Figures updated on July 11, 2022
VMD is aware of media reports and concerns on social media following cases of serious side effects in dogs given a vaccine containing four strains of Leptospira bacteria.
The VMD receives adverse event reports from veterinary surgeons, animal owners and registration holders (MAHs).
We would like to reassure vets, and through them dog owners, that we constantly check adverse event reporting data to ensure that the benefits of every UK licensed veterinary medicine outweigh the risks posed by its potential side effects.
A number of vaccines containing two (L2) or four (L4) strains of Leptospira are authorized in the UK. Based on the most recent periodic safety report data received for each product, the incidence of adverse reactions in animals for all L2 vaccines combined is 0.017%; for L4 vaccine products, this figure is 0.055%.
In other words, VMD received less than 2 adverse reactions for L2 and less than 6 for L4 for every 10,000 doses sold. This includes all suspected adverse events that have been reported, even those that were considered unclassifiable or that were later determined to be unrelated to the vaccine.
Therefore, the overall incidence of suspected adverse reactions for the L2 and L4 vaccine products is considered to be rare.