Does a homemade diet really need supplements?

Is supplementing necessary in a homemade diet?

A homemade diet is one of the healthiest ways to feed your dogs and cats, but only when done right.

There are many dogs and cats out there being fed a wonderfully balanced and complete homemade diet, but unfortunately, there are many more that are not.

People are moving away from commercial foods for their pets, as they learn about the importance of fresh foods. And the more commercial pet foods that get recalled, the faster they move.

Whenever I formulate a diet for a client, I try my best to keep nutrient supplements to a minimum. This doesn’t always work out, and some may bed to be added in.

Why is balance so important?

Dogs and cats have minimum nutrient requirements for many different nutrients, and these have to be met in the diet. If they are not in the foods they are being fed, then they need to be supplemented. Lots of minor nutrient deficiencies can go undetected, but overtime they can present as premature ageing, Poor immunity, rough, dry coat even behavioural problems. Some nutrient deficiencies can be life threatening too, like in the case of taurine deficiency in the cat.

So what are their nutritional needs?

If you look at what a cat or dog would eat in their natural state, you will see that a dog and cat have quite different dietary needs. In cats, their food is usually freshly caught small prey. They eat the entire animal, and they eat a huge range of species. Lizards, rodents, birds, insects, native marsupials, and small mammals. They are killed and eaten straight away. As fresh as it can be.

Dogs on the other hand, will eat whole prey, but they are also not as fussy. They will eat week-old-whatever-dead-creature-this-is when they come by it. They eat faeces of other creatures. They can also hunt together, and bring down larger prey. Then as a pack, will eat through it. Taking a few days to get through it.

Dogs will gorge when food is available, and fast when its not. they will eat large meals, and not hunt for a day or two. Cats on the other hand are constantly prowling around. they are incredibly successful hunters, and they eat lots of small whole animals, frequently. They don’t gorge, and they don’t do well if they fast.

This differences in eating habits, also means they have different nutritional requirements.

The minimum requirements dogs and cats need to thrive has been well studied, and is known as the National Research Council- or NRC guidelines. There has been extensive testing to come up with these guidelines, and they are regularly modified and updated, through research. There is a NRC book available, but a brief outline of the requirements of dogs and cats can be found here  

For a dog or cat to stay healthy, they need to meet these requirements. They are all essential and the biochemistry within their body will start to  dysfunction when these needs are not met.

I will just go through a few that are often under supplied in a homemade diet, and may need supplementing.


There are ten essential Amino acids that dogs need to get in their diet. Arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Cats need these ten, plus Taurine.

These 10 amino acids are readily available in animal flesh. Taurine is not bound to other amino acids within the meat tissue like most other amino acids. It is a free amino acid. It is also water soluble, and can be pulled out of the meat tissue with any water losses.

Continuous and high use muscle, such as heart tissue, and well used muscles, like darker chicken thigh meat is high is taurine.

However taurine is easily damaged through heating and storage. So meats that are not fresh and eaten immediately are going to have lower levels of taurine.

Heating can reduce the taurine levels by 50%.

Bacteria degrades taurine, so any bacterial contamination is also going to affect the level.

Freezing meat doesn’t degrade taurine, however during thawing, the taurine is pulled out of the meat with the liquid that seeps out- which is usually what gets tipped down the sink- taurine and all

And just how fresh is the meat you are buying? Chicken hearts are readily available in the supermarket, but there is no guarantee they have not been frozen before you purchase them. All the liquid that has seeped out of the hearts has soaked into that little absorbent pad in the bottom of the tray- and you guessed it, lots of the taurine has soaked into it too.

So any thaw juice, or cooked juice, of taurine rich meats needs to be added into your cats meal.

If you are not sure how fresh your meats are, or if they have been frozen or not prior to purchase, Taurine is something that really should be supplemented in the cats diet. It can take many months for a taurine deficiency to become obvious, but often by the time it is discovered, there is retinal damage that may not be reversible.

A good rule of thumb is 50mg taurine to every 100g meat for your cat.

Dogs are efficient in making their own taurine from the amino acids methionine and cystine. Cats can’t because they don’t have enough of the enzyme responsible for this conversion.

Vitamin E

Vitamin E is a really fragile vitamin, which is damaged easily by oxygen, light and heat.

Vitamin E is used to protect fats and oils against oxidation, which is why its often used as a preservative in pet foods.

It helps to prevent oxidation of lipids in the body, improves wound healing, circulation, and is important for the nervous and cardiovascular system.

Vitamin E is essential, and the higher the fat content of the diet, the higher the level of vitamin E is needed. The meats readily available for our pets are generally high fat, which is often why they are cheap.

Natural sources of Vitamin E are wheat germ oil, green leafies, organ meats and fish.  Or some nuts and seeds, like sunflower seeds, or almonds.

Vitamin E should be supplemented at around 7.5mg per 1000 kcal/ME daily for dogs and 10mg per 1000 kcal/ME for cats as a minimum. Higher fat diets, or health conditions may require higher amounts.

Vitamin E should be added in just before being fed.

Vitamin D

Dogs and cats don’t synthesise vitamin D from the sun like humans can.

Vitamin D is important for the control of Calcium and Phosphorus levels in the body, and also acts as a hormone, known as Calcitriol, which is important in the immune system, and preventing cellular damage.

The best source of vitamin D is to feed liver. but what happens if your dog or cat don’t like to eat liver? Well, you can try lightly searing it, you can try feeding it frozen. But if they still wont eat it, you have to find the vitamin D elsewhere.

Vitamin D is found in many different fish, such as sardines, trout, mackerel, egg yolks, and fish liver oils.

This is also a fat soluble vitamin, and is stored in the body, and can cause toxicity issues if over supplemented.

A minimum requirement for dogs is 3.2mcg per 1000 kcal/ME daily. Cats need 1.75mcg per 1000 kcal/ME

These three nutrients are the most commonly under supplied nutrients I find in the diets I analyse, and are often the nutrients that will need supplementing. Some animals with health conditions will need other nutrients supplemented, and when there are allergies, or if a pet is particularly fussy, they may have other nutrients that may require supplementation.

The balance in their diets can occur over a week, and not every meal needs to be balanced. However this balance needs to be met. Variety is often mistaken for a balanced meal, and sometimes adding in lots of extras can displace important nutrients out of the diet. Have a look at your homemade diet and see if they are meeting these minimum recommendations, and if not, its time to balance them out with supplements.

Do you supplement any nutrients in your pets diets? what do you find they need?


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