My male desexed 12 year old cat has been having 5mg of overid a fortnight for 10 months, to calm his behaviour of spraying urine in the house and wanting to fight other cats and being over teritorial, when he is outside. Overid has solved all these problems, but he has gained a lot of weight. I started googleing and found this is a side effect of Ovarid and so is diabetes. What is an alternative to this drug. I am waiting for my Vet to call back with their views also.