Vaccination prevents serious infectious diseases that cause significant suffering in companion animals, making it a core welfare intervention.
Unvaccinated pets that contract preventable diseases experience severe, often fatal illness. Canine parvovirus causes hemorrhagic diarrhea, vomiting, and systemic collapse over days to weeks with high mortality. Feline panleukopenia has similar rapid and devastating progression. Vaccination prevents this suffering comprehensively. The welfare case for vaccination of all companion animals is overwhelming.