Hair loss after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) in dogs

The FDA has received 20 reports of hair loss in dogs after Ivermectin + Praziquantel + Pyrantel. That is 0.2% of all reports for this medicine, compared with 1.0% across reports for all dog medicines, so it is reported less often than average with this medicine.

20Reports

30%Marked serious

20%Recovered

0.0%Died or euthanised

7 daysTypical onset

How soon it started

Same day

5 42%

1–2 days

0 0.0%

3–7 days

2 17%

1–4 weeks

2 17%

Over a month

3 25%

How the animals did

Recovered

4 20%

Still unwell when reported

2 10%

Not known

14 70%

Problems reported at the same time

Itching

8 40%

Skin rash or irritation

4 20%

Skin scab

4 20%

Lethargy

2 10%

Hair coat discolouration

2 10%

Breathing problems

1 5.0%

Loss of appetite

1 5.0%

Blood problems

1 5.0%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Ivermectin prevents heartworm disease (monthly). Praziquantel treats tapeworms. Pyrantel treats roundworms and hookworms.

Products with this combination include Iverhart Max. 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 Ivermectin + Praziquantel + Pyrantel cause hair loss 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 7 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).

Hair loss with similar medicines

Hair loss after Ivermectin + Pyrantel (Heartgard Plus) 539 reports · 0.4% of its reports
Hair loss after Milbemycin Oxime + Spinosad (Trifexis) 1,029 reports · 0.8% of its reports
Hair loss after Moxidectin (ProHeart 6) 325 reports · 0.6% of its reports
Hair loss after Milbemycin Oxime + Praziquantel (Interceptor Plus) 158 reports · 0.5% of its reports
Hair loss after Milbemycin Oxime (Interceptor) 132 reports · 0.4% of its reports
Hair loss after Selamectin (Revolution) 1,036 reports · 3.5% of its reports
Hair loss after Ivermectin (Heartgard) 104 reports · 0.9% of its reports

All reported side effects of Ivermectin + Praziquantel + Pyrantel in dogs · Medicines most reported with hair loss