OVERWEIGHT AND OBESE CATS
Overweight and obesity (extreme overweight) is now the most common nutritional disorder affecting cats.
The usual definition of obesity is being 15% - 20% overweight. In Britain, up to a quarter of cats are believed to be obese. The figure may be much higher in the USA where pet cats lead a more restricted lifestyle.
Severe obesity is easy to identify. Mild to moderate obesity (usually referred to as "overweight") is harder to determine. Cats vary greatly in their sizes and weights. Overweight is therefore assessed using "body condition scoring". A vet (or experienced owner) uses a combination of visual inspection and palpation (feeling the cat). Some guidelines are:
None of the above is a single indicator of overweight. For example many cats have a loose apron of skin. In some breeds it is genetic; it may also be due to previous weight loss or to pregnancy. Some obese cats are unable to let their tail droop - the amount of fat causes it to curl upwards from the base of the spine.
EFFECTS OF OBESITY
Obese cats, like obese humans, are generally less healthy and have shorter life expectancies. There will always be exceptions, but it is not safe to assume that your cat is the exception. The detrimental affects of obesity include:
Because obese cats feel less healthy, they are less likely to take exercise and, if the owner doesn't reduce the number of calories fed to the cat, they become more obese. Moderate to severe obesity should not be ignored. Maintaining the cat's bodyweight close to optimal (this can be determined by your vet based on the cat's size and age) avoids obesity-associated diseases.
WHAT CAUSES OBESITY?
Studies have shown that cats at higher risk of obesity include: non-pedigree cats, male cats, neutered cats, indoor cats (and cats with little outdoor access) and cats that are "only cats" or only have one other feline companion to interact with. Neutered cats require fewer calories than unneutered cats. Some cats are genetically predisposed to weight gain. There are breed differences too - the more "hyper" breeds tend to burn off more calories. Endocrine diseased/malfunctions can also cause obesity e.g. under-active thyroid gland. As they age, cats become less active and their food intake needs to be adjusted accordingly. The main cause of obesity is over-feeding. Overweight owners frequently have overweight cats - people who have weak wills with their own diets tend to give in more easily to a begging cat. Boredom is another cause. Just like bored humans, bored cats often snack. Cats can become couch potatoes too!
32 lb (14.5 kg) "Tiddles" lived in the ladies' lavatory at Paddington Station, London, England for 13 years. He was adopted in 1970 as a stray 6 week old kitten by lavatory attendant June Watson. He dined on chicken livers, lambs' tongues, kidneys, rabbit or steak brought in by his admirers and had his own personal fridge. Tiddles piled on the pounds, but his fans continued to send him titbits. Vets' attempts to put him on a diet failed due to all the titbits and, one assumes, the weak wills of his carers. Tiddles became 'London Fat Cat Champion' in 1982 at 30 lb (13.6 kg). By then, he was eating himself to death. He was put to sleep in 1983 after vets found fluid round his lungs. Tiddles had been killed by kindness. Photos show a grotesquely overweight and sad-looking cat, immobilised by his own girth. Unfortunately, killing a cat by over-feeding it is not (yet) classed as animal cruelty.
Tiddles became morbidly obese because he consumed more calories than he expended. He was also an inactive cat and as he grew fatter, he became less and less able to take exercise. Unless they are highly active, most cats don't need a great deal of food. Inactive cats tend to worry their owners because they eat so little. As a result, owners buy specially tasty titbits to tempt their supposedly ailing cat to eat. As long as the cat is maintaining its weight and body condition it doesn't need to be tempted with fancy foods. It is regulating its own food intake. Unfortunately, owners often undermine feline self-regulation.
KILLED BY CONVENIENCE CULTURE
The trend of feeding dried food (biscuit, kibble) is also a contributory factor. Dried food is energy dense. A small amount contains all the calories a cat needs. Unfortunately, this small amount is not filling. Although the cat has eaten enough calories, it continues to feel hungry because its stomach has only registered a small amount of food (the stomach has "stretch" receptors that detect bulk). So it begs for more or it goes scavenging or begging elsewhere in order to fill its stomach so it feels full. The solution is a "light" diet where the biscuits contain fewer calories. The problem is that dried food is convenient for owners, but cats are not designed to eat dried food alone. They are designed to eat prey that is less energy dense than the convenient kibble provided by the owner. Canned food is much bulkier and the cat feels full much earlier.
