Sick but not sick dog

I'm new to the sims world and I just got the Cats and Dogs expansion pack. 
I own a vet clinic where i treated and cured my dog for mild repugnitis, but now he won't stop throwing up everywhere! There is no option to take him to the vet (again) and when we're at the vet there is no way to begin an exam due to "no sick dog on lot". 
What can i do and how do i fix this?! 
I play on Xbox.

Thanks in advance!