Inappropriate urination after Milbemycin Oxime + Praziquantel (Interceptor Plus) in dogs

The FDA has received 124 reports of inappropriate urination in dogs after Milbemycin Oxime + Praziquantel. That is 0.4% of all reports for this medicine, compared with 0.5% across reports for all dog medicines.

124Reports

36%Marked serious

31%Recovered

8.9%Died or euthanised

13 daysTypical onset

How soon it started

Same day

22 25%

1–2 days

15 17%

3–7 days

4 4.6%

1–4 weeks

11 13%

Over a month

35 40%

How the animals did

Recovered

39 31%

Still unwell when reported

34 27%

Died

3 2.4%

Euthanised

8 6.5%

Not known

40 32%

Problems reported at the same time

47 38%

38 31%

33 27%

21 17%

18 15%

18 15%

Inappropriate defecation

17 14%

Wobbliness (ataxia)

16 13%

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). Praziquantel treats tapeworms.

Products with this combination include Interceptor 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 Milbemycin Oxime + Praziquantel cause inappropriate urination in dogs?: 124 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 13 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).

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 (Interceptor) 34 reports · 0.1% 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 + Praziquantel in dogs · Medicines most reported with inappropriate urination