Australian Veterinary Journal最新文献

Our project aimed to investigate whether low maternal calcium status during late gestation decreased weight, growth and survival of lambs born to twin-bearing Merino ewes grazing pasture. On day 130 of gestation, approximately a 10 mL blood sample was collected from 108 twin-bearing Merino ewes. Blood pH and calcium ion concentration were measured in whole blood and serum was analysed for calcium, magnesium, phosphate, beta hydroxy butyrate, non-esterified fatty acids and cholesterol. Six to 18 h after birth and at 49 days of age, lamb live weight was recorded. Ewe serum calcium level at day 130 of gestation were divided into tertiles (1.58–2.13, 2.14–2.30, and 2.31–2.99 mmol/L) with ewes classified as either Low, Med or High (n = 36 per group). A general linear mixed model was used to analyse the data. Survival to 1, 2, 3 and 7 days of age was lower for lambs born to ewes in the Low calcium group compared with those born in the Med and High calcium groups (P < 0.05). At day 49 of age, lamb survival tended to be lower for lambs in the Low (73.6%) compared with Med (86.8%) and High (85.3%) calcium groups (P < 0.1). There were no differences in lamb body weight (P > 0.05). Calcium levels of ewes in the Low calcium group were, on average, indicative of subclinical hypocalcaemia, with this group of ewes also having the lowest lamb survival rate, suggesting that maternal subclinical hypocalcaemia reduces lamb survival. Further studies, particularly on improving maternal calcium levels, are warranted.

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.

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.

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.