Veterinary Medicines Directorate response to concerns in Social Media

From their website in 2022  www.gov.uk/government/news/leptospira-vaccination-in-dogs

Leptospira vaccination in dogs

VMD response to concerns raised following media reports of serious adverse events in dogs given the vaccine containing four strains of Leptospira bacteria.

Figures updated 11 July 2022

The VMD is aware of media reports and concerns raised on social media following cases of serious adverse events in dogs given the vaccine containing four strains of Leptospira bacteria.

The VMD receives adverse event reports from veterinary surgeons, animal owners and marketing authorisation holders (MAH).

We would like to reassure vets, and through them dog owners, that we are constantly reviewing adverse event report data to ensure that the benefits of each UK licensed veterinary medicine product outweighs the risk posed by their potential side-effects.

There are a number of vaccines authorised in the UK containing either two (L2) or four (L4) strains of Leptospira. Based on the most recent periodic safety update report data received for each product, the incidence of adverse animal reactions for all L2 vaccine products combined is 0.017%; for L4 vaccine products this figure is 0.055%.

In other words, the VMD has received fewer than 2 adverse reactions for L2, and fewer than 6 for L4, for every 10,000 doses sold. This includes every suspected adverse event reported, even cases that were considered unclassifiable or were later found to be unrelated to the vaccine.

The overall incidence of suspected adverse reactions for both L2 and L4 vaccine products is therefore considered to be rare.

Further information

The overall incidence of suspected adverse reactions for both L2 and L4 vaccine products is considered rare using the following standardised convention:

- very rare (less than 1 animal in 10,000 animals, including isolated reports)

- rare (more than 1 but less than 10 animals in 10,000 animals)

- uncommon (more than 1 but less than 10 animals in 1,000 animals )

- common (more than 1 but less than 10 animals in 100 animals)

- very common (more than 1 in 10 animals displaying adverse reaction(s) during the course of one treatment).

The majority of reported signs are linked to allergic type reactions which are well recognised potential side effects of any vaccine, and are presented on the product literature. Vets are advised to note that for some brands of L4 vaccines, administering a vaccine that is cold may cause local/systemic reactions, therefore please read the summary of product characteristics (SPC) for these products and ensure these vaccines are always used at room temperature.

The veterinary surgeon and the client should discuss and agree a vaccination programme for an individual animal. This should be based on the local epidemiological situation and risk of leptospirosis, balanced with the potential risks as outlined in the SPC. Careful consideration should be given to whether the additional protection provided by vaccines containing four strains of Leptospira versus those containing two is necessary in each individual dog, depending on their individual circumstances. Dogs that travel from the UK to mainland Europe where there is a known risk of infection with Bratislava and Grippotyphosa should be vaccinated with all four strains.

All suspected adverse events should be reported to the Marketing Authorisation Holder or the VMD. You can submit an interactive reporting form online via the gov.uk website at the following link: 

www.gov.uk/report-veterinary-medicineproblem.

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