More Common Horse Ailments
This is an extension of my common horse ailments article, and covers a few additional things that horse owners should think about.
Horses are very prone to intestinal worms. Only a very heavy worm load becomes symptomatic, but it is then very obvious. A 'wormy' horse is overall underweight, but with a swollen belly.
Worms are treated using proprietary medications. One note is that lower doses should be used with a wormy horse, otherwise there is a risk that the large number of worms, when they die, will cause an impaction colic that could be fatal. Lower doses more frequently are the best way to deal with excessive internal parasites.
Horses do not get fleas. They do, however, get lice - and the experience is pretty unpleasant (if you have ever picked up lice yourself, you can imagine it).
Horses get both chewing and sucking lice. Lice are treated by using lice powder, which should also be applied to the animal's tack and grooming equipment. I would also recommend treating your boots. Alternatively, the horse can be bathed in an anti-louse shampoo. Blankets and riding gear that has come in contact with the horse should be run through the tumble drier at the highest heat setting - this will kill both the lice and their eggs.
The horse should be isolated from other horses until the louse infection is cleared up, and you should wash your hands in hot water before handling another horse, or wear disposable gloves. Unlike fleas, lice do not lay their eggs in bedding, but rather on the animal itself, so sterilizing stalls and run-ins is not necessary.
Sweet itch is an allergic reaction to the bites of certain midges, which are active in the late spring through to late summer. It does not exist in all areas. The affected horse is extremely uncomfortable and itchy, particularly at the base of the mane and tail. A second midge species causes irritating on the face, chest and belly.
This causes the animal to scratch excessively, often rubbing the effected areas raw. As the condition progresses, temporary skin damage can occur. Over the winter, the animal will heal completely, only for symptoms to return in spring.
As the midges are only active at dawn and dusk, traditional management is to bring the horse in at those times. The horse should be stabled for one hour each side of sunrise and sunset. Stable doors and windows should be closed or covered with fine mesh screens...the finest you can get.
Placing a light cooler on the horse with a mane and tail cover will also help, by preventing the midges from landing on the horse. As midges breed in standing water, improving drainage and, if possible, moving the animals further from any such water is also helpful. Clean the water trough regularly.
A DEET-based insecticide is effective against midges and can be applied to rugs, around stable doors, etc. There are some proprietary insecticides that can be sprayed directly on the horse.
In extreme cases, a vet may prescribe a course of corticosteroids to allow the skin to recover.
Mud fever is another ailment associated with wet weather and, like rain rot, is more common in winter.
It's often caused by the same bacteria that causes rain rot, but is what happens when that bacteria ends up on the skin around the heel, fetlock and pastern. It is more common on hind legs. It can also be caused by a fungal infection. The skin becomes scabby and may crack.
Mud fever is caused by...mud. Leaving a horse out in a muddy pasture and not checking on it is the most common cause. When the horse is brought in, its legs should be dried thoroughly.
Treatment involves removing the hair carefully from the affected area and using an antiseptic wash. Anti-fungal creams may also be recommended. The skin should be very carefully dried using either tissue or a hair dryer (with a circuit breaker, please). It's generally best to consult a vet to help determine the most likely cause.
Horses can be vulnerable to certain toxins. The most common cause of poisoning is the horse eating the wrong plant. Ragwort, for example, is highly toxic to horses and it is often recommended that it be removed from pasture, although I have seen horses turned out in fields full of ragwort and never get sick. Horses will generally not eat it...unless there is nothing else to eat.
I do recommend removing as much ragwort as possible so it does not crowd out other plants. The best preventative, though, is to manage your pasture properly, do not overgraze and provide supplemental hay if necessary. Some plants that are toxic to horses, or simply unpalatable to them, are enjoyed by goats - in some parts of the world, co-grazing goats with horses is a traditional part of pasture management.
Also poisonous to horses - poison hemlock, field horsetail, buttercups, oleander, bracken, St. John's Wort and nightshade. Pink clover is also poisonous. (Horses should not be turned out in pasture with a lot of any kind of clover as it has a very high fat content that is not very good for horses, especially ponies).
Yew trees are extremely toxic to horses. If there is a yew tree next to your pasture, fence it off. Horses have also been poisoned by accidentally ingesting acorns, so consider fencing off oak trees.
Choke is food stuck in the esophagus. Because horses have no gag reflex and a long neck, choke can be very serious.
The best prevention for choke is regular visits from the equine dentist. Horses with teeth in good order are unlikely to choke. Older horses that may be beyond much help with their teeth should get senior feed and their hay soaked (This will also help them keep weight on). A horse that has been starved may become vulnerable to choke - it may try to bolt its food. Some horses will bolt their food out of personality. The traditional preventive for that is to put a couple of rocks in the feeder - this will slow them down. Feeding hay from a net may also help.
Some horses, perhaps due to a narrower or oddly shaped esophagus, simply seem to be particularly vulnerable. Many vets recommend scoping a horse that has had repeated choke episodes to check for tumors or other problems.
A horse with choke will appear anxious. They may extend their neck out unnaturally, or cough a lot (they're trying to shift it). In some cases, feed material may drain out of the nostrils.
All food and water should be removed and the vet should be called immediately. The horse should be encouraged to lower its head below its shoulders so that any dislodged material will come back out the nose or mouth and not end up in its lungs. When the vet arrives, he will flush the horse's esophagus with water. This is not a fun operation and often ends up with food everywhere.
Rain Rot or Rain Scald
This is a contagious bacterial disease that causes hair loss and scabs to form, generally across the horse's back. It is associated with wet conditions, but can show up in any climate. It is more common in winter.
The disease happens when a break in the skin allows a specific bacteria entry. It is highly contagious and is one good reason to have a set of grooming tools for each horse. Sharing saddle blankets is also a common means of transmission.
Rain rot is easily prevented by keeping horses clean and dry. Horses with vitamin or mineral deficiency are also more prone to it - if a horse keeps getting it, try a ration balancer.
If a horse gets rain rot, then bathe it in medicated shampoo to loosen the scabs, then treat the affected area with an antiseptic ointment. Also treat tack, grooming equipment and saddle blankets with antiseptic spray or similar. Given how contagious rain rot is, some also recommend treating the stall and any trees or posts that horses might use to scratch in the pasture.