Thanks for asking your question on Just Answer. Parvo is generally thought of as a dog disease, but some of the newer canine parvovirus strains can infect cats. There can be cross-infection, but it would depend entirely on the strain that your cat has. If your dog has been vaccinated for Parvo, the likelihood of transmission is small. I would make sure that the other cats in the household are vaccinated as well because the feline parvo vaccine is 100% cross protective against canine parvo .
I could guess the transmission cycle if I knew the history of your animals -- vaccine status, when they were adopted, from where, etc. It could have come into your home from either the dog or the cat......
Please let me know if you need further information. I hope this is helpful