Anxiety after Milbemycin Oxime (Interceptor) in dogs

70 reports to the FDA describe anxiety in dogs given Milbemycin Oxime. That is 0.2% of all reports for this medicine, compared with 0.5% across reports for all dog medicines, so it is reported less often than average with this medicine.

70Reports

37%Marked serious

33%Recovered

4.3%Died or euthanised

6 daysTypical onset

How soon it started

Same day

13 28%

1–2 days

7 15%

3–7 days

5 11%

1–4 weeks

6 13%

Over a month

15 33%

How the animals did

Recovered

22 31%

Recovered with lasting effects

1 1.4%

Still unwell when reported

19 27%

Euthanised

3 4.3%

Not known

25 36%

Problems reported at the same time

21 30%

18 26%

15 21%

13 19%

Restlessness or agitation

11 16%

Tremors

9 13%

Breathing problems

9 13%

Itching

8 11%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 anxiety in dogs?: 70 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 6 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).

Anxiety with similar medicines

Anxiety after Ivermectin + Pyrantel (Heartgard Plus) 382 reports · 0.3% of its reports
Anxiety after Milbemycin Oxime + Spinosad (Trifexis) 623 reports · 0.5% of its reports
Anxiety after Moxidectin (ProHeart 6) 156 reports · 0.3% of its reports
Anxiety after Milbemycin Oxime + Praziquantel (Interceptor Plus) 194 reports · 0.6% of its reports
Anxiety after Selamectin (Revolution) 54 reports · 0.2% of its reports
Anxiety after Ivermectin (Heartgard) 75 reports · 0.6% of its reports
Anxiety after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 30 reports · 0.4% of its reports

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