Intestinal parasite contamination from infected dogs can place other dogs and humans at risk. A study was initiated to estimate the prevalence of canine intestinal parasitism by collecting fecal samples in cities across Western Europe.
Fresh fecal samples were collected from 2469 dogs visiting 164 parks in 33 cities across 12 countries. Each owner responded to a questionnaire on their dog's signalment and recent anthelmintic treatment history. The collected samples were examined for hookworms, whipworms, ascarids, and Giardia using a coproantigen diagnostic immunoassay and microscopy following centrifugal flotation.
Nematodes or Giardia were detected in at least one sample from 100% of cities and in 93.3% of parks. Nematodes were detected in 57% of parks. Overall, 22.8% of dogs tested positive for an intestinal parasite, with Giardia being the most commonly identified parasite (17.3% of dogs and 83.5% of parks). For nematode infection, 7.6% of all dogs tested positive, with 9.9% of dogs aged < 1 year infected, 7.7% of those aged 1–3 years, 7.3% of those aged 4–6 years, and 6.6% of those aged ≥ 7 years. Among the nematodes detected, ascarids were the most prevalent (3.6% of dogs, parks, 28.7% of parks), most common in dogs aged < 1 year but also present in older dogs, including those aged ≥ 7 years. Hookworms and whipworms were detected in 3.2% and 2.3% of dogs of all ages, respectively, and 37.2% and 17.7% of parks, respectively. A more significant proportion of fecal samples tested positive with the coproantigen immunoassay than with centrifugal flotation. Positive test results for Giardia were sevenfold higher when both diagnostic tests were used than when centrifugal flotation alone was used. There were 60% more positive results for nematodes when both tests were used than when flotation alone was used. Overall, 77.2% of owners reported previous anthelmintic treatment, among whom at least 62.7% failed to follow recommended treatment frequency. Dogs receiving anthelmintics within the previous month had a lower percentage of nematode infection than those in which > 1 month had passed since the last dose.
The prevalence estimates of intestinal parasite infections in dogs reported here highlight the need for owner education concerning regular testing and treatment guidelines, even in older dogs. Failure to adhere to guidelines can result in the ongoing transmission of these infections, including those with zoonotic potential. Combining coproantigen immunoassay with centrifugal flotation for diagnostic testing and regular anthelmintic treatment is essential for ensuring optimal intestinal parasite control.
Refrence: Drake, J., Sweet, S., Baxendale, K. et al. Detection of Giardia and helminths in Western Europe at local K9 (canine) sites (DOGWALKS Study). Parasites Vectors 15, 311 (2022).
