Fever after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) in dogs

The FDA has received 20 reports of fever in dogs after Moxidectin + Pyrantel + Sarolaner. That is 1.7% of all reports for this medicine, compared with 1.4% across reports for all dog medicines.

20Reports

60%Marked serious

0.0%Recovered

30%Died or euthanised

61 daysTypical onset

How soon it started

Same day

2 13%

1–2 days

2 13%

3–7 days

0 0.0%

1–4 weeks

0 0.0%

Over a month

11 73%

How the animals did

Still unwell when reported

10 50%

Died

2 10%

Euthanised

4 20%

Not known

4 20%

Problems reported at the same time

14 70%

9 45%

7 35%

7 35%

6 30%

Leucocytosis

5 25%

Abnormal radiograph finding

5 25%

Urinary incontinence

4 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 fever in dogs?: 20 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 61 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).

Fever with similar medicines

Fever after Ivermectin + Pyrantel (Heartgard Plus) 597 reports · 0.4% of its reports
Fever after Milbemycin Oxime + Spinosad (Trifexis) 881 reports · 0.7% of its reports
Fever after Moxidectin (ProHeart 6) 1,914 reports · 3.8% of its reports
Fever after Milbemycin Oxime + Praziquantel (Interceptor Plus) 194 reports · 0.6% of its reports
Fever after Milbemycin Oxime (Interceptor) 255 reports · 0.9% of its reports
Fever after Selamectin (Revolution) 322 reports · 1.1% of its reports
Fever after Ivermectin (Heartgard) 154 reports · 1.3% of its reports
Fever after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 33 reports · 0.4% of its reports

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