Cats fed entirely on dried food are more likely to become overweight (and constipated!) than cats fed on a mix of canned and dried food. If you don't believe me, try spending a day living on candy or chocolate bars instead of balanced meals - even though you are consuming enough calories, your stomach craves more food. Just as a regular diet of energy dense junk food makes humans fat, an energy dense diet of biscuit can lead to fat cats. The only way to prevent this is to carefully measure out the quantity, avoid titbits and not let the cat outdoors where it might find food elsewhere - you will, however, have to put up with a cat that begs for food because its stomach is not satiated after it has finished its ration.
Owners don't like to see waste. Hence modern cat foods boast that they are "highly digestible". This is not true of the cat's natural prey which contains a degree of indigestible parts known as "animal roughage" and had vegetable matter in its gut. Historically, owners were encouraged to feed their cat small amounts of cooked vegetables with their meat to mimic animal roughage, but most modern owners have gotten out of this habit. Where modern cat foods do contain vegetable matter, it has usually been treated to make it digestible. Some foods boast that they are so digestible and efficient that they reduce the amount of faeces a cat passes. Although what goes into the litter tray seems like wasted money, it is necessary for intestinal health. Just like humans, cats are designed to deal with a certain amount of bulk. Adding that bulk back into the cat's diet can often prevent obesity. Owners need to understand that there is more to feeding a cat than dumping half a cup of kibble in its bowl.
LIKE OWNER, LIKE PET
Owners like convenience food for themselves and their cats. More and more people like to snack while doing other things (watching TV, using the computer) rather than eat set meals at the table. They extend their snacking, food-on-demand, habits to their cats. Research into the snacking lifestyle vs the set meals lifestyle show that snackers underestimate the amount of food they eat. Likewise, owners underestimate the amount of calories fed to their cats in the form of snacks. Studies in humans indicate that snacking also affects the metabolism leading to weight gain. People who are generally less active are less likely to encourage their cats to be active. Fit, active, health conscious owners tend to be more aware of their pet's health needs. Pets' lifestyles mirror the lifestyles of their owners.
If the owner has, or can make, a few extra minutes each day to help a cat lose weight that time would be well spent in interactive play and getting the cat into the "exercise habit". A wand-type toy or games of chase with a table-tennis ball or scrunched ball of paper are suitable interactive games. There is far too much emphasis on static toys such as climbing posts - cats quickly grow bored with static toys and stop playing with them. There is also too much emphasis on technological toys that don't require owner interaction such as battery operated toys, but these are predictable and cats soon lose interest. Most cats want to interact with the owner so those extra 5 minutes should be spent on encouraging the cat to take whatever exercise is suited to its age and state of health.
If the owner is genuinely unable to chase about with the cat (owner disability, illness and heavy pregnancy are valid reasons), there are radio controlled toys that encourage the cat to run around while the owner remains seated.
If you can make more than five minutes extra, alternate the proprietary weight loss diet with some home-prepared foods or use the time to cook some vegetables to add to the cat's diet.
A UK-wide study of feline diabetes mellitus found 1-in-230 cats are likely to develop the disease, with a 1-in-57 chance among Burmese cats. This means around 40,000 of Britain's 8 - 9 million pet cats are likely to develop diabetes. Among hormonal disorders, it has become a greater health threat than hyperthyroidism. In the USA, with its predominantly indoor-only, dry cat-food culture of cat ownership, there has been a fivefold increase since 1977. This indicates modern lifestyle is the main factor.
