The morphology and pathology of Besnoitia sp. in reindeer (Rangifer tarandus tarandus).

This research examines the morphological traits and disease characteristics of the parasite Besnoitia sp. in reindeer, specifically detailing distribution of the cysts and how these resemble or differ from those in other animals like cattle, rodents, and horses.

Research context and purpose

• This research was initiated due to findings at the Assiniboine Park Zoo in Winnipeg, Manitoba, Canada, where the reindeer herd was found infected with a specific parasite known as Besnoitia sp. A minor dermatitis was noted on the articulating surfaces of carpal and tarsal joints of the reindeer in this herd, which aroused curiosity for further study.
• The primary goal was to investigate the characteristics and behavior of this parasite specifically in reindeer and compare it with its behavior in other animals.

Research findings

• The researchers found that cysts of the parasite were present in a variety of reindeer body parts, such as in the dermis, nasal turbinates’ submucosa, periosteum, tendons, testes, and hooves. These cysts sometimes provoked inflammatory reactions in the reindeer, while at other times, there was an absence of any noticeable host response.
• From the examination using a light microscope and histochemical analysis, it was established that the reindeer’s Besnoitia sp. featured the same characteristics as those of other Besnoitia spp. found in cattle, rodents, and horses.
• However, there were unique traits with the reindeer’s Besnoitia sp. The cysts and parasites, in this case, did not show any bradyzoite membrane micropores and cytoplasmic enigmatic bodies, which are usually observed in other hosts.

Diet experiment and results

• As part of the study, the researchers also conducted a dietary experiment. They fed two cats with the cysts of Besnoitia sp.
• Despite these cats being fed the infected cysts, no oocysts – the hardy, environmental stage in the life cycle of such parasites – were detected in their feces even after a monitoring period of 90 days post-consumption.