Dietary hyperthyroidism in dogs

Area of Science:

• Veterinary Medicine
• Endocrinology
• Canine Health

Background:

• Elevated plasma thyroxine concentration in dogs can be associated with raw food diets.
• Hyperthyroidism signs may be present or absent in affected dogs.

Purpose of the Study:

• To evaluate dogs with elevated thyroxine levels on a raw food diet.
• To assess the effect of dietary change on thyroxine levels and clinical signs.

Main Methods:

• Retrospective study of dogs fed raw food with elevated thyroxine (2006-2011).
• Measured thyroxine and thyroid-stimulating hormone levels before and after diet modification.
• Clinical signs were recorded.

Main Results:

• Twelve dogs with a median age of five years were included.
• Median thyroxine was 156.1 nmol/L; five of six dogs had suppressed thyroid-stimulating hormone (<0.03 ng/mL).
• Dietary change normalized thyroxine and resolved clinical signs in all eight re-examined dogs.

Conclusions:

• Dietary hyperthyroidism is a potential diagnosis in dogs consuming raw meat or gullet-based diets.
• Veterinarians should inquire about diet when elevated thyroxine is detected, even without clinical signs.