We know that dental disease is a major problem in cats and particularly older cats. A lot of cats have it. Apparently, 60% of cats older than 3 years of age have dental disease according to a study (Crossley) in 1991. We also know that dental disease is one of the most common reasons why people take their older cats to their veterinarian.
There are 2 major dental problems which exist in cats, (a) periodontal disease (gum disease), which is usually associated with plaque accumulation and (B) feline odontoclastic resorptive lesions (FORLs) – erosions of the tooth’s surface at the gingival border (margin) see image.
Diets which are currently available to promote feline oral health can contribute to the cat’s health but will not, on their own, maintain oral health without the addition of tooth cleaning.
Commercial diets are concerned with changing the environment within the mouth to discourage the formation of plaque forming bacteria, to stimulate the flow of saliva, to maintain healthy gingival tissue together with something that we know about which is to remove plaque by the abrasive action of the food. When we buy dry cat food we sometimes believe that the nature and the texture of it acts somewhat like a toothbrush.
However, cleaning teeth with food is meant to be achieved by the shape, texture and fibre alignment of the food pellets but, as mentioned, although dry food by itself will reduce plaque or calculus the effect is limited because the pellets of dry food are usually broken by the tip of the tooth and therefore have no abrasive action at the gingival margin (border). Also dry cat food can contribute to health issues such as cystitis.
FORLs are associated with diets low in magnesium and also the feeding of non-commercial diets according to a study that took place in 1998 by Lund and associates. There has been speculation that the use of acid sprays as coatings for dry cat food diets may be involved in demineralising the cat’s teeth. A study in 1992 indicated that cats with FORLs had a lower tooth surface pH, although the pH was not related to the diet fed to the cat.
The only way to maintain best feline oral health is to use an appropriate diet in conjunction with toothbrushing and/or the use of oral antiseptics such as chlorhexidine.
You can see, right away, that it is often impractical to brush your cat’s teeth and/or use an oral antiseptic. This is why 60% of older cats have dental disease. There is no easy way around that except, and if, a cat eats as if she was living in the wild and feeding off live prey because as far as I’m aware small wild cats species do not suffer from the same level of dental disease as domestic cats.
Primary source: The Welfare of Cats edited by Irene Rochlitz ISBN 978-1-4020-6143-1