Why do my cats attack each other?

(Q) Last year, my partner and his cat, Lucy, moved into the house I share with my children and two cats, Tilly and Leroy. Two-year-old Tilly is very playful, and gets on well with Leroy. Lucy is seven and has lived with my partner since she was a kitten. After she arrived she began urinating in various rooms, hiding under beds and vomiting furballs on the carpets.

This has now stopped (we bought a Feliway diffuser) and she spends most of her time lying on the tumble dryer. She has taken a dislike to Tilly, constantly hissing at, chasing and attacking her. How can I protect Tilly?

Behaviourist Francesca Riccomini says: Tilly is not the only stressed cat here. Lucy is showing that she cannot cope with this new situation without a lot of understanding and special effort. Evidently Lucy isn't of the right temperament and/or didn't have the early experience to enjoy feline company.

You don't say how you introduced the cats or what provision you made for the newcomer and the negative effect her presence was likely to have on the others. It is crucial to handle introductions with patience and sensitivity, and by allowing the cats to establish different core areas where each group has everything it requires.

Cats also need lots of high and dark places to hide and de-stress in. If Lucy hid and eliminated inappropriately when she first came, the chances are that she didn't have the right environment to have a chance of integrating appropriately. She is likely to have retreated to the tumble dryer and be defending it with vigour because it is the only place in which she can seek refuge.

Work out where Lucy would like to establish her core area and which location she could have, where she could avoid Leroy and Tilly. Then make this her area with food, water, toys, litter trays (if necessary), and loads of hidey-holes. Then make the same effort with Tilly and Leroy's area. Don't impose attention on any of them - cats prefer hands-off interaction using toys and voices.

And never blame Lucy or punish her if she soils the house; try to work out what you can do to help her and you are more likely to achieve a workable arrangement. However, it is unlikely that you will ever have one big happy feline family. Continue using Feliway, but you will need more environmental enrichment, plus understanding, patience and time to resolve this, and you will only find that out by applying knowledge of feline behaviour and working hard.

SIGNS OF IMPENDING AGGRESSION

Cats communicate their emotional state using body language and facial expressions. Displacement activities including grooming in 'odd situations' and 'comfort eating' can also tell us that our cats are aroused and suffering some sort of emotional conflict that could lead to aggression. Look out for:

• Tense posture
• Flattened ears
• Stiffened whiskers held backwards close to the head
• Dilated pupils (although as a cat prepares to attack, his pupils may narrow).

If you notice any of these signs, don't confront or try to handle your cat. Throw a toy to distract him, and remove people and other pets from the room.