Like all cherished family members, pets should be fed the best possible diet. Here’s all you need to know about pet nutrition by David Thomas.
When I was a kid we chopped vast quantities of ox or sheep’s hearts from the butcher to put in the freezer – that’s what we fed the cat, with a saucer of milk on the side. And dogs were fed scraps from the kitchen table. Now we’re told that cats shouldn’t have milk and dogs need special diets! So what should we be feeding our pets?
Generally speaking, cats are known as “strict” or “true carnivores”, which means they need meat to survive. There are no adequate vegetarian diets for cats, as they have evolved to survive on very little, if any, plant material.
Dogs, on the other hand, are omnivorous (able to digest and use both plant and animal material) and are able to survive on plant material alone if necessary – but it’s far from their ideal diet.
There is a difference between surviving and thriving, and as dogs have evolved to be primarily meat-eaters, it is often argued by experts that dogs should have meat in their diets in order to grow to their full potential.
Following are answers to some of the most commonly asked questions about pet nutrition.
Do pets need different foods at different ages?
There are many commercial pet foods available targeting different ages. These are typically marketed as “growth” (kitten or puppy), “maintenance” (adult), “gestation” (pregnancy/lactation) and “mature” (old age). However, the pet food industry has standards for only two nutrient profiles for dogs and cats: growth/lactation and maintenance.
For dogs, diets formulated for growth and lactation have increased levels of protein, fat, vitamins and minerals compared to maintenance diets. For cats, the diets formulated for growth and lactation have similar levels of protein and fat to the maintenance formulation but increased levels of vitamins and minerals. Cats of all ages need similar amounts of protein to maintain normal body tissues.
Studies have shown that older animals have higher protein requirements and lower energy levels. Manufacturers have responded to this and are now commonly including “neutraceutical” ingredients such as glucosamine and chondroitin sulphate to assist in maintaining joint health.
It used to be argued that the level of protein in the diets of older dogs should be reduced to prevent the natural decline in kidney function. In fact, some “mature” formulas for dogs still have lower levels of protein in them. However, recent research has shown that protein levels should not be restricted simply because the dog is ageing (unless the dog has kidney disease), as this will only lead to a loss of protein reserves, resulting in muscle wastage and subsequent weight loss.
Dry or canned food – which is best?
Good-quality dry and canned foods both have their benefits and are suitable for all life stages of cats and dogs. Both provide a complete and balanced diet. Your choice should be based on what’s most convenient for you and what your pet prefers – cats are typically much fussier than dogs.
Dry foods are fine for adult dogs or cats that get normal amounts of exercise, but may not contain enough fat for pregnancy, lactation or growth, or for dogs that undertake a lot of exercise such as working or farm dogs. The major benefits of dry pet food are economy and convenience for the owners in terms of storage.
Good-quality dry foods are highly digestible and have a high nutrient density, which means small quantities of food provide your pet with large amounts of important nutrients that will be absorbed and used, and less faeces will be produced. This may be beneficial if the pet is kept indoors and uses a litter tray.
Dry food can often be left for animals to munch on when they feel like it, and you don’t have to worry about rapid spoilage, especially in hot weather. Serving your pet dry food will exercise their mouth and can help to reduce the build-up of tartar, thereby providing some dental benefits. There are now dental formula pet foods available, however, they can be more expensive than the regular dry food varieties, so rather than feeding your pet exclusively on these, try mixing the dental formula with the regular feed.
Canned foods tend to be more palatable, mainly because of their relatively high amounts of fat and protein, and their appealing texture – you may find your pet enjoys these more than dry food. They are also more digestible than many dry foods.
The canning process is carried out in a high-temperature, high-pressure environment that effectively sterilises the pet food but results in some vitamins being lost. Manufacturers of good quality products usually adjust their dietary formulations to compensate for these losses. Canned pet foods also have the benefit of an extremely long shelf life without the need for special storage considerations.
Comparing canned and dry foods
The two main types of food for pets are canned or dry and both are suitable for most pets. Canned foods contain about 75 per cent moisture and are typically more expensive than dry foods. They usually contain more fat and protein on a dry matter basis. Canned food generally provides good nutrition for all life stages of cats and dogs.
Dry food contains about 5-10 per cent moisture. It is manufactured from grains and meat leftovers and has a shelf life of 12 months or longer. Dry food is formed in an extruder by heating the food ingredients under pressure. Approximately 25 per cent of its kilojoule content is fat. More expensive (premium) dry pet foods have fat sprayed on after extrusion and tend to contain more fat (about 40 per cent energy as fat), are greasy to touch and are packaged in special greaseproof bags.
To directly compare the nutrient content of wet and dry foods, multiply the nutrient levels on the can of wet food by four.
What does “complete and balanced” mean on pet food labels?
The term “complete and balanced” means the diet contains all the nutrients needed by the animal and no other foods need to be added. Foods without this term on the label should be considered only as supplements.
Can you feed a “complete and balanced” homemade diet to a cat or dog?
Homemade diets are fed to pets for a number of reasons. It may be because the owner believes fresh ingredients are purer and safer than commercial products; your pet may simply prefer a homemade diet to commercial products; or the veterinary hospital may have specifically designed a diet for your pet. However, it’s important to note the nutrient content of most whole ingredients is variable, which can make it difficult to give your pet a totally balanced diet. There is also the difficulty of eliminating pathogens and toxins that may be present in the ingredients.
Here’s an example of a homemade maintenance diet for a 3.8kg cat (which will last 3 days) or a 10kg dog (for one day):
raw long-grain white rice (140g dog; 70g cat)
lean beef (70g dog; 140g cat)
liver (30g dog and cat)
bone meal (11g dog and cat)
corn oil (5g dog and cat)
iodised salt (2g dog and cat)
Combine all ingredients in 360ml of boiling water and cook for 20 minutes.
