Department of Veterinary Medical Sciences, Alma Mater Studiorum - University of Bologna, Bologna, Italy.
Acta Vet Scand. 2024 Mar 25;66(1):14. doi: 10.1186/s13028-024-00734-0.
Dogs, as well as a wide variety of other warm-blooded animals, act as intermediate host of Toxoplasma gondii. In dogs, most cases of toxoplasmosis are subclinical, although clinical disease has been sporadically reported. Beyond its role in diagnostic pathways, seropositivity also functions as a reflection of the parasite's spread within the dog's living environment. The aim of the present study was to evaluate the possible risk factor associated with seropositivity to T. gondii in dogs in Central-Northern Italy, analysing 120 dogs sera for the presence of IgG antibodies by indirect fluorescence antibody test (IFAT).
The population examined was composed of 54.2% hunting dogs, 24.2% companion dogs, 14.2% truffle dogs and 7.5% watchdogs. Thirty-four (29.2%) dogs tested positive for T. gondii IgG, with titres ranging from 1:40 to 1:1280. Seroprevalence and antibodies titres were not related to dog gender, age or function. The logistic regression and ordered logistic regression results indicated that seroprevalence, and antibody titres were significantly higher in dogs cohabiting with cats, exhibiting coprophagy habits, and living constantly outdoors. Notably, the lifestyle factor showed the highest odds-ratios in the study: dogs living constantly outdoors were found to be at approximately 5 times greater risk of testing positive and having higher antibody titres compared to dogs living both indoors and outdoors.
Both logistic and ordered logistic regression results support the key role of living with cats, engaging in coprophagy behaviours, and maintaining an outdoor lifestyle in increasing the risk of T. gondii infection in dogs. These identified risk factors collectively suggest that both ingesting oocysts, as observed through cat cohabitation and coprophagy, and engaging in predatory behaviours, as possible for outdoor living dogs, are indicating likely sources of T. gondii infection in this host species.
狗以及其他各种温血动物是弓形虫的中间宿主。在狗中，大多数弓形虫病病例为亚临床感染，尽管偶尔也有临床病例报告。除了在诊断途径中的作用外，血清阳性率还反映了寄生虫在狗的生活环境中的传播。本研究旨在评估意大利中北部地区狗血清中弓形虫 IgG 抗体阳性与可能的风险因素之间的关系，通过间接荧光抗体试验（IFAT）检测 120 份犬血清中 IgG 抗体的存在。
所检查的人群由 54.2%的猎犬、24.2%的伴侣犬、14.2%的松露犬和 7.5%的看门犬组成。34 只（29.2%）狗的 T. gondii IgG 检测呈阳性，滴度范围为 1:40 至 1:1280。血清阳性率和抗体滴度与狗的性别、年龄或功能无关。逻辑回归和有序逻辑回归结果表明，与猫同居、有食粪癖和经常生活在户外的狗的血清阳性率和抗体滴度显著更高。值得注意的是，生活方式因素在本研究中显示出最高的优势比：与室内外都生活的狗相比，经常生活在户外的狗检测呈阳性和抗体滴度更高的风险约为 5 倍。
逻辑回归和有序逻辑回归结果均支持与猫同居、有食粪癖行为和户外生活方式在增加狗感染弓形虫风险方面的关键作用。这些确定的风险因素共同表明，通过与猫同居和食粪行为，摄入卵囊，以及通过户外生活的狗可能的捕食行为，是这种宿主物种感染弓形虫的可能来源。
