Prevalence of Giardia duodenalis in dogs and cats: Age-related predisposition, symptomatic, and asymptomatic cyst shedding.

BACKGROUND AND AIM: Giardiasis is a protozoal disease that is globally prevalent in dogs and cats. The clinical manifestations vary, but asymptomatic cases have also been reported. This study aimed to estimate the prevalence of Giardia duodenalis in domestic dogs and cats, characterize the age susceptibility to this disease, and determine the frequency of cases in which cysts are combined with stool changes.

MATERIALS AND METHODS: After centrifugation in a zinc sulfate solution (specific gravity = 1.32 g/cm3 ), feces of dogs (2761) and cats (1579) were examined microscopically. The age of the animals and the presence of coprological stool characteristics such as fecal odor, consistency, presence of mucus, and other pathological impurities were taken into account.

RESULTS: G. duodenalis infection rates were 18.2% (215/1182) in dogs aged 1-12 months and 3.8% (60/1579) in dogs older than 12 months. The infection rate was 7.8% (48/615) in cats aged 1-12 months and 3.35% (33/994) in cats aged >12 months. The most frequently observed coprological abnormalities in cyst-positive animals were soft and/or mushy stool and pungent odor. In dogs, the frequency of these symptoms was 24.4% (67/275), 27.6% (76/275), and 36.4% (100/275) for soft stools, mushy stools, and pungent fecal odor, and 37.8% (31/82), 25.6% (21/82), and 19.5% (16/82), respectively. No stool changes were found when G. duodenalis cysts were detected in dogs in 24.7% (68/275) of cases and in cats in 24.4% (20/82).

CONCLUSION: G. duodenalis cysts are reported more frequently in domestic cats and dogs under 12 months of age than in dogs under 12 months of age. The presence of Giardia cysts is usually accompanied by a strong odor of feces and changes in their consistency. It can be concluded that it is necessary to conduct periodic surveillance for apparently healthy dogs and cats to rule out G. duodenalis infection.