Effect of metoclopramide treatment of bitches during the first week of lactation on serum prolactin concentration, milk composition, and milk yield and on weight gain of their puppies.

OBJECTIVE To investigate effects of metoclopramide orally administered to healthy bitches on serum prolactin and milk lactose concentrations, gross energy, and dry matter content and on puppy weight gain during early lactation. ANIMALS 20 client-owned bitches and their 121 puppies. PROCEDURES 10 bitches received metoclopramide (0.2 mg/kg, PO, q 6 h for 6 days; treatment group) starting 10 to 24 hours after birth of the last puppy of the litter (day 0), and 10 bitches served as the control group. Blood and milk samples from all bitches were collected on days 0, 1, 2, 4, and 6. Milk samples for days 1 and 2 and days 4 and 6 were pooled because of small volume. Puppies were weighed twice daily. RESULTS Serum prolactin concentration increased significantly over time in both groups, and no treatment effect was detected. When day-to-day changes were analyzed, the prolactin concentration increased from day 0 to day 1 in the treatment group but not in the control group. Milk lactose concentration increased significantly and was higher in the treatment group than in the control group. Milk dry matter content was unchanged, whereas the time course for milk gross energy content differed significantly between treatment and control bitches. Puppy weight gain was not affected by metoclopramide treatment. CONCLUSIONS AND CLINICAL RELEVANCE Oral administration of metoclopramide to healthy bitches after parturition induced a transient increase in serum prolactin concentration and stimulated milk lactose production. It is likely bitches with insufficient or delayed milk production could benefit from metoclopramide treatment.