Swelling after Spinosad (Comfortis) in dogs

The FDA has received 399 reports of swelling in dogs after Spinosad. That is 0.7% of all reports for this medicine, compared with 2.8% across reports for all dog medicines, so it is reported less often than average with this medicine.

399Reports

36%Marked serious

32%Recovered

16%Died or euthanised

1 daysTypical onset

How soon it started

Same day

75 44%

1–2 days

24 14%

3–7 days

7 4.1%

1–4 weeks

18 11%

Over a month

47 27%

How the animals did

Recovered

93 23%

Recovered with lasting effects

35 8.8%

Still unwell when reported

25 6.3%

Died

50 13%

Euthanised

15 3.8%

Not known

181 45%

Problems reported at the same time

118 30%

108 27%

102 26%

64 16%

62 16%

55 14%

35 8.8%

33 8.3%

Age of the animals

Under 1 year

1–3 years

139

4–7 years

101

8–11 years

12+ years

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 swelling in dogs?: 399 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 1 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).

Swelling with similar medicines

Swelling after Lufenuron + Milbemycin Oxime (Sentinel) 219 reports · 0.8% of its reports
Swelling after Imidacloprid + Moxidectin (Advantage Multi) 218 reports · 1.7% of its reports
Swelling after Nitenpyram (Capstar) 127 reports · 1.2% of its reports
Swelling after Lufenuron + Milbemycin Oxime + Praziquantel (Sentinel Spectrum) 70 reports · 0.7% of its reports
Swelling after Fipronil + S-methoprene (Frontline Plus) 42 reports · 1.4% of its reports
Swelling after Flumethrin + Imidacloprid (Seresto) 47 reports · 2.1% of its reports
Swelling after Fipronil 20 reports · 1.4% of its reports
Swelling after Lufenuron 44 reports · 4.3% of its reports

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