Hair loss after Imidacloprid + Moxidectin (Advantage Multi) in dogs

The FDA has received 452 reports of hair loss in dogs after Imidacloprid + Moxidectin. That is 3.4% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

452Reports

71%Marked serious

27%Recovered

2.2%Died or euthanised

7 daysTypical onset

How soon it started

Same day

45 15%

1–2 days

72 24%

3–7 days

52 18%

1–4 weeks

83 28%

Over a month

43 15%

How the animals did

Recovered

121 27%

Recovered with lasting effects

2 0.4%

Still unwell when reported

20 4.4%

Died

5 1.1%

Euthanised

5 1.1%

Not known

299 66%

Problems reported at the same time

Itching

197 44%

Application site reaction

142 31%

Skin rash or irritation

91 20%

91 20%

37 8.2%

33 7.3%

32 7.1%

21 4.6%

Age of the animals

Under 1 year

1–3 years

132

4–7 years

116

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 hair loss in dogs?: 452 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 7 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).

Hair loss with similar medicines

Hair loss after Spinosad (Comfortis) 503 reports · 0.9% of its reports
Hair loss after Lufenuron + Milbemycin Oxime (Sentinel) 227 reports · 0.9% of its reports
Hair loss after Nitenpyram (Capstar) 195 reports · 1.8% of its reports
Hair loss after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 46 reports · 0.5% of its reports
Hair loss after Fipronil + S-methoprene (Frontline Plus) 113 reports · 3.8% of its reports
Hair loss after Flumethrin + Imidacloprid (Seresto) 135 reports · 5.9% of its reports
Hair loss after Imidacloprid 43 reports · 2.3% of its reports
Hair loss after Fipronil 22 reports · 1.6% of its reports
Hair loss after Lufenuron 45 reports · 4.4% of its reports
Hair loss after Imidacloprid + Permethrin + Pyriproxyfen 33 reports · 4.5% of its reports

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