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How to choose the best dog and cat food

By Rachel Christie

From raw dog food to hypoallergenic cat food, we explore what goes into pet food and share advice from top vets.

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Choosing the right food can make all the difference to the health and happiness of your dog or cat, but it can be a daunting task trying to work out what’s actually best for your pet.

Signs that your pet is eating a nutritious diet include clear and bright eyes, a shiny and dandruff-free coat, plenty of enthusiasm for life and a lack of excess body fat – you should be able to feel their ribs and see their waist. 

To help you navigate the pet-food aisles a little more easily and pick the best food for your cat or dog, we've also asked vets for their expert advice on how to choose the right pet food. 

How to choose the best dog food 

Raw, hypoallergenic, home-made, kibble, puppy, senior, vegetarian; there’s an overwhelming amount of choice when it comes to picking the right food for your dog. Here are some pointers to help lead you in the right direction.

Dog food ingredients

  • Dog food that says it is ‘with chicken’ must contain at least 4% chicken, but a ‘chicken-flavoured’ product doesn’t have to contain any at all. High-quality pet foods tend to contain more meat.
  • The higher up the list of ingredients meat is, the more it contains. But while proteins from meat can be better used than plant matter in the body once it’s been digested, a mixture of plant and meat protein is important in a diet. 
  • Try to avoid dog foods where the first listed ingredient is labelled as ‘animal derivative’ or ‘meal’ as these products are much lower in quality.
  • Some dog foods are marketed as ‘complete’, meaning they contain all the nutrients an animal needs, while others are complementary, meaning they should be given to your pet alongside a complete food.  
  • All complete foods have to meet certain feeding requirements, so your dog should be getting all the nutrition that it needs, regardless of how much the product costs. 
  • Complete foods – which can be wet or dry and contain all the nutrients your dog needs to stay healthy. These don’t necessarily cost more, but there may be an element of false economy with cheaper foods, as each individual kibble can contain fewer nutrients.

How much should my dog eat and weigh?

Amount of dog food

PDSA (People's Dispensary for Sick Animals) recommends that the type and amount of food a dog needs depends on their breed, type, age, health and lifestyle. For example, a working sheepdog needs much more energy than a small dog that spends most of the day sleeping.

Cost of dog food

With some dog foods, it will cost as little as £140 a year to make sure your dog has a balanced diet, but others can set you back by more than £850.

How to choose the best cat food 

Cats choose their food based on smell, texture and how they feel once they start to digest it. It's not based on taste like us humans. Here are a few cat-food tips to help keep yours happy and healthy. 

Cat food ingredients

  • Cats aren’t vegetarians – they have to eat meat to be healthy because their bodies need certain amino acids, such as taurine, that can only be found in meat and fish. Without them, your cat could become very ill. The easiest way to make sure you cat is getting all the nutrients they need is to feed them a complete commercial cat food.
  • Commercial cat food, like dog food, is classified as either complete or complimentary and it works in the same way; complete foods provide all the necessary nutrients in the right balance so no other food is needed, while complementary foods need to be combined with other foods for the right balance of nutrients.
  • If you would like to change your cat's diet you can slowly introduce the new food by mixing it with the old food over a period of a week.

Cost of cat food

  • The price difference of varying cat foods is vast, with the cheapest brands we assessed costing less than £60 a year – and the most expensive wet foods being more than 10 times this amount.

Amount of cat food

  • Many companies make food especially for kittens, juniors, adults and seniors so if you pick the correct age or stage food you can be sure your cat’s dietary needs are being met. 
  • Cats prefer lots of small meals to one large one – they ‘graze’, eating between eight and 16 times a day, so it’s best to leave food out for them.
  • But if your cat is eating too much and putting on weight, it may be better to feed them two meals a day, instead of leaving food out.

Vets answer your pet food questions 

Whether you’re curious about a raw-food diet or you think your pet has a sensitive stomach, we asked some top vets and pet food experts about key issues when it comes to feeding your cats and dogs.

Both raw dog food and raw cat food can be made up of raw meat, offal, and raw bone, along with other ingredients such as fruit, vegetables, oils, nuts and seeds. 

Raw food, especially meat, contains bacteria, parasites and other pathogens that would normally be killed during the cooking process. So feeding raw food brings extra risks to your pet's health. 

There are two types of raw feeding; home-made raw diets and commercially prepared ones. The main concern with a home-made option is whether all the right nutrients are provided in the right proportions for healthy bodily function. 

