Leucocytosis after Eprinomectin + Esafoxolaner + Praziquantel (NexGard Combo) in cats

The FDA has received 36 reports of leucocytosis in cats after Eprinomectin + Esafoxolaner + Praziquantel. That is 1.1% of all reports for this medicine, compared with 0.9% across reports for all cat medicines.

36Reports
78%Marked serious
8.3%Recovered
44%Died or euthanised
1 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
8 24%
1–2 days
18 53%
3–7 days
4 12%
1–4 weeks
4 12%
Over a month
0 0.0%

How the animals did

Recovered
3 8.3%
Still unwell when reported
9 25%
Died
2 5.6%
Euthanised
14 39%
Not known
8 22%

Problems reported at the same time

Age of the animals

Under 1 year
10
1–3 years
12
4–7 years
4
8–11 years
3
12+ years
7

About this medicine

Eprinomectin controls worms and prevents heartworm. Esafoxolaner kills fleas and ticks (spot-on for cats). Praziquantel treats tapeworms.

Products with this combination include NexGard Combo. 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 Eprinomectin + Esafoxolaner + Praziquantel cause leucocytosis in cats?
36 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).

Leucocytosis with similar medicines

All reported side effects of Eprinomectin + Esafoxolaner + Praziquantel in cats · Medicines most reported with leucocytosis