Behaviour change after Amoxicillin in dogs

84 reports to the FDA describe behaviour change in dogs given Amoxicillin. That is 6.2% of all reports for this medicine, compared with 2.5% across reports for all dog medicines, so it is reported unusually often with this medicine.

84Reports

65%Marked serious

17%Recovered

24%Died or euthanised

17 daysTypical onset

How soon it started

Same day

8 12%

1–2 days

7 11%

3–7 days

11 17%

1–4 weeks

16 24%

Over a month

24 36%

How the animals did

Recovered

12 14%

Recovered with lasting effects

2 2.4%

Still unwell when reported

23 27%

Died

5 6.0%

Euthanised

15 18%

Not known

27 32%

Problems reported at the same time

37 44%

36 43%

26 31%

20 24%

19 23%

18 21%

15 18%

13 15%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Amoxicillin treats bacterial infections.

Questions owners ask

Can Amoxicillin cause behaviour change in dogs?: 84 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 17 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).

Behaviour change with similar medicines

Behaviour change after Amoxicillin + Clavulanate (Clavamox) 226 reports · 4.2% of its reports
Behaviour change after Doxycycline 135 reports · 3.4% of its reports
Behaviour change after Cefovecin (Convenia) 164 reports · 4.3% of its reports
Behaviour change after Enrofloxacin (Baytril) 196 reports · 5.2% of its reports
Behaviour change after Metronidazole 164 reports · 5.3% of its reports

All reported side effects of Amoxicillin in dogs · Medicines most reported with behaviour change