Objective—To evaluate day-to-day variability of serial
blood glucose concentration curves in dogs with diabetes
Design—Prospective clinical study.
Animals—10 dogs with diabetes mellitus.
Procedure—Paired 12-hour serial blood glucose concentration
curves performed during 2 consecutive days were
obtained on 3 occasions from each dog. Dogs received
the same dose of insulin and meal every 12 hours on both
days. For each pair of curves, comparison was made
between the results of days 1 and 2.
Results—Mean absolute difference (without regard
to sign) between days 1 and 2 for each parameter was
significantly > 0, disproving the hypothesis that there
is minimal day-to-day variability of serial blood glucose
concentration curves when insulin dose and meals are
kept constant. Coefficient of variation of the absolute
difference between days 1 and 2 for each parameter
ranged from 68 to 103%. Evaluation of the paired
curves led to an opposite recommendation for adjustment
of the insulin dose on day 2, compared with
day 1, on 27% of occasions. Disparity between
dosage recommendations was more pronounced
when glucose concentration nadir was < 180 mg/dL
(10 mmol/L) on 1 or both days. In this subset of
20 paired curves, an opposite recommendation for
dosage adjustment was made on 40% of occasions.
Conclusions and Clinical Relevance—There is large
day-to-day variation in parameters of serial blood glucose
concentration curves in diabetic dogs. Day-to-day
variability of serial blood glucose concentration
curves has important clinical implications, particularly
in dogs with good glycemic control. (J Am Vet Med Assoc 2003;222:317–321)
Objective—To compare beta-cell sensitivity to glucose, first-phase insulin secretion, and glucose tolerance between dogs with naturally occurring obesity of > 2 years' duration and lean dogs.
Animals—17 client-owned obese or lean dogs.
Procedures—Frequently sampled IV glucose tolerance tests were performed with minimal model analysis on 6 obese dogs and matched controls. Glucagon stimulation tests were performed on 5 obese dogs and matched controls.
Results—Obese dogs were half as sensitive to the effects of insulin as lean dogs. Plasma glucose concentrations after food withholding did not differ significantly between groups; plasma insulin concentrations were 3 to 4 times as great in obese as in lean dogs. Obese dogs had plasma insulin concentrations twice those of lean dogs after administration of glucose and 4 times as great after administration of glucagon. First-phase insulin secretion was greater in obese dogs.
Conclusions and Clinical Relevance—Obese dogs compensated for obesity-induced insulin resistance by secreting more insulin. First-phase insulin secretion and beta-cell glucose sensitivity were not lost despite years of obesity-induced insulin resistance and compensatory hyperinsulinemia. These findings help explain why dogs, unlike cats and humans, have not been documented to develop type 2 diabetes mellitus.
Objective—To develop a standardized meal challenge test by assessing associations between food-withheld preprandial (ie, fasting) and postprandial triglyceride concentrations, determining the most appropriate sampling time to detect the peak concentration (highest postprandial concentration), and estimating reference intervals for fasting and postprandial concentrations in healthy dogs.
Animals—12 lean healthy mixed-breed dogs.
Procedures—Dogs were fed a dry commercially available diet (fat, 31% metabolizable energy) for 3 weeks. After food was withheld for 23 to 24 hours, plasma triglyceride concentrations were measured 1 and 0.083 hours before and 1, 2, 3, 4, 5, 6, 9, and 12 hours after feeding of a standardized challenge meal (median amount eaten, 63 kcal/kg [127 kcal/kg0.75]). Correlation and agreement between concentrations at peak and other time points were assessed by use of correlation coefficients and Bland-Altman limits of agreement. Reference intervals were calculated by use of a robust method.
Results—Fasting and peak triglyceride concentrations were not closely associated. The highest concentration among samples obtained 2, 5, and 6 hours after meal consumption had closest agreement with peak concentration. In 5 of 12 dogs, concentrations 12 hours after eating were still significantly above baseline concentration (mean of each dog's fasting concentrations).
Conclusions and Clinical Relevance—Fasting triglyceride concentration could not be used to accurately predict peak concentration. When estimating peak concentration, multiple samples should be collected 2, 5, and 6 hours after consumption of a standardized meal. Food may need to be withheld for > 12 hours when assessing fasting concentrations in healthy dogs.
Objective—To estimate disease prevalence among dogs and cats in the United States and Australia and proportions of dogs and cats that receive therapeutic diets or dietary supplements.
Sample Population—Dog and cat owners located in 5 geographic areas.
Procedures—A telephone survey was administered to dog and cat owners.
Results—Of 18,194 telephone calls that were made, 1,104 (6%) were to individuals who owned at least 1 dog or cat and agreed to participate. Information was collected for 635 dogs and 469 cats. Only 14 (1%) respondents indicated that their pet was unhealthy, but 176 (16%) indicated that their pets had 1 or more diseases. The most common diseases were musculo-skeletal, dental, and gastrointestinal tract or hepatic disease. Many owners (n = 356) reported their pets were overweight or obese, but only 3 reported obesity as a health problem in their pets. Owners of 28 (2.5%) animals reported that they were feeding a therapeutic diet, with the most common being diets for animals with renal disease (n = 5), reduced-calorie diets (5), and reduced-fat diets (4). Owners of 107 of 1,076 (9.9%) animals reported administering dietary supplements to their pets. Multivitamins (n = 53 animals), chondroprotective agents (22), and fatty acids (13) were the most common dietary supplements used.
Conclusions and Clinical Relevance—Results suggest that most dogs and cats reported by their owners to have a health problem were not being fed a therapeutic diet. In addition, the rate of dietary supplement use was lower than that reported for people.