Lethargy after Melatonin in dogs

50 reports to the FDA describe lethargy in dogs given Melatonin. That is 20% of all reports for this medicine, compared with 11% across reports for all dog medicines, so it is reported unusually often with this medicine.

50Reports
62%Marked serious
20%Recovered
20%Died or euthanised
33 daysTypical onset
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How soon it started

Same day
3 9.7%
1–2 days
2 6.5%
3–7 days
3 9.7%
1–4 weeks
7 23%
Over a month
16 52%

How the animals did

Recovered
10 20%
Still unwell when reported
14 28%
Died
2 4.0%
Euthanised
8 16%
Not known
16 32%

Problems reported at the same time

16 32%
12 24%
10 20%
Not drinking
7 14%

Age of the animals

Under 1 year
0
1–3 years
5
4–7 years
6
8–11 years
14
12+ years
24

About this medicine

Type: medicine.

Questions owners ask

Can Melatonin cause lethargy in dogs?
50 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 33 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).

Lethargy with similar medicines

All reported side effects of Melatonin in dogs · Medicines most reported with lethargy