Page 126 - January 2021

VETERINARY VIEWS
SMART USE OF NON-STEROIDAL ANTI-INFLAMMATORY DRUGS
by Nancy S. Loving, DVM
Medications that relieve pain are com- monly used for equine athletes to address musculoskeletal issues. Such
anti-inflammatory drugs do just that – reduce inflammation and mitigate pain. The most commonly used medications are called non- steroidal anti-inflammatory drugs, or NSAIDs. These drugs are also the ones used to help reduce discomfort in a horse that is experienc- ing gastrointestinal upset, like colic. But there are some things you might want to know about casual use of NSAIDs, particularly in the face of gastrointestinal upset.
WHAT DO NSAIDS DO?
The usual suspects, phenylbutazone (aka “bute”), flunixin (Banamine), or ketoprofen, are considered COX (cyclo-oxygenase) inhibitors that act as anti-inflammatory agents. These examples are non-specific NSAIDs, so called because there is more than one form of COX – COX-1 and COX-2. These medications block both arms of the COX inflammatory cycle to disrupt the pathways leading to all prostaglandin synthesis in
the body. Prostaglandins normally make nerves, including those innervating the GI tract, sensitive to pain – NSAIDs block prostaglandin production. While NSAID administration works great for controlling pain, inflammation, or fever, it also interferes with normal, daily protective functions of many organs. The result is the potential for significant, unwanted side effects.
“Good” protective prostaglandins in the body are responsible for maintenance of normal blood flow and nutrition to the intestinal
lining and deep portions of the kidneys. Blocking these prostaglandins by non-specific NSAIDs affects blood flow to these areas
with the potential to develop gastric ulcers, colonic ulcers, and necrosis of kidney tubules. Horses are already predisposed to kidney and GI injury during a colic episode; adding an NSAID exacerbates this risk.
THE SAFEST APPROACH TO COLIC
In the face of a colic crisis, first gather information about the three P’s of colic: Pulse, Pain, and Peristalsis (audible intestinal activity) along with mucous membrane color and refill time. Convey this information as you consult with your veterinarian to determine if the horse needs to be examined promptly and what to do in the meantime. Your vet can provide helpful recommendations based on experience and medical training.
Owner-administered NSAID treatment in the face of colic is a concern. Out in the field (or at the barn), NSAIDs tend to mask clinical signs and the severity of a colic that needs more aggressive intervention. An owner or trainer who feels compelled to “do something,” might instead walk the horse for a short bit or place him in a well-bedded stall for monitoring. Vibrations from a trailer ride, especially on gravel roads, may also provide some therapeutic value, particularly for gas colic.
It is important to avoid delay in evaluation and veterinarian treatment of a progressive and serious colic. When an owner or trainer recognizes that a horse is having a problem, rather than just giving a dose of NSAID
and waiting, it is best to contact the vet immediately to relay information about the horse’s vital signs and behavior. This rapid contact to obtain your veterinarian’s recommendations may save a horse’s life.
Short-term colic survival is 80-85%, particularly when horses are treated in the early stages. Even a large colon volvulus (twist) that is admitted quickly to surgery can achieve a similar survival rate. The goal is to reduce the duration of colic – this is best achieved through rapid veterinarian assessment and diagnosis, and rapid medical intervention with diligent monitoring.
THE DOWNSIDES OF NSAID ADMINISTRATION FOR COLIC
As it turns out, on average, the referral time from the onset of a colic crisis to the horse being admitted for aggressive treatment is 12-18 hours. During this delay, a horse becomes progressively sicker – not only does this escalate treatment costs, but it also lessens the chances of successful resolution with or without surgery.
An owner (or trainer) might ask themselves this question: Would you consider taking
the horse to a referral hospital for advanced diagnostics and/or surgery? If yes, then consider the cost and if the horse is insured,
While NSAID administration works great for controlling pain, inflammation,
or fever, it also interferes with normal, daily protective functions of many organs.
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