A number of different things come to minds as possibilities: ingested toxin - something in the treat, garlic, onion; most household cleaners are deadly; antifreeze; rat poison; congestive heart failure; FIP; FIV; FeLK; genetic abnormal clotting factor; autoimmune hemolytic anemia
the only way to get any actual answers would be a necropsy by your vet.
I'm sorry you've lost your wee one :sad:
sweet
baby
She is playing at the
Rainbow Bridge with those who've gone before