Urinary incontinence after Levothyroxine in dogs

39 reports to the FDA describe urinary incontinence in dogs given Levothyroxine. That is 1.3% of all reports for this medicine, compared with 0.6% across reports for all dog medicines, so it is reported unusually often with this medicine.

39Reports

36%Marked serious

18%Recovered

7.7%Died or euthanised

33 daysTypical onset

How soon it started

Same day

3 11%

1–2 days

3 11%

3–7 days

2 7.4%

1–4 weeks

4 15%

Over a month

15 56%

How the animals did

Recovered

6 15%

Recovered with lasting effects

1 2.6%

Still unwell when reported

17 44%

Died

1 2.6%

Euthanised

2 5.1%

Not known

12 31%

Problems reported at the same time

Excessive thirst

14 36%

Excessive urination

11 28%

Didn't work as expected

11 28%

7 18%

6 15%

6 15%

6 15%

5 13%

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 urinary incontinence in dogs?: 39 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).

Urinary incontinence with similar medicines

Urinary incontinence after Trilostane (Vetoryl) 123 reports · 1.0% of its reports
Urinary incontinence after Insulin 58 reports · 0.8% of its reports
Urinary incontinence after Phenylpropanolamine (Proin) 123 reports · 3.0% of its reports

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