According to Danielle Gunn-Moore, Professor of Feline Medicine at the Royal School of Veterinary Studies at Edinburgh University, changes in feline lifestyle are the main contributory factor in obesity and diabetes. Pet cats get less exercise and more calories than their predecessors. This is largely due to increasing confinement indoors and a lack of active play, combined with overfeeding (it is easy to overfeed with calorie dense dried foods that don't make a cat feel full up), titbits and a tendency to give cats food, rather than interaction, whenever the meow. A confined, bored cat will pass its time eating and sleeping. Pedigree cats may have increased risk due to being confined indoors through fear of theft.
According to the report in the Journal of Feline Medicine and Surgery, veterinary records for 14,030 cats and found 61 had diabetes. Questionnaires completed by the owners of 761 cats showed the greatest risk factors for developing the disease were being male, neutered and over 11lbs (5 kgs) in weight. Increased lifespan is also a factor as elderly cats are more prone to developing diabetes. Owners also didn't spot early warning signs of sleepiness/lethargy, increased thirst and frequent urination and only noticed problems when the cat went into a coma, by which time it was usually too late to save its life.
Caught early, feline diabetes can be managed by diet and exercise along with twice-daily insulin injections into the back of the neck. Insulin bills can be around £100/month and some cats resent being restrained and injected. The urine also needs to be checked regularly, which is difficult in cats that won't use litter trays or are secretive about urination.
DOES YOUR CAT NEED TO DIET?
If you think your cat is overweight, it is important that a vet examines it. The vet will rule out any underlying medical causes and will determine the severity of the weight problem. He will discuss a safe and effective weight-reduction programme with the owner and set targets. There will be regular weigh-ins, possibly at an animal weight clinic, usually every 2 weeks. Rapid weight-loss is dangerous for cats, so the regime will be aimed at slow weight loss and long-term success. In many cases, simply cutting out the titbits and encouraging the cat to get more exercise will solve the weight problem.
There are currently no safe drugs for management of feline obesity in the cat. Feline weight control programmes rely on a combination of managing the diet and altering the life-style of the overweight cat. Increasing the activity level includes more play-times with the owner and more access to outdoors - on a harness if necessary. If the cat is indoor-outdoor, then it should be encouraged to spend more time in the garden where there is more scope for activity. If it is an indoor cat, environmental enrichment with climbing frames, hidden low-calories treats and play-times with wand toys will encourage activity.
In most cases, dietary management will be needed alongside lifestyle changes. The aim is to reduce the cat's daily total calorie intake. This won't be a drastic reduction, but a moderate reduction so that the cat loses weight slowly. Importantly, between-meal treats must be cut out. The amount of food given at each sitting is generally reduced or a lower calorie food ("light" food) is given. If the cat eats canned food, mixing a bulking agent allows the cat to eat what feels like a full portion so its stomach feels full and it is less likely to beg or scavenge. Bulking agents include cooked mashed potato, cooked pasta, canned pumpkin and cooked rice. "light" cat foods are available from vets in both canned and biscuit form. "Less active" formulations are also available in many supermarkets and pet supply stores.
Many indoor-outdoor cats will try to make up for small portions by begging for food from a neighbour. If your cat begs food from other households or from neighbours' cats' bowls, fit him with a collar and a tag that states he is on a "special diet". If the other households think he is on a diet because of kidney disease or other problems they are less likely to give him titbits than if you admit to him being on a weight-loss diet. Many people equate "weight loss diet" with "poor starving cat" and will undo all your hard work. If possible visit the neighbours to explain that your cat is on a special diet for the sake of its health. You could always give them a small tub of his low calorie food that they can give him ("just a handful") as a treat - use an unmarked tub e.g. old margarine tub rather than one that says "low calorie cat food" or the ruse will be detected. They may be grateful for an valid reason to shoo him away from their cats' food!
Once you cat's target bodyweight is achieved, his diet and lifestyle still have to be managed so that he doesn't put the weight back on. Adjust his portion size so that he is no longer losing weight and not putting it on either. You may opt for a weight maintenance or "less active" formulation for long term weight control or you may decide to weigh him yourself. Don't be tempted to start feeding titbits all over again.
