Healing of surgical castration wounds: a description and an evaluation of flunixin1

Abstract

Previous studies have shown that surgical castration wounds take between 10 and 61 d to heal. The objectives of this work were to describe healing, inflammation, lying behavior, and serum concentration of substance P after surgical castration in beef calves and to evaluate the effect of a possible intervention, a single injection of flunixin meglumine (1.1 mg/kg IV, a NSAID), on the healing process. Calves (mean±SE: 25±2.0 d of age; 54±1.4 kg BW) were surgically castrated with or without an injection of flunixin immediately before the procedure (n=24/treatment). Healing was measured with a 5-point scale (1=fresh wound, 5=no visible incision or inflammation) as well as weight gain, scrotal size, and scrotal surface temperature, on d 1, 2, 3, 7, 14, 21, 28, 35, 49, and 63 after castration. Serum concentration of substance P was recorded on all d, including d 0, but not d 63. Lying behavior was recorded with loggers from 2 d before to 29 d after castration. Inflammation, as measured by scrotal size, peaked on d 2 and 3 after the procedure (e.g., 51±1.0 mm on d 2 versus 28±1.3 mm before castration) and then declined with time (P<0.001). The first wound to score as fully healed (i.e., 5/5) was seen on d 28; by d 63, 98% of wounds were fully healed. The greatest changes in healing score occurred between d 21 and 35; this was also the peak of wound surface temperature and may correspond with revascularization. Serum concentration of substance P was highest before castration (41±1.2 pg/mL), possibly because the sample was collected after the lidocaine ring block was administered, which was likely painful, and because of separation from the dam and restraint. Values began to drop by d 3 (34±1.2 pg/mL) and leveled out by d 21 (30±1.2 pg/mL; P<0.001). Calves given flunixin had more lying bouts than those that received saline (flunixin by time interaction; P=0.052), but this pattern emerged on and after d 8, well after the 3 to 8 h half-life of this NSAID. In conclusion, castration caused inflammation in the days that followed, and the wounds required a minimum of 4 wk to heal. Provision of an NSAID had no effect on these outcomes.

Effect of a single dose of subcutaneous meloxicam before knife castration alone or combined with hot-iron branding on scrotal healing, inflammatory response, and behaviour in 2-mo-old beef calves over 42 d post procedure

“…However, to date no studies have been conducted evaluating its efficacy in reducing long-lasting stress and inflammatory pain, inflammation, or healing beyond 1 wk post castration. Mintline et al (2014) did not find a reduction in inflammation or improved rate of healing after the administration of a single dose of flunixin meglumine following castration in beef calves. In addition, there are very few published studies on the effects of subcutaneous (s.c.) meloxicam on mitigating pain in calves younger than 3 mo of age (Creutzinger et al 2017;Meléndez et al 2018a), or on multiple painful procedures conducted concurrently.…”

“…Scrotal circumference for KN and KB calves was greater than CN on day 7 and day 14 post castration as a result of the inflammation caused by surgical castration (Molony et al 1995;Stafford et al 2002;Marti et al 2017a). Mintline et al (2014) observed that inflammation peaked 2-3 d post surgical castration, whereas Robb and Wood (1990) and Marti et al (2017b) observed wound swelling up to 14 d after the procedure. In addition, SC of KB calves tended (P = 0.08) to be greater than KN calves the first 14 d post procedure.…”

“…The SC was measured using scrotal tape (Reliabull, Lane Manufacturing, Denver, CO, USA). Wound healing or incision state was assessed using a 5-point scale previously described by Mintline et al (2014).…”

Cattle handling technique can induce fatigued cattle syndrome in cattle not fed a beta adrenergic agonist1

“…This study showed no difference in SUBP between LSH and AH cattle or between NEXH and EXH cattle, but this does not necessarily indicate a lack of pain, as not all studies of painful procedures show a difference in SUBP (Mintline et al, 2014). Also, recent refinements in the assays have led to a change from an ELISA to an RIA method making comparison with results from previous studies that used an ELISA method difficult.…”

Surgical Management of Common Disorders of Feedlot Calves

“…Although NSAIDs may provide analgesic benefit after castration, overall inflammation during healing may not be reduced compared with the cattle not receiving NSAIDs at castration. 22 Inflammation and healing after surgical castration is expected to take on average between 3 and 4 weeks. Contamination is expected; however, infection should be recognized early and treated.…”