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Note for Pet Owners

This information is provided by Provet for educational purposes only.

You should seek the advice of your veterinarian if your pet is ill as only he or she can correctly advise on the diagnosis and recommend the treatment that is most appropriate for your pet.


We have been feeding cats and dogs prepared foods (homemade or manufactured) for many years, but our knowledge of the nutritional requirements of pets throughout their lifecycle stages of growth, adulthood, reproduction and old age is still far from complete.

What is essential ?

All animals need energy and this can be supplied by :

  • Fats - provide the most energy per gram
  • Proteins - especially important for cats
  • Carbohydrates

Vitamins, minerals and water do not supply any energy.

The following nutrients are essential :

  • Water - the most important nutrient
  • Essential amino acids - in proteins
  • Essential fatty acids - in fats/oils
  • Minerals
  • Vitamins

Although carbohydrates, and fibre are beneficial to cats and dogs, they are not essential.

How does diet affect health ?

A pets ration can influence its health in various ways :

  • Nutritional deficiency can occur if :
    • There is not enough essential nutrient in the food
    • Something interferes with nutrient availability e.g. a high fibre content can reduce the bioavailability of minerals.
    • Food processing reduces nutrient availability
  • High energy content diets encourage too much energy intake, which results in weight gain and obesity and has several adverse effects on the body, including increasing the risk of diabetes mellitus.
  • Too much of a nutrient in the ration may cause toxicity. For example, Vitamin A toxicity is common when cats and dogs are fed raw liver. Cleft palate, a defect of the roof of the mouth seen frequently in newborn animals can be caused by too much Vitamin A in the mothers' food.
  • Some nutrients must be in the correct proportions to each other otherwise there is a nutritional imbalance e.g. cat and dog foods should contain slightly more calcium than phosphorus. If there is a lot more phosphorus than calcium present it can affect skeletal development …even though the amount of both minerals exceeds the minimum requirement for the animal.


Species differences

From a nutritional point of view, pets are not just small humans ! We need vitamin C in our ration, but cats and dogs do not because they can manufacture sufficient in their livers.

Also, cats are not small dogs !

Dogs, like us, are omnivores. That is, their digestive system and metabolic processes are designed to deal with a mixture of food types - animal origin and plant origin. So, dogs can be fed a vegetarian diet without any problems (provided it meets their basic nutritional requirements).

Cats, on the other hand, are obligate carnivores, which means they must have a diet that contains nutrients derived from meat. Cats can not be fed a vegetarian diet without serious risks to their health.

Cats have many different nutrient requirements to dogs including :

  • Protein - cats need more protein
  • Amino acids - cats need taurine
  • Fatty acids - cats need arachidonic acid

So, you should not feed dog foods as an exclusive ration for cats.


Nutrition in the management of disease

Dietary management is extremely important for the successful treatment of many diseases and your veterinarian may well advise a change in diet if your pet is ill

Some examples of the role of clinical nutrition include :

  • In disease energy requirements may go up a lot (eg heart failure, cancer, thyrotoxicosis, following major trauma or burns) and sufficient energy must be available in the food
  • Diseases can affect the digestion, absorption or use of a nutrient and so the content of the food, it's form and the route by which it is given may need to be altered. Sometimes nutrition has to be given by injection through a drip direct into the bloodstream.
  • Altering diet can actually be used to treat diseases. An outstanding example of this is our ability to dissolve stones (eg "struvite") that form in the urinary bladder by reducing the protein, magnesium and phosphate content of the diet, and by altering the acidity of the urine.
  • In heart failure various changes are recommended, and salt intake should be reduced
  • In kidney failure various nutrients including protein and phosphorus need to be controlled
  • Finally, some cancers can be influenced by nutrition, and recently a diet has been made available which increases success in the treatment of lymphoma in dogs.

Choosing a pet food

It is almost impossible to make a home made ration that would meet all nutritional requirements and be digestible and acceptable to an animal. Pets allowed to roam might supplement their ration, but pets confined to a home are at risk if they are fed exclusively home made or "fad" diets.

The following are VERY BAD foods for pets :

  • All meat rations - bad for both cats and dogs. Causes thinning of the bones and fractures
  • All fish rations - bad for both cats and dogs. Seen mainly in cats and causes body fat to become inflamed (called pansteatitis).
  • Too much supplementation - eg vitamin A, cod liver oil (contains vitamin D)
  • Vegetarian diets - bad for cats

It is safer to feed a manufactured pet food from a reputable company.

When buying a manufactured pet food read the label carefully. If it states that it is a "COMPLETE" food it must contain all the essential nutrients that the species it is intended for needs. However, if it states that the food is "COMPLEMENTARY" this does not guarantee that the food contains everything that the intended species needs. You have to give other foods to produce a balanced and COMPLETE ration, so, you must find out what should be fed with it.

In addition containing everything that your pet needs based upon it's chemical analysis, it is also preferable that the pet food should be tested in feeding trials. Reputable companies will be able to confirm that they routinely test batches of their products and meet AAFCO standards (the American food industry standards) or an equivalent..

Your veterinarian can advise you on the most appropriate food for your pet, especially if it becomes ill.

Finally, weigh your pet regularly because that will give you a simple and effective indicator of many food-related problems, and don't allow your pet to become obese.


Updated October 2013