Elevated cholesterol (total) after Levothyroxine in dogs

25 reports to the FDA describe elevated cholesterol (total) in dogs given Levothyroxine. That is 0.8% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported unusually often with this medicine.

25Reports

56%Marked serious

8.0%Recovered

16%Died or euthanised

39 daysTypical onset

How soon it started

Same day

4 25%

1–2 days

1 6.3%

3–7 days

0 0.0%

1–4 weeks

1 6.3%

Over a month

10 63%

How the animals did

Recovered

2 8.0%

Still unwell when reported

10 40%

Euthanised

4 16%

Not known

9 36%

Problems reported at the same time

Liver problems

13 52%

Didn't work as expected

11 44%

9 36%

8 32%

7 28%

7 28%

7 28%

Elevated gamma-glutamyl transferase (ggt)

7 28%

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 elevated cholesterol (total) in dogs?: 25 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 39 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).

Elevated cholesterol (total) with similar medicines

Elevated cholesterol (total) after Trilostane (Vetoryl) 312 reports · 2.6% of its reports
Elevated cholesterol (total) after Insulin 83 reports · 1.1% of its reports
Elevated cholesterol (total) after Phenylpropanolamine (Proin) 20 reports · 0.5% of its reports

All reported side effects of Levothyroxine in dogs · Medicines most reported with elevated cholesterol (total)