Winter Health Care for Horses
Colic season is upon us. As is usual this time of year, I am starting to see a lot more colics. Fortunately, most of these cases have been mild and the horses have recovered quickly, but it seems a good time to address this most common and disturbing malady.
While some severe colics involving twisted or displaced intestines require immediate surgery to save the horse, most equine colics are due to gas and intestinal spasms, akin to humans with “upset stomach,” and resolve with time and/or simple medical care. People often ask the cause of these colics and the simple answer is usually change…in just about anything. Horses are fairly sensitive creatures of habit, not fond of changes in, among other things, feed (type or amount), temperature, workload, turnout schedule, new pasturemates, new pastures, just about anything.
The winter season, however, brings a lot of changes: Horses need to be fed more to make up for the cold and the lack of grass; their exercise schedule changes or becomes more erratic depending on the weather; and the composition of hay varies greatly from load to load. Many horses lower their water consumption as water gets colder and this, combined with less activity and sometimes poorer quality hay, leads to an increase in impaction colics. The pain that comes with intestinal impactions is usually due to gas buildup behind the impacted site. By the time the horse shows signs of pain, however, the impaction can be large and sometimes difficult to clear. Horse owners should watch their horses’ manure consistency and output closely. At the first sign that the horse is passing less manure, or if the balls appear small and dry, you should reduce the amount of hay you are feeding so as not to worsen a developing impaction. I would recommend withholding all but a few handfuls of feed for 8 hours and consider calling a vet if the horse shows signs of discomfort or does not begin passing normal manure by this time.
As a general rule, horses need to be fed increasing amounts of feed once the temperature drops to 60 degrees F for wet or clipped horses, to 50 degrees F for horses with a moderate haircoat, and 30 degrees F for horses with a long hair coat (all temperatures based on “critical” temperature, which takes windchill into account). Horses need to be fed about 2 additional pounds of hay for every 10-degree drop in temperature. Everyone knows horses lose weight in the winter and this is partially because of the lack of grass. I see this weight loss, however, in many horses who never had much grass in the first place. It takes energy to keep a horse warm and they will lose weight if they don't have a little extra.
Clipping and Blanketing
Clipped horses are going to have higher “critical temperatures” and feeding requirements in general, as they have lost one of their natural means of fighting off wind and cold. Blanketing offsets this somewhat, but note that a horse sweating in a winter blanket is more prone to colic than an unblanketed horse (imagine eating a large meal and then sweating in a sauna). It is easy (as I have often done myself) to blanket a horse for a cold night, leave for work the next morning and then realize late in the day that it is 60 degrees and the horse is standing sweating in the sun. Nonetheless I think blankets are a good thing for horses standing around in wind and rain, and they are especially useful for older, arthritic, and/or skinny horses who have lost a lot of the fat that helps keep them warm. You will find that geriatric horses maintain their weight and generally fare better over winter when blanketed.
As horses tolerate increases in forage better than increases in grain, additional caloric needs should be met by increasing the amount of hay fed (in older horses with a limited ability to chew and digest hay, you may need to use a complete feed or processed hay product such as Hay Stretcher). Increases in hay should be done gradually over several weeks and new loads of hay should be gradually introduced by mixing it with the old hay. The horse should be observed for any change in the character of his manure as this is often the first sign that a horse is not tolerating a feed change well and that a more serious problem (e.g. colic, laminitis) may be on the horizon. Should the horse develop soft “cowflop” manure or diarrhea, he should be backed off the new feed until his manure returns to normal.
A horse should drink 8 to 12 gallons of water a day. Many horses decrease their water consumption once the water temperature drops below 45 degrees. This should be monitored closely as decreased water consumption is the leading cause of potentially serious intestinal impactions. Horses should always have free access to a salt block, which will help maintain their desire to drink. Providing water warmed about 45 degrees has been shown to improve drinking in the colder months.
Treating Colic with Banamine
No discussion of colic would be complete without mentioning Banamine, one of the first drugs owners and veterinarians reach for when faced with a colicky horse. Banamine is an NSAID (non-steroidal anti-inflammatory drug) similar in mechanism to Tylenol, ibuprofen, and other COX inhibitors used in humans. Everyone has stories of horses that were cured of colic right after Banamine was given -- often faster, in fact, than the drug could have been absorbed into the horse’s system. As mentioned above, most cases of equine colic resolve on their own, and in many, if not most situations, the Banamine had only a minor role in this. While the drug has its place, it is important to note that the injudicious use of Banamine can cause problems far more serious than the one it was originally meant to treat.
While the efficacy of Banamine in treating minor colics is debated among veterinarians, Banamine does have the ability to mask low-grade pain associated with more serious conditions such as early impactions, pneumonia, peritonitis, etc. While Banamine cannot “cure” any of these conditions, it can alleviate signs such that the problem worsens and goes unnoticed. Personally, I think if a colic is going to resolve untreated, it will do so with or without Banamine. I tell owners to give no more than a half-dose (5mL liquid given orally or 500lb paste for a 1200lb horse) of Banamine and that a horse should never be given a second dose without having been seen by a veterinarian and a diagnosis having been made.
Dr. Scott Lewis, DVM