Vitamins are essential substances, without which the body cannot thrive. Like human beings, dog vitamin needs are also the same. When the diet is deficient in any of the vitamins, certain disease conditions arise. The vitamins are called either by their technical names or, simply, by various letters assigned to them. Thus we speak of vitamins A, B, C, D, and so on. The public has been subjected to so much misleading information about vitamins by the press, radio, and television that it would be well to give a few notes of reliable scientific data about them.
Vitamin A is essential to the maintenance of health in the dog, and when the diet is deficient in this substance, a variety of disease manifestations may ensue. These disease conditions will occur only when the deficiency is well marked. Where the deficiency is only slight, distinctive symptoms will not be apparent and its diagnosis can be established only by technical laboratory procedures.
Probably the commonest disease associated with vitamin A deficiency is the eye condition known as xerophthalmia. This is characterized first by a watery and glassy appearance of the eyes, and by a marked congestion of the eye membranes. The tear ducts become blocked and infection appears. The surface (cornea) of the eyeball becomes inflamed, develops a watery swelling, and finally ulcerates. In the advanced stages of eye-tissue degeneration in xerophthalmia, permanent blindness may result.
Growth and reproduction may also be adversely affected by a vitamin A deficiency, and it is occasionally a cause of sterility in dogs. Growth of the ear bones may also be impaired. Deafness can sometimes be traced to this deficiency. Tooth and gum involvements, and a tendency to the formation of kidney and bladder stones, may also be occasioned by a lack of this vitamin.
Where these conditions have not progressed too far, they respond readily to treatment, which consists simply of alleviating the symptoms and incorporating sufficient quantities of vitamin A in the diet. Cod-liver oil and halibut-liver oil are excellent sources of vitamin A. Carrots, lettuce, tomatoes, corn meal, and alfalfa meal also possess considerable quantities of an assimilable form of vitamin A. For the normal animal, a suitable diet should include sufficient vitamin A to prevent any of the deficiency conditions we have mentioned. That is why the section on feeding in this book details the specific doses of cod-liver oil that should be fed to puppies. For the determination of a balanced ration either to prevent or to treat vitamin A deficiencies, consult your veterinarian.
Vitamins of the Vitamin B Complex
Vitamin B-L, Thiamin Chloride
Vitamin B-l is another vitamin essential to the maintenance of dog health. Diets that are deficient in this vitamin may result in loss of appetite, failure to excrete regularly, lowered resistance to infection, paralysis of the hind legs, possibly running fits (or as it is variously known fright disease, barking fits, furious fits, canine hysteria), convulsions, and death. The main sources of this vitamin are meat, brewer's yeast, and wheat germ. The latter two substances are commonly incorporated in commercial dog foods to provide the amount of vitamin B-l necessary to prevent possible deficiencies. Dogs that are fed table scraps usually get sufficient quantities of this vitamin to meet their needs. It is therefore apparent that deficiencies of this vitamin can occur only under fairly extreme cases of improper nourishment, which means that vitamin B-l deficiencies are not too commonly met with in household pets whose owners make even a minimal effort to feed them properly.
This is another essential vitamin. Deficiencies of this vitamin may result in certain forms of liver trouble, anemia, muscular weakness in the hind legs; dermatitis on the hind legs, chest, and abdomen; and sore eyes. The best natural sources of vitamin B-2 are liver and yeast. Other excellent sources are soy flour, beans, eggs, wheat germ, cheese, and milk. Dogs that are fed meat and milk or a standard dog food will rarely be affected by a deficiency of this vitamin. It is therefore fairly uncommon in the well-kept house dog.
Deficiencies of this vitamin will result in a disease of dogs called black tongue. This disease is related to pellagra in humans, from which a synonymous term for niacin deficiency has been coined: the Pellagra Preventive Factor. Deficiencies of this vitamin are extremely rare in ordinary household dogs since commercial dog foods and meat have more than enough of this vitamin to meet the dog's needs. This is a problem found only in areas of extreme poverty.
Not much is known about this vitamin. Deficiencies of it result in certain forms of anemia. It is not common in the ordinary house dog since it is present in sufficient quantities in the fresh or commercial foods commonly fed to dogs. The main sources of pyridoxine are wheat germ, yeast, egg yolk, fish, liver, green vegetables, and whole wheat.
