Catalyst Total T4 Test

The total T4 slide for Catalyst One and Catalyst Dx chemistry analysers 

Always include the Catalyst Total T4 Test when running blood work on a senior dog or cat.

One in seven profiles run on seemingly healthy adult dogs show a low total T4 result, indicating hypothyroidism or a non-thyroidal illness.1

One in 10 cats will be affected by hyperthyroidism in their lifetime.2

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Testing Guidelines

Learn what to do next with your total T4 results for canine and feline patients.

Watch these short videos in which Dr Graham Bilbrough discusses total T4 results, treatment and monitoring for canine and feline patients.

How to Use


It takes just seconds to add the Catalyst Total T4 Test to your profiles for a comprehensive look at your patients' thyroid health.
Storage and Handling Requirements
  • Store in the refrigerator. Do not freeze.
  • No warming required – run directly from the refrigerator.
  • Total T4 (TT4) slides and reagent can be stored in their pouch at room temperature for up to eight hours. After 8 hours, store any unused materials in the refrigerator. Do not cycle more than five times.
  • Can be run on whole blood, serum or plasma. Recommended sample volume:

Whole blood: 600–800 μl
Serum/plasma: 65 μl (300 μl if running with other slides)

Frequently Asked Questions

Answers to the most frequently asked questions about using the Catalyst Total T4 Test


Related products

Get the most out of your Catalyst Total T4 Test

Catalyst One Chemistry Analyzer

Fast, accurate chemistry results

See results for total T4, chemistry, electrolytes and more, in one run with the Catalyst One Chemistry Analyser.

IDEXX Catalyst Dx Analyzer

Multiple samples in minutes

Results for total T4, chemistry, electrolytes and more, for multiple patients with the Catalyst Dx Chemistry Analyser.


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Order tests & supplies

Learn more about ordering directly from IDEXX and order your in-house tests and supplies today.


  1. Results from 8,238 canine patient samples run in-clinic, where “wellness” was selected as the reason for testing. Data on file at IDEXX Laboratories, Inc., Westbrook, Maine, United States.
  2. Peterson ME. Hyperthyroidism in cats: what’s causing this epidemic of thyroid disease and can we prevent it? J Feline Med Surg. 2012;14(11):804-818.