Jan Lievaart

Workplace stress, mental health, and burnout of veterinarians in Australia.

OBJECTIVE To determine the frequency of the states of depression, anxiety, stress and burnout using internationally validated methods and to relate these to the demographic characteristics of veterinarians in Australia. METHODS A postal survey of registered veterinarians with at least one years experience and whose address was available; 1947 returned the questionnaire providing data for analysis. RESULTS Overall, veterinarians describe higher levels of depression, anxiety, stress and burnout than the general population. The severity of these states was determined by gender, background, type of practice and years after graduation. CONCLUSIONS Modifying the curricula of veterinary schools to include the teaching of personal cognitive and coping skills to undergraduate veterinary students, the provision of the opportunity to enhance these skills throughout their veterinary career and changes in the veterinary workplace could result in improved mental health, increased job engagement and work satisfaction.

Subclinical mastitis and associated risk factors on dairy farms in New South Wales.

OBJECTIVE To determine the current prevalence of subclinical mastitis (SCM) and associated risk factors on dairy farms in New South Wales. METHODOLOGY A survey was sent to 382 dairy farmers to acquire information on the relevant risk factors associated with SCM. RESULTS The average herd prevalence of SCM among the 189 respondents (response rate 49.5%) was 29%. Farmers who had herds with a low prevalence (<20% cows with individual somatic cell count (ISCC) >2 × 10⁵ cells/mL) more frequently wore gloves during milking (26% vs 62%), used individual paper towels for udder preparation (16% vs 62%), fed cows directly after milking (47% vs 87%) and more frequently treated cows with high ISCC (69% vs 80%) than farmers who had herds with a high prevalence of SCM (>30% cows with ISCC >2 × 10⁵ cells/mL). The latter more often used selective dry cow therapy (52% vs 24%), compared with low prevalence herds. CONCLUSION The prevalence of SCM in this cross-sectional study is comparable or lower than reported in other studies from North America and the European Union. The outcome provides a benchmark for the current focus of the NSW dairy industry on the management practices associated with a low prevalence of SCM, such as wearing gloves, using paper towels and feeding cows directly after milking.

Pharmacokinetics and Safety of Single and Multiple Oral Doses of Meloxicam in Adult Horses

BACKGROUND Safety of meloxicam, a potent NSAID with selective COX-2 inhibition, has not been evaluated in horses. OBJECTIVES To evaluate pharmacokinetics and safety of single and repeated oral doses of meloxicam in adult horses. ANIMALS Forty-nine healthy, university-owned adult lightbreed horses. METHODS Study conducted in 2 parts. Part I addressed pharmacokinetics of single oral dose meloxicam (0.6 mg/kg) in 16 horses. Part II, 33 horses were randomly assigned to 5 treatment groups to assess prolonged administration (0.6 mg/kg PO q24h for 6 weeks, n = 7) or higher doses (1.8 mg/kg, n = 7, or 3.0 mg/kg PO q24h, n = 7) of meloxicam for 2 weeks, compared with control horses (placebo, n = 7, or phenylbutazone, 4.4 mg/kg q12h on day 1, 2.2 mg/kg q12h for 4 days, then 2.2 mg/kg q24h for 9 days, n = 5). RESULTS Maximum plasma concentration following a single oral dose of meloxicam was 915.1 ± 116.9 ng/mL and elimination half-life 10.2 ± 3.0 hours. Meloxicam (0.6 mg/kg, q24h, PO for 6 weeks) yielded plasma concentrations between 100 and 1000 ng/mL and was well tolerated by healthy adult horses. Administration of 3-5 times the recommended dose of meloxicam was associated with decreased total serum protein and albumin concentrations, gastrointestinal damage, renal damage, or bone marrow dyscrasia. PBZ administration was associated with the development right dorsal colitis, gastric ulceration, and protein losing enteropathy in 2 horses. CONCLUSIONS AND CLINICAL IMPORTANCE Administration meloxicam at 0.6 mg/kg q24h was well tolerated for 6 weeks, without drug accumulation in plasma. Higher doses were associated with dose-dependent adverse effects typical of class of drugs.

