Seroprevalence of Toxoplasma gondii Infection and Associated Risk Factors in Different Populations of Dogs from Aguascalientes, Mexico

Exploring similarities and differences between Toxoplasma gondii and Neospora caninum infections in dogs

Toxoplasma gondii and Neospora caninum infections in dogs are predominantly manifest asymptomatic. However, these infections can also present highly varied and potentially severe clinical signs. This is due to the parasites' ability to replicate in a number of cell types within the host organism, with N. caninum exhibiting a particular tropism for the central and peripheral nervous systems, and T. gondii targeting the central nervous system and musculature. In clinical practice, toxoplasmosis and neosporosis are often considered to be closely related diseases, despite their distinct epidemiological, clinical, diagnostic, and therapeutic characteristics. The present review analyses the similarities and differences between these two protozoan infections, since an accurate and timely aetiological diagnosis is essential for establishing effective therapeutic protocols and control strategies.

Seroprevalence of IgG and IgM Antibodies against Toxoplasma gondii in Dogs in Greece

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is a zoonotic disease that affects various animal species, including dogs, that can serve as sentinels for indirectly estimating the environmental contamination. The current study aimed to determine the seroprevalence of T. gondii IgG and IgM antibodies in dogs across different regions of Greece and assess their living area as a potential risk factor. In total, 1282 blood samples were collected from dogs in urban and rural areas of Greece, including Attica and Thessaloniki. Serum samples were tested for T. gondii-specific IgG and IgM antibodies using an indirect immunofluorescent antibody test. A chi-square test was performed to assess the association between seropositivity for T. gondii and geographical location (urban/rural). The overall T. gondii seroprevalence was 47.6%, while the seroprevalence of IgG and IgM antibodies was 34.3% and 22.2%, respectively. Dogs from rural areas exhibited a significantly higher seroprevalence (53.8%) than those from urban areas (43.9%) (p < 0.001), with the estimated odds ratio being equal to 1.49 (95% CI, 1.18 to 1.65) and the relative risk increased by 22.4%. Dogs in Greece are highly exposed to T. gondii, particularly in rural areas. Measures to prevent canine infections are necessary, and basic hygiene practices, such as hand washing after petting dogs, are required to reduce human infection risk and safeguard public health.

Risk factors for Toxoplasma gondii infection in dogs: a serological survey

BACKGROUND

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).

RESULTS

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.

CONCLUSION

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.