Bacterial skin infection after Levothyroxine in dogs

24 reports to the FDA describe bacterial skin infection in dogs given Levothyroxine. 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.

24Reports

63%Marked serious

21%Recovered

13%Died or euthanised

36 daysTypical onset

How soon it started

Same day

1 5.6%

1–2 days

0 0.0%

3–7 days

1 5.6%

1–4 weeks

5 28%

Over a month

11 61%

How the animals did

Recovered

3 13%

Recovered with lasting effects

2 8.3%

Still unwell when reported

10 42%

Died

3 13%

Not known

6 25%

Problems reported at the same time

8 33%

7 29%

7 29%

6 25%

Didn't work as expected

6 25%

Loss of appetite

5 21%

Skin rash or irritation

5 21%

Lethargy

4 17%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Levothyroxine treats an underactive thyroid.

Questions owners ask

Can Levothyroxine cause bacterial skin infection in dogs?: 24 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 36 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).

Bacterial skin infection with similar medicines

Bacterial skin infection after Trilostane (Vetoryl) 100 reports · 0.8% of its reports

All reported side effects of Levothyroxine in dogs · Medicines most reported with bacterial skin infection