I have noticed a sickly sweet smell coming out of the litter box today. I have 3 cats, one of which is overweight, but otherwise all are healthy and eat well. I'm just wondering if this is something I should be concerned about and what my next step would be? Thank you for your time.
A new or strange odor from the litter box is worth investigating. Sweet-smelling urine could be a sign of feline diabetes or a number of other cat health problems.
I would recommend taking all 3 of your kitties, perhaps starting with the overweight cat, to the veterinarian for a urinalysis. While it has been generally thought that overweight cats are at the highest risk for feline diabetes, this is not always the case, so all of your cats should have a urinalysis to check glucose levels and to check for any signs of infection.