Background: Ticks and fleas are considered amongst the most important arthropod vectors of medical and veterinary concern due to their ability to transmit pathogens to a range of animal species including dogs, cats and humans. By sharing a common environment with humans, companion animal-associated parasitic arthropods may potentially transmit zoonotic vector-borne pathogens (VBPs). This study aimed to molecularly detect pathogens from ticks and fleas from companion dogs and cats in East and Southeast Asia.Methods: A total of 392 ticks and 248 fleas were collected from 401 infested animals (i.e. 271 dogs and 130 cats) from China, Taiwan, Indonesia, Malaysia, Singapore, Thailand, the Philippines and Vietnam, and molecularly screened for the presence of pathogens. Ticks were tested forRickettsiaspp.,Anaplasmaspp.,Ehrlichiaspp.,Babesiaspp. andHepatozoonspp. while fleas were screened for the presence ofRickettsiaspp. andBartonellaspp.Result: Of the 392 ticks tested, 37 (9.4%) scored positive for at least one pathogen withHepatozoon canisbeing the most prevalent (5.4%), followed byEhrlichia canis(1.8%),Babesia vogeli(1%),Anaplasma platys(0.8%) andRickettsiaspp. (1%) [includingRickettsiasp. (0.5%),Rickettsia asembonensis(0.3%) andRickettsia felis(0.3%)]. Out of 248 fleas tested, 106 (42.7%) were harboring at least one pathogen withR. felisbeing the most common (19.4%), followed byBartonellaspp. (16.5%),Rickettsia asembonensis(10.9%) and “CandidatusRickettsia senegalensis” (0.4%). Furthermore, 35Rhipicephalus sanguineusticks were subjected to phylogenetic analysis, of which 34 ticks belonged to the tropical and only one belonged to the temperate lineage (Rh. sanguineus(sensu stricto)).Conclusion: Our data reveals the circulation of different VBPs in ticks and fleas of dogs and cats from Asia, including zoonotic agents, which may represent a potential risk to animal and human health.

These revised guidelines have been developed to assist in the design, execution, and interpretation of studies to assess the efficacy of anthelmintic drugs against internal parasites in dogs and cats. The design and execution of studies are outlined and discussed. Considerations for specific targeted parasites are included. Information is provided on the principles of selection of animals, procedures for randomization, housing, feeding, necropsy procedures, and record keeping for dose determination dose confirmation studies and field studies. Complementary to the WAAVP general anthelmintic guidelines, these species-specific guidelines should assist investigators in the evaluation of anthelmintic drugs in dogs and cats by using comparable and standardized procedures in studies with appropriate numbers of animals.

Background: Mixed strongylid infections significantly impact equine health and performance. Traditional microscopy-based methods exhibit limitations in accurately identifying strongylid species. Nemabiome deep amplicon sequencing approach previously succeeded in describing the strongylid communities in livestock including equids. However, there are no available studies that describe the structural communities of strongylid parasites in horses in Thailand. Therefore, this study was undertaken encompassing the ITS-2 rDNA metabarcoding assay to characterize strongylid species within horse fecal samples collected from a cohort of yearlings at the largest domesticated stud farm in Thailand. In addition, to investigate the capability of ITS-2 rDNA in assessing the phylogenetic relationships among the identified strongylid species. Results: The study identified 14 strongylid species in the examined equine populations, each with varying prevalence. Notably, Cylicocyclus nassatus and Cylicostephanus longibursatus were identified as the predominant species, with Strongylus spp. conspicuously absent. The phylogenetic analysis of 207 amplicon sequence variants (ASVs) displayed a complex relationship among the investigated cyathostomin species, with some species are positioned across multiple clades, demonstrating close associations with various species and genera. Conclusion: The ITS-2 nemabiome sequencing technique provided a detailed picture of horse strongylid parasite species in the studied population. This establishes a foundation for future investigations into the resistance status of these parasites and enables efforts to mitigate their impact.

Dirofilaria immitis and Brugia pahangi are vector-borne parasites found in dogs and cats, including Thailand. In order to evaluate the effects of season and environmental parameters on the prevalence of these parasites, this retrospective study was conducted in 2019. A total of 79,506 canine blood samples were examined. B. pahangi was found in 0.55% of samples (438/79,506; 95% CI 0.50–0.61) while D. immitis was detected in 0.43% (345/79,506; 95% CI 0.39–0.48). One-way ANOVA found no effect of seasonal conditions on prevalence. For B. pahangi, the parameters rainfall, relative humidity and sunshine hours showed associations with p ≤ 0.20 and were included in multiple logistic regressions resulting in adjusted odds ratios of 0.53, 1.31 and 0.55, respectively. For D. immitis, only average temperature showed p ≤ 0.20, resulting in an odds ratio of 0.42. In conclusion, Thailand has environmental parameters that do not change very much during the year, so they might not affect the prevalence of two filarial nematodes. However, the threat of B. pahangi and D. immitis should not be ignored, especially in subtropical regions where their vectors are abundant. Both owners and veterinarians should be concerned about filarial prevention and control of D. immitis and B. pahangi.