Tongue-tie use in Thoroughbred racehorses in Australia.

Tongue-ties (TTs) are used to aid control and aim to conservatively treat upper airway disorders in racehorses. However, welfare concerns have led to their use being banned in other equestrian disciplines. In the United Kingdom, TTs have been reported to be used in approximately 5% of starts. The frequency of their use elsewhere is unknown. The objectives of this retrospective single cohort study were to estimate the frequency of TT use within the Australian Thoroughbred (TB) racing industry, and to describe usage patterns. Data of all Australian TB horse races from 2010 to 2013 calendar years were collected by accessing the Racing Information Services Australia database. Frequency of TT use was calculated, and usage patterns were explored at the start, horse and trainer levels. Between 2010 and 2013, there were a total of 728,678 starts from 62,377 horses prepared by 4927 trainers and that raced on 1453 race dates across 402 venues. Tongue-ties were used in 21.4% of starts; however, frequency varied according to location, race, trainer and horse. At the horse level, 32.2% wore a TT at least once and 7.6% wore it at every race on record. At the trainer level, 71.3% used TTs in at least one of their horses but only 1.4% used them systematically. The present study concludes that TT use in Australian TB racehorses, during the period 2010-2013, was common and considerably higher than previously reported in the United Kingdom. Most Australian trainers use the device and appear to adapt its usage according to individual horse and race factors.

Oesophageal sarcocystosis observed at slaughter provides a reliable and efficient proximate measure of Toxoplasma gondii seroprevalence in sheep.

OBJECTIVE: Successful disease management requires effective surveillance. Slaughterhouse inspections provide opportunities to efficiently collect regular disease data from many animals across large areas. Toxoplasma is a cat-borne parasite that causes reproduction failure in sheep, although it is not visually detectable at slaughterhouses. Macroscopic sarcocystosis is a disease of sheep that is visually detectable at slaughter and is caused by parasites that share a similar biology with Toxoplasma. We investigated if sarcocystosis could act as a proximate measure for Toxoplasma exposure in sheep to facilitate its efficient surveillance at large scales. DESIGN/METHODS: We compared the presence of macroscopic sarcocystosis to Toxoplasma serostatus at the animal and farm levels. RESULTS: At the animal level, we found a weak association between Toxoplasma seropositivity and sarcocysts in the oesophagus (OR = 1.76 [95% CI: 1.17, 2.65; McFadden's R2 = 0.01]) but no association between Toxoplasma seropositivity and sarcocysts in skeletal muscles. At the farm level, the seroprevalence of Toxoplasma was strongly associated with oesophageal sarcocystosis prevalence (OR = 28.59 [95% CI: 13.07, 62.57; McFadden's R2 = 0.34]) but less strongly associated with sarcocystosis prevalence in skeletal muscles (OR = 7.91 [95% CI: 1.24, 50.39; McFadden's R2 = 0.02]). CONCLUSIONS: For Toxoplasma surveillance in sheep at the farm level, routine slaughter inspection and recording of macroscopic oesophageal sarcocystosis could be are liable and efficient proximate measure. The monitoring of oesophageal sarcocystosis may be a useful passive Toxoplasma surveillance tool for guiding the timing and location of other Toxoplasma detection methods to facilitate the management of Toxoplasma impacts within the sheep industry.

Antimicrobial use and stewardship practices on Australian beef feedlots.

OBJECTIVE: Improving antimicrobial stewardship in the livestock sector requires an understanding of the motivations for antimicrobial use and the quantities consumed. However,detailed information on antimicrobial use in livestock sectors is lacking. This cross-sectional study aimed to better understand antimicrobial use in the beef feedlot sector in Australia. DESIGN: A self-administered questionnaire asking about antimicrobial use and reasons for use was designed and mailed to beef feedlot operators in Australia. Respondents were asked to report the percentage of animals treated, purpose of use, and disease conditions targeted for 26antimicrobial agents. RESULTS: In total, 83 of 517 (16.1%) beef feedlot operators completed the survey. Monensin (61.0%of respondents) and virginiamycin (19.5%of respondents) were the most commonly reported in-feed antimicrobials. In-feed antimicrobial agents were most frequently used by respondents for treatment of gastrointestinal diseases (52.8%). Antimicrobials were used for growth promotion by 42.1% of respondents, with most (85.7%) reporting the use of ionophores(a group of compounds not used in human medicine). Short-acting penicillin(69.1%), short-acting oxytetracycline, and tulathromycin (both 57.3%) werethe most common injectable antimicrobial agents used. Injectable antimicrobials were most frequently used to treat respiratory (72.3%) and musculoskeletal (67.5%) conditions. CONCLUSION: Overall,the use of antimicrobials was appropriate for the purpose indicated, and there was a strong preference for drugs of low-importance in human medicine. The data described here stand to be a strong influence on the implementation of an antimicrobial stewardship program in the sector.

Is canine heartworm (Dirofilaria immitis) endemic to South Australia?

BACKGROUND: Canine heartworm (Dirofilaria immitis) was reported as endemic to South Australia over 25 years ago, but the current status of canine heartworm infection in South Australia is unknown. METHODS: We surveyed South Australian veterinary practices to collect evidence about canine heartworm cases, prevention, screening and treatment practices. RESULTS: In total, 141 veterinary practices operating in South Australia (92.3% response rate) completed a 12-question telephone survey. Five confirmed cases of heartworm and one suspected false-positive case were reported from separate practices over the 2016-17 financial year. All confirmed cases had recently relocated to South Australia from interstate. Incidence of canine heartworm was estimated at 0.00% (95% confidence interval (CI): 0.00-0.0006) and prevalence at 0.002% (95%CI: 0.00-0.004) using conservative estimates of the South Australian dog population. Attitudes and protocols regarding heartworm differed significantly between metropolitan and rural veterinary practices. All metropolitan practices recommend systematic medicated prevention against heartworm, while some rural practices (20.7%) recommend prevention only when travelling interstate (P < 0.001). CONCLUSION: Although there is a minor source of heartworm from introduction of infected dogs into South Australia, there is no evidence that the infection is transmitted to other dogs within the state. Therefore, it is unlikely that heartworm is currently endemic to South Australia as reported in the past. This new evidence provides a strong case to refine current prevention practices to reflect the current negligible risk of heartworm infection within South Australia.