yes Thuja can help to prevent reactions to vaccines - I will look up the dose.
From one of my books - Thuja 30c one hour before and one hour after the vaccination.
Also you can give Silicea 30c on the day of vacccination.
Check with your vet what is actually necessary for your area - if there haven't been any cases of leptospirosis, do you need to vaccinate against it?
As Karlin says, at the very least, make sure the vet injects into the thigh. There is some loose skin at the front of the thigh, and this is a good place. If your Cavalier is having any injections at all, or going in for surgery, stress this to you vet that you want injections in the thigh and none in the neck.
I use nosodes, but have researched this thoroughly, and although I am aware of the lack of scientific research, I am also aware of the reasons for this - there isn't the funding {as you prob know it is very expensive}, and there are also serious welfare implications in doing research over the lifetime of the dogs - they have to be kept in isolation.
There is a lot of anecdotal evidence for nosodes, my own supplier has over 400 customes using them all the time, including breeders regularly attending dog shows. None of these have ever had problems.
Dr Richard Pitcairn also has some very interesting information in his book, and there is a brilliant chapter on vaccination in Don Hamilton's Homoeopathy book. Both are available from Amazon.
if you follow this link, then NESSR {spaniel rescue including Cavaliers} benefit from any purchase you may make {UK}
http://www.amazon.co.uk/?&tag=surft...=7038&linkCode=qs1&adid=0666R9SW48ZVR9PHAEWH&
I have one vaccine damaged dog, and now only give Nosodes to my Cavaliers.
This is something that you have to research very carefully and make your own decisions about...