Behaviour change after Ampicillin in cats

36 reports to the FDA describe behaviour change in cats given Ampicillin. That is 12% of all reports for this medicine, compared with 5.4% across reports for all cat medicines, so it is reported unusually often with this medicine.

36Reports
72%Marked serious
8.3%Recovered
33%Died or euthanised
1 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
11 32%
1–2 days
16 47%
3–7 days
2 5.9%
1–4 weeks
2 5.9%
Over a month
3 8.8%

How the animals did

Recovered
3 8.3%
Still unwell when reported
13 36%
Died
2 5.6%
Euthanised
10 28%
Not known
8 22%

Problems reported at the same time

Age of the animals

Under 1 year
6
1–3 years
6
4–7 years
8
8–11 years
6
12+ years
10

About this medicine

Type: medicine.

Questions owners ask

Can Ampicillin cause behaviour change in cats?
36 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 1 day 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).

Behaviour change with similar medicines

All reported side effects of Ampicillin in cats · Medicines most reported with behaviour change