Cat World > Feline Nutrition

What Do Cats Eat? - What To Feed a Cat

Cats are obligate carnivores which mean they must have meat in their diet in order to survive. Their primary ancestors lived on a diet of small rodents. They require a high protein diet with a variety of different nutrients such as taurine, arginine, calcium, niacin (vitamin B3), pyridoxine (vitamin B6) and thiamine (vitamin B1), to name a few. Many of these nutrients are found in animals only, making a vegetarian diet impossible for cats.

Dietary requirements will change during the different life stages. A newborn kitten will require milk for the first three weeks of age, before slowly beginning to eat solid food, around six to ten weeks of age they will begin to wean.

A pregnant and lactating mother will have higher nutritional requirements and your veterinarian may recommend feeding her a kitten diet.

Young adult cats require a maintenance diet.

Senior cats also have unique dietary requirements and should be fed a diet specifically for older cats and/or a special prescription diet to address any underlying medical conditions such as diabetes.

What kind of cat food?

There are two choices when feeding your cat, a commercially prepared diet (dry food, semi-dry food, canned food), or homemade. Many pet owners will feed a combination of the above. I personally prefer a combination of commercially prepared food AND some raw food, including uncooked bones to help keep the teeth in good condition. Feline nutrition is such a complex science which I feel I do not understand enough for me to attempt a raw diet with my own cats. But many well-researched people have moved to a raw/homemade diet with much success.

I prefer to feed my own cats high-quality brands of commercial cat food which. Of course brands available in the supermarket must meet the nutritional requirements of cats, however, the cheaper products often contain more fillers. These come in the form of carbohydrates, usually corn. Cats will need to eat more food to meet their energy requirements, therefore cheaper brands don't always save you money.

Special and prescription diets for cats:

Furthermore, your cat may be required to go on a special "prescription diet" (only available from your veterinarian) to address an underlying medical condition (such as diabetes, urinary crystals, kidney disease, weight reduction, oral health, sensitive skin), there are even breed specific diets available now, varieties to help control hairballs and of course foods to cover each life stage such as kitten, adult, senior etc.

When should you feed your cat?

This depends. Many pet owners prefer to leave dry food out for their cat all day for their cat to graze on. Others prefer to put food down at set times. Kittens and pregnant/lactating cats require more frequent meals than adults. I put moist food out for my cats at breakfast and dinner time and leave a bowl of dry food for them to nibble on.

In the warmer months raw/canned food can quickly go off, so any uneaten food is removed after 30-45 minutes.

What not to feed your cat:

The list of what you should not feed your cat is too long to add to this article, but some big ones include;

Don't forget to provide your cat with 24/7 access to fresh drinking water.

Can cats have cows milk?

Generally speaking no, cats shouldn't drink milk. Most cats are lactose (which are sugars in milk) intolerant and drinking milk may result in an upset tummy and cause diarrhea. If you want to give your cat milk, there are special "cat milk" available from your supermarket or pet store.

When deciding what to feed your cat, it is always advisable to speak to your veterinarian who can provide you with information on the best products to meet your cat's nutritional requirements.

Related content:

What do cats eat   Cats and milk   Human foods cats can eat

Kitten Food - Feeding a Kitten

what to feed a kittenWith such a vast range of kitten food on the market that it can often be confusing for the new kitten owner. This article will hopefully shed some light on the topic and help you decide which food is best for your kitten.


Weaning a kitten:

The weaning process begins around 4 weeks of age. Start out slowly by mixing baby food (check the ingredients to make sure the food contains no onion as this is toxic to cats) canned or dry cat food in with some kitten formula. Not all kittens will take to food immediately, so patience is important. Introduce a small amount initially. You can introduce solids either by placing a small amount of food on your finger  or in a cat bowl. Kittens should be fully weaned by 8 weeks of age.

Kitten food:

Kitten food is designed specifically for the high energy requirements of kittens. Their nutritional requirements are greater than those of older cats due to the rapid growth they are undertaking.

Kitten food generally comes in two forms. Wet (or canned) and dry. One or both of these varieties is fine for your cat.

While pet foods have to meet the nutritional requirements of cats, not all brands are created equally. Cheaper brands tend to contain more fillers, which come in the form of carbohydrates, most often corn. Your cat will have to eat more food to meet it's energy requirements, so cheaper brands don't always actually save you money. Also, these brands tend to be more likely to produce unpleasant smelling feces than the premium brands.

Your veterinarian is the best person to speak to for feeding advice. They can recommend the best product for your kitten.

Introducing either chunks of raw meat or raw chicken necks or bones two to three times a week is also recommended for dental health.

Kitten food should be fed until 12 months of age, at which time you can switch to a balanced adult food.

Changing diet:

When adopting a new kitten, find out what food it has been eating. If you would like to change the type or brand of food, do this gradually by mixing in increasing amounts of the new food with the old food. A sudden change in diet can cause tummy upsets in kittens and cats.

