Q My black Labrador has been diagnosed with a ruptured cruciate ligament. My vet says he needs an expensive operation. Is this really necessary? R Needham, Headington A There are two cruciate ligaments in the knee joints, (the anterior and the posterior cruciate) – they criss-cross within the joint, to provide stability. Most often it is the anterior cruciate ligament which is damaged. Rupture causes the joint to be unstable and painful. This almost certainly will require a surgical repair, especially in a large dog like a Labrador. Failure to do so will result in arthritis and permanent lameness. There are several different types of repair but they are all expensive. If you have insurance for vet fees, this type of surgery should be covered by the policy. If you don’t, you will have a bill of up to £2,500. Q My two-year-old rabbit is having trouble with her stools sticking together on her bum, almost to the size of a golf ball. We had to soak it off. How can we help her? She is eating and drinking normally. S Stevens, Cowley A Two areas of concern here; one is her diet and then her teeth. Rabbits need a diet with lots of fibre and their food should consist of lots of hay, high-fibre nuggets (not muesli-type cereals), fresh greens and water. If you stick to this type of diet, the poo your rabbit produces should be a nice dry pellet, which should not stick to the fur around her bottom. It would be worth having your rabbit’s teeth checked by your vet, as problems here, particularly with sharp edges on the grinding teeth, can affect the consistency of the poo. Also make sure your rabbit is able to have a good run around every day and that she is not getting overweight. Q My springer spaniel has split his toenail away from the quick. It is like the shell has separated from the nail but both are attached higher on the paw. Should I just trim the shell (nail) as far back as I can? A Matthews, Oxford A You can trim the loose nail off but be very careful – this is very painful for your dog and expect him to object. Even if you can trim the broken nail back you will have to bathe the foot in a mild antiseptic solution (like betadine) twice daily to help keep the paw clean and prevent infection setting in. More often than not when I see broken nails like this, I find it is best to actually remove the whole of the loose nail but this requires a local anaesthetic and may require bandaging and antibiotics afterwards. If you are in doubt, please take him to your vet.