How often should you feed cats and dogs?
Cats and dogs have different feeding behaviours. Dogs have relatively large stomachs that hold big volumes of food so they tend to eat everything that is fed to them very rapidly. Cats, on the other hand, have much smaller stomachs and prefer to eat small, frequent meals. Studies have shown that while dogs can voluntarily eat up to 4 meals a day, if given the chance cats eat between 12 and 20.
For dogs, portion-controlled feeding (that is, set amounts at set times) is the best way to go with both canned and dry food. Leaving dry food in your dog’s bowl so they can eat whenever they feel like it (free-choice feeding) can encourage them to over-eat. It’s best to provide one or several meals per day, pre-measured to meet the dog’s daily energy and nutrient needs (see the guidelines on your pet food package for how much to feed – it will depend on your pet’s weight and age)
Cats are often fed using the portion-control method, but if they are fed free choice, they will usually eat small, frequent meals throughout a 24- hour period. Free-choice feeding requires the least amount of work and knowledge on the part of the owner and is most suited to dry food, which will not spoil as quickly as canned food. While cats are better than dogs at self-regulating how much they eat, there is still potential for them to over- or under-eat using this method, so keep an eye on your cat’s weight when feeding this way.
Can cats and dogs have weight problems?
Yes! Just like in humans, obesity levels are increasing worldwide in both cats and dogs. Studies estimate 19 to 40 per cent of cats are overweight or obese; the estimate for dogs is 24 to 45 per cent. Neutering and spaying has been shown to increase the risk of obesity because it reduces energy requirement by 33 per cent while increasing appetite.
Interestingly, studies show weight problems in companion animals to closely mirror those of their owners. It is thought the rise in the number of overweight or obese pets can be attributed to an increasingly sedentary lifestyle coupled with the overfeeding of highly palatable, energy-dense foods – the same factors that contribute to human obesity.
However, other factors such as diet palatability, food composition and texture and the timing and environment of meals appear to be important ones leading to over-eating and obesity. For example, most pets increase food intake when eating in the presence of other animals.
How to put your pet on a diet
If you think your cat or dog is overweight, it’s a good idea to consult your vet, as some breeds are naturally bigger than others. A vet will be able to advise you and assess the body condition of your pet. All pet weight-loss programs have three fundamental components: dietary change, exercise and behaviour modification. Dietary change and exercise create an energy deficit that will result in weight loss. Behavioural modification involves changing the habits that have led to the weight problem in the first place and helps to change both the owner’s and the pet’s behaviour in order to maintain weight loss.
Practical tips to manage weight loss in your pet
Try to restrict your pet’s food intake to 60-70 per cent of what you would usually feed them each day. If using dry food, measure out a day’s worth into a container and only feed from this container each day. This will stop the over-feeding (and overeating) that can easily happen with dry food.
Select an appropriate low-kilojoule food for weight loss – these are available from vet clinics and supermarkets.
Cut out all table scraps and treats. Pat your pet instead.
Include moderate levels of daily exercise. For dogs this means 20-30 minutes of activity every day, so grab the lead and get walking. Regular, moderate exercise every day is better than one big session every weekend.
For cats, if they’re young, encourage them to play by chasing toys or string. With older cats who are in the habit of lounging, restricting their diet is the only realistic way to reduce weight.
The aim is to produce a weight loss of 1-2 per cent of total body weight per week. Any more than this will mean the pet is hungry; any less and the owner will lose hope!
Once weight loss has been achieved, adjust your pet’s intake to maintain the new, ideal body weight. You can increase the amount you feed above the diet amount, but try to keep treats to a minimum.
Prevent weight regain by monitoring energy intake and keeping your pet active. Daily walks will benefit both you and your pet.
Pets and milk: what’s the story?
Most cats and dogs love the taste of milk. Milk contains a simple sugar called lactose that’s broken down in the gut by the enzyme lactase. However, just like humans, some cats and dogs don’t have enough lactase to digest the large quantities of lactose in milk, which results in digestive upsets and diarrhoea. Rather than an everyday food, think of milk as a treat, as most pets can tolerate and enjoy an occasional bowl of milk. There are also specially formulated “pet milks” available that either don’t contain cow’s milk or are pre-treated with the enzyme lactase to break down the lactose and make it more digestible. These varieties should not cause any upsets for your pets.
Danger foods for dogs
Most dogs enjoy sweet flavours, including the taste of chocolate. However, chocolate contains a substance (theobromine) that is toxic to dogs when consumed in large quantities. Small amounts of chocolate given as treats are not likely to be harmful, but it has been calculated that 700g of milk chocolate could be lethal for an 11kg dog.
Grapes and raisins are also toxic for dogs. Ten cases have now been reported in the USA, where five dogs died of kidney failure after eating between 250g and 900g of grapes or raisins. Therefore it’s important to store all chocolate foods, grapes and raisins out of the reach of your dog.
Touted as “essential reading for cat owners with class”, French Cats Don’t Get Fat: The Secrets of La Cuisine Feline, by Henri de la Barb, promises to teach your cat how to savour a meal with all five senses and to provide a “foolproof” exercise regimen. On sharing the book with my furry friends, I found the recipe section a great hit, but “Le Workout” section did not have universal appeal. One of them agreed wholeheartedly with the need to scamper around at regular intervals in a seemingly meaningless way, but another found the thought quite distasteful. And while tearing furniture to shreds can be quite appealing, sometimes, I was told, you just can’t be bothered. This is a quick, light and entertaining read for the whole ”family”. Rose Carr
The rise in the number of overweight pets is attributed to an increasingly sedentary lifestyle coupled with overfeeding.
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