An important part of ensuring your horse’s good health is to have a strong pest control program in place. In addition to flies and other insects, those who keep horses need to concentrate on a management plan for keeping mice, rats and other vermin at bay.
It’s almost a given fact that barns with farm animals and feed attract mice and rats, and some feel that it’s a losing battle, or not even worthwhile, to try to eradicate them. However, when you consider the damage that these small creatures can cause, not to mention the threat of disease that they can carry, rodent control should be at the top of every horse keeper’s list.
In researching information on the importance of rodent control, a fact sheet published by the Ontario Ministry of Agriculture and Food and written by Gerrit Rietveld – Animal Care Specialist, and Dr. Robert Wright – Veterinary Scientist, Equine and Alternative Livestock, stated that a mature rat can eat up to one ounce of feed (which translates to almost 10 percent of its body weight) in a single day. That may not sound like much, but if you multiply that figure, a colony of 100 rats can eat more than one TON of feed in a year — which is more than the amount of grain that is required to feed an average 1,000-pound horse over that same period of time! That figure reflects only what a rat can eat, and does not also include the feed that is spoiled by the rodent’s droppings, urine and hair — which can be up to 10 times the amount of feed that they’ve eaten if they are not kept out of the feed storage area. In fact, the United States Department of Agriculture estimates that rodents destroy approximately two billion dollars’ worth of feed each year. And this feed is not only wasted, but can sicken your horse if rodent droppings, urine and the like have contaminated it. Rats and mice can transmit diseases such as salmonellosis, leptospirosis, trichinosis and rabies. They can also carry and pass along from their fur and feet other disease-harboring organisms such as mites, ticks, lice, fleas and internal parasites. To make matters worse, they can ruin your saddle pads, horse blankets and even leather tack by gnawing; as well as causing damage to your barn and buildings and becoming a fire hazard by chewing through wiring.
What makes rodents so difficult to eradicate once they have taken up residence in your barn is the fact that they reproduce so rapidly — the pregnancy cycle of a rodent is just nine to 21 days. A female mouse can produce from five to 10 litters per year, each of which contains five to six young. And these young mature in six to 10 weeks, and may begin reproducing just three months after their birth.
A rule of thumb is that there are approximately 25 mice or rats present for every one that you see. If you notice shredded material, areas of wood or other items that have been chewed or gnawed, or droppings, you must take action immediately.
As with fly and insect control, the most important part of a good management program is to be pro-active, before the pests become a major problem, and utilize good sanitation procedures.
Starting with sanitation — rats, mice and other vermin are attracted by food. If you remove the source of their attraction, you’ll be much ahead of the game. Keep all feed in metal cans or feed bins with securely fitting lids (as plastic barrels and wooden boxes can be chewed through.) Keep all feed, supplements and other edibles in a closed room. Be careful when measuring out feed, and clean up any that is spilled, disposing of it in a metal container with lid. If possible, keep straw and hay away from your horse barn, as these will often have seed heads and grains that will attract rodents.
Next, you’ll need to block access in even the smallest of places — a rat needs a hole of just 1/2 inch in diameter, and a mouse just 1/4 in diameter to ‘squeak’ through. Replace wood that is gnawed or contains holes, and utilize wire hardware cloth finer than 1/4 inch diameter in narrow spaces. Use calking to seal cracks and take up spaces around pipes and gaps. You can use steel wool as a temporary ‘plug’. Your doors and windows should close properly; consider using metal frames that cannot be gnawed. In addition to feed being an attraction to rodents, keep them away from possible nesting materials (such as rags, blankets etc.) and nest sites. Keep your tack in a closed rodent-proof bin or room. And remember to keep the areas along the base of your barn trimmed and free of grasses, which can become convenient hiding places and nesting areas.
You’ll need to work on eradication of rodents that are already present — many barns rely on cats to keep rodents at bay, as well as terriers and other rodent-killing dogs. In addition, you can use traps very effectively, and can easily remove and dispose of the carcasses of the trapped animals. In addition to the old-fashioned snap traps, there are live traps which use already trapped mice to attract others. These can hold a number of mice, and can be set about 10 feet apart along the base of walls where there is an active population of rodents.
There are a number of baits and poisons on the market, but care should be taken that these are not accessible to pets or small children and handled or accidentally ingested.
Before closing, it should be mentioned that in addition to rodents, it is important to keep opossums away from your barn and premises — as these creatures carry the protozoa S. neurona, which causes the deadly EPM, or Equine Protozoal Myeloencephalitis. The EPM protozoa are spread through the feces of opossums. It takes approximately two to four weeks for the immature stage of the protozoa consumed by the opossum to be shed out in its feces. Horses can ingest the protozoa from contaminated feed, hay, water or pasture. Often, an opossum can come along and eat from a horse’s feed bucket that has been left on the ground; buckets should be removed or at least turned over after the horse has finished eating his food. If you feed barn cats or other pets in or near your barn, pick up uneaten food and store in a container with tight fitting lid. As with rodents, the key is prevention.
Eradicating any nuisance animals, along with using good sanitary procedures and blocking access to pests will go a long way in keeping your horse in good health and condition.