Primary uterine inertia in 27 bitches: aetiology and treatment.

OBJECTIVES: To evaluate two treatment methods in bitches with primary uterine inertia in relation to blood concentrations of oxytocin, calcium and glucose. METHODS: A prospective study where 27 bitches with primary inertia were randomly allocated to treatment groups I and II. Blood samples were collected before and after treatment. Group I was treated with a combination of intravenous calcium solutions and oxytocin and group II with oxytocin only. If unsuccessful, caesarean sections or additional medical treatment was pursued. RESULTS: Plasma oxytocin concentrations were 35+/-15 pmol/l in group I and 30+/-15 pmol/l in group II. Before treatment, the total serum calcium concentrations were 2.1+/-0.2 mmol/l in both the groups, and blood glucose values were 7.0+/-0.5 mmol/l (group I) and 7.3+/-1.4 mmol/l (group II). The number of bitches subjected to caesarean sections and the number of puppies born did not differ between the two groups. CLINICAL SIGNIFICANCE: This study indicates that low plasma oxytocin levels is a cause of primary inertia in bitches with normal serum calcium concentrations and aggravates the condition in bitches with low calcium levels. Hypoglycaemia was not observed. The outcome of labour did not differ between groups I and II.