Collapse after Butorphanol in horses

The FDA has received 29 reports of collapse in horses after Butorphanol. That is 9.7% of all reports for this medicine, compared with 2.5% across reports for all horse medicines, so it is reported unusually often with this medicine.

29Reports

69%Marked serious

17%Recovered

83%Died or euthanised

Same dayTypical onset

How soon it started

Same day

19 90%

1–2 days

1 4.8%

3–7 days

0 0.0%

1–4 weeks

0 0.0%

Over a month

1 4.8%

How the animals did

Recovered

5 17%

Died

18 62%

Euthanised

6 21%

Problems reported at the same time

Death

24 83%

Pale mucous membrane

11 38%

Wobbliness (ataxia)

10 34%

Allergic reaction

10 34%

Seizures

9 31%

Breathing problems

6 21%

Apnoea

5 17%

Nystagmus

4 14%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Type: medicine.

Questions owners ask

Can Butorphanol cause collapse in horses?: 29 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).

Collapse with similar medicines

Collapse after Ceftiofur 61 reports · 5.0% of its reports
Collapse after Detomidine 63 reports · 6.4% of its reports
Collapse after Flunixin Meglumine 55 reports · 8.8% of its reports
Collapse after Xylazine 42 reports · 9.0% of its reports

All reported side effects of Butorphanol in horses · Medicines most reported with collapse