Hi - I have a 10wk choc lab called Jake

Welcome to the forum KAREN2108.

What are you feeding Jake and have you changed his food or wormed him recently?

I've not changed his food - he's getting Purina Beta Puppy - he was wormed on Monday with his 1st jag

I'd say it could be the worming, which I would not do again at the same time as vaccinations.

That's a lot for the system to cope with, after all is said and done a wormer is a poison, and the vaccinations are designed to encourage the body into fight mode, which often can mean the body becomes sensitive to things encountered at the same time as the viruses they are being vaccinated against causing future sensitivities.

Remember your vet is a GP, few will be experts in immunology or parasitology, they just go by the manufacturers guidelines.

Thanks very much - that all makes sense