Ear discharge after Imidacloprid + Moxidectin (Advantage Multi) in cats

The FDA has received 37 reports of ear discharge in cats after Imidacloprid + Moxidectin. That is 0.5% of all reports for this medicine, compared with 0.1% across reports for all cat medicines, so it is reported unusually often with this medicine.

37Reports

78%Marked serious

38%Recovered

2.7%Died or euthanised

10 daysTypical onset

How soon it started

Same day

6 27%

1–2 days

4 18%

3–7 days

1 4.5%

1–4 weeks

7 32%

Over a month

4 18%

How the animals did

Recovered

14 38%

Still unwell when reported

2 5.4%

Died

1 2.7%

Not known

20 54%

Problems reported at the same time

Itching

17 46%

Head shake - ear disorder

13 35%

Didn't stop mites

10 27%

Skin redness

5 14%

Hair loss

4 11%

Ear infection

4 11%

Lethargy

3 8.1%

Application site reaction

3 8.1%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Imidacloprid kills fleas (spot-on or collar). Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs).

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

Questions owners ask

Can Imidacloprid + Moxidectin cause ear discharge in cats?: 37 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 10 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).

All reported side effects of Imidacloprid + Moxidectin in cats · Medicines most reported with ear discharge