Equine gastrointestinal nematodes (GINs) have been the subject of intermittent studies in Australia over the past few decades. However, comprehensive information on the epidemiology of equine GINs, the efficacy of available anthelmintic drugs and the prevalence of anthelmintic resistance (AR) in Australasia is lacking. Herein, we have systematically reviewed existing knowledge on the horse GINs recorded in Australia, and main aspects of their pathogeneses, epidemiology, diagnoses, treatment and control. Six electronic databases were searched for publications on GINs of Australian horses that met our inclusion criteria for the systematic review. Subsets of publications were subjected to review epidemiology, diagnoses, pathogeneses, treatment and control of GINs of horses from Australia. A total of 51 articles published between 1950 to 2018 were included. The main GINs reported in Australian horses were cyathostomins (at least 28 species), Draschia megastoma, Habronema muscae, H. majus, Oxyuris equi, Parascaris equorum, Strongyloides westeri and Trichostrongylus axei across different climatic regions of Queensland, New South Wales, Victoria, and Western Australia. Nematodes are diagnosed based on the traditional McMaster egg counting technique, though molecular markers to characterise common GINs of equines were characterised in 1990s. The use of anthelmintic drugs remains the most widely-used strategy for controlling equine GIN parasites in Australia; however, the threshold of faecal egg count that should trigger treatment in horses, remains controversial. Furthermore, anthelmintic resistance within GIN population of horses is becoming a common problem in Australia. Although GINs infecting Australian horses have been the subject of occasional studies over the past few decades, the effective control of GIN infections is hampered by a generalised lack of knowledge in various disciplines of equine parasitology. Therefore, coordinated and focused research is required to fill our knowledge gaps in these areas to maximise equine health and minimise economic losses associated with the parasitic infections in Australia.

Five of 10 pregnant, lactating mares, each with a foal at foot, developed neurological disease. Three of them became recumbent, developed complications and were euthanased; of the two that survived, one aborted an equine herpesvirus type 1 (EHV‐1)‐positive fetus 68 days after the first signs were observed in the index case and the other gave birth to a healthy foal on day 283 but remained ataxic and incontinent. The diagnosis of EHV‐1 myeloencephalitis was supported by postmortem findings, PCR identification of the virus and by serological tests with an EHV‐1 ‐specific ELISA. At the time of the index case, the 10 foals all had a heavy mucopurulent nasal discharge, and PCR and the ELISA were used to detect and monitor EHV‐1 infection in them. The status of EHV‐1 infection in the five in‐contact mares was similarly monitored. Sera from three of the affected mares, taken seven days after the index case were negative or had borderline EHv‐1 ‐specific antibody titres. In later serum samples there was an increase in the titres of EHv‐1 ‐specific antibody in two of the affected mares. In contrast, sera from the five unaffected in‐contact mares were all EHv‐1 ‐antibody positive when they were first tested seven or 13 days after the index case.

The equine disease strangles, which is characterized by the formation of abscesses in the lymph nodes of the head and neck, is one of the most frequently diagnosed infectious diseases of horses around the world. The causal agent, Streptococcus equi subspecies equi , establishes a persistent infection in approximately 10 % of animals that recover from the acute disease. Such ‘carrier’ animals appear healthy and are rarely identified during routine veterinary examinations pre-purchase or transit, but can transmit S. equi to naïve animals initiating new episodes of disease. Here, we report the analysis and visualization of phylogenomic and epidemiological data for 670 isolates of S. equi recovered from 19 different countries using a new core-genome multilocus sequence typing (cgMLST) web bioresource. Genetic relationships among all 670 S. equi isolates were determined at high resolution, revealing national and international transmission events that drive this endemic disease in horse populations throughout the world. Our data argue for the recognition of the international importance of strangles by the Office International des Épizooties to highlight the health, welfare and economic cost of this disease. The Pathogenwatch cgMLST web bioresource described herein is available for tailored genomic analysis of populations of S. equi and its close relative S. equi subspecies zooepidemicus that are recovered from horses and other animals, including humans, throughout the world. This article contains data hosted by Microreact.

In 2007, Australia experienced the most extensive equine influenza outbreak observed in recent years. Extraordinary measures were rapidly implemented in order to control and prevent the spread of this highly contagious disease. The control strategy involved stringent movement restriction and disease surveillance, seconded by emergency post-outbreak vaccination strategies. Sixteen months after the first case and 12 months following the last reported case, Australia regained its equine influenza-free OIE status. This systematic review reports and summarises information relating to the implementation of emergency vaccination during the 2007 Australian equine influenza outbreak, including the choice of vaccine and implementation strategies.

Summary: Reasons for performing study:During the 2007 Australian equine influenza (EI) outbreak, an accelerated primary course 14 day intervaccination schedule was proposed, but not widely implemented. Expert opinion was divided as to the efficacy of such a schedule given the lack of published data. This study determined the level and duration of humoral immunity following administration of a recombinant canarypox‐vectored vaccine (ALVAC‐EIV) with a primary intervaccination interval of 14 days and booster at 105 days.Objectives:To examine whether protective levels of immunity of adequate duration were achieved following a primary course reduced from a minimum interval of 28 to 14 days. Antibody responses to 2 H3N8 American lineage virus strains (including A/equine/Sydney/6085/2007) were assessed and compared to previous challenge studies using ALVAC‐EIV at conventional intervaccination intervals.Methods:Fourteen Thoroughbred horses and 2 ponies from a rural racehorse training property in Victoria, Australia, were vaccinated with ALVAC‐EIV on Days 0, 14 and 105. Serial blood samples were collected over the next 32 weeks and tested with haemagglutination inhibition and single radial haemolysis (SRH) in full assays to evaluate the serological response.Results:All horses and ponies responded to the accelerated ALVAC‐EIV vaccination schedule. Mean SRH antibodies remained above those consistent with clinical protection for the duration of the study period. All vaccinates demonstrated high SRH antibodies 14 days following V2, thereby achieving 100% herd immunity to homologous viral challenge.Conclusions:An accelerated vaccination schedule conferred long‐lasting protective antibody levels despite a >50% reduction in the recommended V1–V2 interval.Potential relevance:High levels of rapidly acquired herd immunity are critical in containing an outbreak of such a highly contagious pathogen as EIV. In a strategic vaccination programme, it is important that horses remain protected for sufficient time to allow control programmes to succeed. An accelerated 14 day primary course intervaccination interval and booster at 105 days achieves both of these objectives.