Weight loss after Leptospirosis Vaccine in dogs

The FDA has received 239 reports of weight loss in dogs after Leptospirosis Vaccine. That is 3.0% of all reports for this medicine, compared with 1.7% across reports for all dog medicines, so it is reported unusually often with this medicine.

239Reports
76%Marked serious
6.3%Recovered
28%Died or euthanised
7 daysTypical onset
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How soon it started

Same day
35 20%
1–2 days
32 18%
3–7 days
21 12%
1–4 weeks
37 21%
Over a month
50 29%

How the animals did

Recovered
14 5.9%
Recovered with lasting effects
1 0.4%
Still unwell when reported
111 46%
Died
27 11%
Euthanised
41 17%
Not known
45 19%

Problems reported at the same time

Age of the animals

Under 1 year
23
1–3 years
61
4–7 years
64
8–11 years
64
12+ years
26

About this medicine

Type: vaccine.

Mild, short-lived lethargy, soreness or a small lump at the injection site are the most commonly reported vaccine reactions.

Questions owners ask

Can Leptospirosis Vaccine cause weight loss in dogs?
239 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 7 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).

Weight loss with similar medicines

All reported side effects of Leptospirosis Vaccine in dogs · Medicines most reported with weight loss