The effect of the stage of the ovarian cycle (anoestrus or dioestrus) and of pregnancy on the incidence of gastro-oesophageal reflux in dogs undergoing ovariohysterectomy. (September 2015)

• Record Type: Journal Article
• Authors: Anagnostou, Tilemahos L; Savvas, Ioannis; Kazakos, George M; Ververidis, Haralabos N; Psalla, Dimitra; Kostakis, Charalampos; Skepastianos, Petros; Raptopoulos, Dimitris
• Is Part Of: Veterinary anaesthesia and analgesia. Volume 42:Number 5(2015:Sep.)
• Page Start: 502
• Page End: 511
• Publication Date: 2015-09
• Subjects: anaesthesia -- aspiration -- dog -- gastro-oesophageal reflux -- oesophageal stricture -- pregnancy; Veterinary anesthesia -- Periodicals; 636.089
• DOI: 10.1111/vaa.12234
• Languages: English
• ISSNs: 1467-2987

Abstract

Abstract: Objective: To investigate the potential association of increased blood progesterone (P4 ) concentrations and/or late pregnancy with the incidence of gastro-oesophageal reflux (GOR), in healthy bitches undergoing ovariohysterectomy under general anaesthesia during anoestrus or dioestrus or during the second half of pregnancy. Study design: Prospective observational study. Animals: Ninety-four healthy, female, dogs, aged 1–8 years presented for elective ovariohysterectomy. Methods: Non-pregnant animals were classified into group A (anoestrus) ( n = 35) if blood P4 concentration was sufficiently low or group D (dioestrus) ( n = 26) if blood P4 concentration was sufficiently high. All animals in the second half of pregnancy were classified into group P ( n = 33). Acepromazine (0.05 mg kg −1 ) was administered intramuscularly as preanaesthetic medication, and sodium thiopental (10 mg kg −1, with additional doses if needed) was administered intravenously (IV) for induction of anaesthesia. After endotracheal intubation, halothane (1.1–1.3% end-tidal concentration) in oxygen was used for maintenance of anaesthesia. Lower oesophageal pH was monitored continuously throughout surgery using a pH-measuring probe. Reflux was considered to have occurred whenever pH values of >7.5 (alkaline reflux) or <4 (acid reflux) were recorded. On completion of surgery, carprofen (4 mg kg −1 ) was administered IV. Further administration of analgesics post-operatively was dictated by visual analogue scale pain scoring. Result: Acid GOR was observed in five of 26 dogs in group D, six of 35 group A, and 12 of 33 group P ( p = 0.152). The incidence of GOR in group P approached statistical significance and was higher than the incidence in the combined group A + D (one sided p = 0.044, two sided p = 0.077). Conclusions: In dogs undergoing ovariohysterectomy, GOR during anaesthesia occurs with a high incidence in dogs in the second half of pregnancy compared to non-pregnant animals during anoestrus or dioestrus. Clinical relevance: Measures could be taken in such cases to avoid the consequences of potential reflux.