Unable to stand after Milbemycin Oxime + Praziquantel (Interceptor Plus) in dogs

The FDA has received 76 reports of unable to stand in dogs after Milbemycin Oxime + Praziquantel. That is 0.2% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.

76Reports
57%Marked serious
29%Recovered
12%Died or euthanised
3 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
19 36%
1–2 days
7 13%
3–7 days
4 7.5%
1–4 weeks
4 7.5%
Over a month
19 36%

How the animals did

Recovered
22 29%
Still unwell when reported
29 38%
Died
4 5.3%
Euthanised
5 6.6%
Not known
16 21%

Problems reported at the same time

Age of the animals

Under 1 year
15
1–3 years
16
4–7 years
13
8–11 years
12
12+ years
15

About this medicine

Milbemycin Oxime prevents heartworm and controls some intestinal worms (monthly). Praziquantel treats tapeworms.

Products with this combination include Interceptor Plus. 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 Milbemycin Oxime + Praziquantel cause unable to stand in dogs?
76 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 3 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).

Unable to stand with similar medicines

All reported side effects of Milbemycin Oxime + Praziquantel in dogs · Medicines most reported with unable to stand