Lymphocytosis after Leptospirosis Vaccine in dogs

The FDA has received 48 reports of lymphocytosis in dogs after Leptospirosis Vaccine. That is 0.6% of all reports for this medicine, compared with 0.1% across reports for all dog medicines, so it is reported unusually often with this medicine.

48Reports

81%Marked serious

8.3%Recovered

27%Died or euthanised

28 daysTypical onset

How soon it started

Same day

6 14%

1–2 days

4 9.5%

3–7 days

3 7.1%

1–4 weeks

10 24%

Over a month

19 45%

How the animals did

Recovered

4 8.3%

Still unwell when reported

20 42%

Died

4 8.3%

Euthanised

9 19%

Not known

11 23%

Problems reported at the same time

29 60%

29 60%

26 54%

25 52%

24 50%

23 48%

19 40%

18 38%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

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 lymphocytosis in dogs?: 48 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 28 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).

Lymphocytosis with similar medicines

Lymphocytosis after Rabies Vaccine 57 reports · 0.6% of its reports
Lymphocytosis after Bordetella Vaccine 55 reports · 0.6% of its reports
Lymphocytosis after Distemper-parvo Vaccine 56 reports · 0.9% of its reports

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