Collapse after Milbemycin Oxime (Interceptor) in dogs

163 reports to the FDA describe collapse in dogs given Milbemycin Oxime. That is 0.5% of all reports for this medicine, compared with 0.9% across reports for all dog medicines, so it is reported less often than average with this medicine.

163Reports

37%Marked serious

15%Recovered

26%Died or euthanised

5 daysTypical onset

How soon it started

Same day

13 32%

1–2 days

7 17%

3–7 days

1 2.4%

1–4 weeks

3 7.3%

Over a month

17 41%

How the animals did

Recovered

23 14%

Recovered with lasting effects

1 0.6%

Still unwell when reported

22 13%

Died

40 25%

Euthanised

3 1.8%

Not known

74 45%

Problems reported at the same time

46 28%

44 27%

37 23%

33 20%

27 17%

26 16%

26 16%

22 13%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 collapse in dogs?: 163 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 5 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).

Collapse with similar medicines

Collapse after Ivermectin + Pyrantel (Heartgard Plus) 432 reports · 0.3% of its reports
Collapse after Milbemycin Oxime + Spinosad (Trifexis) 471 reports · 0.4% of its reports
Collapse after Moxidectin (ProHeart 6) 1,511 reports · 3.0% of its reports
Collapse after Milbemycin Oxime + Praziquantel (Interceptor Plus) 153 reports · 0.5% of its reports
Collapse after Selamectin (Revolution) 115 reports · 0.4% of its reports
Collapse after Ivermectin (Heartgard) 109 reports · 0.9% of its reports
Collapse after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 60 reports · 0.7% of its reports

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