ObjectiveThis study investigated the effects of administering saline, 100 or 250 μg of gonadotrophin releasing hormone (GnRH) on ovarian response, synchrony of oestrus and ovulation and chronic stress response in Bos indicus cattle.DesignRandomised control.MethodsAnimals were either left untreated (n = 20) or on day 0 treated with an intravaginal progesterone releasing device and either saline (n = 24), 100 μg (n = 35), or 250 (n = 35) μg of GnRH, intramuscular (IM). Blood was sampled 1.4 h after administration of treatment to monitor concentrations of luteinising hormone (LH) and P4 in serum and again 5 days later. On day 5 intravaginal P4 releasing device were removed, cloprostenol was administered IM and again 8 h later. Oestrus and ovulation were then monitored with ultrasonography for 6.5 days. Hair was clipped on day 55 for analysis of hair cortisol concentrations (HCC).ResultsNo significant differences were found between Saline and GnRH treatments in the odds of inducing a new corpus luteum (CL) and the synchrony of oestrus or ovulation. HCC did not differ significantly between treatments. Mean concentrations of LH in serum on day 0 were less in the Saline compared to 100 and 250 μg GnRH treatments but did not differ between different doses of GnRH.ConclusionMean concentrations of LH and the odds of inducing a new CL were not increased after administering 250 μg compared to 100 μg of GnRH. Animal handling events in the study did not influence HCC. Further research is needed to better optimise responses to GnRH in B. indicus cattle.

The authors report an unusual case of Clostridium chauvoei causing severe panophthalmitis in Merino lambs. More than half of the lambs affected survived, which is unusual for clostridial disease; however, there have been reports in humans that the mortality risk for ocular gas gangrene is lower than when other body parts are affected. A combination of factors in this case included environmental contamination (specific to a particular paddock), genetics predisposing to entropion (lambs born of maiden 2-year-old ewes with some inbreeding), the practice of manually everting eyelids for the entropion and vaccination strategies. C. chauvoei was cultured in pure growth from the eye of a lamb affected by severe panophthalmitis. Histopathology was consistent with severe acute infection, and microscopic sections showed Gram-positive organisms associated with the inflammatory response in the eye. In the acutely affected animal examined there were no signs that the lesions were long-standing. Animals that recovered had one or both eyes destroyed. This report describes that malignant oedema in sheep due to C. chauvoei can manifest as acute and severe panophthalmitis. The case fatality rate of lambs with panophthalmitis was less than 50%, lower than normally occurs for clostridial diseases. Clostridial vaccination of the ewes may have provided a low level of protection in reducing the case fatality rate in the affected lambs as well localisation of the infection from the blood-ocular barrier.

The objective of this study was to determine the prevalence of gastrointestinal nematodes among post‐weaned calves aged between 4 and 12 months old within a pasture‐based system of south west Australia and quantify the level of anthelmintic resistance. Pre‐treatment FECs were monitored on 14 dairy farms. Anthelmintic resistance was assessed on 11 of the farms. Control FECs were compared with anthelmintic FECs at 14 days post‐treatment with doramectin (injectable), levamisole (oral), fenbendazole (oral) and a levamisole/abamectin combination (pour‐on). Results demonstrate a strong level of anthelmintic resistance, with at least one class of anthelmintic failing to achieve a 95% reduction in FEC in one or more gastrointestinal nematode species. Doramectin was fully effective against Ostertagia, but C. oncophora displayed resistance in 91% of the farms. Conversely, levamisole was fully effective against C. oncophora, but Ostertagia displayed resistance in 80% of the farms. Fenbendazole resistance was present in both C. onocphora and Ostertagia in 64% and 70% of the farms, respectively. Trichostrongylus showed low resistance, occurring in doramectin (14%) and levamisole/abamectin combination (14%). This study confirms that anthelmintic resistance is common. Regular FEC reduction testing is recommended to monitor and guide decision‐making for appropriate anthelmintic usage.

