Skin disorders after Levothyroxine in dogs

The FDA has received 23 reports of skin disorders in dogs after Levothyroxine. That is 0.8% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported unusually often with this medicine.

23Reports

65%Marked serious

17%Recovered

8.7%Died or euthanised

159 daysTypical onset

How soon it started

Same day

1 8.3%

1–2 days

0 0.0%

3–7 days

0 0.0%

1–4 weeks

1 8.3%

Over a month

10 83%

How the animals did

Recovered

1 4.3%

Recovered with lasting effects

3 13%

Still unwell when reported

8 35%

Euthanised

2 8.7%

Not known

9 39%

Problems reported at the same time

Skin rash or irritation

6 26%

Didn't work as expected

6 26%

5 22%

5 22%

5 22%

4 17%

4 17%

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 skin disorders in dogs?: 23 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 159 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).

Skin disorders with similar medicines

Skin disorders after Trilostane (Vetoryl) 98 reports · 0.8% of its reports

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