Drooling after Levothyroxine in dogs

The FDA has received 42 reports of drooling in dogs after Levothyroxine. That is 1.4% of all reports for this medicine, compared with 1.4% across reports for all dog medicines.

42Reports

76%Marked serious

52%Recovered

21%Died or euthanised

33 daysTypical onset

How soon it started

Same day

4 14%

1–2 days

2 7.1%

3–7 days

7 25%

1–4 weeks

0 0.0%

Over a month

15 54%

How the animals did

Recovered

20 48%

Recovered with lasting effects

2 4.8%

Still unwell when reported

7 17%

Died

2 4.8%

Euthanised

7 17%

Not known

4 9.5%

Problems reported at the same time

16 38%

13 31%

13 31%

11 26%

10 24%

10 24%

9 21%

9 21%

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 drooling in dogs?: 42 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 33 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).

Drooling with similar medicines

Drooling after Trilostane (Vetoryl) 75 reports · 0.6% of its reports
Drooling after Insulin 29 reports · 0.4% of its reports
Drooling after Phenylpropanolamine (Proin) 130 reports · 3.1% of its reports

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