Australian Veterinary Journal最新文献

A mortality event involving 23 allied rock-wallabies (Petrogale assimilis) displaying neurological signs and sudden death occurred in late April to May 2021 in a suburban residential area directly adjacent to Magnetic Island National Park, on Magnetic Island (Yunbenun), North Queensland, Australia. Three allied rock-wallabies were submitted for necropsy, and in all three cases, the cause of death was disseminated toxoplasmosis. This mortality event was unusual because only a small, localised population of native wallabies inhabiting a periurban area on a tropical island in the Great Barrier Reef World Heritage Area were affected. A disease investigation determined the outbreak was likely linked to the presence of free-ranging feral and domesticated cats inhabiting the area. There were no significant deaths of other wallabies or wildlife in the same or other parts of Magnetic Island (Yunbenun) at the time of the outbreak. This is the first reported case of toxoplasmosis in allied rock-wallabies (Petrogale assimilis), and this investigation highlights the importance of protecting native wildlife species from an infectious and potentially fatal parasitic disease.

Antimicrobial resistance (AMR) is a growing global threat that presents a serious risk to human and animal health. Resistance to antimicrobials occurs naturally in microorganisms. But it can be amplified by antimicrobial overuse, underuse, or poor management. Hence, the effective stewardship of antimicrobials—through appropriate and judicious manufacture, administering, dispensing, prescribing and disposal—is critical.

Here, in Australia, the veterinary profession and food producing animal industries have a long history of addressing AMR, working diligently to ensure the safe and continued efficacy of antimicrobials. Their previous and ongoing work—a result of partnerships across the animal sector—has resulted in demonstrated low levels of antimicrobial resistant bacteria in food producing animals. It is encouraging that, in the United Kingdom's 2015 O'Neill Review into Antibiotic Resistance, Australia was ranked the fifth lowest for antibiotic use in agriculture among the 29 countries examined. Strict regulation on antimicrobial registration, high levels of biosecurity and extensive farming systems that do not favour bacterial disease also contribute to the low risk of AMR development from animals in Australia.

With the recent release of Australia's National Antimicrobial Resistance Strategy–2020 and Beyond (2020 AMR Strategy), the veterinary profession will continue to play a critical role in how we minimise AMR. The antimicrobial prescribing guidelines for sheep seeks to “ensure that coordinated, evidence based antimicrobial prescribing guidelines and best practice supports are developed and made easily available, and encourage their use by prescribers”.

These practical guidelines for Australian sheep veterinarians are designed to be a useful resource. They have been developed specifically for the Australian sheep industry and contain best-practice information to help clinical veterinarians make appropriate decisions when prescribing antimicrobials.

They encourage veterinarians to first pause and consider the need to use antimicrobials in the situation and whether there are effective non-antimicrobial alternatives. Prevention and control of infections through strict on-farm biosecurity minimises the need to use antimicrobials. Vaccination may also be available to control several important sheep diseases. If antimicrobial use is indicated, practitioners should consider the five rights—right drug, right time, right dose, right duration and right route. Using a lower rating or narrow-spectrum antimicrobial is the preferred approach, and you can also refer to the Australian Antibacterial Importance Ratings to help with these decisions.

I commend the work of all involved in the development of these guidelines and urge every sheep veterinarian to use this advice. In doing so, you'll help safeguard ongoing access to antimicrobials, ensure their long-term efficacy, deliver the best possible veterinary service to

