Loss of appetite after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) in dogs

The FDA has received 387 reports of loss of appetite in dogs after Ivermectin + Praziquantel + Pyrantel. That is 4.5% of all reports for this medicine, compared with 8.4% across reports for all dog medicines, so it is reported less often than average with this medicine.

387Reports
35%Marked serious
43%Recovered
10%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
135 49%
1–2 days
70 25%
3–7 days
19 6.9%
1–4 weeks
30 11%
Over a month
23 8.3%

How the animals did

Recovered
160 41%
Recovered with lasting effects
6 1.6%
Still unwell when reported
26 6.7%
Died
27 7.0%
Euthanised
12 3.1%
Not known
156 40%

Problems reported at the same time

210 54%
190 49%
107 28%
48 12%
37 9.6%
29 7.5%

Age of the animals

Under 1 year
37
1–3 years
101
4–7 years
115
8–11 years
92
12+ years
33

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 loss of appetite in dogs?
387 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 1 day 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).

Loss of appetite with similar medicines

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