OBJECTIVE To characterize the postprandial nutrient profiles of exercise-conditioned dogs fed a supplemental carbohydrate and protein bar with or without astaxanthin from Haematococcus pluvialis immediately after exercise.
PROCEDURES The study had 2 phases. During phase 1, postprandial plasma glucose concentration was determined for dogs fed a bar containing 25% protein and 18.5% or 37.4% maltodextrin plus dextrin (rapidly digestible carbohydrate; RDC), or dry kibble (30% protein and 0% RDC) immediately after exercise. During phase 2, dogs were exercised for 3 days and fed a bar (25% protein and 37.4% RDC) with (CPA; n = 8) or without (CP; 8) astaxanthin or no bar (control; 8) immediately after exercise. Pre- and postexercise concentrations of plasma biochemical analytes and serum amino acids were determined on days 1 and 3.
RESULTS Phase 1 postexercise glucose concentration was increased when dogs were provided the 37.4% RDC bar, but not 0% or 18.5% RDC. On day 3 of phase 2, the CPA group had the highest pre-exercise triglyceride concentration and significantly less decline in postexercise glucose concentration than did the CP and control groups. Mean glucose concentration for the CP and CPA groups was significantly higher than that for the control group between 15 and 60 minutes after bar consumption. Compared to immediately after exercise, branched-chain amino acid, tryptophan, leucine, and threonine concentrations 15 minutes after exercise were significantly higher for the CP and CPA groups, but were lower for the control group.
CONCLUSIONS AND CLINICAL RELEVANCE Dogs fed a bar with 37.4% RDCs and 25% protein immediately after exercise had increased blood nutrient concentrations for glycogen and protein synthesis, compared with control dogs.
Objective—To determine nitrogen balance in clinically
normal dogs receiving parenteral nutrition solutions.
Animals—8 clinically normal female Beagles.
Procedure—Dogs were randomly assigned to
receive 4 treatments in random order. Treatment A
consisted of IV administration of nonlactated Ringer's
solution. Treatments B, C, and D consisted of IV
administration of isocaloric parenteral solutions containing
0, 1.36, and 2.04 g of amino acids/kg of body
weight/d, respectively, for 7 consecutive days. Urine
and feces were collected on days 5, 6, and 7 of each
treatment period, and Kjeldahl analysis was used to
determine nitrogen balance.
Results—Mean nitrogen balance was negative with
treatments A and B but was not significantly different
from 0 with treatments C and D. Dogs had the lowest
nitrogen balance values and lost the most weight
while receiving treatment A. Dogs were able to conserve
protein and had higher nitrogen balance values
when receiving treatment B, compared with treatment
A. Dogs lost the least amount of weight while
receiving treatment D. Regression analysis indicated
that an IV amino acid intake of 2.32 g/kg/d (95% confidence
interval, 2.00 to 2.81 g/kg/d), as supplied by
the commercial product used in this study, would
result in zero nitrogen balance in clinically normal
Conclusions and Clinical Relevance—Results suggest
that IV amino acid requirement of clinically normal
dogs is approximately 2.3 g/kg/d. ( Am J Vet Res 2001;62:912–920)
Objective—To determine whether repetitive endurance
exercise in sled dogs was associated with
substantial lipid peroxidation, decreases in antioxidant
capacity of the serum, and skeletal muscle
Animals—24 lightly trained sled dogs.
Procedure—16 dogs completed a 58-km run on each
of 3 consecutive days; the other 8 dogs
(control) did not exercise during the study. Blood samples
were collected before the first exercise run and
after the first and third exercise runs. Plasma isoprostane
and serum vitamin E concentrations, total
antioxidant status of plasma, and serum creatine
kinase activity were measured.
Results—Plasma isoprostane concentrations in dogs
in the exercise group were significantly increased
after the first exercise run and further significantly
increased after the third exercise run. Serum vitamin
E concentration was significantly decreased after the
first exercise run in dogs in the exercise group, and
this change persisted after the third exercise run.
There was a significant linear relationship between
plasma isoprostane concentration and the logarithm
of serum creatine kinase activity (adjusted r2 = 0.84).
Conclusions and Clinical Relevance—Results
demonstrate that repetitive endurance exercise in
dogs is associated with lipid peroxidation and a reduction
in plasma antioxidant concentrations. We interpret
these results as indicating that the antioxidant
mechanisms of minimally trained dogs may, in some
instances, be inadequate to meet the antioxidant
requirements of repetitive endurance exercise. (Am J Vet Res 2000;61:512–517)