Received: 26 July 2023 | Accepted: 15 May 2024 DOI: 10.1111/eve.14014


P E R S P EC T I V E A R T I C L E


Closed inguinal castration technique in horses compared with field castrations using post- operative serum amyloid A analysis


Dirk Jan Riemersma 1


1 Pferdepraxis “Den Heyberg” , Kevelaer , Germany 2 European Equine Consultant Surgeon , Wijk bij Duurstede , The Netherlands


Correspondence: Dirk Jan Riemersma Email: riemersma@email.de


| Gerold Fahlbusch 1 | Astrid B. M. Rijkenhuizen 2


Summary The inflammatory response to a truly closed castration procedure in 51 horses using an inguinal approach was quantified by serum amyloid A (SAA) measurements to be on av- erage 94 mg/L on day three after surgery. The average SAA value after field castrations, using a scrotal approach, was reported by four different investigations to be between 480 and 708 mg/L on day three post- operatively. The discrepancy in SAA levels between these different approaches proved to be significant ( p < 0.001), quantifying a substan- tially lower inflammatory response of the closed inguinal technique over regular field castrations using a scrotal approach.


K E YWORDS horse , inflammatory response , inguinal castration , serum amyloid A


INTRODUCTION


The closed inguinal castration, first reported by Keller et al. ( 1996 ), refers to a surgical procedure under general anaesthesia in which the proximal vaginal process is closed by a ligature through an inguinal incision before the distal vaginal process containing the testis is re- moved. Applying this technique, using a slightly different ligation to 554 cases resulted in a complication rate of 2% (Riemersma, 2005 ). This compares favourably with reported complication


rates in


field castrations, ranging from 10% to 48% (Kilcoyne et al., 2013 ; Mason et al., 2005 ; May & Moll, 2002 ; Mezerova et al., 2004 ; Moll et al., 1995 ). The widespread reported complication rates suggests subjective influences, which hampers an objective comparison of the quality of different techniques. A more suitable parameter for quan- tifying the quality of a surgical procedure may be the post- operatively (p.o.) inflammatory response caused by trauma or infection. Serum amyloid A (SAA) proved to be the most sensitive acute


phase reactant associated with inflammation after field castrations using a scrotal approach in either standing (Busk et al., 2010 ; Jacobsen et al., 2005 ) or recumbent horses (Bergstrom et al., 2021 ; Haucke et al., 2017 ). Each of these authors compared two groups of horses: horses with mild or severe post- operative clinical signs of complica- tions (Jacobsen et al., 2005 ), horses with or without peri- operative administration of Penicillin (Busk et al., 2010 ), horses receiving a single


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dose of Penicillin or a triple dose on three consecutive days (Haucke et al., 2017 ) and horses receiving either Ceftiofur or Procaine penicillin intraoperatively (Bergstrom et al., 2021 ). Infection may not always be clinically evident until the fourth day after castration (Killcoyne, 2013 ) and it has accordingly been stated by Jacobsen et al. ( 2005 ) and Haucke et al. ( 2017 ) that the SAA levels up to the first 3 days after surgery would be indicative for surgical trauma. SAA levels recorded several days up to several weeks post- operatively would be related to infection, a common cause of complications after field castrations (Baldwin, 2024 ; Kilcoyne et al., 2013 ; Moll et al., 1995 ). Average SAA levels recorded 3 days after field castration, are reported to be be- tween 480 and 570 mg/L (Jacobsen et al., 2005 ), 543–708 mg/L (Busk et al., 2010 ), 698 mg/L (Haucke et al., 2017 ) and 570–608 mg/L (Bergstrom et al., 2021 ). These SAA levels, although recorded in dif- ferent studies, show remarkable resemblance in magnitude and may therefore be compared with other castration techniques.


Hypothesis


It is hypothesised that a closed inguinal castration will result in a sig- nificantly lower 3- day post- operative SAA, compared with values re- ported in the literature for field castrations (Bergstrom et al., 2021 ; Busk et al., 2010 ; Haucke et al., 2017 ; Jacobsen et al., 2005 ).


aaep.org/wiley-redirect Equine Vet Educ. 2024;36:586–596.


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