Hyperphosphataemia after Spinosad (Comfortis) in dogs

135 reports to the FDA describe hyperphosphataemia in dogs given Spinosad. That is 0.2% of all reports for this medicine, compared with 0.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

135Reports
59%Marked serious
22%Recovered
42%Died or euthanised
2 daysTypical onset
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How soon it started

Same day
23 33%
1–2 days
18 26%
3–7 days
2 2.9%
1–4 weeks
3 4.3%
Over a month
23 33%

How the animals did

Recovered
17 13%
Recovered with lasting effects
13 9.6%
Still unwell when reported
16 12%
Died
36 27%
Euthanised
21 16%
Not known
32 24%

Problems reported at the same time

Age of the animals

Under 1 year
25
1–3 years
22
4–7 years
29
8–11 years
31
12+ years
28

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 hyperphosphataemia in dogs?
135 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 2 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).

Hyperphosphataemia with similar medicines

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