Tachycardia after Imidacloprid + Moxidectin (Advantage Multi) in dogs

The FDA has received 71 reports of tachycardia in dogs after Imidacloprid + Moxidectin. That is 0.5% of all reports for this medicine, compared with 0.5% across reports for all dog medicines.

71Reports
82%Marked serious
41%Recovered
15%Died or euthanised
Same dayTypical onset
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How soon it started

Same day
32 54%
1–2 days
15 25%
3–7 days
3 5.1%
1–4 weeks
7 12%
Over a month
2 3.4%

How the animals did

Recovered
29 41%
Still unwell when reported
2 2.8%
Died
6 8.5%
Euthanised
5 7.0%
Not known
29 41%

Problems reported at the same time

Age of the animals

Under 1 year
13
1–3 years
22
4–7 years
18
8–11 years
10
12+ years
6

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 tachycardia in dogs?
71 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).

Tachycardia with similar medicines

All reported side effects of Imidacloprid + Moxidectin in dogs · Medicines most reported with tachycardia