How often to feed kittens:

Most people like to feed a small amount of wet food 4 times a day and leave dry food out 24/7 for them to graze on.


Plenty of fresh tap water is essential for kittens and should be readily available. Water should be changed daily.

What not to feed your kitten:

  • Cooked bones
  • Dog food
  • Chocolate
  • Cows milk
  • Vegetarian diet
  • Supplements, unless recommended by your veterinarian

Also see:

Bringing your kitten home   Kitten Care   Toilet Training A Kitten

Vitamin D Toxicosis in Cats

Vitamin D is a fat-soluble vitamin (meaning they are stored in the liver and fatty tissues) which is responsible for helping the cat maintain levels of calcium and phosphate in the body and promoting mineralisation the mineralisation of bones. When blood levels of calcium drop, vitamin D is activated, which helps the gut to absorb more calcium from food and reducing urinary calcium loss.

Vitamin D is produced in the fur (or skin in humans)  upon exposure to sunlight and also ingested in small quantities via food. Foods containing vitamin D include fish, liver, dairy products and egg yolk.

There are two major forms of vitamin D:

  • D2 (ergocalciferol)

  • D3 (cholecalciferol)

Vitamin D toxicity (also known as hypervitaminosis) can occur in cats of any age, although kittens and young cats are at greater risk than adult cats.


How do cats develop vitamin D toxicosis?

  • Accidental ingestion of rat poison containing cholecalciferol (vitamin D3) is the most common cause of vitamin D toxicosis in cats.

  • Secondary poisoning. Eating a rodent who has ingested rat poison. 

  • Over-supplementation of vitamins can also occur. Fish liver oils, in particular, can cause high levels of vitamin D. You should never give supplements to your cat without veterinary approval.

  • Ingestion of certain human medications can increase vitamin D levels.

  • Feeding an imbalanced diet containing foods rich in vitamin D such as liver and fish. These are fine in small quantities, but should not be given regularly.

The effects of vitamin D toxicosis can be from acute or chronic exposure. Young cats are more prone to developing vitamin D toxicosis, however, it can occur in cats of any age. Cats with predisposing conditions such as kidney failure or hyperparathyroidism are more susceptible to vitamin D toxicosis than cats with no illness.


What are the symptoms of vitamin D toxicosis?


The mechanism of vitamin D toxicoses relates to raised blood calcium (hypercalcemia) and high blood phosphate (hyperphosphatemia).


Hypercalcemia can lead to calcification of various soft tissues, particularly the kidneys, lungs, arterial walls, myocardium and the intestinal tract. Skeletal abnormalities and eventually renal failure, cardiac upset and GI upset.


Symptoms may vary depending on the level of toxicity. For example, acute vitamin D toxicity is more likely to occur if your cat has ingested rat poison, chronic toxicity if your cat has been fed an improper diet.


Common symptoms include:

  • Weakness
  • Fatigue
  • Vomiting
  • Anorexia
  • Constipation
  • Increased thirst
  • Increased urination
  • Depression
  • Pain in bones
  • Gastrointestinal or pulmonary hemorrhage (bleeding from the lungs)
  • Muscle tremors
  • Seizures
  • Black, tarry feces which contain blood

Long-term complications of vitamin D toxicity can include kidney stones, kidney failure, abnormal heart rhythms and excessive bone loss, mineralisation of certain organs, such as the lungs can produce a chronic cough due to their inability to contract as they should.

How is vitamin D toxicity diagnosed?


Your veterinarian will perform a complete physical examination and obtain a medical history from you including questions on possible exposure to rodenticide or vitamin supplementation in the diet.

He may wish to perform the following tests:

  • Biochemical profile which may reveal hypercalcemia (high blood calcium levels), hyperphosphatemia (high blood phosphate levels), and azotemia (high urea levels in the blood). Elevated BUN (blood, urea, nitrogen) levels can indicate kidney failure.

  • Urinalysis to check for high levels of calcium in the urine.

  • X-Ray may reveal mineralisation of certain tissues and look for bone loss.

  • Echocardiogram (ECG) to evaluate the heart.

How is vitamin D toxicity treated?


Prompt veterinary attention is vital to remove as much vitamin D as possible and prevent further absorption. Your cat will need aggressive treatment, and will be required to stay in hospital for several days.


Treatment is aimed at lowering serum calcium levels, increasing urinary calcium excretion and decreasing absorption of calcium via the intestines. This may include:

  • Induce vomiting for acute exposure to a rodenticide.
  • Activated charcoal to prevent further absorption.
  • Phosphate binders to decrease phosphate levels.
  • Stop supplementation immediately.
  • IV fluids to treat and correct dehydration if necessary.
  • Reduce serum calcium by flushing it out of the body. This may be accomplished by diuresis (facilitation of increased urine output) with normal saline solution.
  • Calcitonin is a hormone which is produced by the C cells of the thyroid gland when blood levels of calcium are elevated. It works by inhibiting the activity and formation of osteoclasts (cells in the bone which breaks down bone tissue). When calcium in the bone is broken down by the osteoclasts, it enters the bloodstream. Your veterinarian may prescribe an injectable synthetic form of this hormone to help bring down calcium levels.
  • Furosemide is a loop diuretic (water tablet) which may be given to increase excretion of calcium via the kidneys.
  • Prednisolone may be prescribed to reduce bone and intestinal absorption of calcium and increase kidney excretion.
  • Obviously, if you have been giving your cat supplements, this should be discontinued.

