The testing of donkeys in a recent study in Israel revealed that most had been previously exposed to two troubling parasites, one of which can infect humans.
Toxoplasma gondii and Neospora species are major pathogenic parasites of animals worldwide, with the first also affecting humans.
These cyst-forming parasites have two-host life cycles, with the cat and the dog being the definitive hosts of T. gondii and N. caninum, respectively.
Both parasites can infect various animal species, as intermediate hosts, in which they form tissue cysts and may cause abortions and neurological disease.
Both parasites have been reported in wild and domestic animals in Israel.
Sharon Tirosh-Levy and her colleagues, in a study reported recently in the open-access journal Animals, set out to evaluate the serologic exposure of donkeys to these parasites.
A total of 98 donkeys were examined. Half of them were from animal shelters in Israel, and the rest were working donkeys from the Palestinian Authority.
Antibodies against T. gondii were found in 94% of the donkeys and antibodies against Neospora species were found in 70% of the animals.
In addition, N. caninum cysts were detected in two of the donkeys.
“This is the first report of the exposure of donkeys to Toxoplasma gondii and Neospora species in the area,” the study team said.
“The exposure of donkeys to both parasites was considerably higher than the exposure of other species in the area and may be the result of poor husbandry conditions and higher exposure to infection.
“The high prevalence found in this study suggests that donkeys may have a role in the maintenance of these parasites in the area, thus serving as a source of infection for the definitive hosts.”
Discussing their findings, the researchers described the seroprevalence of both parasites in donkeys in Israel as high — higher than the recorded prevalence in any other mammals in the area, including horses.
“Half of the donkeys in this survey were sampled in animal shelters that receive neglected donkeys from various locations, while the other half were sampled in Arab villages in the Palestinian Authority, by a veterinarian giving free veterinary care through a humanitarian organization.
The high exposure to both parasites may be the result of the poor sanitation associated with low-income populations, which may increase the chance of exposure to both parasites in water sources or the environment, they said.
The study team comprised Tirosh-Levy, Amir Steinman, Avital Minderigiu, Ori Arieli, Igor Savitski, Ludmila Fleiderovitz, Nir Edery, Gili Schvartz and Monica Leszkowicz Mazuz, variously affiliated with The Hebrew University of Jerusalem and the Kimron Veterinary Institute in Bet Dagan, Israel.
Tirosh-Levy, S.; Steinman, A.; Minderigiu, A.; Arieli, O.; Savitski, I.; Fleiderovitz, L.; Edery, N.; Schvartz, G.; Leszkowicz Mazuz, M. High Exposure to Toxoplasma gondii and Neospora Spp. in Donkeys in Israel: Serological Survey and Case Reports. Animals 2020, 10, 1921. https://doi.org/10.3390/ani10101921