Foaming at the mouth after Imidacloprid + Moxidectin (Advantage Multi) in cats

The FDA has received 104 reports of foaming at the mouth in cats after Imidacloprid + Moxidectin. That is 1.3% of all reports for this medicine, compared with 1.3% across reports for all cat medicines.

104Reports
50%Marked serious
59%Recovered
4.8%Died or euthanised
Same dayTypical onset
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How soon it started

Same day
82 86%
1–2 days
7 7.4%
3–7 days
1 1.1%
1–4 weeks
2 2.1%
Over a month
3 3.2%

How the animals did

Recovered
61 59%
Still unwell when reported
7 6.7%
Died
2 1.9%
Euthanised
3 2.9%
Not known
31 30%

Problems reported at the same time

Age of the animals

Under 1 year
23
1–3 years
47
4–7 years
18
8–11 years
8
12+ years
4

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 foaming at the mouth in cats?
104 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).

Foaming at the mouth with similar medicines

All reported side effects of Imidacloprid + Moxidectin in cats · Medicines most reported with foaming at the mouth