Seizures after Heartgard in dogs

The FDA has received 22 reports of seizures in dogs after Heartgard. That is 5.8% of all reports for this medicine, compared with 4.4% across reports for all dog medicines.

22Reports
95%Marked serious
18%Recovered
18%Died or euthanised
75 daysTypical onset
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How soon it started

Same day
3 27%
1–2 days
0 0.0%
3–7 days
1 9.1%
1–4 weeks
0 0.0%
Over a month
7 64%

How the animals did

Recovered
4 18%
Still unwell when reported
10 45%
Died
2 9.1%
Euthanised
2 9.1%
Not known
4 18%

Problems reported at the same time

Tremors
6 27%
Kidney problems
5 23%
Death
4 18%
Disorientation
3 14%
Weight loss
2 9.1%
Loose stool
2 9.1%

Age of the animals

Under 1 year
1
1–3 years
2
4–7 years
7
8–11 years
7
12+ years
5

About this medicine

Type: medicine.

Questions owners ask

Can Heartgard cause seizures in dogs?
22 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 75 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).

Seizures with similar medicines

All reported side effects of Heartgard in dogs · Medicines most reported with seizures