Urinary tract infection after Ivermectin + Pyrantel (Heartgard Plus) in dogs

135 reports to the FDA describe urinary tract infection in dogs given Ivermectin + Pyrantel. That is 0.1% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported less often than average with this medicine.

135Reports

59%Marked serious

15%Recovered

8.9%Died or euthanised

14 daysTypical onset

How soon it started

Same day

9 12%

1–2 days

10 13%

3–7 days

7 9.2%

1–4 weeks

26 34%

Over a month

24 32%

How the animals did

Recovered

16 12%

Recovered with lasting effects

4 3.0%

Still unwell when reported

36 27%

Died

6 4.4%

Euthanised

6 4.4%

Not known

67 50%

Problems reported at the same time

30 22%

29 21%

29 21%

27 20%

22 16%

19 14%

17 13%

Didn't prevent heartworm

15 11%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Ivermectin prevents heartworm disease (monthly). Pyrantel treats roundworms and hookworms.

Products with this combination include Heartgard Plus, Tri-Heart Plus, Iverhart Plus. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.

Questions owners ask

Can Ivermectin + Pyrantel cause urinary tract infection in dogs?: 135 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 14 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 Milbemycin Oxime + Spinosad (Trifexis) 337 reports · 0.3% of its reports
Urinary tract infection after Moxidectin (ProHeart 6) 111 reports · 0.2% of its reports
Urinary tract infection after Milbemycin Oxime + Praziquantel (Interceptor Plus) 147 reports · 0.5% of its reports
Urinary tract infection after Milbemycin Oxime (Interceptor) 50 reports · 0.2% of its reports
Urinary tract infection after Selamectin (Revolution) 34 reports · 0.1% of its reports
Urinary tract infection after Ivermectin (Heartgard) 52 reports · 0.4% of its reports

All reported side effects of Ivermectin + Pyrantel in dogs · Medicines most reported with urinary tract infection