This isn't a very pleasant topic and I'm rather embarrassed to be writing about it... but it's driving me crazy and I could do with some advice!

My two cats are both usually very clean and do not usually have problems in the litter tray... but over the last few weeks this has changed and they have been making the most horrendous smells when usuing the tray. Sometimes this is accompanied by diarrohea, sometimes not.

One cat - Splodge, the larger and fatter of the two - has been worse than the other.

The problem is that I am at work during the day and I can't bear the house getting so smelly in my absence. At night is even worse; I have been woken up 3 times in just over a week by this problem

Does anyone have any suggestions as to what I can do? What has caused this? Are there any supplements that I can give them to help?

They both seem very healthy otherwise.