The Dangers of Horse Worms

Horses are susceptible to various dangerous intestinal worms that can wreak havoc in the animals' innards. Tapeworms, threadworms, strongyles, pinworms, lungworms, cyathastomes and roundworms are parasites that can easily invade the equine system. Symptoms including hair loss, cough, weight loss, diarrhea, stomach inflammation, lethargy, loss of appetite and death may occur as a result of infestation of some of these parasites. Understanding the effects of worms in horses will help owners recognize symptoms and seek prompt treatments.

  1. Malnourishment

    • Malnourishment is sometimes seen in horses with severe, untreated worm infestations. This condition is the result of the parasites competing with the equine host for nourishment. Severe worm infestations fill the stomachs of horses and take the food that is consumed by the host. Signs of malnourishment include lethargy, loss of appetite and weight loss. If severe worm infestations that result in malnourishment are not treated, death may occur.

    Blockage and Blood Clots of the Gastrointestinal Tract

    • The gastrointestinal tracts of horses may become blocked from worm infestations. This potentially fatal problem occurs when worms such as strongyles and cyathastomes continually suck blood from the lining of the intestines. The damage areas often become swollen, resulting in blood clots. These clots may become so large that they block portions of the gastrointestinal tract. A horse with an intestinal blood clot may lose its appetite, develop diarrhea and become very weak. Veterinary intervention is vital, because blood clots that are left untreated may burst, resulting in life-threatening internal bleeding.

    Lung Damage

    • Some equine worms travel through a horse's system and end up in the lungs. Coughing, wheezing and lethargy are symptoms that occur when parasites such as roundworms and lungworms exist in a horse's lungs. Permanent, severe damage of the lungs is often the result of untreated infestations. In addition, horses with worms in their lungs can develop pneumonia, which can be life-threatening.

    Severe Diarrhea

    • All types of worms found in horses can cause severe diarrhea. As the parasites steal nourishment from the host and irritate the lining of the stomach and intestines, diarrhea occurs. This is often an early sign of worm infestation in a horse that enables an owner to discover the problem and seek prompt treatment from a veterinarian. However, severe diarrhea in foals can be deadly, because their developing systems are more prone to dangerous dehydration.

    Skin Irritation and Hair Loss

    • Though less serious than other effects of equine worms, skin irritation and hair loss caused by the parasites can be very uncomfortable for the hosts. Pinworms and tapeworms are common culprits that cause skin irritation and hair loss in horses. Animals with these problems may become restless because of the discomfort these worms cause. In addition, secondary infections from biting and chewing may occur.