Deficiencies of this vitamin may result in loss of muscle control of the legs and unhealthiness of the gums, it is present in liver, yeast, and crude molasses. Deficiencies are uncommon.
This vitamin is present in liver, eggs, soybean meal, and yeast. Deficiencies result in improper growth and liver trouble, but the adequate supply of this vitamin does not pose a very significant problem for dogs.
This vitamin is not important in dogs since only minute quantities are required and these are readily available. Lack of biotin results in a progressive paralysis.
The data for the dog's requirement of this vitamin are very limited. Deficiencies result in anemia and breeding troubles, but this has been determined in other animals rather than the dog.
Vitamin B-12 is essential to the health of dogs. Deficiencies of it can lead to certain forms of anemia. Natural sources are liver, yeast, meat scraps, and some fish oils. It does not pose much of a practical problem.
Dogs manufacture their own vitamin C and therefore have no special need for this vitamin. Humans that have a deficiency of this vitamin develop scurvy, which is cured by fresh fruit juices and vegetables. No disease resembling scurvy appears hi the dog. However, the bodies of dogs will occasionally fail to manufacture sufficient quantities of vitamin C, and variable degrees of irritation will result in the membranes of the mouth and gums. This condition responds readily to proper doses of this vitamin.
Any person who has ever raised a child knows that the physician will prescribe some sort of vitamin supplement for the infant. Though the vitamins serve as a general body tonic, one of their main purposes is to prevent rickets. Rickets in dogs and children are very similar conditions.
In dogs, rickets is a nutritional disorder characterized by various bone deformities. This is caused by lack of dog vitamin D. It is especially evident in young puppies from weaning time to one year of age and is noted more often in larger breeds than in smaller ones. It is readily amenable to treatment in its early stages, becomes more resistant as the disease progresses, and may terminate in permanent deformity. It is apparent, therefore, that veterinary intervention is essential as soon as the symptoms are recognized.
The disease is caused by a lack in the diet or the improper assimilation of calcium and phosphorus and/or vitamin D. This results in deficient bone development. The leg bones become soft and bend, giving the animal a bow-legged appearance, and the ends of these bones become spongy, thus making the joints appear swollen. The animal may arch its back, maintain a crouched stance, show retarded dental development, develop a tendency to bloat, and have attacks of diarrhea. The animal will generally express an air of benign lassitude and will be inattentive to its surroundings.
A Severe Case of Rickets
Though rickets is readily discernible by clinical symptoms, positive diagnosis is established by X-ray. The X-ray is especially valuable because the disease can be diagnosed in this manner even before the clinical symptoms appear, and thus can be treated before any deformities manifest themselves.
Rickets is treated by incorporating into the diet the elements in which it is deficient, or by correcting the causes of improper assimilation. This can be done by feeding fresh meat and vegetables and backing these up with a standard mineral supplement. Therapeutic doses of vitamin D are additionally supplied in the form of cod-liver oil, halibut-liver oil or any similar preparation.
It is always easier to prevent rickets than to attempt to cure it. As mentioned earlier, it is advisable to give puppies half a teaspoonful of cod-liver oil a day, and to dogs weighing over twenty pounds one whole teaspoonful a day. The very large breeds, such as Great Danes and St. Bernards, may be given two teaspoonfuls a day. This should be continued until the animal is about a year old. At this age the permanent bone formation is established, and the subsequent vitamin D requirement can be amply supplied by the food alone.
The discussion so far has been on the infantile form of rickets. Mature animals suffer from a similar sort of disturbance, due to the same deficiencies, called osteomalacia or late rickets. In this instance, too, the softening of the bones may lead to lameness and deformity. However, since the calcium, phosphorus, and vitamin D requirements are much smaller in older dogs than younger ones, these manifestations are less likely to occur. Late rickets is less common than infantile rickets and much less responsive to treatment.
Vitamin E is an essential dog vitamin need for the preservation of muscles and is reputed to improve reproductivity in animals. It is present in liver, lettuce, and especially in wheat germ oil. It is well to mention that cod-liver oil may destroy the vitamin E in the dog. Thus large doses of cod-liver oil should be judiciously avoided. There is a synthetic form of vitamin E on the market which has been used very successfully in treating deficiencies of this vitamin.
Though vitamin K is essential, no known disease has been recognized in dogs as a result of vitamin K deficiency. Alfalfa leaf meal is rich in this vitamin. Vitamin K appears to be related to the clotting of the blood.
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