Vitamin E (tocopherol) is best known for its immune-boosting function. It serves as an antioxidant, working with selenium to eliminate free radicals. It also helps to repair damage to the body, and ensures the health of the white blood cells. Because of this important role, and its function as a structural component of various membranes, vitamin E is necessary for the function of just about every system in the body.
This vitamin is involved in many complex interactions with other nutrients. Its relationship with selenium has already been mentioned. Research suggests that vitamin E may also aid in the synthesis and metabolism of a number of other vitamins and minerals:
Vitamin E is one nutrient that animals cannot synthesize. Plants, however, produce vitamin E in abundance, making all green, growing forages and fresh, minimally processed grains good sources. Oils derived from grains are also high in vitamin E, provided that they are fresh.
Dogs and cats can use the vitamin E stored in the tissues of other animals. Liver and fatty meats are good sources. Raw or lightly cooked eggs are also suitable, as are nuts, wheat germ, and green vegetables.
Causes of Deficiency
One common cause of vitamin E deficiency is stress, including injury, illness, and high levels of performance.
In grazing animals, a deficiency can be brought about by insufficient amounts of fresh forage in the diet. Sometimes this is caused by drought, while in other cases confinement is the problem.
In pets, particularly cats, a deficiency can be caused by high levels of unsaturated fats, including those found in tuna. Vitamin E is required to protect the body from free radical damage caused by these types of fats, so the higher the level of unsaturated fat in the diet, the higher the requirement for vitamin E will become.
All animals eating grain are at risk for vitamin E deficiency if their rations are not high-quality. Unfortunately, this vitamin is rather unstable and will break down quickly under less-than-ideal conditions. Factors that may cause deterioration of vitamin E in feeds include:
- Rancid oils (unsaturated fats).
- High temperatures.
- Prolonged storage times.
Symptoms of Deficiency
Unfortunately, a vitamin E deficiency can sometimes be hard to identify because of its wide range of symptoms. Some of the symptoms that might occur include:
- Lowered immune system.
- Fever in cats.
- Separation from the herd or flock.
- Eye problems.
- Difficulty swallowing.
- Poor skin health.
- Reduced wool production.
- Increased levels of external parasites.
- Muscle pain.
- Muscular dystrophy (most common symptom in all species).
- Arched back.
- Difficulty standing.
- Muscle tremors.
- Varying degrees of paralysis.
- Difficulty breathing.
- Weak pulse.
- Increased heart rate.
- Cardiac arrhythmia.
- Blue extremities.
- Lack of appetite.
- Metabolic disorders.
- Severe abdominal pain in cats.
- Lumps in fatty tissues in cats.
- Dark urine.
- Low fertility.
- Retained placentas.
- Reduced milk production.
- Weak offspring.
- Poor growth.
- Sudden collapse.
Symptoms of Toxicity
Vitamin E appears to be safe for most pets and farm animals. There are questions as to whether excessive supplementation may reduce milk production and meat tenderness, but this is not certain at the present time. The only known effect of excess vitamin E on pets and most types of livestock is exacerbation of a preexisting vitamin K deficiency.
Chickens, however, have a lower tolerance threshold for vitamin E supplementation than other types of livestock. Symptoms of toxicity include:
- Exacerbation of preexisting vitamin K deficiency.
- Waxy feathers.
- Reduced pigmentation in beaks, legs, and feet.
- Reduced growth.
One of the main uses of vitamin E in livestock is to prevent muscular dystrophy and sudden death in young animals.
The immune-boosting role of this vitamin can also be used to advantage in some cases. For instance, vitamin E is routinely used to ward off disease in stressed calves, can help laying hens cope with heat stress, and is often beneficial for pets suffering from allergies, skin problems, heart disease, and a variety of autoimmune problems. It may also help animals return to health after an illness, as well as slow the aging process.
Vitamin E may improve reproductive performance in a number of ways, as well. It is sometimes used to treat infertility in horses. In sheep, it shows potential to improve lamb weaning weights.
Studies suggest that supplementation may increase the quality of animal-derived foods. For instance, vitamin E is known to prolong the shelf life of beef when fed to cattle before slaughter. It also appears to have a positive effect on the flavor and cheese yield of milk when given to dairy cattle.
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.