Dermal mass after Diphenhydramine in dogs

The FDA has received 26 reports of dermal mass in dogs after Diphenhydramine. That is 0.6% 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.

26Reports

73%Marked serious

7.7%Recovered

23%Died or euthanised

36 daysTypical onset

How soon it started

Same day

3 16%

1–2 days

1 5.3%

3–7 days

2 11%

1–4 weeks

2 11%

Over a month

11 58%

How the animals did

Recovered

2 7.7%

Still unwell when reported

9 35%

Euthanised

6 23%

Not known

9 35%

Problems reported at the same time

Abnormal cytology

7 27%

Didn't work as expected

7 27%

Death

6 23%

Diarrhea

6 23%

Swelling

6 23%

Injection site reaction

5 19%

Vomiting

4 15%

Lethargy

4 15%

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 dermal mass in dogs?: 26 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 36 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).

Dermal mass with similar medicines

Dermal mass after Cefpodoxime 41 reports · 1.0% of its reports
Dermal mass after Tramadol 23 reports · 0.6% of its reports
Dermal mass after Cephalexin 26 reports · 1.0% of its reports

All reported side effects of Diphenhydramine in dogs · Medicines most reported with dermal mass