To evaluate the clinical and radiographic outcome of pes varus deformity correction in dachshunds managed with acute medial opening wedge osteotomy of the distal tibia and stabilised with a mini hybrid external skeletal fixator (HESF). Surgical correction involved a transverse osteotomy over the premeasured location at the distal tibia and application of a IMEX mini HESF. All corrections were evaluated using centre of rotation and angulation methodology. Medical records and radiographies of 20 dachshunds (28 pes varus corrections) were reviewed. All osteotomies healed and fixators were removed between 6 and 12 weeks. Lameness resolved in 18 dachshunds (90%) and significantly improved in two dachshunds (10%). Lateral patella luxation (LPL) was detected in 11/28 (39.2%) of the involved pelvic limbs, all of which resolved following pes varus correction. Mean frontal plane alignment (FPA) of the normal and abnormal tibiae were 12.3° valgus (range: 4°-18°) and 25° Varus (range: 16°-41°) respectively. Angular correction ranged between 30° and 50° (Mean: 39°) and the mean post-operative FPA was 13° valgus (range: 5°-21°). Pes varus deformity in dachshunds can be corrected by medial opening wedge osteotomy of the distal tibia stabilised by HESF. Single-session bilateral pes varus corrections can also be performed with minimal morbidity. LPL was commonly detected in dogs with pes varus deformity and all resolved spontaneously following pes varus correction alone.

Canine myocarditis can result from infection with bacteria Listeria monocytogenes. A 14-week-old female entire Staffordshire Bull Terrier was assessed for lethargy, inappetence and dyspnoea. Radiographs and echocardiography revealed fluid within the pericardial space, a plaque of marked hyperechogenicity within the right ventricular free wall, marked right atrial dilation and myocardial systolic dysfunction. Histopathology of the myocardium was consistent with severe pyogranulomatous myocarditis, with gram stain revealing gram-positive bacilli, consistent with a Listerial infection. Bacterial culture of the myocardium yielded a light growth of Listeria monocytogenes. To the best of the authors' knowledge, this is the first case of canine myocarditis caused by Listeria monocytogenes to be described and should be included as a differential diagnosis of myocarditis. Further, it prompts the consideration of potential zoonotic risks for veterinarians treating dogs with pericardial effusions.

The number of horses leaving the Australian Thoroughbred (TB) racing industry each year is of concern to animal welfare advocates, public and regulators. A horse's previous athletic performance is a significant driver of retirement from racing. Racehorse performance can be measured in terms of the total number of starts, duration of racing and prize money earned. This study investigated Australian racing records for the 2005 and 2010 Victorian TB foal crops to identify factors associated with total number of starts, racing career duration, prize money earned and age of last race start-up to the 10-year-old racing season. Racing Australia registered 4,577 TB horses born in Victoria in 2005 (n=2,506) and 2010 (n=2,071) that raced in Australia. Horses that started racing at 2-years of age had fewer race starts in their first racing season but an increased total number of starts, prize money and duration of racing. The median age of last start (LS) was five (Q1 4; Q3 7) years. Horses that had won a race, had a maximum handicap rating of 61 or above and those racing over distances of more than 2,400 m had an increased racing career duration and an age of last race start greater than 6-years of age. Horses participating in jumps races (n=63) had the longest careers and older age of LS. These horses were more likely to have had a handicap rating over 80 and were just as likely to start their racing careers as 2-years-olds.

The COVID-19 pandemic and associated restrictions have caused major changes in veterinary practice. Utilising a subset of qualitative data from a global survey of 540 veterinarians, veterinary nurses and animal health technicians, we highlight the impact of these changes on communication in veterinary clinical practice. Communication challenges experienced by veterinary team members included lack of face-to-face contact with clients; increased difficulty in communicating in general; inability to demonstrate physical examination, diagnostic findings or treatment information to clients; difficulty in communicating while wearing personal protective equipment; increased 'miscommunication' and challenges in convincing clients of the importance of pandemic-associated protocols. These findings suggest a need for veterinary teams to modify and adapt their communication strategies to facilitate effective communication where social distancing and noncontact consultations are required.