We are repeatedly asked by interested parties whether the horse offered is also PIRO-FREE, as it is already stated in many horse advertisements for Spanish horses. We would like to give some explanations and details on the subject of piroplasmosis.
Piroplasmosis is an infectious disease that is transmitted by certain ticks. We differentiate between two pathogens, the Theileria Equi on the one hand and Babesia Caballi on the other, both of which are single-celled blood parasites. These pathogens attack the red blood cells and destroy them, similar to malaria. It can only be transmitted via a host (in this case the tick) or from blood to blood (syringe, transfusion). The pathogen does not survive outside of its host, so you can also say: “Without ticks, no piroplasmosis”! Mares can pass the pathogen on to their foals in the last third of their pregnancy.
However, an infection with this pathogen does not have to mean that an outbreak occurs and symptoms of the disease appear. A course can be latent, i.e. the pathogen is present, but does not appear, or it can be acute, i.e. there are symptoms of the disease, which can be stronger or weaker. We’ll get to that later.
There are regions in Spain that are more affected than others. In 2013 there was a study on horses, mules and donkeys in Andalusia and it showed that 56.1% tested positive, of which the proportion of horses was 48.6%. Today it is even assumed that there are regions in Spain in which up to 70% of all horses could test positive, especially in the southern provinces of Spain such as Andalusia (e.g. Cadiz, Granada) Extremadura (e.g. Cacéres) or Segovia . But it has to be said that these horses rarely show symptoms and are so-called carriers. These positive horses have produced antibodies which are detected in the Pirotests. Mares pass the piroplasmosis pathogen on to their foals and the foals also receive their mother’s antibodies. So we have complete herds of antibodies in these particularly affected areas. So you can also use the term “herd immunity”.
We spoke to some veterinarians in the most affected areas about this and asked them how often they need to treat horses with symptoms. Your answer was unanimously “hardly”. It only becomes dangerous if a horse without antibodies is infected with the pathogen, e.g. an imported horse or a horse from a northern region of Spain that has not yet come into contact with this pathogen. In general, however, a veterinarian only fights the symptoms and not the pathogen, so that a protective immunity against the pathogen can be built up and maintained (as long as the horse is in an affected region).
In short, a horse that grew up in these particularly affected regions and that caught the pathogen from its mother, including the antibodies, is indeed a carrier, but there is a high probability that the disease will never break out.
Across Spain, around 24% of all horses are piroplasmosis positive. The most commonly used test is called ELISA and, statistically speaking, the pathogen Theileria Equi is more common than Babesia Caballi.
Of course, people in Spain try to prevent the spread of piroplasmosis and the various authorities and breed associations regularly issue recommendations to avoid and slow down the spread. Since there is no vaccination, all that remains is the regular control of the horses for ticks, the pruning of bushes and trees and the regular application of insect repellent to the horses. This is of course very difficult with large herds of mares. Since there are numerous countries that prohibit the import of positive horses, breeders are excluded from the USA, Mexico, Asia. In addition, it means a restriction for Spanish competition horses at international tournaments in these countries.
So let’s assume that a horse without defenses is bitten by several ticks and that these are not removed directly. The pathogens enter the horse’s body via saliva. In an incubation period of approx. 2 to 3 weeks, the protozoa could now multiply before the parasites multiply in the red blood cells of the horse and destroy them.
Now let’s play through the worst case, i.e. the horse has not grown up in this endangered region, nor does it form enough antibodies, and the disease becomes acute and onset. Symptoms such as increased pulse rate, increased breathing rate, loss of appetite, fever attacks of up to 41 ° Celsius and sweats would occur. You may experience swelling and blood in the urine. Overall, the horse would appear listless and it could also show mild colic symptoms. The liver and spleen can also become enlarged. That would be a really serious acute course that we have never heard of here in Spain and absolutely nothing about it can be found on the Internet. Overall, it was not possible for us to find statistics that report horses with symptoms of illness. Perhaps there are also mild cases where a horse has a bit of a fever, eats less and this is not attributed to piroplasmosis in the first place. So to repeat, we asked about 8 to 10 veterinarians, including a doctor from the university clinic here in Las Palmas who regularly takes part in medical symposia on the mainland and everyone unanimously says that piroplasmosis in Spain hardly ever occurs in the acute course of the disease occurs.
Now you can read that the pathogen sits and rests in the horse for years, or can even hide in the horse for a lifetime. Stressful situations and a decreased immune system of the horse can then cause the disease to break out. Of course, it is obvious that transporting a positive carrier horse from Spain to Germany could be such a stressful situation, after all, in the worst case, they are on the road for 3 to 5 days.
Well, with all of our horses for sale, this has never been the case. In addition, we did extensive research on the Internet to find cases of imported horses from Spain and Portugal who were sick in Germany. Despite extensive research, we could hardly find anything about it. Isolated reports of 2 or 3 cases of sick imported horses, which we consider to be extremely low in percentage terms given the high number of Spanish and Portuguese horses in Germany.
Surely one or the other will now ask, is piroplasmosis not curable? Can’t these pathogens slumbering in the horse be killed? Unfortunately, there is indeed a treatment against it, but it has strong side effects, namely the active ingredient imidocarb dipropionate. With Babesia Caballi one injection is often enough, with Theieria Equi multiple injections are necessary and it can still be that negative tests afterwards can lead to a positive test for years, which means that the pathogens could never be completely killed .
So if we can now give a conclusion: For Europe, we do not consider the requests for tests to be relevant. An insider once said that there are no horses with negative tests that take part in tournaments and that if you test the horses at the Sicab in Spain (the largest horse breeding event), then almost all of them would be positive. However, if you have to consider exporting to the USA, Mexico or Asia, you can of course only buy a horse that currently has a negative test with a percentage below 5%. Anything else could turn out to be difficult when the horse arrives in the export country and is tested again there and shows higher values due to the stress. Forwarding agents e.g. often reject a horse that is worth over 25 and is labeled NEGATIVE for transport.
Finally, we would like to note that a pirplasmosis test should not be older than 3 to 6 months and is generally not part of the standard purchase examination. Neither in Spain nor in Germany. If you wish, we can offer you a current Pirotest as part of a new purchase inspection.
