Serum Total Thyroxine Concentrations in Clinically Healthy Pet Rabbits

Area of Science:

• Veterinary Medicine
• Endocrinology
• Laboratory Diagnostics

Background:

• Serum total thyroxine (TT4) is vital for assessing thyroid function in small animals.
• Limited data exists on thyroid disease prevalence and laboratory diagnostics in rabbits.
• Establishing a reference interval for TT4 in rabbits is essential for accurate diagnosis.

Purpose of the Study:

• To establish a device- and method-specific reference interval for serum total thyroxine (TT4) in clinically healthy pet rabbits.
• To provide a baseline for diagnosing thyroid dysfunction in rabbits.
• To contribute to the understanding of rabbit endocrinology.

Main Methods:

• Chemiluminescence assay (CLIA) was used to determine TT4 concentrations in 120 healthy pet rabbits.
• Rabbits were categorized into age groups (7-24, 25-59, >60 months) and housing types (indoor, outdoor, indoor/outdoor).
• The reference interval (95th percentile) was calculated using SPSS following ASVCP standards.

Main Results:

• A median TT4 concentration of 0.8 μg/dL (10.28 nmol/L) and a reference interval of 0.6-1.98 μg/dL (7.71-25.44 nmol/L) were determined.
• No significant differences in TT4 were found based on sex or age.
• Significant differences in TT4 were observed based on housing type (indoor/outdoor vs. indoor or outdoor).

Conclusions:

• Serum TT4 concentrations in pet rabbits, measured by CLIA, are independent of sex and age.
• Device- and method-specific reference intervals are crucial for accurate TT4 measurement in rabbits.
• These findings aid in the laboratory diagnosis of thyroid function in pet rabbits.