Excessive thirst after Milbemycin Oxime (Interceptor) in dogs

The FDA has received 147 reports of excessive thirst in dogs after Milbemycin Oxime. That is 0.5% of all reports for this medicine, compared with 1.4% across reports for all dog medicines, so it is reported less often than average with this medicine.

147Reports

18%Marked serious

8.2%Recovered

12%Died or euthanised

37 daysTypical onset

How soon it started

Same day

8 25%

1–2 days

3 9.4%

3–7 days

1 3.1%

1–4 weeks

4 13%

Over a month

16 50%

How the animals did

Recovered

11 7.5%

Recovered with lasting effects

1 0.7%

Still unwell when reported

18 12%

Died

13 8.8%

Euthanised

4 2.7%

Not known

100 68%

Problems reported at the same time

66 45%

54 37%

40 27%

40 27%

29 20%

21 14%

Decreased urine concentration

18 12%

Kidney problems

18 12%

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 excessive thirst in dogs?: 147 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 37 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).

Excessive thirst with similar medicines

Excessive thirst after Ivermectin + Pyrantel (Heartgard Plus) 404 reports · 0.3% of its reports
Excessive thirst after Milbemycin Oxime + Spinosad (Trifexis) 448 reports · 0.3% of its reports
Excessive thirst after Moxidectin (ProHeart 6) 361 reports · 0.7% of its reports
Excessive thirst after Milbemycin Oxime + Praziquantel (Interceptor Plus) 123 reports · 0.4% of its reports
Excessive thirst after Selamectin (Revolution) 160 reports · 0.5% of its reports
Excessive thirst after Ivermectin (Heartgard) 100 reports · 0.8% of its reports
Excessive thirst after Ivermectin + Praziquantel + Pyrantel (Iverhart Max) 25 reports · 0.3% of its reports

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