Haemorrhagic gastroenteritis after Moxidectin (ProHeart 6) in dogs

The FDA has received 34 reports of haemorrhagic gastroenteritis in dogs after Moxidectin. That is 0.1% of all reports for this medicine, compared with 0.0% across reports for all dog medicines.

34Reports
62%Marked serious
29%Recovered
5.9%Died or euthanised
1 daysTypical onset
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How soon it started

Same day
17 50%
1–2 days
9 26%
3–7 days
1 2.9%
1–4 weeks
5 15%
Over a month
2 5.9%

How the animals did

Recovered
10 29%
Still unwell when reported
20 59%
Euthanised
2 5.9%
Not known
2 5.9%

Problems reported at the same time

Age of the animals

Under 1 year
1
1–3 years
16
4–7 years
9
8–11 years
7
12+ years
1

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 haemorrhagic gastroenteritis in dogs?
34 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 1 day 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).

Haemorrhagic gastroenteritis with similar medicines

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