Cough after Milbemycin Oxime + Spinosad (Trifexis) in dogs

853 reports to the FDA describe cough in dogs given Milbemycin Oxime + Spinosad. That is 0.7% of all reports for this medicine, compared with 0.8% across reports for all dog medicines.

853Reports

40%Marked serious

38%Recovered

13%Died or euthanised

17 daysTypical onset

How soon it started

Same day

171 31%

1–2 days

53 9.6%

3–7 days

30 5.4%

1–4 weeks

45 8.2%

Over a month

252 46%

How the animals did

Recovered

208 24%

Recovered with lasting effects

118 14%

Still unwell when reported

160 19%

Died

67 7.9%

Euthanised

43 5.0%

Not known

257 30%

Problems reported at the same time

Vomiting

281 33%

Lethargy

208 24%

Didn't prevent heartworm

191 22%

Loss of appetite

147 17%

Breathing problems

120 14%

Death

105 12%

Didn't work as expected

102 12%

Abnormal radiograph finding

90 11%

Age of the animals

Under 1 year

1–3 years

271

4–7 years

190

8–11 years

191

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 cough in dogs?: 853 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 17 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).

Cough with similar medicines

Cough after Ivermectin + Pyrantel (Heartgard Plus) 727 reports · 0.5% of its reports
Cough after Moxidectin (ProHeart 6) 434 reports · 0.9% of its reports
Cough after Milbemycin Oxime + Praziquantel (Interceptor Plus) 304 reports · 1.0% of its reports
Cough after Milbemycin Oxime (Interceptor) 193 reports · 0.6% of its reports
Cough after Selamectin (Revolution) 224 reports · 0.8% of its reports
Cough after Ivermectin (Heartgard) 117 reports · 1.0% of its reports
Cough after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 57 reports · 0.7% of its reports
Cough after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 24 reports · 2.1% of its reports

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