Eosinopenia after Diphenhydramine in dogs

38 reports to the FDA describe eosinopenia in dogs given Diphenhydramine. That is 0.8% 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.

38Reports

71%Marked serious

18%Recovered

21%Died or euthanised

5 daysTypical onset

How soon it started

Same day

12 33%

1–2 days

2 5.6%

3–7 days

8 22%

1–4 weeks

3 8.3%

Over a month

11 31%

How the animals did

Recovered

7 18%

Still unwell when reported

15 39%

Died

1 2.6%

Euthanised

7 18%

Not known

8 21%

Problems reported at the same time

25 66%

20 53%

18 47%

18 47%

14 37%

13 34%

13 34%

13 34%

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 eosinopenia in dogs?: 38 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 5 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).

Eosinopenia with similar medicines

Eosinopenia after Polysulfated Glycosaminoglycan 22 reports · 0.4% of its reports
Eosinopenia after Butorphanol 29 reports · 0.7% of its reports
Eosinopenia after Cefpodoxime 33 reports · 0.8% of its reports
Eosinopenia after Famotidine 38 reports · 1.4% of its reports
Eosinopenia after Ketoconazole 30 reports · 1.3% of its reports
Eosinopenia after Ampicillin 34 reports · 3.5% of its reports
Eosinopenia after Ondansetron 31 reports · 4.7% of its reports

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