Vitamin K

Vitamin K is best known for aiding in the synthesis of the proteins necessary for blood clotting.  However, research suggests that this vitamin is much more versatile than was once thought.  Vitamin K is involved in the synthesis of other proteins, as well.  Scientists do not yet know the role that many of these proteins play in the body, but some appear to affect the health of the bones, cartilage, heart, and gastric mucus.

Natural Sources

Grazing animals can synthesize their own vitamin K when consuming forage.  Swine and adult poultry can synthesize vitamin K to some degree, but baby chicks must receive vitamin K in their diets.  Pets, too, can manufacture enough of the vitamin in their intestines to cover most of their dietary requirements.

Green, leafy plants such as forages, vegetables, and kelp are the richest dietary source of vitamin K.  However, high-fat grains and meals will suffice, as will animal-derived feeds such as eggs and liver.

Causes of Deficiency

Vitamin K
Sweet clover

In pets and farm animals, vitamin K deficiency is typically a sign of toxicity.  Warfarin-based rat poison is the most notorious offender, and is most likely in small, inquisitive animals such as dogs and goats; however, other drugs and poisons have similar effects.  Grazing animals in general can become deficient when eating moldy hay or silage made from legumes, particularly sweet clover.  Vitamin A or calcium toxicity can also lead to vitamin K deficiency.

Another possible cause of vitamin K deficiency is severe stress.  This can include drug treatment, internal parasites, and disease, especially any disease that causes diarrhea.  Feeding grains to grazing animals can also qualify as stress in this case because it unbalances the pH of the gut.

For swine and poultry, a vitamin K deficiency can be triggered by insufficient amounts of fat in the diet.  Seeds and meals will only have the necessary amount of vitamins if they retain their natural fat.  Extraction of the oil interferes with the vitamin K content of the feed.  Irradiation has a similar effect.

Vitamin K deficiencies are sometimes seen in cats on fish-based diets.  The cause of this is unknown at present.

Symptoms of Deficiency

  • Weakness.
  • Lameness.
  • Fractures.
  • Nose bleeds.
  • Gum bleeding.
  • Pale mucous membranes.
  • Increased clotting time.
  • Bruising.
  • Spontaneous bleeding.
  • Anemia.
  • Abnormal breathing.
  • Swollen abdomen.
  • Bloody vomit.
  • Blood in urine.
  • High embryonic mortality.
  • Navel bleeding in newborn piglets.
  • Sudden death.

Symptoms of Toxicity

The natural forms of vitamin K appear to be relatively nontoxic for livestock and most pets.  Some pets, however, may experience a severe allergic reaction when given this vitamin for medical purposes, particularly if they receive it in an injection or in an intravenous form.

Synthetic vitamin K (menadione), however, is extremely dangerous when given in large doses.  Symptoms of toxicity include:

  • Depression.
  • Weakness.
  • Muscle stiffness.
  • Laminitis.
  • Anemia.
  • Loss of appetite.
  • Severe weight loss.
  • Colic.
  • Jaundice.
  • Excessive urination.
  • Blood in urine.
  • Death within 12 hours.

There is also a question, still awaiting a definitive answer, as to whether smaller doses of menadione given over long periods of time can cause organ and immune system damage.

Medicinal Uses

Because synthetic vitamin K is so dangerous, it is primarily used as an antidote to warfarin poisoning, often in conjunction with the natural forms.

Natural forms of vitamin K are a little more versatile.  They are typically used to treat clotting disorders such as pulmonary hemorrhaging in horses and pets.  Studies indicate that this vitamin also has the potential to increase bone density in animals.

Content regarding medical conditions and treatment is provided for general information purposes only, and is not to be construed as legal, medical, or professional advice.  Please consult your veterinarian for advice regarding your specific animal’s needs.

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