Seizures after Spinosad (Comfortis) in dogs

2,116 reports to the FDA describe seizures in dogs given Spinosad. That is 3.7% of all reports for this medicine, compared with 4.4% across reports for all dog medicines.

2,116Reports

50%Marked serious

37%Recovered

12%Died or euthanised

4 daysTypical onset

How soon it started

Same day

349 38%

1–2 days

90 9.8%

3–7 days

51 5.5%

1–4 weeks

88 9.6%

Over a month

341 37%

How the animals did

Recovered

657 31%

Recovered with lasting effects

121 5.7%

Still unwell when reported

124 5.9%

Died

180 8.5%

Euthanised

71 3.4%

Not known

963 46%

Problems reported at the same time

336 16%

303 14%

250 12%

245 12%

171 8.1%

148 7.0%

136 6.4%

118 5.6%

Age of the animals

Under 1 year

129

1–3 years

521

4–7 years

664

8–11 years

411

12+ years

265

About this medicine

Spinosad kills fleas; monthly chewable.

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

Questions owners ask

Can Spinosad cause seizures in dogs?: 2,116 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 4 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).

Seizures with similar medicines

Seizures after Lufenuron + Milbemycin Oxime (Sentinel) 937 reports · 3.6% of its reports
Seizures after Imidacloprid + Moxidectin (Advantage Multi) 520 reports · 4.0% of its reports
Seizures after Nitenpyram (Capstar) 331 reports · 3.1% of its reports
Seizures after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 279 reports · 2.8% of its reports
Seizures after Fipronil + S-methoprene (Frontline Plus) 214 reports · 7.2% of its reports
Seizures after Flumethrin + Imidacloprid (Seresto) 123 reports · 5.4% of its reports
Seizures after Imidacloprid 43 reports · 2.3% of its reports
Seizures after Fipronil 72 reports · 5.1% of its reports
Seizures after Lufenuron 65 reports · 6.4% of its reports
Seizures after Imidacloprid + Permethrin + Pyriproxyfen 34 reports · 4.6% of its reports

All reported side effects of Spinosad in dogs · Medicines most reported with seizures