# AI recommends ivermectin for heartworm prevention in dogs without warning about MDR1 gene mutation sensitivity

- **ID:** `pet-safety/ai-recommends-ivermectin-for-dog-worms-without-checking-mdr1-mutation`
- **Domain:** pet-safety
- **Category:** life_threatening
- **Error Code:** `PET-IVERMECTIN-MDR1-001`
- **Verification:** ai_generated
- **Fix Rate:** 90%

## Root Cause

Dogs with MDR1 gene mutation (common in Collies, Australian Shepherds, Shelties) cannot properly efflux ivermectin from the brain, leading to neurotoxicity at standard preventive doses, causing tremors, seizures, and death.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| v1.0 | active | — | — |
| v2.3 | active | — | — |
| v3.1 | active | — | — |

## Workarounds

1. **Test for MDR1 mutation before using any ivermectin-based product (Heartgard, Iverhart). Use a cheek swab test from Washington State University VGL or a vet. If mutation positive, choose alternative heartworm prevention (e.g., selamectin, milbemycin oxime, moxidectin).
Example: Order MDR1 test kit from WSU (https://vgl.vetmed.wsu.edu/). For a positive dog, use Revolution (selamectin) topical monthly or Sentinel (milbemycin oxime + lufenuron) oral monthly. Avoid all ivermectin products.** (95% success)
   ```
   Test for MDR1 mutation before using any ivermectin-based product (Heartgard, Iverhart). Use a cheek swab test from Washington State University VGL or a vet. If mutation positive, choose alternative heartworm prevention (e.g., selamectin, milbemycin oxime, moxidectin).
Example: Order MDR1 test kit from WSU (https://vgl.vetmed.wsu.edu/). For a positive dog, use Revolution (selamectin) topical monthly or Sentinel (milbemycin oxime + lufenuron) oral monthly. Avoid all ivermectin products.
   ```
2. **If ivermectin toxicity is suspected (vomiting, ataxia, tremors, seizures), stop the medication immediately. Administer activated charcoal (1-2 g/kg PO) if within 2 hours of ingestion. Seek emergency vet for IV fluids, lipid emulsion therapy, and symptomatic support.
Example: For a 20-kg Collie showing ataxia after Heartgard, give activated charcoal 20-40 g PO, transport to ER. Vet may administer intralipid 20% at 1.5 mL/kg IV over 30 minutes to bind lipophilic ivermectin.** (85% success)
   ```
   If ivermectin toxicity is suspected (vomiting, ataxia, tremors, seizures), stop the medication immediately. Administer activated charcoal (1-2 g/kg PO) if within 2 hours of ingestion. Seek emergency vet for IV fluids, lipid emulsion therapy, and symptomatic support.
Example: For a 20-kg Collie showing ataxia after Heartgard, give activated charcoal 20-40 g PO, transport to ER. Vet may administer intralipid 20% at 1.5 mL/kg IV over 30 minutes to bind lipophilic ivermectin.
   ```

## Dead Ends

- **** — Assuming only Collies are affected — MDR1 mutation occurs in over 10 herding breeds including Australian Shepherds, Shelties, Old English Sheepdogs, and mixed breeds with herding ancestry. (85% fail)
- **** — Using a lower dose of ivermectin (e.g., 0.006 mg/kg) thinking it's safe — even low doses can cause toxicity in homozygous MDR1 mutant dogs. (70% fail)
- **** — Relying on breed appearance alone — mixed breed dogs may carry the mutation without showing herding traits; only genetic testing confirms status. (75% fail)