Purines

What are purines and how are they broken down?

Purines are organic compounds that occur as building blocks in every cell nucleus and are therefore necessary components of the genetic material. This means that the more cells a food has, the more purines it contains. Purines are therefore a natural and vital product of cell metabolism.

Excess purine that is not needed in the dog's body to build up cells must be broken down. This also happens with the purine from food during the digestive process. In the end, a multi-stage process produces uric acid, which the dog usually converts to allantoin and excretes via the kidneys. Enzymes are always involved in such processes, for example xanthine oxidase and uricase.

In some dogs, this is precisely where a disruption occurs and they are unable to break down the purines properly. There can be various reasons for this, such as a genetic defect or a disease that impairs purine metabolism.

When is a low-purine diet necessary for dogs?

There are various reasons why a dog should be fed a low purine diet. Either they suffer from a genetic defect or have a disease that makes it necessary to avoid food containing too much purine, either directly or because of the medication to be taken.

The Dalmatian and its genetic defect

Many Dalmatians, for example, have a genetic defect that leads to a problem with purine metabolism. Uric acid is produced when purine-containing foods are digested. Healthy dogs that do not suffer from the genetic defect can break it down further and excrete the resulting substance (allantoin) via the kidneys without any problems.

Dalmatians cannot do this, however, as they lack the enzyme uricase. As a result, the urine contains more uric acid, which encourages the formation of urinary stones, semolina or crystals. These in turn can cause bladder and kidney disease or even lead to a life-threatening urinary blockage.

To avoid this, owners of Dalmatians are generally recommended to feed a low-purine diet. This is especially true for male dogs, as their anatomy makes them more susceptible to urinary tract problems than females.

Leishmaniasis in dogs

Leishmaniasis is a disease that is primarily transmitted by sand flies and can affect both bipeds and quadrupeds. When the sand fly bites, it releases the pathogen "leishmania" via its saliva. The pathogens often spread unnoticed in the dog's body and can lead to secondary diseases such as inflammation of the kidneys, eyes, joints or blood vessels as well as anemia.

Unfortunately, there is no cure for leishmaniasis, but there is a treatment that alleviates the symptoms and improves the dog's quality of life. Very often dogs are treated for life with allopurinol, which stops the pathogens from multiplying.

However, the drug has the side effect of inhibiting the enzyme xanthine oxidase, which is normally responsible for the breakdown of uric acid. This means that the dog has more uric acid in the blood and urine and therefore has an increased risk of kidney and bladder stones.

For this reason, a low-purine diet is essential during treatment with allopurinol. This also applies to other diseases or medications that disrupt or influence purine metabolism.

What does a low-purine diet look like for dogs?

A low-purine diet for dogs does not mean that you are no longer allowed to feed them purines at all. Rather, it is about reducing the purine intake and focusing on low-purine foods. You should always pay attention to your dog's individual needs and consult a vet or nutritionist if necessary.

Avoid foods containing purines

The first step is to avoid or at least severely limit foods containing purines. This includes above all

• Animal offal such as liver, kidney, heart or spleen
• Red meat such as beef, lamb or game
• Fish and seafood such as sprats, mussels or crabs
• The skin of poultry or fish
• Soy products such as tofu or soy flour
• Legumes such as peas, beans or lentils
• Mushrooms and spinach
• Apples

These foods contain more than 100 mg of purines per 100 g and should therefore be removed from your dog's diet if possible.

Give preference to low-purine foods

The second step is to give preference to low-purine foods or at least feed them in moderation. This includes above all

• White meat such as chicken, turkey or rabbit (without skin)
• Eggs and dairy products such as quark, yoghurt or cheese
• Cereals such as rice, oatmeal or spelt
• Vegetables such as carrots, cucumbers or zucchinis
• Fruit such as bananas, pears or berries

These foods contain less than 50 mg purines per 100 g and are therefore suitable for a low-purine diet. However, you should still make sure that you don't feed your dog too much, as even small amounts of purines can add up.

Offer sufficient water

The third step is to always offer your dog enough water. This is important to support the kidneys and flush uric acid from the body. Water can also help to dilute the urine and prevent the formation of crystals or stones.

You should make sure that your dog always has fresh water available and encourage him to drink regularly. If your dog doesn't like to drink, you can also offer him wet food or soak his dry food in water.