Randomized, double-blinded, controlled trial of the effects of coenzyme Q 10 supplementation on plasma coenzyme Q 10 concentration in dogs with myxomatous mitral valve disease.

OBJECTIVE: To determine the dose of coenzyme Q10 (CoQ10 ) needed to achieve at least a 3-fold increase in plasma CoQ10 concentration in dogs with myxomatous mitral valve disease (MMVD) and congestive heart failure (CHF).

ANIMALS: 18 dogs with CHF due to MMVD and 12 healthy dogs.

PROCEDURES: In a randomized, double-blinded, controlled trial, dogs with MMVD were given 50 or 100 mg of water-soluble CoQ10 (ubiquinone; total daily dose, 100 mg [n = 5] or 200 mg [6]) or a placebo (7), PO, twice a day for 2 weeks in addition to regular cardiac treatment. Plasma CoQ10 concentration was measured in dogs with MMVD before (baseline) and at various time points after supplementation began and in healthy dogs once. Concentrations were compared among and within groups.

RESULTS: No significant difference in median baseline plasma CoQ10 concentration was detected between healthy dogs and dogs with MMVD. Fold increases in plasma CoQ10 concentrations ranged from 1.7 to 4.7 and 3.2 to 6.8 for individual dogs in the 100-mg and 200-mg groups, respectively. The change in plasma CoQ10 concentration after supplementation began was significantly higher than in the placebo group at 4 hours and 1 and 2 weeks for dogs in the 200-mg group and at 1 and 2 weeks for dogs in the 100-mg group.

CONCLUSIONS AND CLINICAL RELEVANCE: A daily CoQ10 dose of 200 mg was sufficient to achieve at least a 3-fold increase in plasma CoQ10 concentration and may be used in CoQ10 supplementation studies involving dogs with CHF due to MMVD.