title: Healing of surgical castration wounds: a description and an evaluation of flunixin.
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.
authors.affiliation: Department of Animal Science, University of California, Davis 95616.
authors.forename: E M
authors.initials: EM
authors.lastname: Mintline
authors.affiliation: School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: A
authors.initials: A
authors.lastname: Varga
authors.affiliation: Department of Animal Science, University of California, Davis 95616.
authors.forename: J
authors.initials: J
authors.lastname: Banuelos
authors.affiliation: Animal Welfare Program, University of British Columbia, Victoria, BC V6T 1Z4, Canada.
authors.forename: K A
authors.initials: KA
authors.lastname: Walker
authors.affiliation: Western Institute for Food Safety and Security, School of Veterinary Medicine, University of California, Davis 95616.
authors.forename: B
authors.initials: B
authors.lastname: Hoar
authors.affiliation: Department of Animal Science, University of California, Davis 95616.
authors.forename: Daniel
authors.initials: D
authors.lastname: Drake
authors.affiliation: Animal Welfare Program, University of British Columbia, Victoria, BC V6T 1Z4, Canada.
authors.forename: D M
authors.initials: DM
authors.lastname: Weary
authors.affiliation: Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames 50011.
authors.forename: J F
authors.initials: JF
authors.lastname: Coetzee
authors.affiliation: Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames 50011.
authors.forename: M L
authors.initials: ML
authors.lastname: Stock
authors.affiliation: Department of Animal Science, University of California, Davis 95616 cbtucker@ucdavis.edu.
authors.forename: C B
authors.initials: CB
authors.lastname: Tucker
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D002417:Cattle / Q000502:physiology*; D003002:Clonixin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D007267:Injections / Q000662:veterinary; D008012:Lidocaine / Q000627:therapeutic use; D008297:Male; D009919:Orchiectomy / Q000379:methods / Q000662:veterinary*; D010146:Pain / Q000188:drug therapy / Q000662:veterinary*; D012611:Scrotum / Q000187:drug effects / Q000473:pathology; D013373:Substance P / Q000097:blood; D013997:Time Factors; D016896:Treatment Outcome; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D013373:Substance P; C014558:flunixin meglumine; D008012:Lidocaine; D003002:Clonixin
keywords: NSAID; animal welfare; castration; cattle; healing; substance P