Detection of Giardia and helminths in Western Europe at local K9 (canine) sites (DOGWALKS Study)

Abstract

Background 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. Methods Fresh fecal samples were collected from 2469 dogs visiting 164 parks in 33 cities across 12 countries. Each owner responded to a questionnaire focusing 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. Results 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 parasites (17.3% of dogs, 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), being 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 in 37.2% and 17.7% of parks, respectively. A larger 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, and there were 60% more positive test 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 anthelmintic within the previous month had a lower percentage of nematode infection than those in which > 1 month had passed since the previous dose. Conclusions The prevalence estimates of intestinal parasite infections in dogs reported here highlight the need for owner education concerning guidelines for regular testing and treatment, even in older dogs. Failure to adhere to guidelines can result in ongoing transmission of these infections, including those with zoonotic potential. Combining coproantigen immunoassay with centrifugal flotation for diagnostic testing and regular anthelmintic treatment are important measures for ensuring optimal intestinal parasite control. Graphical Abstract

Toxocarosis in humans: how much of a problem is it in the UK?

“…38 There were no samples positive for ascarids (the group including Toxocara species) among the 304 uK samples. 38…”

“…In a more recent study of fresh faecal samples collected from 2469 dogs visiting 164 parks in 33 cities across 12 countries, Cardiff, Glasgow, Manchester and Reading were sampled in the UK 38. There were no samples positive for ascarids (the group including Toxocara species) among the 304 UK samples 38.…”

“…There were no samples positive for ascarids (the group including Toxocara species) among the 304 UK samples 38. Of the owners of these dogs in the UK, 64.5% reported that they had treated their dog with anthelminthics within the previous 3 months 38…”

“…38 The proportion of intestinal parasites by owner-reported time of last anthelmintic administration across all countries was 2.2% (95% ci 0.9% to 4.5%) at <1 month, 3.5% (95% ci 2.2% to 5.2%) at 1-3 months, 4.1% (95% ci 2.4% to 6.6%) at 4-6 months, 5.8% (95% ci 3.0% to 9.9%) at 7-12 months and 4.9% (95% ci 2.6% to 8.3%) at >12 months. 38 The risk in dogs under 1 year old (6.2%) was higher than in older dogs (3.1%) or dogs who had been treated within the last 6 months (3.4%), implying that focusing deworming efforts on dogs under 1 year old has a greater potential to reduce soil contamination than increasing the frequency of treating older dogs from 4-6 monthly to 1-3 monthly, or 1-3 monthly to monthly. conversely, reducing the treatment frequency from monthly to 3-monthly would not increase the risk of soil contamination with Toxocara by a large amount (from 2.2% to 3.5%), but would reduce the amount of parasiticides potentially reaching the environment by 67%.…”

“…In a more recent study of fresh faecal samples collected from 2469 dogs visiting 164 parks in 33 cities across 12 countries, Cardiff, Glasgow, Manchester and Reading were sampled in the UK 38. There were no samples positive for ascarids (the group including Toxocara species) among the 304 UK samples 38. Of the owners of these dogs in the UK, 64.5% reported that they had treated their dog with anthelminthics within the previous 3 months 38…”