy adult horses. PROCEDURE: Anesthesia was maintained with isoflurane or halothane (crossover study). At 6 intervals during anesthesia and surgery, cardiopulmonary variables and related derived values were recorded. Recovery from anesthesia was assessed; gastrointestinal tract motility was subjectively monitored for 72 hours after anesthesia. Horses were administered chromium, and fecal chromium concentration was used to assess intestinal transit time. Venous blood samples were collected for clinicopathologic analyses before and 2, 24, and 48 hours after anesthesia. RESULTS: Compared with halothane-anesthetized horses, cardiac index, oxygen delivery, and heart rate were higher and systemic vascular resistance was lower in isoflurane-anesthetized horses. Mean arterial blood pressure and the dobutamine dose required to maintain blood pressure were similar for both treatments. Duration and quality of recovery from anesthesia did not differ between treatments, although the recovery periods were somewhat shorter with isoflurane. After isoflurane anesthesia, gastrointestinal motility normalized earlier and intestinal transit time of chromium was shorter than that detected after halothane anesthesia. Compared with isoflurane, halothane was associated with increases in serum aspartate transaminase and glutamate dehydrogenase activities, but there were no other important differences in clinicopathologic variables between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with halothane, isoflurane appears to be associated with better hemodynamic stability during anesthesia, less hepatic and muscle damage, and more rapid return of normal intestinal motility after anesthesia in horses undergoing arthroscopic procedures.     

Efficacy of using an internal teat sealer to prevent new intramammary infections in nonlactating dairy cattle

OBJECTIVE: To determine whether insertion of an internal teat sealer (ITS) at the end of lactation would prevent development of new intramammary infections (IMIs) during the nonlactating period. DESIGN: Controlled clinical trial. ANIMALS: 939 Holstein-Friesian dairy cows from 16 herds. PROCEDURES: Results of bacteriologic culture of milk samples collected 14 days prior to the end of lactation were used to assign cows to groups (group 1 = negative results for all quarters; group 2 = positive results for > or = 1 quarter). Quarters of cows in group 1 were treated with an ITS or a single intramammary dose of cloxacillin; quarters of cows in group 2 were treated with cloxacillin in conjunction with an ITS or with cloxacillin alone. Milk samples were collected at the end of lactation and within 8 days after calving. RESULTS: Regardless of whether the outcome of interest was new IMIs caused by any pathogens, major pathogens, environmental pathogens, or streptococci other than Streptococcus agalactiae, quarters in group 2 treated with both cloxacillin and an ITS were less likely to develop a new IMI than were quarters treated with cloxacillin alone. For cows in group 1, no significant difference in risk of new IMIs was found between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for dairy cattle with an IMI late in the lactation period, intramammary administration of cloxacillin at the end of lactation followed by insertion of an ITS enhanced protection against development of new IMIs, compared with use of cloxacillin alone.     

Isolation and characterization of an adventitious avian leukosis virus isolated from commercial Marek's disease vaccines

Commercial Marek's disease (MD) vaccines produced by two manufacturers were tested for possible contamination with avian leukosis virus (ALV). Samples of MD vaccines manufactured by two companies (A and B) were received from a breeder company; samples were also received directly from vaccine company B. Using virus isolation tests, samples initially tested positive for subgroup E (endogenous) ALV. However, upon repassage, the vaccines also tested positive for exogenous ALV. The isolated exogenous ALV proved to be a subgroup A virus, as determined by flow cytometry using polyclonal chicken antibodies specific for various subgroups of ALV, and by DNA sequencing of the envelope glygoprotein (gp85). The exogenous ALV isolated from MD vaccines was inoculated in chickens from ADOL lines 15I(5) x 7(1) and 0 to determine its pathogenicity and compare it with that of Rous-associated-virus-1 (RAV-1), the prototype strain of ALV-A. Each chicken from each line was inoculated with approximately 10,000 infectious units of RAV-1 or the ALV-A isolated from vaccines termed B-39 virus at 7th day of embryonation. At hatch, and at 4, 8, and 16 wk of age, chickens were tested for viremia and cloacal shedding; chickens were also observed for ALV-induced tumors within 16 wk of age. Viremia and cloacal shedding results suggest that chickens from both lines were susceptible to infection with either virus. Within 16 wk of age, the proportion of ALV tumors induced by strain B-39 in line 0 and line 15I5 x 7(1) chickens was 0% and 12%, respectively, compared with 62% and 67% in chickens inoculated with RAV-1. The data indicate that commercial MD vaccines produced by two manufacturers were contaminated with endogenous subgroup E and an exogenous subgroup A ALV. Further, data from biological characterization suggest that the ALV-A isolated from commercial MD vaccines is of low oncogenicity, compared with that of RAV-1. GenBank accession numbers: The gp85 gene sequences of ALV isolated from commercial Marek's disease vaccines have been deposited in GenBank and assigned the following accession numbers: A46 subgroup A, DQ412726 ; B53 subgroup A, DQ412727; A46 subgroup E, DQ412728; B53 subgroup E, DQ412729.