ingestion | Horse Racing Free Tips

The Scoop On Eating Dirt

Many horse owners have been told that a horse that eats dirt is missing specific nutrients in his diet—but this line of thinking is outdated. Seeing a horse licking or chewing dirt is concerning as the ingestion of soil can increase the likelihood he will develop sand colic.

A horse fed the proper amount of a commercial feed formulated for his age and lifestyle should lack for nothing with regards to vitamins, minerals and nutrients; so ingesting soil isn't to “make up” for a deficiency in his diet. If a horse was lacking something in his diet severely enough to make him want to eat dirt, he would show other signs of the deficiency, including weight loss or a dull coat.

Horses typically eat dirt because they're bored. In a natural setting, horses graze nearly constantly—and that time spend chewing is good for their mental health. A horse eating dirt might be seeking the feeling the chewing motion brings, so offering him something like hay in of a slow feeder might give him something to pass the time. Increasing his workload (if possible) or giving him a playful pasturemate may also help ease his boredom.

Sand Colic Survey Results Lead To Interesting Conclusion

Horse owners and veterinarians have assumed for many years that horses develop sand colic because they accidentally ingest sand. A new study out of Finland suggests some horses may develop sand colic because they actually seek out and eat the soil.

Drs. Kati E.Niinistö, Meri Määttä, Mirja Ruohoniemi, Maria Paulaniemi and Marja Raekallio conducted an online survey of owners whose horses had been radiographed at some point in their lives to check for sand accumulation in their gut. Survey questions included what signs prompted the call to the veterinarian, how the horse was managed at the time of the vet call and how much sand had accumulated. A total of 447 surveys were used.

The scientists found that the veterinarian was called because the owner suspected sand accumulation and X-rays confirmed the suspicion. Symptoms of sand ingestion seen most often among respondents were colic, diarrhea and poor performance, which his often a subtle sign. “Poor performance” can mean that the horse doesn't want to go forward or may not be moving well.

Horses that exhibited signs of colic often had significant accumulations of sand in their gut. The team also found a correlation between poor performance and large sand accumulation. Horses that were colicky and had poor performance had the highest levels of sand in their gut.

Interestingly, the study team found no connections between sand accumulation, management or housing. This may be because some horses habitually ingest soil. The scientists are collecting samples to determine if any of the horses with sand accumulation are deficient in trace minerals, which would cause them to seek out soil to ingest.

The team also discovered that horses that cleaned up every scrap of hay had larger sand accumulations than horses that didn't eat all their hay. This may be related to keeping horses out for long periods without access to proper grass.

Whether sand ingestion is intentional or a byproduct of greedy horses, prevention of sand accumulation is key. Treating susceptible horses with psyllium a few times a year can clear sand that has already been ingested; feeding in a bucket and offering hay or muzzling horses that forage too much are also options.

Botulism: A Deadly Disease

Botulism in not a disease many horse owners are familiar with—but they should be as the disease is often deadly. Caused by the Clostridium botulinum bacterium, the soil-borne disease is more common in certain areas of the country, like Kentucky. The spores of the bacterium produce a neurotoxin that block the transmission of nerve impulses to muscles. This results in progressive weakness that makes the horse unable to swallow. Up to 50 percent of horses that receive supportive care can die; those that get no assistance are even more likely to perish from the disease.

Horses can get botulism in three ways:

Ingestion of decaying plant material or animal carcasses in hay or on pasture grass
Infection through wounds
Ingestion of spores and vegetative cells that cause Shaker Foal syndrome

There are different types of botulism: Types and B are associated with forage, while Type C is associated with the accidental ingestion of decaying animals.

A vaccination for botulism type B is available, but it is not considered a core vaccination as it is found mainly in Kentucky and the mid-Atlantic states. A horse's risk of getting the disease should be discussed with its treating veterinarian to determine if vaccination is necessary.

Foals are at particular risk of developing botulism, so pregnant mares should be vaccinated against the disease before they foal. Foals born in areas of the country where botulism abounds should receive Botulism type B toxoid at 2, 4 and 8 weeks old even if the mare was vaccinated.

There are no licensed vaccines for botulism A or C.

Read the AAEP botulism vaccination recommendations here.

Anthrax And Equines: A Deadly Combination

Though anthrax may be more familiar to people for its use as a biological weapon, the bacteria should also be a concern to equine owners for the potential harm, including death, it can cause to their animals.

Bacillus anthracis, the bacteria that causes anthrax, can lie dormant in soil for years; it is particularly hardy in alkaline soil. If anthrax spores are inhaled or ingested, or if they encounter a wound, horses can develop and anthrax infection. Ingestion is the most common way for horses to get an anthrax infection. Ingestion often occurs after a heavy rain, when anthrax spores are pushed to the surface of grass; it can also occur during drought conditions when grasses are eaten down to the soil.

Once anthrax enters the body, it becomes active and multiplies rapidly, causing toxins that spread throughout the body. The septicemia anthrax causes progresses rapidly; killing many affected animals within two to four days.

Horses with anthrax will have trouble breathing; they will also have a high fever, and swelling on the neck and chest. Affected horses may colic, have bloody diarrhea or have seizures. The disease can be spread to humans, so an anthrax infection must be reported to the state's veterinarian.

Anthrax is not endemic to all parts of the United States, so the vaccine is recommended only for horses that live in areas that are known to have anthrax spores. It is a live vaccine, so reactions to the injection site may occur. Antimicrobials may interfere with the vaccine response, so they should not be administered at the same time.

Read the AAEP's anthrax guidelines here.