Lethargy after Butorphanol in dogs

The FDA has received 661 reports of lethargy in dogs after Butorphanol. That is 15% of all reports for this medicine, compared with 11% across reports for all dog medicines.

661Reports
67%Marked serious
19%Recovered
25%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
201 36%
1–2 days
120 22%
3–7 days
91 17%
1–4 weeks
78 14%
Over a month
61 11%

How the animals did

Recovered
125 19%
Recovered with lasting effects
2 0.3%
Still unwell when reported
231 35%
Died
76 11%
Euthanised
88 13%
Not known
139 21%

Problems reported at the same time

Age of the animals

Under 1 year
50
1–3 years
146
4–7 years
183
8–11 years
190
12+ years
78

About this medicine

Type: medicine.

Questions owners ask

Can Butorphanol cause lethargy in dogs?
661 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).

Lethargy with similar medicines

All reported side effects of Butorphanol in dogs · Medicines most reported with lethargy