Preventing vitamin D toxicity in cats:

Never give your cat supplements unless told to do so by a veterinarian.

Avoid the use of rodenticides if possible. Keep all poisons locked away from cats.

Feed a well-balanced diet. Home prepared is fine, but liver and fish should only be given occasionally and in small amounts.

Keep all medications and creams away from your cat. While most tend to be more discriminating than dogs, some cats are curious enough to eat medications they shouldn't, especially kittens.

Don't let your cats hunt. This is a hard one to control but there are many risks associated with hunting. A poisoned rat or mouse is going to be slower and easier prey than a healthy one.

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Vitamin A toxicosis

Vitamin A Toxicosis in Cats

Vitamin A is a fat-soluble vitamin that has multiple functions within the body. It helps in the formation and maintenance of healthy teeth, skeletal and soft tissue, mucous membranes, and skin.  Approximately 80% of vitamin A is stored in the liver and is released in small amounts as it is needed. Vitamin A toxicity (also known as hypervitaminosis) occurs when too much vitamin A is ingested leading to toxicity.

The effects of high doses of vitamin A vary depending on the amount given and the age of the cats. Cats can develop either chronic or acute vitamin toxicosis. Acute is sudden onset and occurs when large doses of vitamin A are suddenly ingested, chronic toxicosis occurs more slowly, over a prolonged period of time.

  • High levels of vitamin A are toxic to the liver, the major storage site of the vitamin.
  • Excess intake leads to excess bone formation (exostosis), particularly in adult cats. The cervical/thoracic spine and joints are particularly affected. Over a prolonged period of time, complete fusion of the spine can develop.
  • Kittens can develop loose teeth, gum problems and abnormalities with bone growth. Their bones can easily fracture.
  • Vitamin A supplemented during pregnancy can result in cleft palate.

How does vitamin A toxicosis occur in cats?

Cats can develop vitamin A toxicosis when they are fed a diet containing foods which are rich in vitamin A, most often this would be a diet high in liver.

Supplementing your cat's diet with cod liver oil.

What are the symptoms of vitamin A toxicosis?

Often symptoms are subtle and can take months to develop. One of the first symptoms the pet owner may notice is an unkempt coat. Other presenting signs may include:

  • Poor appetite
  • Depression
  • Poor coat condition due to discomfort when grooming
  • Bone pain
  • Sluggishness
  • Cervical vertebrae stiffness
  • Lameness, the joints may be enlarged and painful
  • Yellowing of the teeth can sometimes occur
  • Kittens but not adults can develop gingivitis and loose teeth [1]

Chronic cases can show ankylosis fusion of cervical vertebrae and elbow joints, making grooming painful and therefore cats may have an unkempt appearance. Jaundice may be seen in cats with liver damage.

Which foods are high in Vitamin A?

Liver, cod liver oil, and vitamin supplements are all common causes of hypervitaminosis A in cats. According to Neils Pederson in his book Feline Husbandry - Diseases and Management in the Multiple Cat Household pet mixes obtained from butchers may also on occasion be a cause as they often contain high amounts of liver.

How is vitamin A toxicosis diagnosed in cats?

A diagnosis will be made by obtaining a dietary history and clinical signs. Your veterinarian will need to perform some diagnostic tests as well as imaging to assess changes in the bones and joints.

  • X-rays to check the condition of the cervical spine and forelimbs.
  • Blood tests to check your cat's vitamin A levels.
  • Biochemical profile to check the overall health of your cat, including the liver which can suffer damage from high levels of vitamin A.

How is vitamin A toxicosis treated in cats?

Bony changes are irreversible, however, other symptoms should improve once a proper and balanced diet is fed.

Treatments are generally aimed at relieving discomfort associated with bone changes and may include:

  • Placing food and water bowls on a platform may ease the pain for your cat.
  • Your veterinarian may prescribe anti-inflammatories or analgesics to relieve pain.
  • In some cases, your veterinarian may opt to surgically remove the excess bone growth.

Preventing vitamin A toxicosis in cats:

Only feed organ meat to your cats in small quantities and occasionally. Be careful feeding your cat liver, it can be highly addictive to cats who can go on to refuse other types of food.

Never give your cat vitamin supplements unless advised to do so by your veterinarian.


[1] The Feline Patient - Gary D. Norsworthy, Mitchell A. Crystal, Sharon K. Fooshee and Larry P. Tilley.

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Vitamin D toxicosis