Hyperphosphataemia after Moxidectin (ProHeart 6) in dogs

219 reports to the FDA describe hyperphosphataemia in dogs given Moxidectin. That is 0.4% of all reports for this medicine, compared with 0.6% across reports for all dog medicines.

219Reports

50%Marked serious

4.6%Recovered

46%Died or euthanised

1 daysTypical onset

How soon it started

Same day

44 34%

1–2 days

32 25%

3–7 days

19 15%

1–4 weeks

18 14%

Over a month

15 12%

How the animals did

Recovered

10 4.6%

Still unwell when reported

73 33%

Died

66 30%

Euthanised

35 16%

Not known

35 16%

Problems reported at the same time

164 75%

135 62%

114 52%

108 49%

106 48%

100 46%

70 32%

65 30%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 hyperphosphataemia in dogs?: 219 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).

Hyperphosphataemia with similar medicines

Hyperphosphataemia after Ivermectin + Pyrantel (Heartgard Plus) 164 reports · 0.1% of its reports
Hyperphosphataemia after Milbemycin Oxime + Spinosad (Trifexis) 236 reports · 0.2% of its reports
Hyperphosphataemia after Milbemycin Oxime + Praziquantel (Interceptor Plus) 56 reports · 0.2% of its reports
Hyperphosphataemia after Milbemycin Oxime (Interceptor) 59 reports · 0.2% of its reports
Hyperphosphataemia after Selamectin (Revolution) 57 reports · 0.2% of its reports
Hyperphosphataemia after Ivermectin (Heartgard) 44 reports · 0.4% of its reports

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