Malaise after Milbemycin Oxime (Interceptor) in dogs

106 reports to the FDA describe malaise in dogs given Milbemycin Oxime. That is 0.4% of all reports for this medicine, compared with 0.4% across reports for all dog medicines.

106Reports

26%Marked serious

18%Recovered

12%Died or euthanised

1 daysTypical onset

How soon it started

Same day

15 45%

1–2 days

5 15%

3–7 days

1 3.0%

1–4 weeks

3 9.1%

Over a month

9 27%

How the animals did

Recovered

17 16%

Recovered with lasting effects

2 1.9%

Still unwell when reported

18 17%

Died

12 11%

Euthanised

1 0.9%

Not known

56 53%

Problems reported at the same time

30 28%

28 26%

27 25%

15 14%

15 14%

15 14%

15 14%

9 8.5%

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 malaise in dogs?: 106 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 1 day 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).

Malaise with similar medicines

Malaise after Ivermectin + Pyrantel (Heartgard Plus) 204 reports · 0.1% of its reports
Malaise after Milbemycin Oxime + Spinosad (Trifexis) 778 reports · 0.6% of its reports
Malaise after Moxidectin (ProHeart 6) 121 reports · 0.2% of its reports
Malaise after Milbemycin Oxime + Praziquantel (Interceptor Plus) 253 reports · 0.8% of its reports
Malaise after Selamectin (Revolution) 65 reports · 0.2% of its reports
Malaise after Ivermectin (Heartgard) 51 reports · 0.4% of its reports
Malaise after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 23 reports · 0.3% of its reports

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