My BC who is now 3yrs reacted to his C4 , he was ill for a few days and on a drip at the Vets.
Our Vet always says dogs are like kids, some react to the vaccinations some dont,
they prefer to only give the C3 for the early vaccinations unless specifically requested and usually only give the C4 at 16 weeks.
they seem to think that younger pups cant handle the C4 before their 16 week
vaccinations, which is probably right.
And if you get a Vet that mis-calculates the dosage for the age and size of the pup
well that could have deadly results.
they must accurately weigh the dogs each time they see the Vet, ours do as part of their records so it is updated automatically.
my baby BC is having his C4 tomorrow afternoon, he is 16 weeks, his Mum is also having her annual booster, I believe in vaccinating,
I have seen the results of dogs who are not, its a very sad and painful way to die, not to mention people who have lost whole litters to Parvo and that is just tragic.
Parvo can live in the soil for a couple of years, and if you get a wet Summer
it seems to bring it out of the woodwork. this current Summer has had a high rate
of Parvo.
Certain breeds are more prone to it as well, like Rotties and other large breeds.