Predicting parturition in Beagles using foetal membrane measurements

Abstract

Dog breeders invest a lot of time and money into breeding efforts and it is important for veterinarians to assist clients in achieving a successful outcome of a breeding attempt. Being able to predict when a bitch is likely to whelp will assist the owner in managing the pre-parturient bitch optimally—via a well-timed restricted observation period which would allow for a timely intervention, when needed, to prevent unnecessary foetal loss. Studies aimed at predicting the parturition dates in bitches used foetal measurements and applied formulas to specific breeds or bitches in predetermined weight categories. The aim of this study was to predict the parturition date in bitches based on measurements, taken during the ampullary phase of gestation, which are not influenced by the size of the foetus, which in turn is influenced by the breed and size of the sire and dam. Various measurements of extrafoetal fluid compartments of the conceptus in an axial longitudinal view (ALV) and in an equatorial transverse view (ETV) were recorded daily between 17 and 32 days after the onset of cytological dioestrus. Measurements were categorised as direct variables (a measured datum) or relative variables (the relationship between measured data) . A linear function was used to generate models to predict the day of parturition using either the direct or relative predictor variables. Some of the measurements were excluded from the data used to generate the models, and these values were used to test the accuracy of the generated models in predicting the day of parturition in bitches. This study, using the model for direct variables, predicted the day of parturition accurately in 62% of bitches, within one day in 94% of bitches and within two days in all bitches. The model for relative variable predicted the day of parturition within one day in 56% of bitches, within two days in 81% of bitches and within three days in all bitches.