Fat cats and portly pups

Photo: U of S Communications.

Q. How prevalent is obesity in pets?
There are tremendous variations among the few research studies that focus on pet obesity. One study estimates that about 40 per cent of dogs and 25 per cent of cats are overweight. Other studies report more conservative numbers.

Pet obesity is a global problem that varies from area to area. Demographics, climate and owners’ education levels also influence obesity, and I suspect the problem is more prevalent today because of the changes in pets’ lifestyle. For example, cats have evolved from a predominately outdoors species to a predominately indoors animal.

Q. Why are so many pets overweight?
Pet food manufacturers focus on producing highly palatable diets. By adding more fat and protein, they can make pet food extremely tasty. And if dogs and cats are allowed to overeat, they will since it’s their natural instinct to eat when food is available. Cats and dogs used to hunt for their meals — nowadays, they wait for humans to fill their bowls.

Q. Are certain cat and dog breeds more prone to obesity?
There’s no predisposition to obesity among cat breeds, but it’s rare to see a thin beagle, Labrador retriever or schnauzer. Many things regulate obesity: some of it has to do with endocrinology, and we also assume that there’s a genetic propensity to obesity, but that hasn’t been determined yet.

Q. Are owners responsible for managing pets’ weight?
A cat can’t go grocery shopping or open the fridge door, so most of the onus is on pet owners. Of course, pets can be quite obstinate about losing weight. Dogs can steal food and cats can be very insistent about being fed.

Q. When is a dog or cat overweight?
Veterinarians use body condition score charts that outline differences between underweight, normal, overweight and obese pets. The larger the number, the larger the degree of obesity. At the WCVM, we use a scale from one to nine because it gives us more latitude in scoring individual pets.

We measure three main indicators. First we feel for the pet’s ribs: if we can’t feel them, there’s some extra fat that shouldn’t be there. Second, we look for a sagging belly. Third, we look for a waist: cats’ and dogs’ chests should taper into a waist.

The scores and indicators differ from breed to breed, but parameters are the same for young and old pets. Once puppies and kittens begin eating regular food, their food intake should be monitored. If food becomes too much of a pleasure for them, it’s a hard habit to break later in life.

Q. What are health risks related to obesity in pets?
Obesity is one cause for developing non-insulin dependent diabetes in cats (just as in humans). With this form, cats continue producing insulin but their bodies develop an insulin resistance. The relationship between obesity and diabetes isn’t as clear in dogs. If dogs do develop the disease, they develop the juvenile diabetes form where their insulin production stops abruptly.

Fat cats that suddenly go off food can develop fatty liver syndrome, a potentially fatal disease that causes severe liver dysfunction. Obese cats must always get enough nutrition, and that’s why fat cats shouldn’t be on strict diets.

While higher blood pressure isn’t significant in healthy dogs, it becomes risky in obese dogs that have heart disease or renal failure. An overweight dog may not be able to tolerate a combination of these problems.

We also see more orthopedic conditions in overweight cats and dogs. Obesity isn’t the cause, but if the animals already have any underlying orthopedic issues in their limbs, it certainly aggravates them.

Q. Does obesity shorten a pet’s life?
Obesity has been shown to significantly decrease lifespan in dogs. Overweight dogs and cats are happy in their state, but in the long run, obesity affects their quality of life if it affects their health.

After research conducted at the WCVM, we noticed a significant increase in activity level as the dogs lost weight. Animals wanted to play more and that seems to improve their quality of life.

Q. Do pet owners recognize when their pets are overweight?
A study conducted by Purina showed that even when owners had access to a canine body condition score chart, most owners didn’t recognize that their dog was overweight without professional guidance.

A veterinarian can outline health risks associated with obesity and help you start a safe weight loss program. If your pet is on a diet but hasn’t los weight or continues to gain weight, see a veterinarian. It’s important to have your pet examined since other medical problems like hypothyroidism and Cushing’s disease can cause obesity.

Q. What do you recommend for a weight loss program?
Go slow: aim for a one per cent bogy weight loss per week. In dogs that are markedly obese (20 to 30 per cent overweight), it can take from three to six months to reach a healthier weight.

Use diet variations of pet food. Their caloric count has been significantly, reduced, they’ve been formulated to make pets feel “full” with less food and their use increases owner awareness. It’s also easy to determine how many calories are in diet food, making it easier to calculate your pet’s daily intake of calories.

Gradually switch obese cats over to a new type of food so they never go without nutrition. You also need to customize rations for every pet: two cups of dog food may cause rapid weight loss in one dog while another may gain weight with that same ration. Start your pet on the recommended ration for its weight category, use that ration size for a couple of weeks, then reweigh the pet check for weight loss.

If you give treats, one option is to buy special weight loss biscuits. By calculating the number of calories in each biscuit, you can deduct that from your pet’s daily caloric intake.

Q. What about exercise?
For overweight dogs, start with a half-hour walk every day. Remember, morbidly obese dogs completely lose exercise tolerance. But as soon as they lose some weight, they’re able to resume walking.

Sports like dog agility and fly ball are options, but be careful with very obese dogs since these types of exercise can be hard on their joints and may cause or aggravate orthopedic problems.

Cats are more challenging to exercise: try to get them into a predatory mood so they’ll chase a ball, some string or a laser pointer.

Q. Can pets keep off excess weight?
In a previous study, dogs lost an average of 16 per cent of their body weight in six months. They moved from a body condition score of 8 to a much healthier 6, and they were able to maintain it for a 24-month period.

The success of pet weight loss programs really depends on owner awareness. It also depends on species since cats don’t respond to weight loss programs as well.

Q. Is it ever too late for an obese pet to go on a diet?
No, but it’s more work if the animal is morbidly obese and can’t exercise. The best way to deal with obesity is to prevent it. If your pet is gaining weight, cut back on its food today.

Read “Blood pressure drops in dieting dogs” to learn more about the results of dog obesity study that was conducted at the WCVM.

Reprinted with permission from Vet Topics, news publication for the Western College of Veterinary Medicine’s Companion Animal Health Fund. Visit www.cahf.usask.ca for more information.