Incidence rate of musculoskeletal injuries and determinants of time to recovery in young Australian Thoroughbred racehorses

Objective To describe the incidence rate of musculoskeletal (MS) injuries and investigate the factors that influence recovery from MS injury in young Thoroughbred horses in Australia. Methods Training and injury data were collected at fortnightly intervals from 14 trainers in New South Wales. Incidence rates were calculated for initial injuries stratified by age‐class and sex. Survival analysis methods were used to investigate the time to recovery after the first MS injury (measured as a start in a race or barrier trial). Results For the 248 racehorses enrolled, there were 428 injuries recorded; 2‐year‐olds were 2.99‐fold more likely than 3‐year‐olds to sustain an MS injury. The cumulative percentage of horses that had recovered within 6 months was 55%. The time to recovery was longest in horses whose fast gallop speed prior to injury was < 890 m/min. Conclusion This study supports the finding that shin soreness is the most common MS injury in young Australian Thoroughbreds. There was an increased rate of MS injury in 2‐year‐olds compared with 3‐year‐olds. However, it was impossible to determine if the increased risk in 2‐year‐olds was related to age, the start of training or a combination of both. The study also found that horses performing at higher exercise speeds prior to injury were more likely to recover. There was a significant effect of trainer, suggesting that other factors related to trainer may influence the time to the recovery. Additional research is required to understand the determinants of time to recovery.     

Chloramphenicol 1. Hazards of use and the current regulatory environment

Chloramphenicol is a broad-spectrum antibiotic which has enjoyed extensive use in both medical and veterinary practice. Shortly after its introduction in the late 1940s, the use of chloramphenicol was associated with the induction of an idiosyncratic form of aplastic anaemia in man. This rare and unpredictable adverse effect has since been associated not only with systemic use but with topical applications, as well as occupational exposure. Recognition of the small risk of a potentially fatal adverse reaction, together with the risk of selection of chloramphenicol-resistant pathogens, has led to restrictions on the veterinary uses of chloramphenicol. In Australia at present, the use of chloramphenicol is only permitted in small animals. Its use is specifically prohibited in food-producing animals, including horses.     

Diethylstilboestrol—historical background and current regulatory status

Diethylstilboestrol is a non-steroidal orally active oestrogen that in the past has been widely used in a variety of conditions in both medical and veterinary fields. In recognition of potential systemic availability to man of DES in the tissues of treated food-producing animals, together with an understanding of the potential teratogenic and carcinogenic toxicity of DES in man, the veterinary use of DES has been restricted to oral use in small animals only. Use of DES is prohibited in all food-producing animals.     

Lung worm (Marsupostrongylus spp.) infection in common brushtail possums (Trichosurus vulpecula)

Marsupostrongylus spp. are the metastrongyloid nematodes most commonly associated with verminous pneumonia in Australian marsupials. Currently, there is a scarcity of information regarding this parasite in the common brushtail possum (Trichosurus vulpecula). Thirty-four free-living possums submitted to two wildlife hospitals in Sydney, Australia, between 2008 and 2015 were diagnosed with verminous pneumonia on postmortem examination. The majority of possums presented ill with multiple comorbidities. However, only five cases had clinical signs of respiratory disease. Necropsy and histopathology revealed extensive lung lesions characterised by diffuse, mixed interstitial infiltrates of macrophages, lymphocytes and plasma cells with mild to marked concentrations of eosinophils. Bronchopneumonia, pulmonary oedema, interstitial fibrosis, atelectasis and type II pneumocyte hyperplasia were also present in most cases. Adult nematodes, first-stage larvae and embryonating eggs were present in the large airways and alveolar spaces. The parasites were definitively identified as Marsupostrongylus spp. in eight cases with presumptive diagnoses based on histopathological characteristics reached in a further 26 cases. Twenty-nine of the 34 affected possums were adults with no sex predisposition. A review of the brushtail possum records at Taronga Wildlife Hospital from 1999 to 2015 revealed no lungworm infections were reported in the 45 possums examined before 2008. However, between 2008 and 2015, 30 of 47 possums (63.8%) examined were diagnosed with metastrongyloid lungworms. This case series is the first detailed report of Marsupostrongylus nematodes in common brushtail possums and highlights the clinical and pathological features, along with epidemiological findings.