Risk of iatrogenic damage to the sciatic nerve in dairy cattle.

Sciatic nerve damage in cattle could lead to pain, paralysis and lameness, creating welfare and productivity issues. Damage following intramuscular injection is highlighted in some clinical texts although there is no indication of prevalence. This cross-sectional study investigated the anatomical size and position of the sciatic nerve in four dairy cattle type cadavers. To evaluate the risk of iatrogenic damage, 54 participants placed needles in the dorsal gluteal region of two cadavers each, as per their routine intramuscular injection method. The distance from needle tip to the sciatic nerve was estimated for each. Sixty-nine per cent of injections were placed within 5 cm of the sciatic nerve. Direct nerve puncture occurred in the cadaver in poorest body condition. A short questionnaire revealed that 70 per cent of the participants regularly used the dorsal gluteal region for intramuscular injection and 50 per cent commonly used a volume of ≥20 mL at a single site. It is concluded that the sciatic nerve is at considerable risk of iatrogenic damage. The neck should be promoted as the optimum site for intramuscular injection and improved guidelines are required if the gluteal region is to remain in common use. A lateral site, between the tuber coxae and tuber ischium, is recommended.

Clinician attitudes to pain and use of analgesia in cattle: where are we 10 years on?

Pain in cattle can arise though disease or injury or may result from veterinary or husbandry procedures. Controlling pain is important to safeguard animal welfare. Previous studies indicated that the use of analgesics in cattle has lagged behind use in companion animals. Over the last decade, more analgesic products have become available for use in cattle and there have been increased efforts to communicate the importance and benefits of analgesia. A questionnaire (based on that used in a similar study published in 2006) was sent to UK cattle practitioners asking them to score pain severity for several conditions of cattle and asking about their attitudes towards and use of analgesic medicines. A total of 242 surveys were returned. Male clinicians and those graduating before 1990 scored pain severity significantly lower and were significantly less likely to use NSAIDs. Generally, use of NSAIDs was more common for conditions assigned higher pain scores. However, uptake of NSAID use was much lower for a number of routine procedures in calves than would be expected from the pain scores they were assigned. A need remains to increase use of analgesic products, especially NSAIDs in calves, in line with best practice recommendations.

Quantitative analysis of antibiotic usage in British sheep flocks.

The aim of this study was to examine the variation in antibiotic usage between 207 commercial sheep flocks using their veterinary practice prescribing records. Mean and median prescribed mass per population corrected unit (mg/PCU) was 11.38 and 5.95, respectively and closely correlated with animal defined daily dose (ADDD) 1.47 (mean), 0.74 (median) (R2=0.84, P<0.001). This is low in comparison with the suggested target (an average across all the UK livestock sectors) of 50 mg/PCU. In total, 80 per cent of all antibiotic usage occurred in the 39 per cent of flocks where per animal usage was greater than 9.0 mg/PCU. Parenteral antibiotics, principally oxytetracycline, represented 82 per cent of the total prescribed mass, 65.5 per cent of antibiotics (mg/PCU) were prescribed for the treatment of lameness. Oral antibiotics were prescribed to 49 per cent of flocks, 64 per cent of predicted lamb crop/farm. Lowland flocks were prescribed significantly more antibiotics than hill flocks. Variance partitioning apportioned 79 per cent of variation in total antibiotic usage (mg/PCU) to the farm level and 21 per cent to the veterinary practice indicating that veterinary practices have a substantial impact on overall antimicrobial usage. Reducing antibiotic usage in the sheep sector should be possible with better understanding of the drivers of high usage in individual flocks and of veterinary prescribing practices.

Quantitative analysis of antimicrobial use on British dairy farms.

Antimicrobial resistance has been reported to represent a growing threat to both human and animal health, and concerns have been raised around levels of antimicrobial usage (AMU) within the livestock industry. To provide a benchmark for dairy cattle AMU and identify factors associated with high AMU, data from a convenience sample of 358 dairy farms were analysed using both mass-based and dose-based metrics following standard methodologies proposed by the European Surveillance of Veterinary Antimicrobial Consumption project. Metrics calculated were mass (mg) of antimicrobial active ingredient per population correction unit (mg/PCU), defined daily doses (DDDvet) and defined course doses (DCDvet). AMU on dairy farms ranged from 0.36 to 97.79 mg/PCU, with a median and mean of 15.97 and 20.62 mg/PCU, respectively. Dose-based analysis ranged from 0.05 to 20.29 DDDvet, with a median and mean of 4.03 and 4.60 DDDvet, respectively. Multivariable analysis highlighted that usage of antibiotics via oral and footbath routes increased the odds of a farm being in the top quartile (>27.9 mg/PCU) of antimicrobial users. While dairy cattle farm AMU appeared to be lower than UK livestock average, there were a selection of outlying farms with extremely high AMU, with the top 25 per cent of farms contributing greater than 50 per cent of AMU by mass. Identification of these high use farms may enable targeted AMU reduction strategies and facilitate a significant reduction in overall dairy cattle AMU.