THE MULTI-CAT DILEMMA
What happens if only one of the household cats is overweight? How can the owner prevent it from eating the other cats' food as well as its own? The most usual solution is to feed set meals in different rooms and to remove any uneaten food once the cats have eaten their fill. The fat cat is probably eating a different diet and is likely to view the other cat's food as tastier.
Ad lib feeding is right out in a household where one cat is becoming obese. The overweight cat probably snacks more often than its thinner housemate(s) and is probably eating the thinner cat's rations as well as its own. If the thin cat is agile, but the fat cat is not agile, then food could be placed on a counter or shelf. The thin cat can reach it, but the fat cat cannot (at least not until it gets slimmer and fitter). Another solution involves fitting a small cat flap in the door to a closet or room and putting the thin cat's food in that closet or room. The thin cat can get through the cat flap to its food (especially if it is fed ad lib), but the fat cat can't get through the cat flap.
THE ROLE OF EXERCISE
Exercise burns off calories. Cats that have outdoor access tend to spend time exploring, climbing, interacting with other cats, chasing things, investigating interesting sights, smells and noises etc. They are less likely to become overweight because they are using up the calories they have eaten. Indoor-only need to be encouraged to take exercise to prevent them from turning into feline couch potatoes. Unstimulated cats get bored and spend much of their time snacking (if fed ad lib) and sleeping. Snacking can be prevented by having set mealtimes and removing the uneaten portion after the cat loses interest in the meal. A cat used to being fed ad lib will take a few days to get used to not snacking.
Paranoia about the outside world means that more and more cats have less and less opportunity to burn off the excess calories through outdoor play. Indoor only cats need plenty of environmental enrichment: climbing and perching posts, toys that can be chased or thrown about, hidden (low calorie) food treats for them to hunt out and interactive games with the owner e.g. wand toys. Otherwise they tend to become inactive and the laziness habit is as hard to break in cats, as it is in humans. Just as there is growing acceptance of human obesity, there is growing acceptance of pet obesity and owners who take insufficient exercise themselves, often don't understand the importance of exercise for their pets.
As owners work longer hours, they spend less time playing with their cats. The TV-dinner culture (inactive owners) contributes to this. To compensate for working longer and longer hours, guilt-ridden owners give their pets treats which adds to the excess calories. Owners should compensate for long work hours by making time for interactive play.
EXERCISE AND THE DISABLED CAT
There are many types of disability and severe obesity is also a disability as the cat is physically unable to be fully active. It is possible to find an activity or exercise regime suitable for most types of disability. The first challenge is that owners must learn not to be over-protective as this does not permit a disabled cat to achieve its full potential for active life. The cat's ability and mobility need to be assessed (if necessary with a vet's help) and activities should then be geared to what the cat is capable of doing. Encouraging activity burns off calories and prevents boredom (which in turn prevents snacking).
A blind cat will chase an audible object e.g. a jingle ball or a noisy scrunchy paper ball. Playing inside a noisy scrunchy bag (either a paper grocery bag or a specially made cat "rattle-sack") is also exercise. Play is best in an open area (centre of a room) so it doesn't bump into furniture when excited. Blind cats that are familiar with the room's layout will jump and climb, but not usually at full speed so more patience is needed if the game encourages the cat to jump onto or off of a chair or box. It will also respond to a scented object, so if it reacts to catnip it may enjoy a catnip mouse. A blind cat's remaining senses should be stimulated including smell and hearing.
A deaf cat will respond to visual cues e.g. toys to be chased and this usually present little problem for the owner as it will jump and climb as well as a hearing cat. A cat that is both deaf and blind relies on its sense of smell and on texture. A textured toy, perhaps impregnated with catnip, inside a rattle-sack is a good option though not all cats respond to catnip. A play area with several textures (sisal, carpet, felt etc) encourages climbing (once the cat knows the layout of an area, it rarely falls so a 2-level "cat gym" is generally safe if the cat is well co-ordinated). Games that encourage exploration and use the sense of smell are useful e.g. hunting for hidden low-calorie food treats.
