Zinc–carnosine and vitamin E supplementation does not ameliorate gastrointestinal side effects associated with ciclosporin therapy of canine atopic dermatitis

Chelated zinc–carnosine and vitamin E GastriCalm^® (GCM); Teva Animal Health] is marketed as an anti‐emetic supplement for dogs to assist the repair of damaged stomach and intestinal mucosa. The purpose of this prospective, double‐blinded, placebo‐controlled trial was to determine whether GCM reduced the frequency of vomiting, diarrhoea and appetite changes during initiation of ciclosporin (Atopica^®; Novartis Animal Health) therapy for the treatment of canine atopic dermatitis. Sixty privately owned dogs diagnosed with atopic dermatitis were randomly assigned to GCM (n = 30) or placebo (n = 30) groups. All dogs received ～5 mg/kg ciclosporin (range, 3.5–5.8 mg/kg) once daily. Dogs <13.6 kg received half a tablet of GCM or placebo; dogs ≥13.6 kg received one tablet once daily. GastriCalm^® or placebo was administered 30 min prior to eating, and the ciclosporin was administered 2 h after feeding. Owners recorded episodes of vomiting, diarrhoea and appetite changes. Dogs were examined on days 0 and 14. Forty‐one of 60 dogs (68.3%) had at least one episode of vomiting, diarrhoea or appetite change, leaving nine placebo dogs (30%) and ten GCM dogs (33.3%) free of adverse events (AE). Twenty‐seven of 60 dogs (45%) vomited, and 15 of 60 (25%) had diarrhoea. There was no significant difference in episodes of individual AEs, but the placebo group had a significantly lower total AE score (summation of episodes of appetite change, vomiting and diarrhoea; P = 0.022). Small dogs (<6.82 kg) had significantly fewer total AEs in both treatment groups and tolerated ciclosporin better than larger dogs (P < 0.05).