Foaming of the Mouth in Horses

Horses may foam at the mouth for two primary reasons. When the horse is being worked, foaming is normally a good sign as it shows that the horse is relaxed and accepting of the bit. If the horse foams at the mouth after eating or whilst at rest or is producing long strings of saliva as well as foam, then this probably indicates a health issue, whether dental problems or poisoning.

  1. Foaming Whilst Working

    • Horses have a saliva duct behind their jaw and when the jaw is relaxed and supple the horse will salivate a lot. When a horse is being worked correctly, it will have its hind legs positioned well underneath the body and its back up and slightly rounded. The neck will be flexed at the poll (just behind the ears), and the jaw and mouth will be soft and relaxed. This position helps the horse to balance and carry its weight correctly and is sometimes referred to as the horse being "on the bit". As soon as the horse tenses, the saliva duct does not work as freely and the horse's mouth dries out and becomes less relaxed.

    How to Work a Horse Correctly

    • Foaming is a strong visual sign that your horse is working correctly and is comfortable and relaxed. Some manufacturers even make bits with mouths made of "sweet iron," which encourages salivation. To encourage this correct posture, use the "half-halt". Ride your horse into the corner of the arena and ride a small circle, asking it to bend its head slightly to the inside by feeling your inside rein. As you come out of the circle, squeeze both legs firmly about the horse's sides, let your seat-bones sink down into the saddle and squeeze your outside hand slightly upwards. The horse should bring its hind legs underneath it and re-balance itself, bringing its head into the right position.

    Dental Problems

    • If you have a horse that foams at the mouth when it is not wearing a bridle, this could be indicative of a problem, particularly if there are flecks of blood in the foam. Horse's teeth grow continuously throughout their lives and the continual process of grinding down grass can cause sharp edges on the teeth. Dental problems such as mouth ulcers caused by excessively sharp teeth can cause excessive salivation and will need treatment by a veterinarian or equine dental technician. Examine your horse's mouth carefully, running your thumb over the inside of the gums and feeling the shape of the teeth from the outside. If your horse shows signs of pain, consult your veterinarian.

    Poisoning

    • The final reason for a horse to foam at the mouth is if it has eaten something poisonous or foul-tasting. If a horse has eaten an unpleasant but non-toxic substance, it may drool and foam at the mouth for a little while afterward until the taste is gone. Prolonged or repeated foaming, however, could indicate poison. In the case of poison, there may well be other physical signs of distress including excessive sweating, a high temperature, restlessness and coughing. If you see these symptoms, consult your veterinarian immediately and search your horse's pasture for the cause of the problem.