Effects of an iodine-restricted food on client-owned cats with hyperthyroidism.
The objective of this prospective, multicentre, non-controlled, open-label study was to evaluate the effects of an iodine-restricted food on circulating total thyroxine (TT4) concentrations and clinical parameters in client-owned cats with hyperthyroidism. Two hundred and twenty-five cats were enrolled in the study and adapted to the iodine-restricted food. Data from physical examinations, questionnaires completed by veterinarians and owners, and circulating concentrations of TT4, urea and creatinine were recorded at weeks 0, 4 and 8. The study group included 136 female and 89 male cats (median age 15 years, range 4-21 years). Group 1 (n = 113) had been on previous anti-thyroid medication, while group 2 (n = 112) consisted of newly diagnosed cats. No differences were found between the two groups at any time point. Circulating TT4 concentrations had decreased (P <0.0001) at week 4 and did not change significantly from week 4 to week 8. Circulating TT4 concentration was within the reference range in 56/88 cats at week 4 and in 51/68 cats at week 8. Clinical parameters (vomiting, polyuria, polydipsia, hyperactivity, polyphagia, weight loss, hair coat quality, and quality of life) had improved (P <0.0001) by week 4. Circulating creatinine concentration decreased (P = 0.001) from week 0 to week 4. Side effects associated with feeding the iodine-restricted food were not observed. In conclusion, in client-owned cats with hyperthyroidism an iodine-restricted food is a valuable management option to normalise circulating TT4 concentrations, and improve clinical signs of hyperthyroidism within 4 weeks. This applies to newly diagnosed cats, as well as to previously diagnosed cats receiving anti-thyroid drugs.
Department of Clinical Sciences of Companion Animals, Utrecht University, the Netherlands m.vanderkooij@uu.nl.
Marieke
M
van der Kooij
Hill's Pet Nutrition, Prague, Czech Republic.
Iveta
I
Bečvářová
Hill's Pet Nutrition, Prague, Czech Republic.
Hein P
HP
Meyer
Department of Clinical Sciences of Companion Animals, Utrecht University, the Netherlands.
Erik
E
Teske
Department of Clinical Sciences of Companion Animals, Utrecht University, the Netherlands.
Hans S
HS
Kooistra
D000821:Animal Feed / Q000706:statistics & numerical data*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002371:Cat Diseases / Q000178:diet therapy* / Q000209:etiology*; D002415:Cats; D005260:Female; D006980:Hyperthyroidism / Q000178:diet therapy / Q000209:etiology / Q000662:veterinary*; D007455:Iodine / Q000009:adverse effects*; D008297:Male; D011446:Prospective Studies
D007455:Iodine