Assessing the effects of seasonal variation and climatic factors on gastrointestinal and pulmonary parasitism in dogs and cats from the Azores archipelago - Portugal

The current study aimed to assess the potential seasonal variations on parasite prevalence and intensity in dog and cat feces from the Azores archipelago (Portugal), as well to evaluate the effects of climatic variables (rainfall and temperature) in the development of parasitic infections. Between Januray-December 2023, a total of 297 and 301 fecal samples from dogs and cats (respectively) were collected on five Azorean islands - Flores, Corvo, Terceira, São Miguel and Santa Maria - and then analyzed using the Mini-FLOTAC and Baermann methods. Weather data was also retrieved for this timeframe, to assess the effects of climatic factors in parasite infection. Toxocaridae reached significant prevalence values in summer (21-23 %), for dogs and cats. The opposite occurred regarding parasites intensity, being overall EPG/OPG/LPG counts higher in autumn. The presence of certain parasite species in canine and feline feces, namely Ancylostomatidae and Cystoisospora spp., was correlated with rainfall. Temperature favored the shedding of Trichuris vulpis and Toxocara cati eggs in pets' feces, as well as Aelurostrongylus abstrusus larvae. The present study was the first one to entail on effects of seasonality and climatic variables in populations of domestic carnivores from the Azores archipelago. It allowed us to successfully confirm seasonal variation on parasite intensity, as well as some prevalence variation in certain parasites species (Toxocaridae), filling this gap in the archipelago. Moreover, we have successfully proven the influence of climatic factors such as rainfall and temperature in the prevalence of certain parasitic forms in dog and cat feces. Plus, the identification of zoonotic species still presents a concern to public health, highlighting the need to implement more effective measures to control these agents, namely under the scope of ESCCAP Guidelines.