Prevalence of intestinal parasites in companion dogs with diarrhea in Beijing, China, and genetic characteristics of Giardia and Cryptosporidium species

Abstract

Companion animals including dogs are one of the important components in One Health. Parasites may cause not only diseases in pet animals but also many zoonotic diseases infecting humans. In this study, we performed a survey of intestinal parasites in fecal specimens (n = 485) collected from outpatient pet dogs with diarrhea in Beijing, China, for the entire year of 2015 by microscopic examination (all parasites) and SSU rRNA-based nested PCR detection (Giardia and Cryptosporidium). We observed a total of 124 (25.6%) parasite-positive specimens that contained one or more parasites, including Giardia duodenalis (12.8%), Cryptosporidium spp. (4.9%), Cystoisospora spp. (4.3%), trichomonads (4.3%), Toxocara canis (3.5%), Trichuris vulpis (0.6%), and Dipylidium caninum (0.2%). Among the 55 dog breeds, infection rates were significantly higher in border collies and bulldogs, but lower in poodles (p < 0.05). Risk factor analysis suggested that age was negatively correlated with the infection rate (p < 0.00001), while vaccination and deworming in the past 12 months could significantly reduce the parasite infections (p < 0.01). Among the 62 Giardia-positive specimens, 21 were successfully assigned into assemblages using glutamate dehydrogenase (gdh) and/or beta-giardin (bg) genes, including assemblage D (n = 15), C (n = 5), and F (n = 1). Among the 24 Cryptosporidium-positive specimens by SSU rRNA PCR, 20 PCR amplicons could be sequenced and identified as Cryptosporidium canis (n = 20). Collectively, this study indicates that parasites are a significant group of pathogens in companion dogs in Beijing, and companion dogs may potentially transmit certain zoonotic parasites to humans, particularly those with weak or weakened immunity.

Occurrence and genotypes of Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. in household, shelter, breeding, and pet market dogs in Guangzhou, southern China

“…were found at considerably low prevalences (3.2%, 3.1%, and 5.4%, respectively) in the surveyed canine populations. This finding is comparable to the prevalences in Poland (2.0% for G. duodenalis) 41 , India (3.0% for G. duodenalis) 42 , the United States (2.0% and 3.8% for Cryptosporidium) 43,44 , China (3.8% and 4.9% for Cryptosporidium) 10,14 , Italy (3.3% for Cryptosporidium) 9 , Australia (2.5% for Blastocystis) 29 , Brazil (2.6% for Blastocystis) 31 , and France (3.4% for Blastocystis) 20 . However, higher prevalences of 21% of Cryptosporidium from Japan, 36.5% of G. duodenalis from Spain, and 37.5% of Blastocystis from Colombia were also previously found in dogs 22,24,33 .…”

“…Assemblages A and B have a wide host range and are responsible for the majority of known human disease cases, whereas assemblages C–H seem to be host-specific for non-human species 1 . Dogs are predominantly infected by assemblages C and D 1 , 12 – 14 . Additionally, at least 17 distinct Blastocystis subtypes were identified.…”

“…, G. duodenalis , and Blastocystis sp. in dogs have been conducted worldwide, and numerous species/assemblages/subtypes have been detected, such as C. canis , C. parvum , C. muris , C. meleagridis , C. hominis , G. duodenalis assemblages A–F, and Blastocystis ST1–ST6 and ST10 10 , 14 (Tables 1 , 2 , 3 ). However, little information on Blastocystis sp.…”

Metronidazole treatment of acute diarrhea in dogs: A randomized double blinded placebo‐controlled clinical trial

“…Lower parasitism prevalence rates have been reported in some studies, but these results reflect convenience samples from both healthy and diarrheic dogs . Regional prevalence studies are not available for the State of Michigan, but a similar prevalence rate has been reported in diarrheic dogs in other regions . Although not an intended study aim, the high rate of gastrointestinal parasitism underscores the importance of fecal flotations in dogs with acute diarrhea.…”

Massive Cryptosporidium infections and chronic diarrhea in HIV-negative patients

“…Protozoa of the genus Cryptosporidium are common parasites of domestic and wild animals—mammals, birds, reptiles, and fishes (Zehedi et al 2015 ; Osman et al 2017 ; Yu et al 2018 ). The invasive forms for all hosts are thick-walled oocysts, strongly resistant for chlorine disinfection, which can be present in water supplies, on fruits, vegetables, or in the soil contaminated with feces (Toledo et al 2017 ; Squire and Ryan 2017 ; Domenech et al 2018 ).…”