Death after Milbemycin Oxime (Interceptor) in dogs

1,015 reports to the FDA describe death in dogs given Milbemycin Oxime. That is 3.4% of all reports for this medicine, compared with 5.2% across reports for all dog medicines, so it is reported less often than average with this medicine.

1,015Reports

37%Marked serious

0.1%Recovered

97%Died or euthanised

9 daysTypical onset

How soon it started

Same day

66 35%

1–2 days

13 6.8%

3–7 days

14 7.3%

1–4 weeks

22 12%

Over a month

76 40%

How the animals did

Recovered

1 0.1%

Still unwell when reported

3 0.3%

Died

837 82%

Euthanised

146 14%

Not known

28 2.8%

Problems reported at the same time

Didn't prevent heartworm

218 21%

204 20%

194 19%

185 18%

135 13%

114 11%

111 11%

104 10%

Age of the animals

Under 1 year

1–3 years

138

4–7 years

235

8–11 years

274

12+ years

192

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly).

Products with this ingredient include Interceptor. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.

Questions owners ask

Can Milbemycin Oxime cause death in dogs?: 1,015 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within 9 days of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Death with similar medicines

Death after Ivermectin + Pyrantel (Heartgard Plus) 2,810 reports · 1.9% of its reports
Death after Milbemycin Oxime + Spinosad (Trifexis) 3,307 reports · 2.5% of its reports
Death after Moxidectin (ProHeart 6) 2,447 reports · 4.8% of its reports
Death after Milbemycin Oxime + Praziquantel (Interceptor Plus) 920 reports · 2.9% of its reports
Death after Selamectin (Revolution) 785 reports · 2.7% of its reports
Death after Ivermectin (Heartgard) 609 reports · 5.1% of its reports
Death after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 125 reports · 1.5% of its reports
Death after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 60 reports · 5.2% of its reports

All reported side effects of Milbemycin Oxime in dogs · Medicines most reported with death