MDR1 medication sensitivity

Key facts

Primary university resource

Washington State University Program in Individualized Medicine [source]

Test purpose

Identify a relevant MDR1 mutation associated with medication handling [source]

Understand the question

Washington State University’s Program in Individualized Medicine offers testing for an MDR1 mutation associated with altered handling of some medications. This is a pharmacogenetic question, not a diagnosis that every medicine is dangerous or that a dog cannot receive veterinary care. Keep the exact variant and result available rather than using the shorthand sensitive collie.

Keep the report with the patient

Send the original result to the treating practice and retain a copy with travel and emergency records. Tell a new practice about known status before medication, sedation or a procedure. If the result is unknown, say unknown rather than inferring status from appearance, a breed label or another dog in the family.

Avoid self-adjustment

Do not stop prescribed medication, choose a substitute or change a dose from an online list. The relevant decision involves the actual drug, formulation, reason for use and individual patient. Ask the veterinarian to consult the authoritative pharmacogenetic resource where needed and record the resulting instructions clearly for other caregivers.

Interpret testing responsibly

Verify that a commercial panel includes the relevant test and that the report identifies the correct dog. A result for one variant does not establish freedom from every medication reaction. For a breeding discussion, interpret the actual parents’ records with appropriate advice. This guide provides context and no drug list, dosage recommendation or emergency treatment instructions.

Common questions

Sources & further reading

References for this guide. Rules and services can change; check the responsible organisation for current details.

• WSU: MDR1 testing and ordering (opens in a new tab)
• WSU Washington Animal Disease Diagnostic Laboratory: Dogs (opens in a new tab)

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