Inappropriate urination after Milbemycin Oxime (Interceptor) in dogs

The FDA has received 34 reports of inappropriate urination in dogs after Milbemycin Oxime. 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.

34Reports

50%Marked serious

32%Recovered

12%Died or euthanised

1 daysTypical onset

How soon it started

Same day

9 43%

1–2 days

3 14%

3–7 days

1 4.8%

1–4 weeks

1 4.8%

Over a month

7 33%

How the animals did

Recovered

9 26%

Recovered with lasting effects

2 5.9%

Still unwell when reported

11 32%

Died

1 2.9%

Euthanised

3 8.8%

Not known

8 24%

Problems reported at the same time

10 29%

8 24%

8 24%

6 18%

6 18%

4 12%

4 12%

4 12%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly).

Products with this ingredient include Interceptor. 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 Milbemycin Oxime cause inappropriate urination in dogs?: 34 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 1 day 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).

Inappropriate urination with similar medicines

Inappropriate urination after Ivermectin + Pyrantel (Heartgard Plus) 352 reports · 0.2% of its reports
Inappropriate urination after Milbemycin Oxime + Spinosad (Trifexis) 494 reports · 0.4% of its reports
Inappropriate urination after Moxidectin (ProHeart 6) 168 reports · 0.3% of its reports
Inappropriate urination after Milbemycin Oxime + Praziquantel (Interceptor Plus) 124 reports · 0.4% of its reports
Inappropriate urination after Selamectin (Revolution) 35 reports · 0.1% of its reports
Inappropriate urination after Ivermectin (Heartgard) 60 reports · 0.5% of its reports
Inappropriate urination after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 20 reports · 0.2% of its reports

All reported side effects of Milbemycin Oxime in dogs · Medicines most reported with inappropriate urination