Phalaris aquatica is pasture species introduced into Australia during early European settlement. Consumption of the plant can cause the neurological condition chronic phalaris toxicity (CPT) in sheep and cattle. In recent years, there has been an increase in reports of CPT in macropods, which has raised concerns regarding its impacts on their welfare. Currently, little is known about the distribution or seasonal patterns of this disease in wildlife, information pivotal in assessing its potential risks. Between 2021 and 2022, we conducted a survey targeting government bodies, veterinary businesses and wildlife organisations to investigate the locations and time of occurrence of CPT in macropods in the state of Victoria, Australia. We received 13 survey responses, 12 verbal reports, a full record of investigated cases from a university veterinary school and cases from a wildlife rescue organisation. Over the period of 11 years, Victoria had 918 cases of CPT recorded in macropods from 36 local government areas, with cases concentrated centrally just north of the state capital of Melbourne and July (midwinter) being the month with the highest case count (n = 220). There was a significant positive correlation between case count and both the abundance of kangaroos (Macropus giganteus and Macropus fuliginosus) (P < 0.01) and the abundance of P. aquatica (P = 0.009), and a significant negative correlation between annual case count and average rainfall of March (P = 0.016) and April (P = 0.02). Understanding these relationships will assist land and wildlife managers in predicting the risk and magnitude of disease outbreaks of CPT each in Victoria.

No reference intervals for serum biochemistry and haematology of sea turtles in Thailand exists to assist veterinarians who are responsible for sea turtle health management and treatment. This study determined serum biochemistry and basic haematology of healthy juvenile green sea turtles (n = 92) in captivity in Thailand following the American Society for Veterinary Clinical Pathology (ASVCP), Quality Assurance and Laboratory Standards Committee (QALS) guidelines for the determination of reference intervals in veterinary species. Biochemistry tests, including blood urea nitrogen, creatinine, uric acid, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were analysed using an IDEXX VetTest Chemistry Analyzer. Haematology parameters were measured manually using a microhaematocrit for packed cell volume (PCV), Neubauer counting chamber for red blood cell count and cyanmethemoglobin method for haemoglobin concentration. mean corpuscular volume and mean corpuscular haemoglobin concentration were calculated using the PCV, red blood cell count and haemoglobin. Turtles in this study were found to have higher mean values for PCV (28.70%), haemoglobin (92.13 g/L), mean corpuscular haemoglobin concentration (327.03 g/L), uric acid (247.15 μmol/L), alanine aminotransferase (16.53 IU/L), aspartate aminotransferase (209.44 IU/L), and alkaline phosphatase (245.08 IU/L) compared to sea turtles in Brazil. The reference intervals established using high numbers of healthy turtles in this study will assist veterinarians with diagnostic and treatment decisions when evaluating laboratory results for juvenile green sea turtles.

Distance examination is an important part of veterinary investigation into ruminant herd health and welfare. The Department of Primary Industries and Regional Development (DPIRD) explored the use of drones to conduct assessments of the health and welfare status of sheep and cattle. Three methods of distance examination were compared comprising observations; from a vehicle, a “micro” category drone and a “very small” category drone. The disturbance and behavioural reactions caused by the methods were compared. Assessments of adverse health and welfare conditions by each method were compared to observations made at yarding. The preferred method was the use of the very small drone which had the best sensitivity for detection of conditions potentially associated with adverse health or welfare and the best optics at a distance that did not disturb the animals. The optics of the very small drone enabled distance examination without disturbance in both cattle and sheep. Cattle were more sensitive to the presence of the drones than sheep. The micro drone was unable to approach cattle close enough to allow undisturbed distance examination. All methods had similar specificity, however, sensitivity varied markedly. The very small drone had the best sensitivity 86% which was statistically greater than the micro drone (44%, P = 0.05) and better than the vehicle observations, which had sensitivity of 77% (not statistically significant). The selection of an appropriate drone model is essential for accurate distance examination. Distance examination of livestock with drones of suitable optic quality and resolution represents an effective method for assessing animal health and welfare.

