Sterilising Cats: The Big Decision

Sterilisation is widely recognised as beneficial for feline health, in fact it can actually double a cats life expectancy. It is now thought to be a responsible action for most pet owners. More than 90% of cats in the UK are sterilised and while the procedure has many benefits, it also results in physiological changes which need to be addressed through diet.

The Benefits
Cats reach sexual maturity as early as around five months of age and an unsterilised female cat can have two or three litters a year (that’s a lot of kittens needing good homes!). Owners should be made aware that the idea that a female cat should have at least one litter before sterilisation is a myth. Sterilisation also reduces the risk of accident and disease. Sterilised cats wonder less so road accidents may become less likely, and wounds or abscesses caused by fighting with other cats are much less common in sterilised cats.
This characteristic also significantly reduces the risk of infectious diseases such as Feline Immunodeficiency Virus, for which there is no vaccine and the Feline Leukaemia Virus, both spread through close contact and fighting and are extremely prevalent in unsterilised cats.
Spaying a female cat removes the risk of infections and tumours in the uterus. If the testicles are retained in the abdomen of a male cat they are at hight risk of developing tumours, so castration is always advised. Sharing your home with unsterilised cats is not always fun! Females come into season regularly attracting unsterilised males from the neighbourhood. Males will often stray and display high territorial behaviour such as spraying urine in the home. Sterilisation tends to result in a calmer and more a affectionate pet that’s easier to live with.

The Process
Cats are usually sterilised from five to six months of age, when they reach sexual maturity, although earlier sterilisation is possible. The procedure is performed under general anaesthetic and is known as spay in females and castration in males.
Females are spayed through an incision into the abdomen, either on the side or the tummy, with the uterus and both ovaries removed the incision is closed with stitches.
In males, castration usually involves both testicles being removed through small incisions in the scrotum which are left to heal on their own.
Sterilisation is a relatively short procedure and cats usually recover quickly from the anaesthetic. Most can go home on the same day. Follow ups are required to check the wound healing, check that no further pain relief is required and if necessary, remove the stitches.

After The Operation
Hormonal changes induced by the sterilisation take place almost immediately. The cat’s energy requirements reduce by around 30% following the procedure, but most cats tend to want to increase their food intake! This is because the metabolic changes are so fast the cat’s diet needs immediate adaption to prevent dramatic weight gain.
Males tend to gain more weight than females after being sterilised and they rapidly accumulate more body fat. Obesity increases the risk of a number of health conditions, most notably Diabetes Mellitus, but also joint issues, certain liver problems and constipation.

Post-Op Diet and Excercise
The ideal choice is a diet aimed at sterilised cats. You should make the transition during the week before the op so that the dietary change is made gradually. PetShopBowl offers Pro Plan’s Cat Food for Sterilised Cats which promotes a lean body mass, maintain good regulation of glucose metabolism and healthy urinary tract and Royal Canin’s range of food for young and adult neutered cats, which provides reduced energy density, along with high protein levels and L Carnitine to help preserve muscle mass, along with selected dietary fibres which increase the feeling of satiety to help reduce over eating.
Owners should also keep an eye on the cats weight and body condition, and if necessary adjust the amount of food given to the cat. Cats should be kept active so why not have a look at PetShopBowl’s cat toys and accessories for your cat to play with. Constant access to a litter tray, outdoors will increase the activity of the cat. Encouraging the cat to drink away from the food and litter tray will help to support the cats urinary health.

Keeping Your Tabby In Trim

Let’s face it, life for the average urban pet cat is hardly taxing and, with a ready supply of food and no requirement to get out and about to catch their next meal, it’s not surprising that an estimated 25 to 30% of pet cats in the UK are obese – which is defined as being more than 20% above their ideal body weight.

Most domestic cats lead a much more sedentary life than their predecessors, and a proportion of pet cats are kept entirely indoors, or with access only to limited runs outdoors, which further reduces the amount of exercise they get.

