Localised pain (see other 'socs' for specific pain) after Milbemycin Oxime + Spinosad (Trifexis) in dogs

194 reports to the FDA describe localised pain (see other 'socs' for specific pain) in dogs given Milbemycin Oxime + Spinosad. That is 0.1% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

194Reports

51%Marked serious

46%Recovered

9.3%Died or euthanised

13 daysTypical onset

How soon it started

Same day

44 32%

1–2 days

17 13%

3–7 days

4 2.9%

1–4 weeks

14 10%

Over a month

57 42%

How the animals did

Recovered

67 35%

Recovered with lasting effects

23 12%

Still unwell when reported

33 17%

Died

9 4.6%

Euthanised

9 4.6%

Not known

53 27%

Problems reported at the same time

100 52%

56 29%

52 27%

51 26%

50 26%

41 21%

36 19%

32 16%

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 localised pain (see other 'socs' for specific pain) in dogs?: 194 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).

Localised pain (see other 'socs' for specific pain) with similar medicines

Localised pain (see other 'socs' for specific pain) after Ivermectin + Pyrantel (Heartgard Plus) 76 reports · 0.1% of its reports
Localised pain (see other 'socs' for specific pain) after Moxidectin (ProHeart 6) 126 reports · 0.2% of its reports
Localised pain (see other 'socs' for specific pain) after Milbemycin Oxime + Praziquantel (Interceptor Plus) 47 reports · 0.1% of its reports
Localised pain (see other 'socs' for specific pain) after Milbemycin Oxime (Interceptor) 23 reports · 0.1% of its reports

All reported side effects of Milbemycin Oxime + Spinosad in dogs · Medicines most reported with localised pain (see other 'socs' for specific pain)