Rotate or rest? That is a very good question when it comes to the use of deworming products. After speaking with parasitic disease expert and Ontario Veterinary College researcher Dr. Andrew Peregrine, I am not only eager to pick up more poop but I am keen to have it analyzed. When a growing resistance to dewormers is cited as a major issue concerning horse owners today, a fecal exam to see if your parasite control program is working makes logical sense. The results may indicate it’s time to rotate wormers or perhaps your deworming is being applied to a problem that does not exist? Parasite burdens are not the same for every horse.
“Less than three percent of horse owners perform fecal exams and to date this is the only way to find out if your horse is carrying an unhealthy parasite burden,” says Peregrine. He recommends all horse owners get in the habit of performing a fecal at least once a year, ideally in July or August when strongyles are most active. There are other physical signs such as weight loss, diarrhea and unusual levels of colic occurrence but these signs are not exclusive to parasite overload. They are good reasons to call your vet to determine the cause!
Peregrine advises horse owners to discuss the right parasite control program with their vet to be sure they are following an individual program that is right for their horse. Rotation of deworming products (not just switching brands but switching drug classes) should not be the only point of conversation. Environment and stage of life plays a key role in determining what measures can be taken to keep the parasite population in check. And of course, the starting point is a fecal exam to learn if the egg count warrants action. If the fecal egg count is high – another exam a two weeks after deworming will let the horse owner know if what they are doing is working.
Peregrine points out a few factors affecting parasite control planning:
• foals are predisposed to roundworms
• horses spending long periods indoors are more at risk for roundworms and pinworms
• horses on pasture are more at risk to pick up strongyles while grazing.
This risk increases in paddocks that are overstocked with horses. While not every horse owner has the luxury of keeping their horse on 5 - 10 acres of pasture (a minimum of two acres/horse is recommended but more is optimal), management of their environment can vastly decrease the chances of parasitic disease:
1. Picking up manure twice a week (more in wet conditions) can have a massive impact decreasing parasite populations.
2. Rotating pastures can be beneficial during grazing season when implemented for 2 – 3 months at a time.
3. Graze other species on the pasture (ie. Cows for one month).
4. Clean stalls daily.
5. Steam clean stall walls and flooring when occupants change.
Work closely with your veterinarian for the right parasite control program for your horse. For more information please refer to Equine Guelph’s info sheet