Seropositivity to Campylobacter and association with abortion and lamb mortality in maiden ewes from Western Australia, South Australia and Victoria.

This case-control study investigated associations between Campylobacter fetus or Campylobacter jejuni titre and reproductive outcomes in 22 flocks of Merino and non-Merino maiden ewes aged 1-2 years old. Campylobacter titres were also determined for multiparous ewes aged 3 years or older on the same farms. C. fetus 'positivity' (titre ≥1:80) was detected for 12% (57/462; 95% confidence interval [95% CI] 9.6 to 15.6) of maiden ewes and 31% (65/210; 95% CI 25.0 to 37.4) of mature ewes. The odds for failing to rear a lamb in C. fetus-'exposed' maiden ewes (titre ≥1:10) was 2.01 times that of seronegative ewes (95% CI 1.09 to 3.77; P = 0.027), but there was no association between C. fetus-'positivity' (titre ≥1:80) and failure to rise (OR 1.69; 95% CI 0.77 to 3.76; P = 0.191). C. fetus abortions were confirmed with microbial culture in one maiden ewe flock. In this flock, C. fetus titres fluctuated and often waned by lamb marking, highlighting the value of necropsies during abortion investigations. C. jejuni-'positivity' (titre ≥1:80) was detected for 44% (204/462; 95% CI 39.7 to 48.7) maiden ewes, but odds of failing to rear were decreased for C. jejuni-'positive' ewes (OR 0.52; 95% CI 0.32 to 0.83; P = 0.007). The association between Campylobacter serology and the reproductive outcome was inconsistent in these flocks. Serology should be considered in the context of other risk factors and used in conjunction with other strategies to investigate the impact of Campylobacter exposure on ewe reproductive performance such as monitoring for abortions and lamb necropsies to determine aetiological diagnosis, and vaccination trials.

Ovine abortion and stillbirth investigations in Australia.

Fetal loss and lamb mortality between mid-pregnancy and weaning are important economic and welfare issues for the Australian sheep industry. The aim of this study was to determine common causes of ovine abortion and stillbirths based on submissions to veterinary laboratories and identify factors that impact the determination of an aetiological diagnosis. Data for 529 investigations on abortion or stillbirth between 2000 and 2018 were retrieved from four state veterinary laboratories in Western Australia, South Australia, Victoria and Tasmania. An aetiological diagnosis was made for 57% of investigations. Investigations that included placental tissue samples were more than twice as likely to have an aetiological diagnosis compared to investigations without placenta (P = 0.017, 95% confidence interval 1.1, 4.5). Of the investigations where an aetiological diagnosis was made, 81% involved infectious abortion, with Campylobacter spp. (32%), Listeria spp. (25%) and Toxoplasma gondii (9%) being the three most common abortigenic pathogens implicated. The remaining 19% of investigations with an aetiological diagnosis included a wide range of infectious and non-infectious diseases. Diagnoses made varied year to year and between states. No evidence of exotic abortigenic pathogens were reported. Veterinary practitioners can improve the probability of an aetiological diagnosis by emphasising to farmers the importance of collecting any aborted material, especially placenta, and appropriate storage of the tissues until they can be submitted to the laboratory. Some diseases that cause abortion in Australian sheep have zoonotic potential, and veterinary practitioners play an important role in educating clients about appropriate hygiene when handling pregnant and lambing ewes or any aborted material.

Endurance veterinarians detect physiologically compromised horses in a 160 km ride.

REASONS FOR PERFORMING STUDY: This study investigated the physiology of endurance horses competing in warm weather over technical terrain, a situation where horses may become metabolically compromised. HYPOTHESES: There will be changes in physiological, haematological and biochemical variables as horses progress through the 160 km ride and horses detected clinically at the veterinary inspections as metabolically compromised will have significant differences in measured laboratory variables compared to horses that complete the ride successfully. METHODS: Forty-eight horses competing in the Australian Tom Quilty 160 km endurance ride were monitored and weighed, and blood samples collected for analysis of electrolytes, packed cell volume (PCV), plasma protein and acid-base variables, preride, mid-ride, at the end of their ride and the following morning after a period of recovery. Statistical analysis was performed using multinomial logistic regression and repeated measures ANOVA. RESULTS: Of the 48 horses participating in the study, only 18 successfully completed the ride (SC), 16 were eliminated for lameness (VOL) and 10 for metabolic reasons (VOM); 4 were voluntarily withdrawn by the riders. A lighter preride bodyweight was predictive for VOM. PCV and total plasma protein increased mid-ride in all groups compared to preride, with significantly greater increases in PCV for VOM compared to the other horses. Changes were detected in blood concentrations of sodium, chloride and calcium over time and between the groups, with lower mid-ride sodium and chloride in VOM compared to SC and VOL. CONCLUSIONS: VOM horses weighed less preride and were, on analysis of blood and physiological variables mid-ride, more dehydrated with greater electrolyte depletion than the SC or VOL horses.