Humate may be a valuable livestock feed additive, with potential effects on nutrient utilisation and animal performance. Thus, the aim of this study was to investigate the effect of K Humate S 100R supplementation on the feed intake, liveweight gain, and carcass parameters of Angus steers. Within individual pens, 40 weaned steers were allocated to four treatment groups (n = 10/potassium humate K Humate S100R, Omnia Specialities Australia) for 100 days. The treatment groups included Group 1, 35 g K Humate S100R/animal/day; Group 2, 70 g K Humate S100R/animal/day; Group 3, 140 g K Humate S100R/animal/day; and Control Group, which were not supplemented with K Humate S100R (0 g K Humate S100R/animal/day). Chemical and mineral composition of the feed ingredients, dry matter intake (DMI), and average daily weight gains were recorded. The steers were slaughtered as a single group at a commercial Australian abattoir. Standard measures for hot standard carcass weight, eye muscle area, fat depth and coverage, marbling, ossification, meat and fat colour, dressing percentage and loin pH values at 24-hour postmortem were recorded. It was found that the steers allocated to Group 2 had higher DMI (P = 0.003) and feed conversion ratio (FCR) (P < 0.001) compared with those allocated to Group 1 and the Control Group. The MSA marbling score was lowest for steers allocated to the Control Group (P < 0.05) and comparable for those allocated to Groups 1, 2, and 3. Together, these results demonstrate that increased levels of K Humate S100R supplementation improved the carcass quality, via an increase in MSA. However, further research is warranted on the potential effects of humates supplementation on intramuscular fat associated qualities of beef.

Hypotension is a common and potentially life-threatening complication of general anaesthesia in dogs. Due to the combination of cardiovascular side effects of many anaesthetic, sedative and analgesic drugs used peri-operatively hypotension is frequently reported even in healthy dogs undergoing elective procedures. Several treatment options for hypotension have been advocated. Potential treatments include rapid administration of either crystalloid or colloid fluids; pharmacological treatments to increase cardiac output and/or systemic vascular resistance; or reduction in the delivery of the volatile anaesthetic agents. This critical appraisal considers the current evidence for which treatment is the best option for treating hypotension in healthy euvolemic dogs undergoing general anaesthesia maintained with isoflurane. Fourteen relevant studies were appraised, including 12 laboratory studies and two small clinical trials. One study demonstrated that reduction in the delivery of isoflurane may correct hypotension, but this treatment may not always be feasible. In general, rapid administration of fluids did not increase blood pressure and failed to correct hypotension. Synthetic colloids demonstrated some efficacy, but results were inconsistent between studies and large volumes may be required. Infusion of dopamine appears to be the most reliable pharmacological option consistently increasing blood pressure, cardiac output and correcting hypotension.

A juvenile grey-headed flying fox (GHFF) (Pteropus poliocephalus) presented to the Australia Zoo Wildlife Hospital after a wildlife carer found the animal hanging on the outside of an aviary. On presentation, the animal was emaciated and moribund with disseminated, multifocal, depigmented and proliferative lesions on the wing membranes and skin of the neck. Histopathology revealed multiple, well-circumscribed proliferative epidermal lesions with intracytoplasmic inclusion bodies. A poxvirus was identified via transmission electron microscopy and next-generation sequencing (NGS). Analysis of sequences obtained demonstrated 99% nucleotide identity to Pteropox virus strain Australia (GenBank KU980965). To the authors' knowledge, this paper describes the first case of Pteropox virus infection in a GHFF.

Wildlife hospitals play a critical role in safeguarding diverse animal species, but their admissions data are also valuable for investigating threats and challenges impacting local wildlife. This study examines 10 years of admissions data from the Phillip Island Wildlife Clinic in Victoria, Australia, to identify species, primary causes, outcomes, and temporal trends of hospital admissions. Avian species constitute the majority of admissions (64.5%), with sea and water birds being the most frequently admitted group. Motor vehicle accidents (MVAs), injuries of unknown cause, and orphaning are the dominant causes of admission for birds and mammals. Car strikes are the leading cause of admission for land birds, land mammals, macropods, and turtles. Orphaning exhibits a seasonal pattern, with a higher number of cases in spring. Overall, 70.3% of admissions resulted in mortality, with causes related to trauma showing significantly higher mortality risks than others. The findings emphasize the impact of tourism on wildlife populations and the urgent need for targeted conservation strategies on Phillip Island.