Distension of abdomen after Diphenhydramine in dogs

The FDA has received 32 reports of distension of abdomen in dogs after Diphenhydramine. That is 0.7% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported unusually often with this medicine.

32Reports

81%Marked serious

22%Recovered

38%Died or euthanised

3 daysTypical onset

How soon it started

Same day

10 40%

1–2 days

2 8.0%

3–7 days

5 20%

1–4 weeks

2 8.0%

Over a month

6 24%

How the animals did

Recovered

5 16%

Recovered with lasting effects

2 6.3%

Still unwell when reported

9 28%

Died

4 13%

Euthanised

8 25%

Not known

4 13%

Problems reported at the same time

15 47%

15 47%

13 41%

13 41%

12 38%

12 38%

10 31%

9 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 distension of abdomen in dogs?: 32 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).

Distension of abdomen with similar medicines

Distension of abdomen after Melarsomine (Immiticide) 54 reports · 0.2% of its reports
Distension of abdomen after Butorphanol 24 reports · 0.5% of its reports
Distension of abdomen after Cefpodoxime 30 reports · 0.7% of its reports
Distension of abdomen after Tramadol 55 reports · 1.5% of its reports
Distension of abdomen after Desoxycorticosterone Pivalate 20 reports · 0.6% of its reports
Distension of abdomen after Propofol 21 reports · 0.7% of its reports
Distension of abdomen after Dirlotapide 21 reports · 0.7% of its reports
Distension of abdomen after Isoflurane 24 reports · 0.9% of its reports
Distension of abdomen after Famotidine 32 reports · 1.2% of its reports
Distension of abdomen after Furosemide 20 reports · 1.3% of its reports

All reported side effects of Diphenhydramine in dogs · Medicines most reported with distension of abdomen