Thursday, March 18, 2010

Int/Adv Preventative Care

Preventative care includes the things we do to avoid the horse getting sick in the first place. There are four important preventative care considerations: parasite control, vaccinations, teeth, and introducing new horses.

Parasite Control:

All horses have parasites. Let me repeat that: All horses have parasites. Since most cause problems and we do everything we can to eradicate them. There are a few things you can do to help control parasites:

  • De-worm your horse (more on this next paragraph :)
  • Avoid overgrazing pasture
  • Avoid keeping too many horses in one pasture
  • Rotate pastures (horse parasites won't live in cattle and vise versa)
  • Keep hay and grain away from manure

So deworming -- horses should be dewormed every 8-12 weeks (most people seem to do once/season). Different dewormers kill off different parasites in different phases of their life-cycles. It is important to rotate dewormers so as to eliminate a wide variety and to help prevent any of the worms developing an immunity to the dewormer. Some of the common worms include:
  • Large Strongyles: these can cause serious damage. A blocked mesenteric artery (which supplies the intestine) can lead to severe colic, or a blocked iliac artery (which supplies the hind legs) can cause lameness or paralysis.
  • Small Strongyles: also cause serious damage. Signs include weight loss, loss of appetite, diarrhea, and colic.
  • Ascarids: most common in foals. These are disgustingly large worms. Signs include: poor coat, coughing, diarrhea, lack of appetite, pot belly, apathetic behaviour, and stunted growth.
  • Bots: these are less harmful and among the easier to avoid. They lay their eggs on the horse's legs, chest, etc where they get licked off and swallowed. They look like little yellow dots, and if you make a point of removing them when they appear you'll help cut down significantly on the bot population. They can cause sores in the mouth, and sometimes stomach ulcers.
  • Pinworms: not overly harmful in itself, but a sign that your strongyles dewormer probably isn't working overly well since they're killed off by the same thing. Pinworms lead to the horse rubbing its tail and sometimes you can see gray or yellow eggs around the anus. Pinworms are very rare in horses that live outdoors 24/7.

You'll notice the signs for most of these are similar. In general, any combination of inexplicable weight loss, poor coat condition, rubbing the tail, lethargy, and constipation or diarrhea should have you de-worming your horse or at very least having a fecal test done. Colic is also a sign of parasites gone horribly wrong (really you should catch it before then), but since it can be caused by so many other things may not be a sign in itself.

In areas with winter, the only things you'll really be able to kill after the frost are small strongyles -- so a Moxidectin based dewormer is best used in the winter months. This should be followed with an Invermectin based wormer in the spring to kill off any adult strongyles that survived the winter. Through spring/summer/fall you can alternate between Ivermectin-based and Pyrantel-based. There are multiple brands and types of each of these. Twice a year a Praziquiantel (which is a relatively new super-wormer) is a good idea.

So just for the curious, here's a sched for one horse as an example for the year. This is a 5yo TB mare in good health who lives in Ontario and will be competing from May though Sept. Keep in mind this is just a sample -- your plan should be created in consultation with your vet.


Like people, horses can be vaccinated against common diseases. Most vaccinations need to be boosted -- some annually, some more often. What you vaccinate against will depend, among other things, where you live and how much contact your horse has with outside horses. If you have a private farm with two back-yard ponies who never go anywhere, they're far less likely to catch something than a competitive horse at a large boarding barn where they get shipped to multiple shows, all obviously with other horses, AND all the ones they live with at home are doing the same thing. Anybody could bring something home and spread it.

Some of the common ones include:
  • Tetanus -- aka Lockjaw. Just as with people, this disease affects the nervous system. Usually caused by a dirty would, signs include stiffness of the head, neck and hind end, muscle spasms of the jaw, and the appearance of a third eyelid. There is an 80% mortality rate. Annual boosters are required. If you are working on a farm you would be smart to make sure YOUR tetanus vaccination is also up-to-date (although requires far less often booster).
  • Rabies -- affects attitude and behaviour. Rabid horses will become violent -- biting, striking and rolling. It is almost always caused by a bite from an infected animal. This is also one of the few diseases that is transmissible to humans. Usually fatal.
  • Encecphalitis (Eastern: EEE, Western: WEE, Venezuelan: VEE) -- a viral disease often transmitted by mosquitoes. 50-90% mortality rate. Booster shots annually if you have winter, every 6 mths if not.
  • Influenza -- same concept as with people. Highly contagious but rarely fatal viral disease characterized by a high fever, cough, nasal discharge, depression and loss of appetite. Bi-annual vaccine, usually given spring and fall.
    Rhinopneumonia -- a highly contagious viral infection with signs much like flu. This is most common in young horses.
  • Potomac Horse Fever -- believed to be carried by ticks (uncommon in this area). Signs include depression, loss of appetite, profuse watery diarrhea, distended abdomen, severe colic and sometimes laminitis. May be fatal. Annual vaccination.
  • Strangles -- highly infections viral infection which affects the lymph nodes in the upper respiratory and cheek mucous membranes. This has been going around Ontario for the last few years, so be very aware if you're in this area and showing at all, you might want to consider this vaccination seriously. Signs are inflammation of the throat and cheeks, a fever of 39.5-41C (103-106F), reluctance to eat, and a moist cough. Annual Vaccination.
  • West Nile -- a mosquito-spread neurological infection. Symptoms include listlessness, muscle twitching, weakness or paralysis in limbs, sometimes a fever. Can be fatal or have permanent complications. Annual booster.
  • Equine Infections Anemia (EIA) -- aka Swamp Fever. Very serious, and any horse who survives it could become a carrier (who looks and acts normal while infecting the rest of the barn). Highly contagious, signs include a really high fever (40.5-41.2C, 105-106F0, rapid weight loss, anemia and hemorrhages of the mucous membranes. There is no cure, and most provinces require any horse that tests positive for EIA to be humanely destroyed. Most farms require proof that a horse is EIA negative before allowing any horse on the property. This proof is in the form of a Coggins test -- a simple blood test done by your vet. An annual coggins test is required for horses showing on most recognized circuits. There is no vaccination or cure for this disease.

As always, check with your vet about what they would recommend in your area.


Horses teeth continually grow. A horse's upper-jaw is wider than his lower-jaw. When they graze, the jaw moves in a side-to-side motion, and the molars wear out unevenly causing sharp points ("hooks") to appear on them. These can hurt. So every six months they should be checked and the sharp points need to be "floated" or filed. This is not a painful procedure but it is awkward and some horses really don't like the noise.

If a horse's mouth seems sore (particularly evident when the previously accepting horse starts flipping their head with any bit contact), or if they start quidding (which is when food dribbles out the side of their mouth as they're eating) they should absolutely be checked.

More on teeth another Thursday :)

New Horses:

When a new horse comes to a facility, proof of negative coggins should always be required. They should also be quarantined until their health is assured and introduced to the other horses slowly. Similarly, when bringing your horse away (ie to a show) it is important to keep them from the other horses. No rubbing noses, no sharing water buckets, food, or brushes. Little things that will keep your horse much healthier in the long run!

No comments:

Post a Comment