Leucocytosis after Phenobarbital in dogs

The FDA has received 27 reports of leucocytosis in dogs after Phenobarbital. That is 1.7% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported unusually often with this medicine.

27Reports
74%Marked serious
3.7%Recovered
37%Died or euthanised
23 daysTypical onset
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How soon it started

Same day
2 15%
1–2 days
3 23%
3–7 days
1 7.7%
1–4 weeks
3 23%
Over a month
4 31%

How the animals did

Recovered with lasting effects
1 3.7%
Still unwell when reported
10 37%
Died
4 15%
Euthanised
6 22%
Not known
6 22%

Problems reported at the same time

Age of the animals

Under 1 year
1
1–3 years
0
4–7 years
7
8–11 years
15
12+ years
4

About this medicine

Type: medicine.

Questions owners ask

Can Phenobarbital cause leucocytosis in dogs?
27 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 23 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).

Leucocytosis with similar medicines

All reported side effects of Phenobarbital in dogs · Medicines most reported with leucocytosis