Once the big hurdle of colic surgery is over, practitioners seek to make the horse as comfortable as possible, and to also minimize inflammation, restore intestinal function and motility, control fever, and improve appetite and recovery. Non-steroidal anti-inflammatory drugs (NSAIDs) are helpful to these objectives. A British study surveyed 60 board-certified clinicians (mostly in Europe and North America) to determine the most-used NSAIDs and the decisions that dictate treatment duration and then discontinuation. [Gibbs R, Duz M, Shipman E. A survey of non-steroidal anti-inflammatory drug use in the post-operative period following equine colic surgery. Equine Veterinary Education April 2022; DOI: 10.1111/eve.13660]
The online questionnaire consisted of 21 questions about NSAID use in the seven days following colic surgery—what product, dose, dosing interval, route of administration, and time to discontinue. It also presented three fictitious cases for the clinician to inform how they would use NSAIDs in those situations: 1) correction of a primary colon displacement with no complications and discharge on day 6; 2) surgical resection of a strangulating obstruction of the small intestine with the horse developing SIRS and post-operative ileus and then discharged on day 9; and 3) correction of a primary colon displacement with development of a surgical site infection and eventual discharge on day 9.
Nearly all respondents (95%) used NSAIDs for post-operative management. The most commonly used NSAIDs post-operatively were flunixin meglumine (97%) and phenylbutazone (83%). Firocoxib and meloxicam were used by 53% of respondents. Only about 15% voiced use of ketoprofen or comparable products.
A practitioner’s decision to discontinue NSAID treatment was based on a number of factors: The absence of active colic signs by 83%; diminishing pain scores by 81%; and the absence of fever in the preceding 24 hours by 78%. The presence of incisional swelling or drainage also was factored in to whether or not to continue NSAIDs.
For the case 1 scenario, NSAIDs were discontinued between days 2-5. For cases 2 and 3 scenarios, treatment tended to continue for 7 days, but some continued past day 10.
Flunixin was the most administered NSAID (~96%) up to day 7. Then, if NSAIDs were continued, there was a switch to phenylbutazone. Half of the surveyed practitioners administered flunixin at 1.1 mg/kg every 12 hours to maintain analgesia rather than the labeled dose of 1.1 mg/kg every 24 hours. Low-dose flunixin (0.25 mg/kg every 6-8 hours) to combat endotoxemia was used by 17%.
Clinicians (56%) administered phenylbutazone at a dose of 2.2 mg/kg every 12 hours. Firocoxib, when used, was administered at the licensed dose rate.
A previous study (2011) noted that by day 4, post-operative pain decreases in cases with no post-operative complications. Another study (2005) pointed out that small intestinal lesions are associated with higher rates of pain than large intestinal surgery and so need longer analgesia support. In most cases, NSAIDs were discontinued within 5-7 days following colic surgery provided no complications developed. The longer the duration of treatment with NSAIDs, the more at risk the horse could be for gastric ulcers, right dorsal colitis, renal effects, and inhibition of healing of the mucosal barrier.