Urinary incontinence after Milbemycin Oxime + Spinosad (Trifexis) in dogs

309 reports to the FDA describe urinary incontinence in dogs given Milbemycin Oxime + Spinosad. That is 0.2% of all reports for this medicine, compared with 0.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

309Reports

51%Marked serious

40%Recovered

8.7%Died or euthanised

10 daysTypical onset

How soon it started

Same day

76 39%

1–2 days

14 7.2%

3–7 days

5 2.6%

1–4 weeks

21 11%

Over a month

78 40%

How the animals did

Recovered

78 25%

Recovered with lasting effects

47 15%

Still unwell when reported

91 29%

Died

11 3.6%

Euthanised

16 5.2%

Not known

66 21%

Problems reported at the same time

110 36%

93 30%

55 18%

42 14%

39 13%

34 11%

31 10%

26 8.4%

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). Spinosad kills fleas; monthly chewable.

Products with this combination include Trifexis. 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 + Spinosad cause urinary incontinence in dogs?: 309 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 10 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 Ivermectin + Pyrantel (Heartgard Plus) 190 reports · 0.1% of its reports
Urinary incontinence after Moxidectin (ProHeart 6) 171 reports · 0.3% of its reports
Urinary incontinence after Milbemycin Oxime + Praziquantel (Interceptor Plus) 112 reports · 0.4% of its reports
Urinary incontinence after Milbemycin Oxime (Interceptor) 86 reports · 0.3% of its reports
Urinary incontinence after Selamectin (Revolution) 86 reports · 0.3% of its reports
Urinary incontinence after Ivermectin (Heartgard) 46 reports · 0.4% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with urinary incontinence