Page 128 - January 2021

VETERINARY VIEWS
When pain-relieving medication is ineffective and/or pain returns, this puts the horse into a risk category for more extensive treatment or surgery.
ALTERNATIVES TO NSAIDS FOR COLIC
Besides NSAIDs, there are a variety of pain-managing medications, such as a short-acting analgesic like xylazine or butorphanol – these achieve pain relief
for about 40 minutes. If the horse is fine after such medication wears off, then flunixin (at half or one-quarter dose) could then be given. However, if pain persists, the horse’s situation needs further veterinary investigation.
Short-acting analgesic agents have few adverse effects while effectively blocking pain. For simple gas colic, interrupting pain often allows sufficient intestinal muscle relaxation to allow gas to move through the bowel and evacuate. These analgesic agents also reduce intestinal motility for a short time and that helps mitigate painful GI spasms.
Use of longer-acting analgesics such as detomidine (Dormosedan) is recommended in cases where pain is uncontrollable,
and the horse is at risk of injuring itself. Detomidine is also useful for transport to a surgical facility in cases of very severe colic. An oral formulation of Dormosedan gel can be safely applied to the horse’s gums
for rapid absorption.
A common indication for the need for surgery is when repeated drug administration is required to control pain. Repeated dosing is not recommended and can result in dehydration from diuretic effects.
Check with your equine insurance agent as in some cases, insurance coverage is denied if there is an adverse event subsequent to owner administration of an injectable sedative or analgesic.
NSAIDS FOR MUSCULOSKELETAL CONCERNS
Horses with lameness problems are often managed for weeks or even months with anti-inflammatory doses of NSAIDs. But this is not without its pitfalls. Right dorsal colitis (RDC) is a serious condition that may result from chronic administration of NSAIDs. Ulcers in the right dorsal colon lead to protein loss, colic, and permanent colon strictures. How long it takes to develop RDC is highly variable between
horses – for sensitive individuals, it may develop within a few weeks after the onset of NSAID treatment. Higher doses may contribute to greater colon injury. That said, many horses have been known to survive for years on low-dose NSAID treatment with no apparent problems.
Gastric ulcers are also known to develop from chronic NSAID use, especially when coupled with stress and high performance. Stomach erosions can occur quickly, within days. While ulcers in the glandular stomach area don’t usually affect performance, gastric ulcers can elicit episodes of colic
– treating such a horse with NSAIDs is counterproductive and ill-advised.
In studies comparing phenylbutazone and flunixin for musculoskeletal pain, the two drugs appear comparable when administered at label dosages. Giving more phenylbutazone or giving both phenylbutazone and flunixin together for musculoskeletal pain provides no added analgesic benefit and is likely harmful to the kidneys and GI tract.
The advent of COX-2 specific NSAIDs, such as firocoxib (Equioxx®), has increased safety margins for long-term administration of NSAIDs. Still, adverse effects can develop over time or for sensitive individuals.
Caution should always be exercised by an owner who is inclined to treat a lameness concern with an NSAIDs
without a veterinary exam. Excessive use
of NSAIDs can mask pain from injuries and potentially result in fatal consequences, especially in racehorses. For example, a non-displaced limb fracture or stress fracture may progress to a life-threatening, complete fracture if NSAID-blockage
of pain allows a horse to overuse the injured limb.
Another common yet highly inappropriate practice is for a horse owner to hand off their NSAID medication to another with sugges- tions on how to use it despite lacking a veteri- nary diagnosis or counsel. It is reported that 82% of horse owners use NSAIDs without advice from their veterinarian.
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Caution should always be exercised by an owner who is inclined to treat a lameness concern with an NSAID without a veterinary exam.