One of the most difficult decisions a pet owner will ever have to make is — 'when is the time right for euthanasia'. As a veterinary nurse and cat behaviour counsellor I have counselled owners about the importance of letting go in order to prevent suffering. Every one has very individual views on this emotive subject but it is essential that an owner is able to make an informed decision.

This year has been a very bad one for my feline family and me. Three of my seven cats have died and I still have one at home that is fighting bravely against a terminal illness. I have had to face the final dreadful moments too often just recently but have coped by focusing on the wellbeing of my beloved cats and trying to assess their quality of life objectively.

Determining the presence of pain in cats is notoriously difficult, particularly when assessing chronic pain or that associated with disease. A cat's behaviour or normal routine can be affected in many ways if pain is present; some of these changes are obvious while others are far subtler. The type or location of the pain will be significant, for example, aural (ear) pain can cause scratching or rubbing of the affected area. Musculoskeletal pain will affect the animal's ability or desire to climb, jump and play and may even cause lameness or an unusual gait. Often cats will be less active, filling the time with sleep. An understanding of the individual is as important as recognising normal feline behaviour when assessing pain in cats. It is often difficult to view a cat at any one moment and see obvious signs of pain. If changes to a cat's normal routines and activities are potential indicators then it would be useful to have a means of assessing what is normal or abnormal for that individual.

'Activity budgets' and pain

I first explored the concept of `activity budgets' in 1994 to look at how domestic cats had adapted their natural behaviour to live with us in our homes. In this particular context the word 'budget' relates to a unit of time rather than money and gives an indication of the average time allocated to a number of normal cat activities in a 24-hour period. All cats have an activity budget that is dependent on their lifestyle, breed, character and environmental influences. For example, a cat in a natural state spends approximately 15 hours sleeping or resting, six hours a day grooming, playing and indulging in social activities and approximately three hours hunting, eating and exploring.

My cat, Bln, was my first 'guinea pig' in trying to assess the activity budgets of my own cats. I watched him continuously for 24 hours with a stopwatch and a clipboard and pen. I stayed awake for the entire time, rather foolishly, as he slept on and off for 18 hours, but it was a fascinating insight into how our pets fill their time. Since then all my cats and many more besides have shown, via their activity budgets, how they are creatures of habit. Obtaining this knowledge in such a structured way enables us to look at changes to our own cats' normal routines as significant warning signs for potential problems. Many factors influence a cat's activity budget, both external and internal, including weather, house moves, disease, pain, the presence of other cats, age and enforced confinement. This is not an exhaustive list.

If these activity budgets are being used specifically to gauge the presence and level of pain then it is important to assess them in conjunction with other observations relating to the animal's general behaviour.

Puddy

Sadly I had the opportunity recently to put this method of pain assessment to the test. At the end of February I took my favourite cat, Puddy, to the vet because she had started to dribble slightly and she was reluctant for me to open and examine her mouth. Imagining nothing more sinister than an infected tooth I was shocked to be told that she had an invasive malignant oral tumour. The vet felt that using steroids to reduce inflammation and antibiotics to fight the infection would alleviate her pain. Surgery or curative treatment was not an option. Puddy was sent home for love and observation until such time as she and I were ready to call it a day.

During the last 40 days of her life, Puddy was carefully and discreetly watched and her deteriorating health became increasingly apparent. She had always been a loving and affectionate little cat, approaching me several times every day with an insistent 'miaow' for the particular type of patting and rubbing on her back that she so enjoyed. This pattern of social interaction stopped and Puddy became silent and withdrawn. Her previous good relationship with all of the other six cats became strained and she hissed and growled at them whenever they approached. I so wanted to hug her and hold her during those last few weeks. Tender loving care is so important when your cats are ill but Puddy was withdrawing from me and choosing to be solitary and private. I thought she would have started to sleep more as the condition became more painful but instead she slept less and filled the time by resting, always in sternal recumbency, and staring blankly into space. Even in the last few days she continued to eat but only when hand fed, almost as if she was doing it for me and not because she had a strong will to live. Puddy gradually stopped grooming, stopped all social interaction with her cat companions and with us and stopped going outside,but she continued to display brief moments of apparent pleasure in familiar activities. However, by the 40th day things had deteriorated. Looking at her normal activity budget when she was a happy, healthy 12 year old and comparing it with the last 24 hours of her life strongly indicated that Puddy was, by then, in sufficient pain to severely compromise her quality of life. She was quietly and peacefully put to sleep by her vet in April, just before her 13th birthday.

It wasn't the easiest thing in the world to monitor Puddy over the last few weeks of her life and sometimes it felt remote and clinical, but I am so glad in retrospect that I was able to do so. I have already taken comfort from the fact that I took an active and compassionate role in ensuring that the timing was right for her.

Behavioural observation is so important to assess the presence of pain to ensure prompt and effective treatment. As I have just shown it can also be invaluable when a cat is suffering from chronic or acute disease to judge the appropriate time for euthanasia. As owners we are well equipped to make an important contribution to this decision if we have a knowledge and understanding of the changes in our cats' behaviour at the end.