31.01.2016

Equine piroplasmosis - increasing number of infected spanish horses in Spain

Piroplasmosis - is it a problem that you have to consider when buying your dream PRE andalusian horse?

As with many things, the answer to this more often asked question these days, is very subjective and it basically just depends on your circumstances, point of view, values, preferences...There are many andalusian horses for sale in Spain these days of various qualities and the process of selecting the one that will fulfill all your expectations while being healthy and trusting is already complicated enough, even without worrying about diseases like piroplasmosis. So here is some information to help you through this when navigating through all those andalusian horses for sale and looking for your spanish soulmate.

Lately, more and more tests are coming back positive in Spain when testing prior to export to the USA, Mexico, South America etc... there might be more reasons for this... more spanish horses might be infected than anybody realized..... piro is spreading much faster than before..... or the last option, the only difference is the new more strict testing method called cELIZA. See, before, a different test was used to test for the parasitic presence in the blood of the horse and this test was only able to detect them in recently infected horses, usually up to 14 days positive. It was not able to uncover horses who were infected for a longer period of time, were chronic carriers etc. A while back, a new testing method, cELIZA, became the required test by countries like USA, Mexico, South America and other export destination countries, which is able to detect these horses. Since then many PRE andalusian breeders had an unpleasant surprise when finding out that the andalusian horse they sold to one of these countries is not sold after all because it cannot travel and enter the country of the buyer. Given Mexico followed by USA and South America are the biggest markets for PRE breeders, this has been a problem of course...

When using the cELIZA method, the percentage of the parasites present in the blood of the horse, determines whether it is considered "positive" or "negative". Anything below 40% is oficially considered negative, anything above 40% positive. You have to be careful though when exporting the horse who is very close to the 40% mark, because it is believed that dehydration and general stress of long transport might increase this number by few percent, which could result in a horse arriving to customs of the export country already positive and testing over 40%, even though he was negative prior to export. Everybody involved wants to avoid this as it is a very difficult situation to face. However, we are talking only few percent so it rarely is an issue. But something to think about it the horse tests 37-39% for example...

So, what exactly is piroplasmosis? There are many articles on this topic on the web and of course I recommend your read them. Simply said, it is a tick borne disease, which is spread by a certain type of ticks - ones that love a more tropical like, warmer weather. With Spain that means, that in general you have more chances of finding negative horses in northern parts of Spain than in the south. Seems like Andalusia has the highest number of positive horses unfortunatelly. Could also be spread from a used needle from horse to horse and it is also spread to the offspring of the infected horse. For example, if you have a positive mare, there is a high probability her offspring will be also positive. Or if you breed to a positive stallion whose semen is also positive, then you might have the same issue. This is of course an additional concern for PRE breeders. It is not known yet whether the positive mare can also have negative offspring - possibly yes if she has been infected a long time ago. See, once infected and after the acute phase (if there was one), the horse becomes a carrier and has these parasites in the blood for a long time. However, the numbers go down and it could result at some point in negative offsprings. This is an area where I could not find many answers to on the web and this information comes from few veterinarians I talked to about this. The incubation period once infected also varies, it could be anywhere between 5 and 30 days before the horse shows symptoms. Some horses have the acute phase of the disease very difficult with life threatening course or even death. On the other hand, it is believed that some horses go through such a mild acute phase that it does not even become noticed, which is why people believe the horse is negative and never got infected. Nobody really knows what makes this difference, except that it is known that a horse who is used to the parasite, meaning he comes from an "infested" environment, can deal with this disease easier compared to a horse who lives in an geographical area free of this. 

There is much more to piroplasmosis, here is a good article that talks about the most common symptoms and is quite nicely written and easy to navigate through: http://www.aaep.org/info/horse-health?publication=758

How much to worry about this then?
This is a difficult question. I know many breeders / most breeders in Spain who do not worry about this at all. They breed and never test and they test only for export. They do care when the sale falls through of course due to a positive test. But mostly not because they are worried about the disease itself. In the past, I did not even know what piro is and so it was not an issue for me. However, in the last years since spending so much time in Spain and knowing more and seeing all these positive tests, some very high numbers in the very top of the percentage bracket, I decided to start worrying. I have seen a horse with an acute phase and given how much I love the horses and how our breeding program is small and quality oriented with individual attention to each horse then, it is not something I ever want to have to deal with. However, some horses do have a very mild phase and live happy and healthy long lives with it without any issues what so ever. So, if you are lucky, it might never be an issue even if your horse is positive. Given I am in Europe where piroplasmosis in not tested at this point in time, the EU does not require it, it would not make a difference for our program in terms of local sales. However, with a tough economy and growing global market and our recent USA sales, I believe it is important to be a piro negative farm for us. So we have decided to test everybody and only offer PRE horses for sale here that are negative using cELIZA testing. It is of course up to you to decide. Unless you are in the USA or one of the other countries who require negative test results, then obviously you need to be aware of it and only purchase and fall in love with piro negative andalusian horse for sale.

One more comment on this: There is an experimental treatment being done now in Spain and I think even USA, which at the end does produce a negative horse in about 3 weeks. I did some digging in Spain and at this moment in time, it is not available and NOT legal to use. The reason being the treatment is difficult for the horse, very difficult, and life threatening. But lets hope that in the future a more viable treatment will become available and get rid of this disease for good.

I hope this was at least a tiny bit of help, feel free of course to contact us if you feel we could help you any further....