Pain control in horses: What do we really know?

Pain behaviours, such as rolling, kicking at the abdomen, flank watching or lameness, may be obvious. Subtle signs of pain can include changes in facial expression or head position and response to palpation or interaction. This review article discusses drug options in clinical situations like:

1. Acute, moderate and perioperative pain 
   For example, horses with a minor foot abscess or uncomplicated corneal ulceration. Nonsteroidal anti-inflammatory drugs (NSAIDs) are in many of these cases sufficient and are probably the most frequently used analgesics worldwide, mostly because many causes of pain are mediated by inflammation.
2. Acute and severe pain
   Horses in severe pain can have either central sensitisation and/or stress-induced hyperalgesia, therefor combining analgesics with different mechanisms can be beneficial. An acute hospital situation usually involves NSAID’s in combination with an infusion of lidocaine, ketamine, butorphanol or a combination of those.
3. Chronic pain
   Chronic orthopaedic disorders, like osteoarthritis, are often seen in clinical practice. In many cases, NSAIDs provide some degree of relief, but long-term management is required. In these cases, drugs with increased cyclo-oxygenase-2 selectivity, such as firocoxib, may decrease the possibly negative side effects of NSAID’s. Therapies like physiotherapy or chiropractic could be useful in such situations.
4. Severe pain
   If repeated injections are required, an epidural catheter can be placed for long-term treatment. Local analgesics produce loss of both sensory and motor function, therefor the given volume must be calculated carefully.

> From: Sanchez et al., Equine Vet J.. 46 (2017) 517 - 523. All rights reserved to EVJ Ltd.. Click here for the online summary.