Swollen limb after Diphenhydramine in dogs

The FDA has received 79 reports of swollen limb in dogs after Diphenhydramine. That is 1.7% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

79Reports

41%Marked serious

16%Recovered

16%Died or euthanised

3 daysTypical onset

How soon it started

Same day

10 15%

1–2 days

18 27%

3–7 days

12 18%

1–4 weeks

14 21%

Over a month

13 19%

How the animals did

Recovered

13 16%

Still unwell when reported

18 23%

Died

5 6.3%

Euthanised

8 10%

Not known

35 44%

Problems reported at the same time

Swelling

54 68%

Injection site reaction

53 67%

38 48%

35 44%

32 41%

26 33%

23 29%

22 28%

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 Diphenhydramine cause swollen limb in dogs?: 79 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 3 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).

Swollen limb with similar medicines

Swollen limb after Butorphanol 83 reports · 1.9% of its reports
Swollen limb after Propofol 26 reports · 0.8% of its reports
Swollen limb after Atipamezole 46 reports · 1.7% of its reports
Swollen limb after Famotidine 65 reports · 2.5% of its reports
Swollen limb after Tigilanol Tiglate 236 reports · 12% of its reports

All reported side effects of Diphenhydramine in dogs · Medicines most reported with swollen limb