The clinical and metabolic effects of rapid weight loss in obese pet cats and the influence of supplemental oral L-carnitine

J Vet Intern Med. 2000 Nov-Dec;14(6):598-608. doi: 10.1892/0891-6640(2000)014<0598:tcameo>;2.


The efficacy, safety, and metabolic consequences of rapid weight loss in privately owned obese cats by means of a canned weight-reduction diet and the influence of orally administered L-carnitine on rate of weight loss, routine clinical evaluations, hepatic ultrasonography, plasma amino acid profiles, and carnitine analytes were evaluated. A double-blinded placebo-controlled design was used with cats randomly divided into 2 groups: Group 1 (n = 14) received L-carnitine (250 mg PO q24h) in aqueous solution and group 2 (n = 10) received an identical-appearing water placebo. Median obesity (body condition scores and percentage ideal body weight) in each group was 25%. Caloric intake was restricted to 60% of maintenance energy requirements (60 kcal/kg) for targeted ideal weight. The reducing formula was readily accepted by all cats. Significant weight loss was achieved by week 18 in each group without adverse effects (group 1 = 23.7%, group 2 = 19.6%). Cats receiving carnitine lost weight at a significantly faster rate (P < .05). Significant increases in carnitine values developed in each group (P < .02). However, significantly higher concentrations of all carnitine moieties and a greater percentage of acetylcarnitine developed in cats of group 1 (P < .01). The dietary formula and described reducing strategy can safely achieve a 20% weight reduction within 18 weeks in obese cats. An aqueous solution of L-carnitine (250 mg PO q12h) was at least partially absorbed, was nontoxic, and significantly increased plasma carnitine analyte concentrations as well as rate of weight loss.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • 3-Hydroxybutyric Acid / blood
  • Abdomen / physiology
  • Amino Acids / blood
  • Animal Feed
  • Animals
  • Animals, Domestic
  • Biological Availability
  • Blood Chemical Analysis / veterinary
  • Carnitine / administration & dosage*
  • Carnitine / blood
  • Carnitine / pharmacokinetics
  • Cat Diseases / diet therapy*
  • Cat Diseases / metabolism
  • Cats
  • Diet, Reducing / veterinary*
  • Dietary Supplements
  • Double-Blind Method
  • Eating
  • Female
  • Liver / diagnostic imaging
  • Male
  • Obesity / diet therapy
  • Obesity / metabolism
  • Obesity / veterinary*
  • Spectrometry, Mass, Fast Atom Bombardment / veterinary
  • Statistics, Nonparametric
  • Ultrasonography
  • Weight Loss*


  • Amino Acids
  • Carnitine
  • 3-Hydroxybutyric Acid