Spectrophotometry and Ultracentrifugation for Measurement of Plasma Lipids in Dogs with Diabetes Mellitus.

BACKGROUND: There are conflicting reports of plasma lipoprotein lipid content in dogs with diabetes mellitus (DM). OBJECTIVES: To determine lipoprotein lipid content of plasma of dogs with DM by spectrophotometry and ultracentrifugation; to compare lipoprotein lipid content in diabetic and healthy dogs; and to quantify apolipoprotein B-100 (ApoB) in dogs with DM. ANIMALS: 22 dogs with DM and 9 healthy dogs. METHODS: Cross-sectional study. Triglyceride (TG), total cholesterol (TC), and high-density lipoprotein cholesterol (HDL-C) concentrations were measured by spectrophotometry. Very low-density lipoprotein cholesterol (VLDL-C) and low-density lipoprotein cholesterol (LDL-C) concentrations were calculated after ultracentrifugation. Non-HDL-C cholesterol was calculated by subtracting HDL-C from TC. ApoB was quantified by ELISA. The Mann-Whitney test was used for comparison of median lipoprotein concentrations, and Spearman's correlation was used to assess associations between ApoB and lipoprotein fractions. RESULTS: All values are reported in mg/dL. Median TG (122), TC (343.5), HDL-C, (200), VLDL-C, (27) LDL-C (68), non-HDL-C (114), and ApoB (320) were significantly higher in dogs with DM, compared to healthy dogs (57, 197, 168, 12, 16, 31, and 258, respectively, P-values 0.0079, <0.001, 0.029, 0.011, <0.001, <0.001, 0.025, respectively). A significant association was found between ApoB and LDL-C (Spearman's rho = 0.41, P = 0.022) and between ApoB and non-HDL-C (Spearman's rho = 0.40, P = 0.027). CONCLUSIONS AND CLINICAL IMPORTANCE: Dyslipidemia of dogs with DM is characterized by pronounced increases in LDL-C and non-HDL-C concentrations, although all lipoprotein fractions are significantly increased. Knowledge of specific lipoprotein fraction alterations in dogs with DM can enhance treatment options for diabetic dyslipidemia in dogs.

Beta-hydroxybutyrate Concentrations in Dogs with Acute Pancreatitis and Without Diabetes Mellitus.

BACKGROUND: ß-hydroxybutyrate (BOHB) concentrations have not been quantified in dogs with acute pancreatitis (AP). OBJECTIVE: The aim of this study was to investigate BOHB concentrations in dogs with AP. ANIMALS: A total of 154 client-owned dogs without DM. METHODS: Prospective clinical study. Dogs were enrolled into 1 of 3 groups: AP, sick without an AP diagnosis, or fasted. Dogs were diagnosed with AP (44) if they had vomiting or anorexia, and either ultrasonographic findings consistent with AP or increased pancreatic lipase. Sick dogs without AP (68) had vomiting or anorexia but a diagnosis of AP was either not suspected or was excluded based on ultrasonographic findings or a normal pancreatic lipase. Dogs without anorexia or vomiting that were fasted for over 10 hours for a procedure were also enrolled (42). BOHB was measured on whole blood with a portable ketone meter. The Kruskal-Wallis test was performed to compare BOHB in the 3 groups. Pair-wise comparisons were performed using the Mann-Whitney test and Bonferroni corrected P-values are reported. RESULTS: Median BOHB concentration was significantly higher in dogs with AP (0.3 mmol/L, range 0-2.9 mmol/L) compared to sick dogs without AP (0.20 mmol/L, range 0-0.9 mmol/L, P = .007) and fasted dogs (0.1 mmol/L, range 0-0.4 mmol/L, P = .0001). Median BOHB concentration was significantly higher in sick dogs without AP compared to fasted dogs (P = .0002). CONCLUSIONS AND CLINICAL IMPORTANCE: In dogs without DM, BOHB is significantly higher in dogs with AP compared to other dogs. The diagnostic utility of this finding remains to be investigated.

Cortisol Concentrations in Well-Regulated Dogs with Hyperadrenocorticism Treated with Trilostane.

BACKGROUND: There are no clear treatment guidelines for dogs with clinically well-regulated hyperadrenocorticism in which serum cortisol concentrations before and after an ACTH stimulation test performed 3-6 hours after trilostane administration are < 2.0 µg/dL. OBJECTIVE: To determine if serum cortisol concentrations measured before (Pre1) and after (Post1) ACTH stimulation at 3-6 hours after trilostane administration are significantly lower than cortisol concentrations measured before (Pre2) and after (Post2) ACTH stimulation 9-12 hours after trilostane administration, in a specific population of dogs with clinically well-regulated hyperadrenocorticism and Pre1 and Post1 <2 µg/dL. ANIMALS: Thirteen client-owned dogs with clinically well-regulated hyperadrenocorticism and Pre1 and Post1 serum cortisol concentrations <2.0 µg/dL 3-6 hours after trilostane administration. METHODS: Prospective study. Dogs had a second ACTH stimulation test performed 9-12 hours after trilostane administration, on the same day of the first ACTH stimulation test. Cortisol concentrations before and after ACTH stimulation were compared using a paired t-test. RESULTS: Cortisol concentrations before (1.4 ± 0.3 µg/dL) and after the first stimulation (1.5 ± 0.3 µg/dL, mean ± SD) were significantly lower than cortisol concentration before the second stimulation (3.3 ± 1.6 µg/dL, P = .0012 each). Cortisol concentration before the first stimulation was also significantly lower than cortisol concentration after the second stimulation (5.3 ± 2.4 µg/dL, P = .0001). CONCLUSIONS AND CLINICAL IMPORTANCE: In dogs with clinically well-regulated, trilostane-treated, hyperadrenocorticism, and cortisol concentrations <2 µg/dL before and after the first stimulation, a second ACTH stimulation test performed 9-12 hours after treatment can result in higher cortisol concentrations that could support continued trilostane treatment.