Blood problems after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) in dogs

The FDA has received 30 reports of blood problems in dogs after Moxidectin + Pyrantel + Sarolaner. That is 2.6% of all reports for this medicine, compared with 1.8% across reports for all dog medicines.

30Reports

67%Marked serious

10%Recovered

23%Died or euthanised

63 daysTypical onset

How soon it started

Same day

1 4.2%

1–2 days

1 4.2%

3–7 days

2 8.3%

1–4 weeks

5 21%

Over a month

15 63%

How the animals did

Recovered

3 10%

Still unwell when reported

8 27%

Died

2 6.7%

Euthanised

5 17%

Not known

12 40%

Problems reported at the same time

12 40%

9 30%

8 27%

7 23%

Decreased haematocrit

7 23%

Pale mucous membrane

6 20%

Diarrhea

6 20%

Vomiting

6 20%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs). Pyrantel treats roundworms and hookworms. Sarolaner kills fleas, ticks and some mites; monthly.

Products with this combination include Simparica Trio. 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 Moxidectin + Pyrantel + Sarolaner cause blood problems in dogs?: 30 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 63 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).

Blood problems with similar medicines

Blood problems after Ivermectin + Pyrantel (Heartgard Plus) 545 reports · 0.4% of its reports
Blood problems after Milbemycin Oxime + Spinosad (Trifexis) 735 reports · 0.6% of its reports
Blood problems after Moxidectin (ProHeart 6) 1,343 reports · 2.7% of its reports
Blood problems after Milbemycin Oxime + Praziquantel (Interceptor Plus) 225 reports · 0.7% of its reports
Blood problems after Milbemycin Oxime (Interceptor) 251 reports · 0.8% of its reports
Blood problems after Selamectin (Revolution) 327 reports · 1.1% of its reports
Blood problems after Ivermectin (Heartgard) 145 reports · 1.2% of its reports
Blood problems after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 37 reports · 0.4% of its reports

All reported side effects of Moxidectin + Pyrantel + Sarolaner in dogs · Medicines most reported with blood problems