Excessive thirst after Spinosad (Comfortis) in dogs

The FDA has received 374 reports of excessive thirst in dogs after Spinosad. That is 0.7% of all reports for this medicine, compared with 1.4% across reports for all dog medicines, so it is reported less often than average with this medicine.

374Reports

22%Marked serious

22%Recovered

13%Died or euthanised

4 daysTypical onset

How soon it started

Same day

42 34%

1–2 days

13 11%

3–7 days

7 5.7%

1–4 weeks

18 15%

Over a month

43 35%

How the animals did

Recovered

43 11%

Recovered with lasting effects

38 10%

Still unwell when reported

29 7.8%

Died

35 9.4%

Euthanised

14 3.7%

Not known

215 57%

Problems reported at the same time

139 37%

124 33%

124 33%

110 29%

74 20%

50 13%

46 12%

43 11%

Age of the animals

Under 1 year

1–3 years

4–7 years

114

8–11 years

117

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 excessive thirst in dogs?: 374 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).

Excessive thirst with similar medicines

Excessive thirst after Lufenuron + Milbemycin Oxime (Sentinel) 131 reports · 0.5% of its reports
Excessive thirst after Imidacloprid + Moxidectin (Advantage Multi) 114 reports · 0.9% of its reports
Excessive thirst after Nitenpyram (Capstar) 50 reports · 0.5% of its reports
Excessive thirst after Fipronil + S-methoprene (Frontline Plus) 23 reports · 0.8% of its reports
Excessive thirst after Flumethrin + Imidacloprid (Seresto) 21 reports · 0.9% of its reports
Excessive thirst after Fipronil 23 reports · 1.6% of its reports

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