@OmegaGamer123456 Hi! Please believe me when I say that I understand your frustration here. However, the rental properties are considered a part of the owned business system. So, what @simsplayer818 mentioned actually could be what is causing the issue.
I don't know if this would be considered a bug though. The game was not designed to accommodate more than one business on a lot. If anything, I would think the fact that sims can offer vet services on a rental lot might be a bug. That is something for the Sims team to decide. I'm sure they will see this thread and investigate further.
Whatever the case, I think the best option to cure the pet is to give wellness treats as @Sketch793 and @simsplayer818 have mentioned. If you don't want to go to a vet clinic to buy them or have your sim make them and you don't mind using cheats, you could use the bb.showhiddenobjects cheat and then search for "wellness treat" in BuildBuy. You may also want to filter by the Cats & Dogs pack to find it more quickly.
I'm glad you guys are all trying to give advice here, but I'm not trying to run a vet business or offer vet services. I'm just trying to treat my own dog on my own lot so I don't have to go to a vet clinic. It shouldn't require "business funds" unless it's on a vet clinic lot type.
@OmegaGamer123456 Does it work on a normal residential lot ?
If it does, it's best to report it in the bug forum as suggested above.
