EPM and breeding

[Derby Lyn Farms]

Does EPM cause any side effects on the fertility of a stallion?

[Stacie]

Given that EPM is often due to a dysfunctional immune system, I would think carefully about using a stallion who had EPM.

[Derby Lyn Farms]

What is your reason for advising to stay away from a stallion with epm? Is it because the stallion may carry other diseases/virus' due to the dysfunctional immune system? I am mostly interested in the fertility rate. I will not be using a stallion with epm, I have other reasons for asking. thanks

[Stacie]

Only 1% of horses that are exposed to the protozoa get EPM. Research suggests that the reason these horses are not able to control the parasite is that their immune system is dysfunctional. Immune systems can be dysfunctional for genetic reasons, environmental reasons or both.

I wouldn't chance passing on bad genes that produce horses with dysfunctional immune systems.

[Derby Lyn Farms]

Thanks for the info Stacie. If anyone has any information on how it effects the fertility rate i would appreciate hearing about that. I had a mare with epm that would not get pregnant. I was wondering if it has any of the same effects on a stallion.

[Tiki]

Given that EPM is often due to a dysfunctional immune system, HUH???? If that were true, then I have a mare that should be staggering all over the yard because of a dysfunctional immune system. She is coming 25 and has never been lame in her life, but she has some kind of infection on her hind legs that no vet has ever been able to diagnose and she has had 2 foals, both born with FTP who required transfusions. Neither of them have problems and the mare is never sick. She does heal very slowly when she gets a cut and cuts require very special care. She has raced and has a good record and YES, I have seen possum in the yard and in her run-in shed. I just find this very hard to believe. I have heard of perfectly sound horses with no immune system problems getting the disease and here's one with an obviously compromised system that hasn't gotten EPM.
Actually, there is a similar disease in humans, with very few, comparatively, cases world wide. Generally you get that from swimming and/or diving in swimming holes and immunity, or lack thereof, in humans is not a factor in that disease.

[Tiki]

I had a mare with epm that would not get pregnant. I have a friend who has a mare with very, very bad EPM who has had several foals during this time. I would look for other causes. EPM is a disease of the nervous system, not the reproductive system. Your mare may have a low-grade infection that is difficult to detect except when she is in heat or she may have cysts or a fibrosed uterus. Have you had a biopsy and a culture done? especially during a heat cycle?

[YankeeLawyer]

Actually, there is some research suggesting that deficiencies in the immune system may explain why only a fraction of horses exposed to the protozoa contract EPM. Here is a link to an article discussing such research results in mice:

The article goes on to state that in horses, "there is strong evidence that stress and possibly immune suppression play a role in the development of clinical disease."

Regarding the impact of EPM on a mare's fertility, I am not familiar with EPM specifically in that regard but I have seen a number of instances where mares that had some illness were unable to conceive until that illness was treated - for example, Lyme disease.

[YankeeLawyer]

Actually, there is some research suggesting that deficiencies in the immune system may explain why only a fraction of horses exposed to the protozoa contract EPM. Here is a link to an article discussing such research results in mice:

http://www.thehorse.com/ViewArticle.aspx?ID=8413

The article goes on to state that in horses, "there is strong evidence that stress and possibly immune suppression play a role in the development of clinical disease."

Regarding the impact of EPM on a mare's fertility, I am not familiar with EPM specifically in that regard but I have seen a number of instances where mares that had some illness were unable to conceive until that illness was treated - for example, Lyme disease.

[Derby Lyn Farms]

The mare that wouldn't get pregnant was years and years ago, so I have no idea if the mare had an infection or not. I am mostly interested in any side effects in stallions, not mares. I was just using that as an example, and I couldn't say if it was due to epm or not.