Itching after Milbemycin Oxime (Interceptor) in dogs

563 reports to the FDA describe itching in dogs given Milbemycin Oxime. That is 1.9% of all reports for this medicine, compared with 4.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

563Reports
13%Marked serious
17%Recovered
2.3%Died or euthanised
11 daysTypical onset
SponsoredWorried about your pet? Ask a veterinarian online, 24/7

How soon it started

Same day
51 32%
1–2 days
21 13%
3–7 days
5 3.1%
1–4 weeks
20 12%
Over a month
64 40%

How the animals did

Recovered
79 14%
Recovered with lasting effects
18 3.2%
Still unwell when reported
78 14%
Died
9 1.6%
Euthanised
4 0.7%
Not known
375 67%

Problems reported at the same time

Age of the animals

Under 1 year
68
1–3 years
185
4–7 years
159
8–11 years
100
12+ years
27

About this medicine

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

Products with this ingredient include Interceptor. 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 cause itching in dogs?
563 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 11 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).

Itching with similar medicines

All reported side effects of Milbemycin Oxime in dogs · Medicines most reported with itching