We have 4 year old cat and a 16 week old kitten. Since getting the kitten 4 weeks ago, both the cats' poos have been fairly sloppy and very stinky! The kitten also does regularly produces smelly farts. They are both fine in themselves and eat loads. Big cat has always been on Royal Canin Sensitive and, until we got the kitten, his poos were fairly firm and not too stinky. The breeder told us to give the kitten Royal Canin Kitten food but she prefers big cat's food (which is supposed to be ok for kittens too). In truth, the 2 cats are eating a mixture of the 2 foods.
Clearly some change in diet is needed but not sure what to go for??