Thrombocytosis after Spinosad (Comfortis) in dogs

63 reports to the FDA describe thrombocytosis in dogs given Spinosad. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported less often than average with this medicine.

63Reports
57%Marked serious
22%Recovered
22%Died or euthanised
94 daysTypical onset
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How soon it started

Same day
7 25%
1–2 days
5 18%
3–7 days
0 0.0%
1–4 weeks
1 3.6%
Over a month
15 54%

How the animals did

Recovered
7 11%
Recovered with lasting effects
7 11%
Still unwell when reported
9 14%
Died
7 11%
Euthanised
7 11%
Not known
26 41%

Problems reported at the same time

Age of the animals

Under 1 year
3
1–3 years
7
4–7 years
21
8–11 years
14
12+ years
18

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 thrombocytosis in dogs?
63 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 94 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).

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