Australia has over 400,000 wild horses, the largest wild equid population in the world, scattered across a range of different habitats. We hypothesised that wild horse populations unexposed to anthelmintics would have a high prevalence of Strongylus vulgaris infections. Verminous endarteritis and colic due to migrating S. vulgaris larvae is now absent or unreported in domestic horses in Australia, yet wild horses may pose a risk for its re-emergence. A total of 289 faecal egg counts (FECs) were performed across six remote wild horse populations in south-east Australia, of varying densities, herd sizes and habitats. Total strongyle egg counts ranged from 50 to 3740 eggs per gram (EPG, mean 1443) and 89% (257/289) of faecal samples had > 500 EPG, classifying them as ‘high level shedders’. There were significant differences in mean total strongyle FECs between different locations, habitats and population densities. Occurrence of S. vulgaris was not predictable based on FECs of total strongyle eggs or small (<90 μm) strongyle eggs. A high prevalence of S. vulgaris DNA in faecal samples was demonstrated across all six populations, with an overall predicted prevalence of 96.7%. This finding is important, because of the ample opportunity for transmission to domestic horses. The high prevalence of S. vulgaris suggests vigilance is required when adopting wild horses, or when domestic horses graze in environments inhabited by wild horses. Appropriate veterinary advise is required to minimize disease risk due to S. vulgaris . Monitoring horses for S. vulgaris using larval culture or qPCR remains prudent. Gastrointestinal parasites in wild horse populations may also serve as parasite refugia, thus contributing to integrated parasite management when facing emerging anthelmintic resistance.

Canine parvovirus (CPV-2) remains an important cause of devastating enteritis in young dogs. It can be successfully prevented with live attenuated CPV-2 vaccines when given at the appropriate age and in the absence of maternal antibody interference. Rapid diagnosis of parvoviral enteritis in young dogs is essential to ensuring suitable barrier nursing protocols within veterinary hospitals. The current diagnostic trend is to use multiplexed PCR panels to detect an array of pathogens commonly responsible for diarrhea in dogs. The multiplexed PCR assays do not distinguish wild from vaccine CPV-2. They are highly sensitive and detect even a low level of virus shedding, such as those caused by the CPV-2 vaccine. The aim of this study was to identify the CPV-2 subtypes detected in diagnostic specimens and rule out occult shedding of CPV-2 vaccine strains. For a total of 21 samples that tested positive for CPV-2 in a small animal fecal pathogens diagnostic multiplexed tandem PCR (MT-PCR) panel during 2014-2016 we partially characterized the VP2 gene of CPV-2. Vaccine CPV-2 strain, wild type CPV-2a subtypes and vaccine-like CPV-2b subtypes were detected. High copy number was indicative of wild-type CPV-2a presence, but presence of vaccine-like CPV-2b had a variable copy number in fecal samples. A yardstick approach to a copy number or C-value to discriminate vaccine strain from a wild type virus of CPV-2 can be, in some cases, potentially misleading. Therefore, discriminating vaccine strain from a wild type subtype of CPV-2 remains ambitious.

Giardia intestinalis and Tritrichomonas foetus are frequent enteric protozoan parasites of the gastrointestinal track of domestic cats. Because of different treatment options for the parasites, confirmation of presence of one or both pathogens is necessary. The PCR based assays are suitable for differential diagnosis. We evaluated the performance of Small Animal Diarrhoea panel, a multiplexed-tandem real-time PCR (MT-PCR) assay, that detects DNA of both G. intestinalis and T. foetus. The sensitivity and specificity were compared to reference real-time PCR assays using 105 faecal samples, 39.05% (n = 41) positive for G. intestinalis and 30.48% (n = 32) were positive for T. foetus. The faecal samples positive for T. foetus had a high proportion of late amplifiers, determined by an arbitrary threshold of C t -values > 35. On the other hand, only one G. intestinalis positive sample was considered a late amplifier. For G. intestinalis DNA, the MT-PCR assay had 95.1% sensitivity and 92.1% specificity. For T. foetus DNA, the MT-PCR assay had 41.9% sensitivity and 100.0% specificity. To evaluate the interlaboratory reproducibility of the MT-PCR assay, results were compared in two different laboratories and found to be in a very good agreement (Kappa = 0.9). Further analysis of the DNA using conventional PCR determined presence of G. intestinalis Assemblage F and T. foetus genotype 'feline'. In conclusion, the MT-PCR Small Animal Diarrhoea panel had a good and poor performance against reference assays for G. intestinalis and T. foetus, respectively. The assay is suitable for detection and differential diagnosis of G. intestinalis and moderate to high burdens of T. foetus in small animal clinical practice.