Drinking a lot after Ivermectin (Heartgard) in dogs

The FDA has received 35 reports of drinking a lot in dogs after Ivermectin. That is 0.3% of all reports for this medicine, compared with 0.2% across reports for all dog medicines, so it is reported unusually often with this medicine.

35Reports

40%Marked serious

43%Recovered

14%Died or euthanised

31 daysTypical onset

How soon it started

Same day

8 33%

1–2 days

2 8.3%

3–7 days

0 0.0%

1–4 weeks

2 8.3%

Over a month

12 50%

How the animals did

Recovered

11 31%

Recovered with lasting effects

4 11%

Still unwell when reported

11 31%

Died

1 2.9%

Euthanised

4 11%

Not known

4 11%

Problems reported at the same time

18 51%

13 37%

11 31%

10 29%

8 23%

Frequent urination

6 17%

Breathing problems

6 17%

Vocalising

6 17%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Ivermectin prevents heartworm disease (monthly).

Products with this ingredient include Heartgard. 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 Ivermectin cause drinking a lot in dogs?: 35 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 31 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).

Drinking a lot with similar medicines

Drinking a lot after Ivermectin + Pyrantel (Heartgard Plus) 118 reports · 0.1% of its reports
Drinking a lot after Milbemycin Oxime + Spinosad (Trifexis) 229 reports · 0.2% of its reports
Drinking a lot after Moxidectin (ProHeart 6) 37 reports · 0.1% of its reports
Drinking a lot after Milbemycin Oxime + Praziquantel (Interceptor Plus) 83 reports · 0.3% of its reports

All reported side effects of Ivermectin in dogs · Medicines most reported with drinking a lot