Conference Agenda

Fleas (Siphonaptera) are globally important blood-feeding ectoparasites that infest companion animals, livestock, and humans. They are vectors of bacterial pathogens such as Rickettsia and Bartonella. Yet, many flea species and their associated bacterial communities in Cambodia remain poorly characterised. This project aims to identify flea species parasitising dogs in Cambodia and characterise their bacteriome. Fleas collected from dogs across multiple Cambodian regions were morphologically identified using established dichotomous keys. Genomic DNA was extracted from individual fleas, and full-length 16S rRNA gene nanopore metabarcoding will be performed, following previously developed and validated workflows to characterise flea-borne bacteria (FBB). This flea bacteriome data will be analysed alongside previously generated dog blood bacterial profiles, using paired samples from the same individual hosts. Preliminary morphological work revealed that most fleas parasitising Cambodian dogs belong to the genus Ctenocephalides, with C. orientis predominating. Sequencing will confirm species identity and the diversity of FBB pathogens, potentially detecting well known zoonotic agents and novel taxa that conventional PCR-based approaches may fail to detect. Integrating flea species identification with bacteriome data and host blood infection status provides initial evidence on the potential vector role of canine fleas in Cambodia and identifies gaps for future surveillance in under-resourced settings.

Exposure to Toxoplasma gondii in dogs has been recognised for decades, including an Australian study conducted at the University Veterinary Teaching Hospital in Sydney (UVTHS) in 1982, which showed that exposure was common among dogs presented for veterinary care. Since then, major changes in canine lifestyle, urbanisation and veterinary practice have occurred, raising questions about whether exposure patterns have shifted and what factors now best explain risk. Using diagnostic serology data from approximately 500 dogs, we examined a contemporary cohort of client‑owned dogs presented to a veterinary teaching hospital. Serological evidence of prior exposure remains common, consistent with historical findings. Age was the dominant predictor of seropositivity, with dogs aged four years or older showing substantially higher odds of exposure, reflecting cumulative lifetime contact with the parasite. Breed‑associated exposure ecology further clarified risk: Toy breeds consistently showed the lowest likelihood of seropositivity, while other purebred dogs had markedly higher odds, suggesting lifestyle and environmental exposure, rather than fine breed distinctions, drive risk. From a veterinary perspective, canine T. gondii seropositivity reflects prior exposure rather than disease, and positive serology (particularly in older, non‑Toy dogs) represents an expected background finding rather than evidence of toxoplasmosis.

Strongyloides stercoralis is an intestinal nematode infecting humans and dogs, but its occurrence in dogs from temperate, traditionally non-endemic regions is poorly characterised, partly due to limited veterinary diagnostics. Recent reports from metropolitan areas raise concern that infections may be under-recognised. This study screened archived canine faecal DNA (n = 448) collected between 2014 and 2024 from two university veterinary teaching hospitals in Sydney, New South Wales, Australia, using a highly sensitive 18S rRNA real-time qPCR (limit of detection: two DNA copies). One sample (0.02%) was positive, containing approximately 6.8 × 10³ 18S rDNA copies, equivalent to 3.2 Strongyloides ratti third-stage larvae per 250 mg of faeces. Deep amplicon sequencing of partial cox1 and 18S rDNA (HVR‑I and HVR‑IV) confirmed S. stercoralis potentially circulating between dogs and humans. The positive sample originated from a Border Collie puppy with gastrointestinal signs. Although rare, detection confirms the parasite’s presence in companion dogs in a temperate urban setting. These findings support the utility of 18S rDNA-based qPCR for retrospective surveillance and its inclusion in molecular diagnostic panels for canine gastrointestinal disease and highlight the need for expanded surveillance in non-endemic regions.