Gagging after Milbemycin Oxime + Praziquantel (Interceptor Plus) in dogs

The FDA has received 71 reports of gagging in dogs after Milbemycin Oxime + Praziquantel. That is 0.2% of all reports for this medicine, compared with 0.2% across reports for all dog medicines.

71Reports

21%Marked serious

41%Recovered

4.2%Died or euthanised

3 daysTypical onset

How soon it started

Same day

24 46%

1–2 days

1 1.9%

3–7 days

2 3.8%

1–4 weeks

6 12%

Over a month

19 37%

How the animals did

Recovered

29 41%

Still unwell when reported

17 24%

Died

2 2.8%

Euthanised

1 1.4%

Not known

22 31%

Problems reported at the same time

39 55%

16 23%

12 17%

10 14%

9 13%

9 13%

7 9.9%

6 8.5%

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 gagging in dogs?: 71 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 3 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).

Gagging with similar medicines

Gagging after Ivermectin + Pyrantel (Heartgard Plus) 194 reports · 0.1% of its reports
Gagging after Milbemycin Oxime + Spinosad (Trifexis) 296 reports · 0.2% of its reports
Gagging after Moxidectin (ProHeart 6) 78 reports · 0.2% of its reports
Gagging after Milbemycin Oxime (Interceptor) 40 reports · 0.1% of its reports
Gagging after Selamectin (Revolution) 56 reports · 0.2% of its reports
Gagging after Ivermectin (Heartgard) 20 reports · 0.2% of its reports

All reported side effects of Milbemycin Oxime + Praziquantel in dogs · Medicines most reported with gagging