Didn't stop ticks after Milbemycin Oxime + Praziquantel (Interceptor Plus) in dogs

311 reports to the FDA describe didn't stop ticks in dogs given Milbemycin Oxime + Praziquantel. That is 1.0% of all reports for this medicine, compared with 2.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

311Reports

9.0%Marked serious

1.9%Recovered

0.3%Died or euthanised

114 daysTypical onset

How soon it started

Same day

6 4.0%

1–2 days

4 2.7%

3–7 days

6 4.0%

1–4 weeks

25 17%

Over a month

108 72%

How the animals did

Recovered

5 1.6%

Recovered with lasting effects

1 0.3%

Still unwell when reported

27 8.7%

Died

1 0.3%

Not known

277 89%

Problems reported at the same time

Didn't work as expected

182 59%

Lethargy

15 4.8%

Didn't prevent heartworm

13 4.2%

10 3.2%

9 2.9%

9 2.9%

8 2.6%

8 2.6%

Age of the animals

Under 1 year

1–3 years

149

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 didn't stop ticks in dogs?: 311 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 114 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).

Didn't stop ticks with similar medicines

Didn't stop ticks after Ivermectin + Pyrantel (Heartgard Plus) 438 reports · 0.3% of its reports
Didn't stop ticks after Milbemycin Oxime + Spinosad (Trifexis) 312 reports · 0.2% of its reports
Didn't stop ticks after Milbemycin Oxime (Interceptor) 41 reports · 0.1% of its reports
Didn't stop ticks after Selamectin (Revolution) 1,191 reports · 4.1% of its reports
Didn't stop ticks after Ivermectin (Heartgard) 38 reports · 0.3% of its reports

All reported side effects of Milbemycin Oxime + Praziquantel in dogs · Medicines most reported with didn't stop ticks