Modern cat food has almost eliminated feline diseases caused by an inadequate diet. At one time most people fed their cats human food scraps – whatever came to hand. Certainly cat food was far less refined than it is today.
However, it could be argued that in some respects commercial cat food is too refined in 2012. It is an unusual situation but there are two customers for cat food manufacturers, the cat and the cat’s caretaker. It might be fair to say that in recent years the manufacturers have tended to prioritize the person and not the cat. After all, from the pet food manufacturer’s standpoint the primary customer is the cat’s owner as they spend the money. The manufacturer must satisfy the primary customer. Convenience is a major factor in marketing cat food.
Dry cat food is very refined in respect of convenience. It is long lasting and allows a cat to graze – eat small amounts frequently – which is suitable for cats. However, after 6 months storage it can lose some of its nutritional value. I don’t recall seeing it until around the 1970s but apparently extruded dry cat food that is so commonplace today was first produced in the 1950s. It has become very popular and some veterinarians recommend it as an exclusive food. It is also cheaper on a portion by portion basis that wet or canned cat food.
The manufacturing process for modern dry cat food or kibble (in the USA) requires high carbohydrate levels, from 20-50%. They have less animal tissue. The protein content may be too low for a cat.
Despite big advances in feline cat food there are concerns amongst some vets and experts over the role that diet plays in respect of feline obesity, urinary tract disease (FLUTD) and feline diabetes mellitus¹.
Diabetes is a disease that results in elevated blood sugar levels. Insulin is a hormone that regulates blood sugar levels. It is made in the pancreas. In diabetic cats, not enough insulin is produced because the pancreas does not respond to the rise in blood sugar levels. Diabetes is a serious and often fatal disease. Diabetic cats will usually drink more water and urinate more. This is also a symptom of advanced kidney failure. Diabetic cats may also vomit frequently and lose weight. Overweight unneutered tom cats seem to be overrepresented amongst diabetic cats.
Type 2 diabetes (adult onset diabetes) is the most common form in cats. Feline diabetes is caused by environmental and genetic factors. That is, diet and an inherited predisposition to the disease. Genetic factors as a cause of diabetes is supported by the fact that Burmese cats are overrepresented in the pool of domestic cats that contract the disease. That is Burmese cats are predisposed to the disease. Environmental factors, specifically diet as a factor in developing type 2 diabetes is supported by case studies of individual cats who had diabetes while on a full-time dry cat food diet and who were cured or their condition improved when placed on a wet food diet².
Dry cat food is a high carbohydrate diet which increases blood glucose and insulin levels. This may cause diabetes in cats that are already predisposed to obesity and diabetes because of genetic factors.
The estimated number of cats in the United States in 1990 suffering from diabetes was 150,000. In 2007 an estimate placed the number at 1,500,000². The increase can be partly explained by the greater awareness of cat caretakers which leads to more frequent veterinary visits. However, it has been argued that the modern diet and increased use of dry cat food is a major contributing factor.
Not only does high carbohydrate dry cat food put more glucose into the cat’s blood it can also contribute to a cat feeling sluggish and unwilling to exercise which contributes to weight gain and an increased likelihood of developing diabetes. Although some vets will say that obesity is not the cause of diabetes but one symptom of the underlying cause.
It is said that the high levels of carbohydrates in dry cat food stresses or in some way damages the pancreas², which causes feline diabetes to develop. Also the liver fails to respond quickly to falling blood sugar levels when flooded with high sugar levels.
There is evidence that suggests that a cat with diabetes that is on a dry food diet will respond quickly and beneficially when started on a low sugar, high protein canned wet food. Diabetic cats are often given insulin injections. On conversion to a wet food diet it seems that the cat’s pancreas recovers and is able to produce sufficient insulin sometimes to the extent that insulin injections can be stopped. Conversions to a different food type might have to be gradual – mixing the old and new food together.
If insulin is still required after a switch to wet food a recommended type of insulin is animal-source PZI (USA)².
Conclusion: Diet is important. I think you will find that modern thinking has concluded that a dry cat food to the exclusion of all other foods is unwise. High quality wet cat food that more accurately reflects the cat’s natural diet is preferable. Dry cat food is unnaturally high in carbohydrates. Some domestic cats that are predisposed to diabetes are unable to process it without health problems.
- The Welfare of Cats page 229.
- Your Cat ISBN 0-312-35801-6
- Link to photo of dry cat food
- Link to photo of insulin in syringe
- Link to picture of Bramwell – I don’t know if Bramwell’s diabetes was brought on by dry cat food. I have asked his caretaker.