Cat Health Month is commemorated during February.

“Cats are not small dogs that climb trees” is a phrase I heard from one of my lecturers in the previous century. And for veterinarians especially this is very true – we cannot treat cats as if they are merely small dogs. Cats have different physiology, anatomy and behaviours, and are predisposed to different diseases than dogs. They are a whole different ball game to treat (never mind to even pick up, in some cases!).   

Let’s look at a few differences: Cats are carnivores. They need to eat meat. They cannot digest carbohydrates. They cannot make many important amino acids, so they need to obtain these amino acids from their diets. Your cat cannot be a vegan or vegetarian or even pescatarian – it needs red meat. Cats on pure fish diets will also develop vitamin B12 deficiency and nervous system disorders. One must remember that cats eat birds and small mammals - and do not fish.  

Cats are solitary, stealth hunters and quite secretive animals. They don’t show illness and pain very easily, so small symptoms are often quite important. By the time we notice they are ill, they are often very ill. Cats also need to be handled very differently to dogs. The tighter you hold them to perform an examination, the more they will struggle to get free. A light touch from the vet or vet nurse is a definite advantage. 

Cats have very concentrated urine, and it can become supersaturated with minerals, causing a crystalline stone formation. Cats that eat cheaper bulk-brand pellets are especially predisposed to developing bladder stones, and male cats often develop a complete obstruction of the urethra, causing severe pain and accumulation of toxins in the blood. Before premium cat foods were available, this was a very common occurrence. Over the past 20 years, the cause of bladder inflammation has changed – from dietary related to stress. Many cats now develop stress-related cystitis and bladder obstructions, which are treated primarily through behavioural interventions. 

Cats can be passive-aggressive with each other. Don’t look for the obvious fighting, look for the blocking of an entrance or exit, the casual lying in a pathway to the litter box or food source. Cats are solitary animals as mentioned, so most cats in multiple-cat households are not friends – they just tolerate each other. Much of their stress is caused by the high population density we force them to live in. Supplementing your cat’s diet with medication or diets supplemented with anxiolytics for anxiety, depression or obsessive-compulsive disorder can help manage these symptoms. 

Dental disease and kidney disease are two conditions that frequently affect cats. Just like dogs, cats develop periodontal disease as they get older, but younger cats are predisposed to a painful autoimmune inflammation of the gums due to a reaction to the plaque on their teeth. These cats need full-mouth dental extractions to control the reaction. Older cats are also predisposed to gradually declining kidney function. This is often accompanied by high blood pressure. If diagnosed early and the hypertension is managed, the progression of renal deterioration can be delayed, and your cat can live for many more years. Unmanaged hypertension causes rapid progression of renal disease as well as damage to the heart and eyes with retinal haemorrhage and detachment. Another cause of hypertension in cats is an overactive thyroid, which also causes overactivity and weight loss. 

A cat’s liver doesn’t have all the same enzymes for metabolising drugs and toxins that a dog’s does. This means they are especially sensitive to some drugs – especially Paracetamol, which is toxic to cats. They are also more sensitive to anti-inflammatory drugs, and can only have one specific anti-inflammatory medication, at much lower doses. 

Two different blood types are present in cats: Type A and Type B, and as with people, cats will develop a transfusion reaction when transfused with a different blood type. The small amounts of blood we can safely collect from donors also means we cannot store blood. Instead we collect from a donor and transfuse immediately into a recipient. This makes blood transfusions problematic to perform in cats. Dogs can receive any blood for their first transfusion and acquire sensitivity to the second transfusion if a mismatch has occurred. 

Most domestic short-haired cats and Siamese cats (99%) are Type A. Type B is more common in some of the pedigreed breeds such as Sphynx, Persian and British shorthair. Kittens, if of a different blood type to their mother, may acquire antibodies after they have suckled as newborns, which causes them to become anaemic in their first week of life. This requires interventions by breeders, who need to check the parents’ blood types to avoid this from occurring and – if unavoidable – to manage the situation in the first few days of life with a ‘wet nurse’ instead of the mother or withhold colostrum and transfuse plasma to supply antibodies. None of this occurs in dogs.  

Cats go into a heat cycle every two weeks when the season is right – usually in spring when days are getting longer. They will stop showing repeated heat signs once they ovulate, which only happens if they mate. They will be fertile again while they are still suckling their kittens. When daylight hours start to shorten, the breeding season is over. In contrast, dogs go into a heat cycle every six months, regardless of the season, and they ovulate even if they have not mated.

This is just the tip of the iceberg of these interesting animals. They can also be infected with feline immunodeficiency virus (similar to HIV), and they can live for many years being FIV-positive without developing immunodeficiency. They can also be infected with feline leukaemia virus which, unless naturally eliminated from the body by their own immune system within a few months, may predispose them to the development of leukaemia and bone marrow disorders, and is fatal.

So don’t ever think that cats are just small dogs that climb trees. Cats are different, mysterious, and often a law unto themselves – and need to be treated as such.

   Dr Liesel van der Merwe with a kitten.

Disclaimer: The opinions expressed in the article are solely those of the author and do not necessarily reflect the views of the University of Pretoria.