A study conducted by Canine Health Concern during 1997, involving 4,000 dogs, showed that 68.2% of dogs in the survey with parvovirus contracted it within three months of being vaccinated. Similarly, 55.6% of dogs with distemper contracted it within three months of vaccination; 63.6% with hepatitis got it within three months of vaccination; 50% with parainfluenza contracted it within three months of vaccination; and every single dog with leptospirosis contracted it within that three month timeframe.
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