Vomiting after Milbemycin Oxime (Interceptor) in cats

69 reports to the FDA describe vomiting in cats given Milbemycin Oxime. That is 17% of all reports for this medicine, compared with 18% across reports for all cat medicines.

69Reports

5.8%Marked serious

30%Recovered

4.3%Died or euthanised

Same dayTypical onset

How soon it started

Same day

17 57%

1–2 days

7 23%

3–7 days

1 3.3%

1–4 weeks

1 3.3%

Over a month

4 13%

How the animals did

Recovered

21 30%

Still unwell when reported

2 2.9%

Died

3 4.3%

Not known

43 62%

Problems reported at the same time

Lethargy

15 22%

Loss of appetite

12 17%

Diarrhea

6 8.7%

Drooling

5 7.2%

Didn't work as expected

4 5.8%

Wobbliness (ataxia)

3 4.3%

Death

3 4.3%

Pale mucous membrane

3 4.3%

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 vomiting in cats?: 69 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 the same 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).

Vomiting with similar medicines

Vomiting after Selamectin (Revolution) 2,379 reports · 11% of its reports
Vomiting after Eprinomectin + Esafoxolaner + Praziquantel (NexGard Combo) 445 reports · 14% of its reports
Vomiting after Ivermectin (Heartgard) 292 reports · 30% of its reports
Vomiting after Eprinomectin + Praziquantel 99 reports · 17% of its reports
Vomiting after Milbemycin Oxime + Spinosad (Trifexis) 142 reports · 47% of its reports
Vomiting after Ivermectin + Pyrantel (Heartgard Plus) 31 reports · 47% of its reports

All reported side effects of Milbemycin Oxime in cats · Medicines most reported with vomiting