Echinococcus granulosus and other intestinal helminths: current status of prevalence and management in rural dogs of eastern Australia

OBJECTIVES Ascertain the prevalence of intestinal helminths in rural dogs from eastern Australia and Tasmania. Identify farm management practices contributing to the perpetuation and transmission of Echinococcus granulosus. METHODS Helminth infection in dogs was determined microscopically through faecal flotation. Infection with E. granulosus was determined via faecal antigen-capture ELISA and coproPCR. Taeniid eggs were identified using molecular methods. Data on dog management and owner understanding of hydatid disease were collected via questionnaire. RESULTS Faeces were collected from 1425 Australian rural dogs (1119 mainland; 306 Tasmania). Eggs of hookworms were most prevalent, up to 40.2%, followed by whipworms (Trichuris vulpis), up to 21.2%. Roundworms (Toxocara canis and Toxascaris leonine) were least common, up to 6.1%. Taeniid eggs were found in 11 dogs (5 Taenia pisiformis; 2 T. serialis; 4 T. hydatigena); 2 of the T. hydatigena-infected dogs were also E. granulosus coproantigen-positive. Of the 45 dogs found to be E. granulosus coproantigen-positive, 24 were in Tasmania, 16 in NSW, 3 in Victoria and 2 in Queensland. Three Tasmanian coproantigen ELISA-positive dogs were also coproPCR-positive. The most common dog ration was commercial dry food, but half the owners fed raw meat to their dogs and some fed offal of lambs (8.9%) or mutton (7.8%). More than half (69%) of owners weighed their dogs before deworming. Few dewormed their dogs often enough to ensure they remained cestode-free and owners hunting wildlife usually left carcases where they were shot. CONCLUSIONS E. granulosus is still present in Australian rural dogs, including Tasmania, but at low levels. Owner behaviour perpetuates transmission of cestodes.

Effect on time in quarantine of the choice of program for eradication of footrot from 196 sheep flocks in southern New South Wales.

OBJECTIVE To identify and compare programs for eradicating virulent footrot (VFR) chosen by owners of quarantined sheep flocks in southern New South Wales. METHOD Data from 196 sheep flocks in the Wagga Wagga and Young Rural Lands Protection Boards were used to determine the program chosen, the influence of flock size on the program chosen and the effects of the program chosen and the use of contractors on the time in quarantine. RESULTS The most popular programs in flocks using a single program were: total destocking (61/173; 35.3%) and inspection and culling of affected animals (71/173; 41.0%). Treatment of known infected animals was chosen in 41 flocks and of those, 10 (5.8%) used antibiotics for treatment and 31 (17.9%) used foot-bathing. Combined programs were used in 23 flocks and in 10 flocks a change of program occurred before eradication was achieved. The choice of program was, to some extent, affected by flock size, with owners of small flocks (<500 sheep) more likely to destock. The chosen program strongly influenced the time in quarantine, the shortest time being for destocking (mean 284 days), followed by culling of infected sheep (395 days), treatment with antibiotics (433 days) and finally foot-bathing (502 days). Time in quarantine was significantly shorter when contractors were used. CONCLUSION All the options chosen led to the eradication of VFR. However, in this sample both the choice of program and the use of contractors influenced the time taken to achieve eradication and therefore the time in quarantine. Based on time in quarantine, foot-bathing was the least desirable option for the eradication of VFR because of the significantly greater time involved, perpetuation of risk to neighbours and increased cost of inspections. These findings were derived from flocks that were quarantined, but they are relevant to all flock owners considering eradication of VFR.

Factors involved in high ewe losses in winter lambing flocks grazing dual-purpose wheat in southern New South Wales: a producer survey

A comparative survey was undertaken with 43 sheep producers in southern New South Wales using a semi-structured interview to investigate factors associated with high ewe mortality rates in winter lambing flocks grazing dual-purpose wheat. Participants were classified as either control (n = 23), who had not observed abnormally high ewe deaths, or case (n = 20), who had observed abnormally high ewe mortality rates when sheep grazed dual-purpose wheat. Ewe losses associated with grazing wheat were higher in the case group compared with the control group (8.6 vs 1.8%; P < 0.001) and there was also more deaths attributed to metabolic disease (3.4 vs 0.6%; P < 0.05). A higher proportion of control respondents had provided magnesium or sodium supplementation to ewes grazing wheat (P < 0.05). The body condition score of ewes entering the grazing period was significantly higher in the control group (3.2 vs 2.8; P < 0.05). The proportion of respondents who fed roughage to ewes grazing wheat did not differ significantly between control and case groups (48 vs 35%). A higher proportion of respondents in the case group had supplied grain to ewes (25 vs 0%; P < 0.05), which may have been associated with the lower body condition of sheep in these flocks compared with the control group. It was concluded that supplying ad libitum access to mineral supplements that include magnesium, sodium and possibly calcium, and maintaining adequate body condition score can reduce the risk of high ewe mortality rates when reproducing ewes graze dual-purpose wheat.

