Objective—To compare bone mineral measurements
obtained by use of dual-energy x-ray absorptiometry
(DEXA), peripheral quantitative computed tomography
(pQCT), and chemical-physical analyses and
determine effects of age and femur size on values
obtained for the various techniques.
Sample Population—Femurs obtained from 15 juvenile
and 15 adult large-breed dogs.
Procedure—In each femur, 7 regions of interest
were examined by use of DEXA to measure the
bone mineral content (BMC) and bone mineral density
(BMD), and 5 were examined by use of pQCT
to measure BMD. Among these, 1 region was
examined by both noninvasive methods and an
invasive method. Volume of the femur was determined
by water displacement. Volumetric bone
density (VBD) was calculated. Calcium (Ca), phosphorus
(P), total Ca, and total P contents were
Results—DEXA- and pQCT-derived results revealed
that all values increased with age in juvenile dogs. In
adults, VBD and pQCT-derived BMD decreased significantly
and DEXA-derived BMD increased with
increasing femur length. The pQCT-derived BMD correlated
well with VBD and Ca content, whereas
DEXA-derived BMC was strongly correlated with Ca
content. In juveniles, values correlated regardless of
the technique used, whereas in adult dogs, DEXA-derived
BMD did not correlate with pQCT-derived
BMD, Ca concentration, or VBD unless data were
adjusted on the basis of femur length.
Conclusions and Clinical Relevance—DEXA-derived
BMD adjusted for femur length yields
approximately the same percentage variability in VBD
as for pQCT-derived BMD. However, pQCT-derived
BMD is still more sensitive for determining variability
in Ca concentration, compared with DEXA-derived
BMD adjusted for femur length. (Am J Vet Res 2004;65:891–900)
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.