In addition, most domestic cats are now neutered, mainly to prevent unwanted kittens, but also to reduce undesirable behaviours such as urine spraying and territorial warfare, which are more common in entire cats. Neutered cats tend to utilise their food more efficiently and will therefore put on weight if fed the same amount as before the procedure was carried out. If they begin to put on weight, they will tend to become less active as a result, and can easily get into a downward spiral leading to obesity.

Health risks

This is something that needs to be addressed, as there are significant risks associated with being severely overweight, including an increased incidence of disease such as:

  • Diabetes mellitus (sugar diabetes)
  • Lower urinary tract disease (such as idiopathic cystitis)
  • Osteoarthritis
  • Hepatic lipoidosis (fatty liver disease)
  • Breathing problems (and thus increased anaesthetic risks)

Although pet food manufacturers produce feeding recommendations for their diets, the correct amount of food to feed is simply that which keeps a cat at their correct body weight.

Danger period

The danger period is when the main growth phase ends, which is also not long after most pet cats are neutered. Kitten foods are relatively high in energy, so a cat should be switched to an adult food or even onto a ‘light’ version to prevent a problem from developing. Leaving food down ‘ad lib’ is much more likely to lead to a problem than measuring out a set amount and feeding it in small meals throughout the day. In multiple cat households, it’s good practice to feed each cat separately, as their feeding requirements may differ throughout their lives. It will be much more difficult to tailor their diet to their individual needs if they are accustomed to feeding communally from shared bowls.

The key to obesity prevention is regular weighing – at least once a month – but every week if there is thought to be a problem. Keep the records on a chart, because it’s easy for a gradual increase in body weight to go unnoticed until it has become very significant. If your cat is getting tubby, your vet is the best person to oversee a controlled weight reduction programme.


  • Before you attempt to put your cat on a ‘diet’, get advice from your vet. Many vet practices run nurse-led weight reduction clinics, which can provide you with expert advice and support.
  • Keep a food diary so that you can really keep track of what your cat eats.
  • Make sure no-one else in the family or the neighbourhood is feeding your cat – a clearly marked collar may help
  • Spend some time each day playing with toys that encourage the cat’s natural hunting and chasing instincts.
  • If you feed dry food, make your cat work for it by hiding it in food-based toys.

Cats don’t have to watch their fat intake

Researchers have found that, unlike humans, cats are able to consume a diet relatively high in fat without raising cholesterol levels. The research also showed that, as long as cats’ daily calorie intake remains constant, increasing the proportion of fat in the diet will not affect the likelihood of weight gain.

The findings advance understanding of how cats handle dietary fat and reinforce the differences between the nutritional needs of cats and humans.

Their research was conducted by scientist from the University of Glasgow and the Waltham Centre for Pet Nutrition – the science centre supporting brands such as Whiskas, Royal Canin and James Wellbeloved.

It is widely recognised that a diet rich in saturated fats can lead to increased levels of cholesterol in the blood. But what works for humans doesn’t necessarily work for our feline friends. In a study of healthy adult cats, researchers have found that increasing the proportion of saturated fat in the diet has no impact on cats’ cholesterol levels.

“These intriguing findings reinforce how different cats’ nutritional needs are from those of humans. If the same diet fed in this study were given to humans, it would result in a significant increase in bad (LDL) cholesterol – a recognised risk factor for cardiovascular disease” said Dr. Richard Butterwick, head of nutrition at Waltham.

“The study findings therefore add weight to previous research showing that cats have developed physiological coping mechanisms, which have enabled them to successfully evolve on a meat-based diet that is higher in protein and fat than that typically recommended for humans.”

The research also showed that increasing the proportion of fat in a cat’s diet will not increase the likelihood of weight gain, provided that their daily calorie intake remains constant.

This finding reinforces the importance of monitoring daily calorie intake, rather than fat alone, for keeping cats at a healthy body weight. The study forms part of a wider programme of ongoing collaborative research by Waltham into the impact of nutrition on body weight in cats and dogs.