Red foxes (Vulpes vulpes) and wild dogs (dingoes (Canis lupus dingo) and dingo/domestic dog hybrids), as sylvatic hosts for Australian Taenia hydatigena and Taenia ovis.

Graphical abstract

Incidence of calf scours and associated risk factors in southern New South Wales beef herds

Objective The aim of this study was to identify the incidence of morbidity and mortality associated with calf scours in beef calves between birth and 14 days of age. Farm characteristics, animal factors and management practices were also assessed for any association with calf scours being present on the farm. Methods A questionnaire and return address envelope were distributed to 721 farms with at least 50 head of beef cattle in the Hume area of New South Wales, Australia. Results In total, 147 (20.4%) farmers responded to the survey, of which 76 (51.7%) indicated calf scours did occur on their farm. On average, farmers estimated the morbidity of calf scours was 4.5%, but only 0.2% of all calves died as a result of scours. Affected herds were more likely to have multiple breeds and a higher proportion of cows with mismothering problems or weak calves compared with unaffected herds. These differences were confirmed with regression analysis. A large proportion of farmers with affected herds reported the loss of many calves from ‘unexplained’ or ‘sudden’ death within the first 14 days of life. Conclusions The incidence of calf morbidity was lower and mortality was within the same range compared with other studies on beef farms around the world. The high percentage of farms reporting losses from ‘unexplained’ or ‘sudden’ death of calves requires further monitoring and diagnostic and economic investigations.

Survey on the occurrence of milk fever in dairy cows and the current preventive strategies adopted by farmers in New South Wales, Australia.

OBJECTIVE The aim of this study was to investigate general and specific strategies adopted by New South Wales (NSW) farmers to prevent milk fever (MF) and its occurrence at calving within their dairy herds. DESIGN AND METHODS Of 300 dairy farmers in NSW randomly chosen and sent questionnaires, descriptive analysis of the returned data was performed for 102 questionnaires. To identify the various strategies used to prevent MF and its incidence, farms were classified as having a low (<3%) or high (>3%) incidence of MF. The data were analysed using a multivariable logistic regression model and backwards stepwise elimination to identify significant preventive strategies adopted by farmers having a low or high incidence of MF. RESULTS Based on the 102 responses, the median incidence of MF in the NSW dairy region was 3% (range 0-30%). The farms with low MF incidence practised specific MF control strategies, such as feeding dry cows separately, grain supplementation and feeding a low-potassium ration before calving and using a commercial ration mix immediately after calving. The time to first milking post-calving was on average 13.6 h on the low-incidence farms compared with 21.1 h on the high-incidence farms. CONCLUSIONS The low median incidence of MF (3%) in NSW was probably related in part to awareness of the importance of feeding a low-potassium, high-grain diet before calving. However, the incidence of MF was high on the farms not practising specific MF preventive methods.

Selecting an appropriate genetic evaluation model for selection in a developing dairy sector.

This study aimed to identify genetic evaluation models (GEM) to accurately select cattle for milk production when only limited data are available. It is based on a data set from the Pakistani Sahiwal progeny testing programme which includes records from five government herds, each consisting of 100 to 350 animals, with lactation records dating back to 1968. Different types of GEM were compared, namely: (1) multivariate v. repeatability model when using the first three lactations, (2) an animal v. a sire model, (3) different fixed effects models to account for effects such as herd, year and season; and (4) fitting a model with genetic parameters fixed v. estimating the genetic parameters as part of the model fitting process. Two methods were used for the comparison of models. The first method used simulated data based on the Pakistani progeny testing system and compared estimated breeding values with true breeding values. The second method used cross-validation to determine the best model in subsets of actual Australian herd-recorded data. Subsets were chosen to reflect the Pakistani data in terms of herd size and number of herds. Based on the simulation and the cross-validation method, the multivariate animal model using fixed genetic parameters was generally the superior GEM, but problems arise in determining suitable values for fixing the parameters. Using mean square error of prediction, the best fixed effects structure could not be conclusively determined. The simulation method indicated the simplest fixed effects structure to be superior whereas in contrast, the cross-validation method on actual data concluded that the most complex one was the best. In conclusion it is difficult to propose a universally best GEM that can be used in any data set of this size. However, some general recommendations are that it is more appropriate to estimate the genetic parameters when evaluating for selection purposes, the animal model was superior to the sire model and that in the Pakistani situation the repeatability model is more suitable than a multivariate.