[The therapy of equine sarcoid with a non-specific immunostimulator–the epidemiology and spontaneous regression of sarcoids].

This research study focused on the testing of the effectiveness of an immunostimulator (Baypamun P) in treating equine sarcoid, a common horse skin tumor. However, the results indicated that the tumor regression observed was likely due to spontaneous regression, rather than the treatment, and factors such as the age of the tumor and the equine leucocyte antigens (ELA) type showed no significant influence on tumor regression.

Research Parameters and Methodology

• The study involved observing 20 horses from a northern Jura practice that were affected by sarcoid tumors. Each horse, on average, had 4.4 tumors, and the average age of the horses was 3.9 years at the time of the first tumor observation.
• The researchers conducted a double-blind study, where half of the horses were treated with an immunostimulator, Baypamum P, while the other half received a placebo. Only one tumor per horse was treated, through injections under and around the sarcoid.

Findings and Conclusions

• Eight horses, out of the total 20, showed a regression of all tumors by either completely or 50% of their original size. Five of these had received a placebo and three received the immunostimulator.
• The remaining 12 horses showed either a small reduction in tumor size, no change, or an increase in the size of the tumor.
• The researchers concluded that the tumor regression observed was likely due to spontaneous regression, rather than the treatment’s action. Spontaneous regression was seen more in horses where sarcoid developed within the last three months compared to those with older tumors.
• Additionally, the researchers observed that the haplotype of the equine leucocyte antigens (ELA) in 12 out of the 20 horses seemed to predispose them to sarcoid. However, they found that the ELA-type did not have a measurable correlation to tumor regression.

Implications of the Study

• This study indicates that the immunostimulator, Baypamun P, may not be effective in treating sarcoid tumors in horses, as no significant difference was observed between its group and the placebo group.
• The findings suggest that spontaneous regression could play a role in the reduction of sarcoid tumor sizes, particularly in tumors that have developed recently.
• The non-effect of ELA-type on tumor regression opens up a new area for research to understand the complex interplay between a host’s genetic factors and the behavior of the sarcoid tumors.