Cant take healt care of stray dogs?

I usually just give them a wellness treat.

I believe that unless your sim owns the pet they cannot do vet treatments. If your sim has befriended the dog then have them adopt the pet and then they should be able to visit the vet for treatment. If you don't want your sim to adopt the dog you can always buy the Wellness treats from the vending machine at the Brindleton Bay Pawspital and give the strays Wellness treats.

Out of pity, I used to adopt all the sick animals that crossed my path, so i could bring them to te vet. But shortly after the fourth cat, i discovery that it was simple if i just carried in my Sim inventory some wellness treats, like above-mentioned... ?

I have a vet clinic table on my home lot and a surgery table in my family inventory so my main sims can at least cure their own sick pets. Might just have to stock up on wellness treats though, that seems easier! Is a wellness treat a fix all for any illness?

Finally. I can have Catarina Lynx be the informal vet I knew she could always be. Thanks for the wellness treat knowledge. I did have a small vet area with all the formal vet stuff for keeping pets healthy but I really wanted to just perk up all of those strays that visited. Thanks! ^^