How long do you think you will live? Until at least 70? Maybe 82? Dogs' and cats' average lifespans are much shorter, between 10 and 16 years, while a rabbit can expect to live for about 12. But if your pet lives until its golden years, when will you start to see the signs of ageing? In a two-part series on common age-related illnesses, this week we look at elderly dogs' and cats' problems, while next week's column examines those of ageing rabbits and parrots. As most pet owners know, heart disease and arthritis are prevalent in felines and canines. Veterinarian Hugh Stanley, of Dr Hugh's Veterinary Hospital, points out some of the lesser-known conditions for ageing animals. 'Cancers are very common in cats and dogs,' he says. 'They can be anything from a skin lump that is completely harmless to malignant cancers that are fatal.' It's very difficult for owners to detect cancers inside the body, such as around the lungs or liver, Stanley says. Cancers and lumps that develop on or beneath the skin are easier to notice, but the only way of determining whether one is benign or malignant is to cut it off and send it to a laboratory, the veterinarian says. 'My general advice is check your pet frequently, and if you feel a bump then see a vet,' says Stanley, the former director of veterinary services at the Hong Kong Society for the Prevention of Cruelty to Animals. If you find a fatty tumour on your pet, don't worry, as they are usually harmless, he says. However, a veterinarian can easily check its malignancy by sucking a little of the tumour out with a fine needle, and then putting it under a microscope. 'If it's a fatty tumour, you don't have to take it out unless it's on an uncomfortable spot like the eyelid or lip, or the dog has to stand on it,' he says. Stanley says many pet owners don't act fast enough when a problem is first detected. 'Rather than doing something when [a lump] is small, they wait until there's a big lump because they are scared of [putting their dog under] anaesthetics,' he says. 'It's safe these days. And the more you leave it, the more chance there is for the cancer to spread.' Waiting too long could also make your ailing pet harder to cure. 'It's surgically more complicated,' Stanley says. '[A lump] might be easier to cut out, but [it's] harder to close a big hole, so it's better to do something early rather than late.' Strange behaviour, such as restlessness, excessive barking, walking in circles or signs of disorientation, could be symptoms of dementia, another common disease in ageing felines and canines. 'You can get bizarre behaviour,' Stanley says. '[Pets] can look confused, not recognise the owner and show all the same signs that a human can have [with dementia]. The problem with dementia is it can be confused with other conditions like [poor] eyesight or hearing.' Dementia can be traced to a number of causes, from dying nerve cells to decreased blood flow to the brain, Stanley says. But only a veterinarian can test whether your ageing feline or canine has dementia, or whether its strange behaviour is caused by another condition. After proper diagnosis, medication or simple changes around the home can improve the quality of life for pets, he says. 'Some medicines increase blood flow to the brain and this seems to help. The other thing is to adapt the environment,' Stanley says. 'If a cat starts to pee in the wrong place, make it very easy for them to find the litter tray.' Like humans, ageing animals can also develop a host of small problems as they get older, from loss of hearing and eyesight to stiffness and an inability to digest food or react to surroundings. 'If it's not a life-threatening disease try to make life as comfortable as possible.' When taking your dog for a walk, let the dog set its own pace instead of power walking, Stanley says. Diet also plays an important role in the length of your pet's life. As your cuddly cat or devoted dog turns eight, it's time to switch to a food that gives your pet better protein and lower energy density. If your cat is constipated every day, you might take it to the vet. 'You need to watch if it is passing faeces on a daily basis,' Stanley says. 'For older cats, a diet-related [condition] is constipation, possibly from lack of fibre, a colonic tumour or dehydration from kidney failure, which may be secondary to another underlying problem.' Stanley says the most common complaint among elderly cats is kidney disease. So if you notice your cat is drinking more water, then 'something is going on that needs to be checked out'. He says animals should not drink more than 100ml per kilogram, or a 10kg dog shouldn't drink more than a litre of water a day. Cataracts can also indicate that your pet is getting older. This condition can start when your pet is about eight, makes the eye appear cloudy and can eventually lead to blindness. A veterinarian can easily tell if your pet has cataracts, but this may also signal an underlying diabetes problem. The only remedy for a cataract is surgery, which could cost between HK$10,000 to HK$20,000. 'You need to think carefully about it,' Stanley says. 'A lot of dogs don't rely on their sight anyway, so if they lose it slowly, the dog doesn't have a concept of it being any other way.' Older dogs and cats also suffer from dry eyes. Its symptoms including chronic discharge and red eyes but this condition is easy to treat with medication. Ageing dogs can also suffer from strokes. 'A stroke isn't subtle,' Stanley says. 'The dog will collapse and have a seizure. It could be left in the same condition as a human, such as a head tilt, but if you nurse them for a week to 10 days, they can make a good recovery.'