A cat with a physical disability has other needs. Generally, an amputee is as active as a 4-legged cat since the other limbs become stronger. Such cats can run, jump and climb as normal, so normal types of play/exercise are feasible. Over-protective owners is the main problem where amputees are concerned. Cats with radial hypoplasia (reduced front legs) are also usually active. Although they may be able to climb and scramble upwards, they have a problem when jumping down as their under-sized forelegs cannot act as proper shock absorbers and they could land heavily. Interactive games should avoid situations where the cat has to jump down off of furniture etc.
A cat with inco-ordination (e.g. cerebellar hypoplasia) may need play sessions at ground level. Wand toys, table tennis balls and the usual ground-level toys are suitable as the cat can lie on its back and bat at them, but play is best in an open area (centre of a room) so it does not bump into furniture at high speed when its co-ordination fails. A cat with poor co-ordination does not realise it is any different to other cats - however clumsy it looks, it will still want to chase wand toys and table tennis balls. The only difference is that the owner may need to pace the game so that the cat manages to catch the toy.
A cat with reduced mobility (including elderly cats) may be better playing "goalkeeper" or "catcher" with the owner playing the more active part of rolling a toy in the cat's direction for the cat to catch. Many enjoy lying on their backs batting at toys dangled above them. The owner needs to watch out for signs that the cat is tiring e.g. puffiness or panting. Cats with severe mobility problems pose a special problem. Exercise may not be feasible and diet may be the only way to control weight. If the cat has long term severe mobility problems (e.g. part paralysis) then its quality of life needs to be assessed. If the problem is short term (e.g. broken pelvis necessitating cage rest), its level of activity should be increased once the vet gives it the all clear. Such cats normally shed excess weight once they become fully active again.
HOW TO WEIGH A CAT
Weigh the cat's empty carrying basket. Put the cat in the basket and weigh the full basket. Deduct the weight of the empty basket from the weight of the full basket. This gives you the weight of the cat.
Method 2 (this one also helps you keep an eye on your own weight):
Weigh yourself. Pick up the cat and weigh yourself holding the cat. Deduct your weight from the weight of both of you. This gives you the weight of the cat. Since your weight varies from day-to-day, always weigh yourself first and don't just assume you weigh the same as you did 2 weeks earlier.
CATS AND SUGAR
Previously, studies frequently used unsweetened water and sweetened water to see if cats showed any preference. The cats did not appear to distinguish between sweetened and unsweetened water which raised two hypotheses: either cats could not taste sweetness at all, or the receptors for water overrode any receptors for sweetness.
In those studies cats, did not respond to sugars at any behaviourally-meaningful concentration (Boudreau, 1989). Cats did not distinguish between plain water and water sweetened with sucrose (Carpenter, 1956; Bartoshuk et al. 1971; Beauchamp et al. 1977), but they preferred milk if sucrose or lactose was added to it (Frings, 1951; Beauchamp et al. 1977). Beauchamp et al. (1977) suggested that the cats might have been reacting to the texture of sweetened milk rather than to the taste. Earlier studies by by Bartoshuk et al. (1971) found that cats preferred sweetend saline solution over unsweetend saline solution. The conclusion drawn from these various studies was that cats had a limited ability to taste sugars directly. Cats were thought to have a "water" taste that responded to pure water (Bartoshuk et al. 1971) which meant that early studies of whether cats could taste sugars dissolved in water could be confounded by their reaction to the water itself.
It is only following the sequencing of the feline genome, that there has been more detailed study into whether or not cats are able to detecting sweetness at all. The receptor for sweet tastes is formed by 2 genes called Tas1r2 and Tas1r3. While a cat's Tas1r3 gene appears normal, the Tas1r2 gene is different to that in most other mammals. This true of wild cat species (big cats and small cats) as well as domestic cats. The mutation means that cats lack a receptor that is believed necessary for detecting sweetness (Li et al, 2005). This mutation was probably an important one in the evolution of obligate carnivores.