The unknown metabolism disorder Kryptopyrroluria (KPU)

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As a cranio sacral therapist and herb and food specialist I meet a lot of horses who have metabolic disorders. Horses with laminitis, sweet itch, insulin resistance, EMS, diarrhea, mud fever, chronic cough and many more issues. 

Some horses will even have more than 1 of these issues!

Most horse owners will try and treat that certain issue. Which mostly involves a vet, antibiotics, steroids, bute and big fat vet bills. But the underlying disorder is not recognised. These horses are what they call multimorbid, which means that they have many diseases at the same time. Or you could also call them `non-responders`. Because sometimes the medication does not work for them. 

How does KPU arise?

Unfortunately, cryptopyrroluria (KPU) is now a very widespread detoxification disorder in horses. The reason for this lies in a disturbed intestinal flora.

These helpful microorganisms not only digest the cellulose from hay and pasture grass, but also produce a lot of nutrients that are important for the horse. These include essential amino acids and activated vitamins. In particular, activated vitamin B6 in the form of pyridoxal-5-phosphate is required by the horse's liver in order to effectively "defuse" waste and toxins and make them excretable.

We will have to explain a bit more about how the liver works, in order to explain how KPU arises.

The liver is where detox takes place. All waste materials that are produced in the body as well as absorbed toxins, such as mould, drugs and poisonous plants must be rendered harmless by the liver. 

Detoxification in the liver: phase 1

This detox takes place in two phases. In phase 1, the fabrics are converted. At the end there are intermediate products, which are sometimes more toxic than the starting products, so it is important that phase 2 starts immediately. 

Detoxification in the liver: phase 2

In this phase, the toxins are further defused and changed so that they can be excreted later. After this step, the liver releases the waste material into the bloodstream so that it can leave the body via the kidneys and urine. A catalyst is necessary for phase 2 of the detoxification to take place. In horses, this is pyridoxal-5-phosphate, or also known as P5P. It is an activated form of vitamin B6.

If the catalytic converter P5P is missing

If P5P is missing, the detoxification process stops after phase 1 and the body carries a modified but still highly toxic substance that it cannot excrete. In healthy horses, the P5P is made available in sufficient quantities by the intestinal flora. Since horse and intestinal flora live in symbiosis and the horse is always adequately supplied from there, it has apparently lost the ability to activate vitamin B6 to P5P itself in the course of evolution. This is a big difference to humans, who can produce P5P from vitamin B6 themselves. However, kryptopyrroluria or hemopyrrolactamuria (HPU) also occurs in humans, namely when a genetic mutation prevents them from being able to produce P5P themselves. These KPU or HPU sufferers have to take P5P for their entire life to make up for the deficiency.

Trace element deficiency due to defective detoxification cascade *

If P5P is missing in order to allow phase 2 of the detoxification to proceed normally, the liver begins to couple the waste to certain trace elements in order to be able to excrete at least some of it. These include primarily zinc and selenium as well as sulphur. But manganese or iron can also be used. Since horses react very sensitively to a zinc deficiency in their blood count, but are tolerant of a selenium or manganese deficiency, this is seen more frequently in the blood count.

* Cascade = In biochemistry, a sequence of reactions in a metabolic pathway    

Selenium deficiency - a common phenomenon

Many horses show a selenium deficiency in their blood count. Selenium-poor soils are often used as the cause. Much more often, however, it is not the insufficient supply, but the excessive consumption due to the defective detoxification cascade. The addition of selenium supplements raises the selenium level in the blood plasma for a short time, but the selenium deficiency can be detected again soon after these agents are discontinued. So it is not a real defect. The selenium deficiency actually hides a zinc deficiency and this results from a deficiency in P5P. The cause of a P5P deficiency and thus an incorrectly proceeding detoxification lies in a disturbance of the intestinal flora.

Symptoms of zinc deficiency

The latent zinc deficiency caused by the KPU or already noticeable in the blood often results in secondary diseases and symptoms such as eczema, mud fever, poor horn growth, poor coat change, thin long hair, weak immune system with allergies, susceptibility to infection or chronic cough. The more trace elements are deficient, the more diseases and symptoms manifest themselves and the less the horse can react to therapies or medication.

How does this happen?

The cause of the KPU is therefore the lack of supply with P5P. How can this happen? Most mueslis, pellets and mineral feed are rich in vitamin B6. However, this is the inactive form that the horse cannot activate itself. Brewer's yeast is also not a good supplier of P5P. It is therefore important to enable the horse's natural intestinal flora to work normally again. The horse is thus automatically supplied with all active B vitamins, with vitamin K and many essential amino acids, which are also produced by the intestinal symbionts. In addition, everything that disrupts the horse's intestinal flora should be avoided. These disorders mainly come from wrong feeding.   

What to do about it

If KPU is suspected, a urine test should be carried out, even if the blood count shows no abnormalities. A laboratory in Germany offers these tests which can be ordered via The Horse Therapist. You can order it here

To be continued…… 

1. Urine test

Two values are determined here: indican as a value for intestinal putrefaction and kryptopyrrole as a value for the derailment of the liver metabolism. The Indican value is more meaningful for horses, because this is where the onset of KPU is shown, even if the liver can still compensate. If the result is positive, please contact The Horse Therapist for the necessary therapeutic and accompanying measures, because they can differ in detail - depending on the level of the values, horse breed and age and depending on existing diseases.

2. Optimize feeding

In any case, the first priority is to optimize the feeding. This includes a 24-hour supply of good, stalky hay to feed the intestinal flora again. Empty periods of over 4 hours must be avoided at all costs. Haylage and other ensiled products must be removed from the feed plan. Likewise, all feed that is poorly tolerated such as bread, bananas, large quantities of carrots or apples, and large quantities of apple pomace (which is often added to concentrated bags of feed ).

3. Intestinal cleansing and regeneration

An intestinal rehabilitation is necessary to bring the intestinal flora back into balance. To do this, feed a custom made herbal mix for 4 - 6 weeks, which supports the horse where needed.

4. KPU therapy

KPU horses must always be supplied with essential B vitamins and zinc. Depending on the urine values, the horse should become healthier over 6-18 months. If haylage was fed, a deacidification cure is also necessary. To do this, you could give Fir Humic Clay  for 2-4 weeks, it binds acids and makes it easier for the body to get rid of them . In any case, a cure of spirulina (as powder or pellets ) can be carried out. This binds toxins in the body and is mainly excreted via the liver-bile-intestine, thus relieving the kidneys. I would advice to get a professional to help you out and do not experiment yourself. Every horse is different and every horse has it`s own needs. 

Support in the long term

After the intestinal rehabilitation, KPU horses also benefit from constant metabolic support until the body is back in balance. Here we recommend the custom made herbal mix, which basically represents a healthy concentrate alternative or supplement. In addition, you should ensure the mineral balance with Okapi mineral feed . Please let us advise you before starting therapy.   

Written by Sharon Bronsveld from The HorseTherapist

References: Dr.Christina Fritz from Sanoanimal:

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