Validation of computerized Swedish horse insurance data against veterinary clinical records

The aim was to evaluate the agreement between computerized insurance data in a large Swedish horse insurance database and the information in the corresponding clinical records (CR). A random sample of 400 veterinary care and 140 life claims was included. Information on name of the horse, breed and gender, year of birth, specific diagnosis and system diagnosis (e.g. joints, digestive and skeletal) was compared between sources. The concordance for demographic variables was categorized as agreement, disagreement or data missing. For diagnostic information, the categories were agreement, minor disagreement and major disagreement and for system information agreement or disagreement. There were missing values for demographic information in the CR, varying from 2% for name to 16% for breed. The overall agreement for demographic information was >94% (disregarding missing data), 92% for system and 84% for specific diagnosis. For veterinary care and life claims, the observed agreement for diagnosis was 85 and 83%, minor disagreement 6 and 5%, and major disagreement 9 and 12%, respectively.

Using the CR data as gold standard, for the systems evaluated (joints, digestive, skeletal, skin and hooves), sensitivity varied between 62% (skin) and 89% (digestive) whereas the specificity was >96% for all systems. The positive predictive values ranged from 86% (skin) to 97% (digestive). Logistic regression analysis was used to examine factors associated with agreement for diagnosis. Analyses were performed separately for veterinary care and life claims. Factors examined were type of visit (clinic/field), treating veterinarian/clinic (categorized as district veterinarians, private practitioners, small clinics, medium clinics and, for the clinics with ≥20 claims, the specific clinics), computerized or manual CR, processing clerk, whether the CR was included in the paper file, if the claim was rejected or reimbursed, system diagnosis and if a immediate settlement (in analysis for veterinary care claims) or death certificate (in analysis for life claims) was included in the paper file. For veterinary care claims, in the logistic regression model type of visit was significantly associated with agreement, with clinic visits generating better agreement than field visits.     

Decreased susceptibility to doxycycline associated with a 16S rRNA gene mutation in Brachyspira hyodysenteriae

The objective of this study was to assess whether nucleotide substitutions in the 16S rDNA sequence of selected Brachyspira hyodysenteriae isolates could explain differences in doxycycline minimal inhibitory concentrations (MICs). The main part of the 16S rRNA gene was sequenced and compared for 19 isolates with different doxycycline MICs. A mutation in the 16S rRNA gene at the position corresponding to 1058 in Escherichia coli has been shown to cause tetracycline resistance in other bacteria. In the B. hyodysenteriae sequences a G1058C mutation was found for all isolates with increased doxycycline MICs whereas all susceptible isolates had the wild type sequence.     

Effect of frusemide on transvascular fluid fluxes across the lung in exercising horses

Reasons for performing study: Frusemide (Fru) is widely prescribed for management of racehorses experiencing EIPH. The effect of Fru in the lung appears to be a reduction in transcapillary pressures and inhibition of the erythrocyte anion exchange, which may lead to attenuation of transpulmonary fluid fluxes during exercise. Hypothesis: Treatment with Fru will attenuate transpulmonary fluid fluxes in horses during high intensity exercise. Methods: In a crossover study, 6 race‐fit Standardbred horses were treated with 250 mg of Fru i.v. (FruTr) or placebo (Con) 4 h before exercise on a high speed treadmill until fatigue. Arterial and central mixed venous blood, as well as CO₂ elimination and O₂ uptake, were sampled. Volume changes across the lung and transvascular fluid fluxes were calculated from changes in haemoglobin, packed cell volume, plasma protein and cardiac output (Q). Results: During exercise, Q increased in both Con and FruTr, with Q being significantly lower in FruTr (mean ± s.e. 301.8 ± 8.5 l/min at fatigue) compared to Con (336.5 ± 15.6 l/min) (P<0.01). At rest frusemide had no effect on erythrocyte (J_ER) and transvascular (J_V‐A) fluid fluxes across the lung. Exercise had a significant effect on J_ER and J_V‐A (P≤0.02). During exercise, J_ER (at fatigue 14.6 ± 2.3 l/min and 11.6 ± 2.2 l/min in Con and FruTr, respectively) and J_V‐A (at fatigue14.9 ± 2.3 l/min and 12.0 ± 2.2 l/min in Con and FruTr, respectively) were not significantly different between Con and FruTr (P = 0.6 and P = 0.8 for J_ER and J_V‐A, respectively). Conclusions and clinical importance: Fru does not have a measurable effect on J_ER and J_V‐A. Cardiac output was reduced in FruTr, suggesting that there were also smaller changes in the capillary recruitment and transvascular transmural hydrostatic pressures; however, this did not effect J_V‐A. Therefore, Fru at the dose of 250 mg does not appear to be an effective treatment for regulating pulmonary transvascular forces during exercise in horses.     

Fatal Clostridium botulinum toxicosis in eleven Holstein cattle fed round bale barley haylage.

Twenty-two lactating Holstein cattle in Tennessee had clinical signs of intoxication with preformed Clostridium botulinum toxin. These signs included weakness, paralysis of the tongue and chest muscles, abdominal breathing, and, in 11 of the 22 cows, death. Differential diagnoses included hypocalcemia, hypomagnesemia, carbohydrate overload, and several toxicoses including mycotoxin, lead, nitrate, organophosphate, atropine or atropine-like alkaloid, and botulism. A diagnosis of botulism by the ingestion of preformed C. botulinum type B toxin was made by eliminating these other diseases, by finding C. botulinum type B spores in 3 bales of round bale barley haylage fed to these cattle, and by isolating preformed type B toxin from 1 of the 3 bales. Confirmation of the toxin type was made by demonstrating mouse lethality by intraperitoneal injection of specimen extracts with neutralization by C. botulinum type B antitoxin. The haylage, harvested green and encased in black plastic bags to facilitate fermentation, was presumably contaminated by the botulinum toxin when fermentation failed to produce enough acid to lower the pH to 4.5, the pH below which C. botulinum growth is inhibited. Farmers and ranchers who use round hay balers to produce haylage should be alert to this potential problem.