my tenant's cat has fleas -- vet bill was $340

[Jimmy S.]

One of my current roommates who moved in two months ago found fleas on her cat. We got rid of it with weekly anti-flea spray and daily vacuuming. The vacuuming we’ve been doing together switching every other day for 3 weeks. She did have a bill from the vet for $340. From reading the internet, getting rid of pests with a cleaning service is the landlord’s responsibility if it was caused by negligent care of the house. If it can be proven that the tenant caused it, it's their responsibility.

Her cat has always been an indoor cat so she thinks the fleas came from the room. She thinks it could be my previous roommate’s dog but my previous roommate apparently has always given him anti-flea medicine so I can’t really prove anything either way.

Do you think I should cover her vet bill or split it? Should I split it three ways with the previous tenant who had the dog?