Chronic Vitamin A Deficiency
What is hypovitaminosis A (Vitamin A deficiency)?
Hypovitaminosis A, or vitamin A deficiency, is the result of feeding a diet low in β-carotene. This is commonly seen in animals fed imbalanced diets, such as reptiles that are being fed only insects without supplements or vegetables low in these nutrients such as fruit and iceberg lettuce.
What are the symptoms of Vitamin A deficiency?
Hypovitaminosis A results in changes to the layers of the skin, eyes, and lining of the respiratory system. These changes lead to the formation of large amounts of cellular debris in these areas. Animals with this condition often have thin, flaky skin, and abnormal nail and beak growth. Many will have swelling around the eyes as debris becomes trapped under the eyelids leading to eye infections. Many may have narrowed nostrils resulting from the buildup of cellular debris, often continuing down the respiratory tract. Prolonged changes to the respiratory system may lead to upper respiratory infection and eventual pneumonia. Some animals may also develop abscesses within the ears or failure to lay eggs in females. Prolonged deficiency has even resulted in damage to the kidneys.
What species most commonly develop these problems?
Box and aquatic turtles are often seen with middle ear and respiratory tract infections, retained eggs, or eye infections. Box turtles also often develop deformed nails and overgrown beaks. While the condition is rare in tortoises, they can also will present with similar symptoms. Leopard geckos often develop retained skin on the eyelids and subsequent eye infections. Chameleons, along with other lizards, may develop swelling of the lips and have thick, oozing saliva.
How is Hypovitaminosis A diagnosed?
Definitive diagnosis of hypovitaminosis A is difficult because it requires a biopsy of the liver or large volume blood samples. Therefore, it is normally diagnosed based on correlation of dietary history with clinical signs.
How is Hypovitaminosis A treated?
Treatment is aimed at dietary correction and management of secondary infections. Supplementing vitamin A in the diet and offering foods that contain vitamin A is important to long term recovery. In severe cases injections of vitamin A may be recommended, howeve,r because of the danger of overdosing, this should only be done as directed by a veterinarian. If secondary infections exist, your vet will prescribe any necessary antibiotics.
How can I prevent hypovitaminosis A? What foods are a good source of vitamin A?
The most obvious answer is by making sure your reptile is receiving adequate amounts of vitamin A and carotenes. Examples include dark leafy greens and vegetables (collards, dandelion, mustard, and turnip greens, bok choy, and broccoli) and yellow or orange-colored vegetables and fruits (squashes, carrots, peppers, sweet potatoes, cantaloupes).
For insectivores, these foods can also be fed to their insect prey prior to being fed to the reptile as well as a way to introduce vitamin A to the diet.
For aquatic turtles good sources of vitamin A also include whole feeder fish, algae and pond weeds, and commercial turtle foods (making sure to pay attention to expiration dates). Many supplements are available as well that contain vitamin A. Ask your veterinarian for advice on suitable choices.
