Horse owner warned about new tick-borne disease
By Dr Sadaqat Ali and Dr Muhammad Ijaz
Horse owners in Pakistan are being warned about an occurrence of an animal disease that is carried by ticks.
It is the first time that an occurrence of theileriosis was established in the country with the help of molecular diagnostic tool. It is almost impossible to stop the spread of the disease, which is caused by a single-celled parasite. The ticks carrying the Theileria equi parasite have been founds in the territories of Lahore and Sargodha districts. The parasite enters the bloodstream, attacks the blood cells, and multiplies leading to rupture of the cells. So horse becomes very anaemic.
The disease is expected to exist throughout the country. At present we have a very well defined area. The problem in the future is that every female tick lays a couple of thousand eggs and all those offspring after biting infected animal also carry the disease. As mammals move around they start spreading the disease. Although you can advise horse owners not allow ticks to infest their animals, it’s possible that dogs and other animals will transport these ticks.
The symptoms of theileriosis within horses include weakness, lethargy, anemia, pale gums, red urine and fever. A serious problem is that Theileria can be mistaken for other less dangerous disease. It’s easy to miss it. And because it’s a disease of unknown status to this country, we as a profession aren’t used to look for this disease on a regular basis.
The tick acts as a vector. In the same way that a mosquito transmits malaria by sucking the blood from a person, the tick does the same to an animal. It also sucks blood and in the process of feeding the parasite will transmit from the tick to the horse. It’s not contagious between horses themselves. However, use of contaminated needles, surgical instruments and blood transfusion bags could transfer the infection to naïve horses.
The economic survey of Pakistan estimates that there are 0.4 million horses in the country. The horses, that spend a lot of time outdoors especially during various games, competitions and meetings, are most at risk.
The only solution is to kill the ticks quickly. Some of the tick products available will kill the tick quick enough to prevent the tick spreading the disease to the horse, because the tick needs to be fed before it transmits the disease. But not all tick products do that and you need to seek advice from your vet.
The ticks found in the Pakistan carrying the Theileria equi belong to genus Hyalomma. People who work on ticks and tick-borne disease are concerned about this disease. It could be the tip of the iceberg. If it is prevalent throughout Pakistan then it is a very significant problem, but we don’t have enough information at this stage to make a prediction.
It’s highly unlikely that problem will now disappear, we have the vectors, we have the parasite established in the Pakistan. The population of ticks is getting bigger year on, year on. That’s because there is better over winter survival of the adults – it’s warm and mild through our winters and that means they can breed more quickly in the spring and there are a lot more of them. These vectors are very good at what they do, and they need to find hosts to suck its blood to reproduce, and they do it brilliantly. So if you walk in an area where there are ticks, with a horse, they will get on to your horse.
The first thing that horse owners can do to protect their animals is to be aware of the problem. Your horse could become very seriously ill or die.
The authors are faculty members of The Islamia University of Bahawalpur, and University of Veterinary and Animal Sciences Lahore, respectively. They can be contacted at firstname.lastname@example.org, email@example.com