Shivering after Spinosad (Comfortis) in dogs

The FDA has received 73 reports of shivering in dogs after Spinosad. That is 0.1% of all reports for this medicine, compared with 0.1% across reports for all dog medicines.

73Reports

26%Marked serious

58%Recovered

4.1%Died or euthanised

Same dayTypical onset

How soon it started

Same day

33 57%

1–2 days

8 14%

3–7 days

1 1.7%

1–4 weeks

5 8.6%

Over a month

11 19%

How the animals did

Recovered

33 45%

Recovered with lasting effects

9 12%

Still unwell when reported

5 6.8%

Died

2 2.7%

Euthanised

1 1.4%

Not known

23 32%

Problems reported at the same time

40 55%

23 32%

17 23%

14 19%

11 15%

9 12%

6 8.2%

6 8.2%

Age of the animals

Under 1 year

1–3 years

4–7 years

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 shivering in dogs?: 73 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).

Shivering with similar medicines

Shivering after Lufenuron + Milbemycin Oxime (Sentinel) 20 reports · 0.1% of its reports
Shivering after Imidacloprid + Moxidectin (Advantage Multi) 26 reports · 0.2% of its reports
Shivering after Nitenpyram (Capstar) 22 reports · 0.2% of its reports

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