Cryptococcosis in domestic animals in Western Australia: a retrospective study from 1995-2006.

A retrospective study of cryptococcosis in domestic animals residing in Western Australia was conducted over an 11-year-period (from 1995 to 2006) by searching the data base of Murdoch University Veterinary Teaching hospital and the largest private clinical pathology laboratory in Perth. Cryptococcosis was identified in 155 animals: 72 cats, 57 dogs, 20 horses, three alpacas, two ferrets and a sheep. There was no seasonal trend apparent from the dates of diagnosis. Taking into account the commonness of accessions to Murdoch University, cats were five to six times more likely to develop this disease than dogs, and three times more likely than horses, while horses were almost twice as likely as dogs to become infected. Amongst the feline cohort, Ragdoll and Birman breeds were over-represented, while in dogs several pedigree breeds were similarly overrepresented. Dogs and horses tended to develop disease at an early age (one to five years), while cats were presented over a much wider range of ages. In cats and dogs the upper respiratory tract was the most common primary site of infection, while horses and alpacas tended to have lower respiratory involvement. The most striking finding of the study was the high frequency with which C. gattii was identified, with infections attributable to this species comprising 5/9 cats, 11/22 dogs, 9/9 horses and 1/1 alpaca, where appropriate testing was conducted. Preliminary molecular genotyping suggested that most of the C. gattii infections in domestic animals (9/9 cases) were of the VGII genotype. This contrasts the situation on the eastern seaboard of Australia, where disease attributable to C. gattii is less common and mainly due to the VGI genotype. C. gattii therefore appears to be an important cause of cryptococcosis in Western Australia.

Evaluation of an autologous red cell agglutination test, VetRED FIV, for the presence of FIV antibody in cats.

A commercially available whole blood agglutination test, VetRED FIV, used for the detection of antibodies to feline immunodeficiency virus (FIV), was evaluated. The test is based on the use of a synthetic peptide conjugated to a non-agglutinating anti-feline red blood cell monoclonal antibody. The amino acid sequence of the synthetic peptide was derived from the predicted sequence of the transmembrane protein of FIV. The sensitivity and specificity of VetRED FIV was 100% when 34 known FIV-positive and 15 known FIV-negative cats were tested. These cats were part of studies on experimentally induced FIV infection, with their FIV status confirmed by virus isolation. Further, VetRED FIV was compared with another commercially available test for FIV antibody, PetChek in a field trial on 548 feline blood samples received by a diagnostic laboratory. Of the test results 94.2% (516/548) were in agreement: 112 were positive by VetRED FIV and PetChek; 404 were negative by both tests and 32 were discordant. These 5.8% discordant samples producing VetRED FIV-positive/PetChek-negative or VetRED FIV-negative/PetChek-positive were further assessed by Western blot assay. In the field trial, the sensitivity and specificity of VetRED FIV was 97% and 97%, respectively, comparable to the 98% sensitivity and 99% specificity for PetChek. The results from the trial also confirm the relatively high overall prevalence of FIV in Australian cats predominantly among mature male cats in the 9-12 year age group. Given the simplicity of the VetRED FIV procedure, it is concluded that VetRED FIV is a useful addition to the available commercial tests for FIV infection.

The use of the glutaraldehyde coagulation test for detection of hypogammaglobulinaemia in neonatal foals.

The effectiveness of the glutaraldehyde coagulation test (GCT) in detecting failure to acquire colostral immunoglobulin in neonatal foals was investigated. This was achieved by comparing and correlating results from the GCT with those obtained by single radial immunodiffusion (SRID) of equine IgG. The GCT was found to be a practical, inexpensive, semiquantitative test with a high specificity and sensitivity at critical IgG levels.