How much did you vaccinate Halo? Yearly? I was reading the other day about why pets (young) are getting cancer when cancer in pets was unheard of fifty years ago. They said it's from preservatives in pet foods, environmental toxic substances , and vaccinations repeated yearly. They're saying now that yearly vaccinations are unnecessary because they last three years and up to a lifetime. To do it more frequently is to end up with disease-ridden , chronically -sick pets.