Urinary tract infection after Levothyroxine in dogs

64 reports to the FDA describe urinary tract infection in dogs given Levothyroxine. That is 2.1% 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.

64Reports

66%Marked serious

16%Recovered

14%Died or euthanised

148 daysTypical onset

How soon it started

Same day

2 5.1%

1–2 days

1 2.6%

3–7 days

3 7.7%

1–4 weeks

6 15%

Over a month

27 69%

How the animals did

Recovered

7 11%

Recovered with lasting effects

3 4.7%

Still unwell when reported

23 36%

Died

2 3.1%

Euthanised

7 11%

Not known

22 34%

Problems reported at the same time

16 25%

16 25%

16 25%

15 23%

15 23%

Didn't work as expected

12 19%

Liver problems

12 19%

Excessive urination

11 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 urinary tract infection in dogs?: 64 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 148 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 tract infection with similar medicines

Urinary tract infection after Trilostane (Vetoryl) 593 reports · 5.0% of its reports
Urinary tract infection after Insulin 177 reports · 2.4% of its reports
Urinary tract infection after Phenylpropanolamine (Proin) 100 reports · 2.4% of its reports

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