Liver problems after Milbemycin Oxime (Interceptor) in dogs

531 reports to the FDA describe liver problems in dogs given Milbemycin Oxime. That is 1.8% of all reports for this medicine, compared with 4.6% across reports for all dog medicines, so it is reported less often than average with this medicine.

531Reports

32%Marked serious

6.0%Recovered

21%Died or euthanised

24 daysTypical onset

How soon it started

Same day

25 22%

1–2 days

13 11%

3–7 days

10 8.6%

1–4 weeks

16 14%

Over a month

52 45%

How the animals did

Recovered

21 4.0%

Recovered with lasting effects

11 2.1%

Still unwell when reported

96 18%

Died

82 15%

Euthanised

28 5.3%

Not known

293 55%

Problems reported at the same time

182 34%

168 32%

166 31%

114 21%

93 18%

88 17%

77 15%

65 12%

Age of the animals

Under 1 year

1–3 years

104

4–7 years

134

8–11 years

149

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 liver problems in dogs?: 531 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 24 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).

Liver problems with similar medicines

Liver problems after Ivermectin + Pyrantel (Heartgard Plus) 1,518 reports · 1.0% of its reports
Liver problems after Milbemycin Oxime + Spinosad (Trifexis) 2,221 reports · 1.7% of its reports
Liver problems after Moxidectin (ProHeart 6) 2,025 reports · 4.0% of its reports
Liver problems after Milbemycin Oxime + Praziquantel (Interceptor Plus) 534 reports · 1.7% of its reports
Liver problems after Selamectin (Revolution) 560 reports · 1.9% of its reports
Liver problems after Ivermectin (Heartgard) 369 reports · 3.1% of its reports
Liver problems after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 149 reports · 1.7% of its reports
Liver problems after Moxidectin + Pyrantel + Sarolaner (Simparica Trio) 63 reports · 5.4% of its reports

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