Catalyst Total T4 Test

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

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

1 in 7 profiles run on seemingly healthy adult dogs show a low total T4 result, indicating hypothyroidism or a nonthyroidal illness.1

1 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 8 hours. After 8 hours, store any unused materials in the refrigerator. Do not cycle more than 5 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 Analyzer.

IDEXX Catalyst Dx Analyzer

Multiple samples in minutes

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

Clip bundle for the Catalyst One Chemistry Analyzer

Chemistry profiles in bundles

The Catalyst SDMA Feline Bundle and Catalyst SDMA Comprehensive Bundle make it easy to buy and run a full chemistry profile every time.


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Customer Service: 1-800-248-2483

IDEXX Test Promise

IDEXX customers enjoy hassle-free returns for unopened, expired products.* In addition, if an IDEXX test does not perform as promised, just call us and we’ll credit your IDEXX Points account with 100% of the test’s value.

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*Credit available for unopened tests in the form of a discount on a replacement order or as IDEXX Points credited to your account, at IDEXX discretion.

  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 USA.
  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.