Some manufacturers produce frozen and freeze-dried raw cat food and raw dog food with both 'complete' and 'complementary' varieties. These products help owners to feed their pets a raw diet responsibly. 

Professor Daniel Chan, professor of clinical nutrition at the Royal Veterinary College, warns that feeding a raw diet could lead to bacteria spreading around the home, which could have an impact on your health or others in your household. Owners are advised to thoroughly research raw feeding if it’s something they are considering, consult their vet and then review the options. 

There are a couple of quick checks you can do to see if your pet is overweight. You should be able to see and feel the outline of your dog's ribs without excess fat covering and you should be able to see and feel your cat's ribs, spine and hip bone. 

Both cat and dogs' waists should be clearly visible when viewed from above. Your dog's belly should be tucked up when viewed from the side and there should only be a small amount of belly fat on your cat.

‘Always check the packaging to see how much your pet should be eating for the weight they should be, not the weight they currently are,’ says Vicki Larkham-Jones, a vet with veterinary charity PDSA. 

'Weigh out the exact amount of food needed so you aren’t swayed by puppy-dog eyes as you prepare dinner.' If you’re giving your pet a treat, give them a bit less food to balance out their diet for the day. 

If you're worried, book your animal in for a medical checkup at the vet. Diet dog food and diet cat food from the vet are calorie-controlled and can be an effective way  for your pet to lose weight. 

Many vets run weight control clinics providing regular checkups. They are often free of charge and help to ensure that the diet is working and that weight loss isn't happening too quickly.

Experts we spoke to don't advise DIY homemade dog food or cat food. ‘It’s extremely difficult to put together a balanced home-made diet for your pet, and I wouldn’t recommend it unless you’re under the direct supervision of a vet,’ says Gudrun Ravetz, junior vice president of the British Veterinary Association. 

‘Yes. It is essential that puppies and kittens are fed on puppy dog food and kitten cat food, as they have specific energy and nutrient requirements,’ says Gudrun Ravetz of the British Veterinary Association.

‘As they get older, different breeds of dog will age at different rates,’ she says. ‘For example, a Great Dane is likely to be “senior” before a Yorkshire terrier.’ 

Your vet will be able to advise on the best diet for your pet’s life stage – whether that's puppy, junior or senior dog food – breed and lifestyle, and tell you if your pet has any special dietary needs. 

Cats are carnivores, and a vegetarian diet is not recommended for them. 

This is the same with dogs, although, in theory, it’s easier to find and feed your dog a vegetarian diet that will still meet its needs,’ Gudrun Ravetz of the British Veterinary Association says. 

However, she warns that it can be difficult to do it well and, unless you work with a veterinary-trained nutritionist, there is a risk of harm to your pet’s health.

Wet pet foods are very popular and are generally very appetising to cats and dogs. However, they are more expensive as the recommended feeding amounts are generally higher. 

You can feed your animals wet food or dry food, or a mixture of both. 

Wet cat food is normally available in tins or pouches either with gravy or jelly. Owners who feed their pets wet food should also monitor their pet's teeth as wet foods tend to predispose them to dental disease. 

Wet dog food is much the same and its high moisture content will help keep your hound hydrated.

Dry foods are usually the most economical and easiest for you to feed and store. Dry cat food can be left out all day for your cat to nibble on and is beneficial for their teeth and gums. 

Dry dog food has a much lower water content, so it takes less to provide your dog with everything they need. The best dry dog food will be high in protein, low in carbohydrates and made with good-quality ingredients. The best dry cat food will include meat and fish, vegetables, cereals, vitamins and minerals.

In general, it’s better not to give your pet any variety, which could cause havoc with its digestion. The most suitable diet should be easily digested and produce dark brown, firm, formed stools.

Some pets appear to be sensitive or intolerant to certain ingredients and additives and this can cause a variety of problems. 

Common symptoms include, lethargy, aggressive or hyperactive behaviour, chronic skin and ear problems, slime and jelly being passed with the stools and flatulence,bloating and weight gain or loss. 

The most common food intolerances appear to be colourings, sugars, wheat, milk and soya. Obviously not all pets are sensitive to these things, but if the effects keep re-occurring, it’s best to consult your vet.

Always follow your dog food and cat food manufacturers' guidelines and, where possible, weigh out food using a set of electronic weighing scales. 

Remember, these are intended as a guide and you may need to adjust the amount you feed depending on a number of factors including age, size and level of activity.

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