Hyperkalaemia after Moxidectin (ProHeart 6) in dogs

The FDA has received 79 reports of hyperkalaemia in dogs after Moxidectin. That is 0.2% of all reports for this medicine, compared with 0.3% across reports for all dog medicines, so it is reported less often than average with this medicine.

79Reports
37%Marked serious
1.3%Recovered
43%Died or euthanised
2 daysTypical onset
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How soon it started

Same day
11 29%
1–2 days
11 29%
3–7 days
7 18%
1–4 weeks
3 7.9%
Over a month
6 16%

How the animals did

Recovered
1 1.3%
Still unwell when reported
24 30%
Died
26 33%
Euthanised
8 10%
Not known
20 25%

Problems reported at the same time

Age of the animals

Under 1 year
4
1–3 years
23
4–7 years
23
8–11 years
19
12+ years
10

About this medicine

Moxidectin prevents heartworm disease (monthly topical, or a 6- or 12-month injection for dogs).

Products with this ingredient include ProHeart 6, ProHeart 12. 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 Moxidectin cause hyperkalaemia in dogs?
79 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 2 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).

Hyperkalaemia with similar medicines

All reported side effects of Moxidectin in dogs · Medicines most reported with hyperkalaemia