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.

High prevalence of fasciolosis and evaluation of drug efficacy against Fasciola hepatica in dairy cattle in the Maffra and Bairnsdale districts of Gippsland, Victoria, Australia.

Liver fluke (Fasciola hepatica) is a common parasite amongst grazing livestock in the south-eastern region of Australia and is responsible for significant production losses in the beef and dairy industries. Gippsland in Victoria is a major region for dairy production but no fluke prevalence data in livestock has been obtained in this region since the late 1970s prior to the introduction of Triclabendazole (TCBZ). TCBZ resistance is also now widespread in cattle in south east Australia. In this study, we evaluated the prevalence and intensity of liver fluke infections in dairy cattle in Gippsland and assessed the efficacy of TCBZ and other drenches against F. hepatica on one farm. We obtained 30 individual faecal samples from each of 15 different farms and, using the liver fluke coproantigen ELISA, tested bulk faecal samples pooled from each farm. Any farm that returned a positive bulk sample had all of the samples tested individually to assess the intra-herd prevalence. One farm in the Maffra district also had a coproantigen reduction test and faecal egg count reduction test to assess the efficacy of TCBZ, Clorsulon (CLOR) and Oxyclozanide (OXY). The coproantigen ELISA proved to be a highly sensitive test for liver fluke with a high correlation (R(2)=0.8849) observed between ELISA data from bulk samples and individual samples, suggesting that future larger scale screening on farms for fasciolosis could use the bulk analysis technique. The ELISA data revealed that animals on six of the 15 farms were infected with F. hepatica and the herd prevalence of the infected herds ranged from 47 to 100% (mean 81%) which exceeds the prevalence value for production losses of 25%. The intensity of fluke infection in cattle varied considerably both within and between herds with a proportion of animals exhibiting a positive control value in the coproantigen ELISA of 50-88%. We also confirmed that TCBZ resistance was present on one farm but that CLOR or OXY can be used to remove the adult stage of the TCBZ-resistant parasites. We conclude that fasciolosis is a significant disease and a likely cause of production losses in dairy cattle in the irrigation zones of Gippsland and that TCBZ resistance is a serious threat to fluke control. We suggest that more work needs to be performed in Gippsland to further define the extent of fasciolosis and drug resistance and to ensure that effective chemical and non-chemical methods of fluke control are incorporated on farms in order to improve animal welfare and reduce financial impacts on producers.

Oral administration of immunoglobulin G-enhanced colostrum alleviates insulin resistance and liver injury and is associated with alterations in natural killer T cells.

Insulin resistance and metabolic syndrome are chronic inflammatory conditions that lead to hepatic injury and non-alcoholic steatohepatitis (NASH). Bovine colostrum has therapeutic effects in a variety of chronic infections. However its effectiveness in NASH was never studied. Natural killer T (NKT) cells have been shown to be associated with some of the pathological and metabolic abnormalities accompanying NASH in leptin-deficient (ob/ob) mice. In the present study, we used hyperimmune bovine colostrum to treat hepatic injury and insulin resistance and we also assessed the effects on NKT cells. We used ob/ob mice that were fed for 6 weeks with either 0·1 mg bovine colostrum prepared from non-immunized cows, 0·1 mg hyperimmune colostrum raised against a bacterial lipopolysaccharide (LPS) extract or 0·001, 0·1 or 1 mg of immunoglobulin (Ig)G purified from hyperimmune colostrum (IgG-LPS). NKT cells were phenotyped by flow cytometry, and hepatic injury and insulin resistance were assessed by measuring fasting glucose levels, glucose tolerance tests and liver enzymes. Fat accumulation was measured in the liver and plasma. Oral administration of hyperimmune colostrums decreased alanine aminotransferase (ALT) serum levels and serum triglycerides compared to controls. Glucose intolerance was also improved by the hyperimmune colostrum preparations. These results were accompanied by a decrease in serum tumour necrosis factor (TNF)-α levels following oral treatment with 0·1 or 1 mg of IgG-LPS. The beneficial effects of hyperimmune colostrums were associated with an increase in the number of splenic NKT cells. These data suggest that oral administration of hyperimmune colostrum preparations can alleviate chronic inflammation, liver injury and insulin resistance associated with NASH.

Topically acquired bacterial zoonoses from fish: a review.

The main pathogens acquired topically from fish (through spine puncture or open wounds) are Aeromonas hydrophila, Edwardsiella tarda, Erysipelothrix rhusiopathiae, Mycobacterium marinum, Streptococcus iniae, Vibrio vulnificus and Vibrio damsela. S. iniae has recently emerged as a public health hazard associated with aquaculture, and M. marinum often infects home aquarium hobbyists. With the expansion of aquaculture and popularity of recreational fishing in Australia, medical practitioners can expect to see more infections of this nature. Diagnosis and treatment may be difficult, especially in view of emerging antibiotic resistance in fish pathogens.