Hypocalcemia issues at a glance:
Low blood calcium can cause many problems in parrots and may be caused from excessive egg-laying, poor diet, inadequate calcium intake, excessive fruit consumption, uropygial gland problems, metabolic problems, issues with the parathyroid and ultimobranchial glands, lack of ultraviolet B light (UVB) or hypovitaminosis A.
Interestingly, African grey parrots, and other African parrots, can suffer from seizures related to low blood calcium. I would estimate that almost all seizuring African greys are having problems related to low blood calcium levels. This condition is usually only ever diagnosed in greys living indoors, or those not exposed to any natural sunlight (not filtered through glass or plastic) or those that do not have access to a full-spectrum light that emits UVB light. Other African parrots in the Poicephalus group are also prone to hypocalcemia related to lack of UVB lighting. However any hen that is excessively ovipositing is also prone to hypocalcemia.
When I am looking at African greys or other birds with hypocalcemia problems, I always closely examine the uropygial gland (also called the preen gland or oil gland). This gland produces vitamin D3 precursors that are spread on the feathers when it preens. This secretion is then spread on the feathers and must be activated by UVB light to convert the precursors to active vitamin D3. Then the bird must preen to ingest the now active vitamin D3, which is vital for normal calcium metabolism. So, if there is not enough calcium in the diet, or if the uropygial gland isn’t functioning properly, or if the bird does not receive UVB light, then any one of those things can result in a bird with low blood calcium and eventually seizures or perhaps folding fractures and other signs of nutritional secondary hypoparathyroidism. Even if the blood calcium level tests within the normal range during the veterinary evaluation, the only time the level may be low is during or right after an actual seizure. Remember that the plasma calcium level is a fluid number, that may rise and drop throughout the day and when tested, the plasma calcium only provides one frozen moment in time.Normal plasma calcium levels for psittacines ranges from 8-13 mg/dl. For individual species, check in Carpenter’s Formulary, veterinary textbooks or ISIS (the zoo data base). Elevated calcium levels usually will only occur from reproductive activity in a hen, or rarely from malignancy or thyroid/parathyroid dysfunction. The plasma calcium level is tightly controlled and oversupplementation with calcium supplements almost never results in an elevation in the calcium level in the plasma. While, in theory, running an ionized plasma calcium level is important, ensuring that the entire complex metabolic cascade is functioning properly is most likely more important that running a single ionized calcium level initially.
Any hen with hypocalcemia that is laying an excessive amount of eggs should be advised to allow the hen to sit on the clutch of eggs for the length of time that they would normally incubate them instead of removing eggs as they are oviposited (cockatiels: 19-20 days, budgies: 16 days, conures: 21-23 days, Eclectus: 26 days). At this time the eggs may be removed. If eggs are removed as they are laid, the bird may continue laying in an attempt to complete the clutch. Decreasing daylight hours may also be helpful in shutting down egg laying in some hens. Some hormones are also helpful in stopping a cycling hen.
I always recommend a beta-carotene supplement for all birds with hypocalcemia and this is why: any problems with vitamin A deficiency can result in squamous metaplasia of the uropygial gland. Beta-carotene is converted to active vitamin A in the body and the rest is excreted unchanged, so unlike vitamin A, beta-carotene is very safe and non-toxic. It can resolve any nutritional imbalances that might be causing the uropygial gland to not function properly.
Because I have seen several birds, on second opinion, suffering from toxicosis from hypervitaminosis A from injectable vitamin A, I always recommend oral beta-carotene and not injectable or oral vitamin A as a supplement. Injectable vitamin A is quite concentrated, as it is produced for large animals, unless it is compounded by a special compounding pharmacy to come in a less concentrated solution.
In addition to beta-carotene, hypocalcemic birds should also be supplemented with additional calcium. TumsTM are made from calcium carbonate and are fruit flavored so many birds will happily eat some when provided. TumsTM can also be crushed and sprinkled on moist food daily. In hypocalcemic birds, we should aim to provide approximately 100 mg/kg PO daily of calcium. For maintenance, 50 mg/kg per day is a good amount. Calcium glubionate can be used to administer in drinking water, at approximately 750 mg per liter of drinking water. Oral dosing may also be employed at doses ranging from 23 mg/kg PO q24 hrs up to 150 mg/kg PO q12 hrs, depending on the situation.
Almonds are also a good source of calcium. Ensure that you check with your clients about what other supplements are being offered to prevent overdosing or imbalanced nutrients. Cuttlebones or mineral blocks can also provide adequate calcium supplementation for birds that will actually chew on them. Yogurt, cottage cheese and other types of cheese contain only minute amounts of lactose (birds do not have the enzyme lactase, to digest lactose or milk sugar) so these items are considered safe as a source of calcium for birds. Keep in mind that fruits have an inverted calcium:phosphorus balance, so excessive fruit consumption can cause excess phosphorus levels.
I think natural sunlight is beneficial to all birds but especially so for African greys and other African species. The last piece of the puzzle for hypocalcemia in birds can be corrected by allowing some outdoor time, supervised and providing shade and water and safety from predators. Never place a bird in direct sunlight without adequate shade and fresh water, in an escape-proof cage, safe from predators.
Sunlight should not be filtered through glass or plastic, as those materials will eliminate a great portion of UVB rays. Screens can also filter out a percentage of UVB light. If natural sunlight is neither possible nor practical, then these birds should be provided with a full-spectrum light that emits ultraviolet light in the UVB range. There are special fixtures that can be mounted safely at the correct distance from the cage to allow the birds to benefit from the ultraviolet light. The cord should be protected from inquisitive beaks that may end up chewing through the insulation, resulting in shock or worse! Fixtures designed especially for birds often have the cord covered with flexible metal for that very reason.
Studies performed by the Chicago Herp Society proved that the off-brands and generic full-spectrum lights may not provide adequate amounts of UVB light, neither in the distance from the bulb nor in the length of time that the bulb produces therapeutic levels of ultraviolet light. I always recommend that pet owners purchase a good quality, name brand light, such as those sold by ZoomedTM.
If seizures are diagnosed in any bird, a thorough physical exam should be performed, including palpation of the uropygial gland, ensuring that the papilla is identified and that the wick is rolled through the fingers. The wick feather should be oily and leave a clear, greasy secretion on the finger tips. Rarely the wick will be dry, often due to the channels in the papilla becoming clogged. This may appear visually as little black lines seen through the skin of the papilla. Hot-packing the gland for several minutes may soften and loosen the impaction. Then gently massaging the gland, applying pressure towards the wick, may result in either a clear, pale yellow or opaque yellow secretion being expressed from the channels.
Be aware that there are families of birds that do not possess an uropygial gland, which is the principal cutaneous gland of birds. Birds that do not possess this gland include the purple macaws (hyacinth, Spix's, Lear's), Amazon parrots, ratites (Ostrich, Emu, cassowaries), frogmouths, many pigeons, woodpeckers, and bustards. I have researched, but have found NO refereed research paper that reports one way or another whether or not pionus parrots have an uropygial gland, but in all my years of examining these birds, I have NEVER found one!
In addition to providing vitamin D precursors for many species of birds, the uropygial gland also provides antibacterial and antifungal components, helps waterproof the feathers and also keeps the feathers supple. Often overlooked, but very important for the overall health of many species of birds.
Any necessary tests should be performed and any problems diagnosed should be treated. In many cases once the cause has been identified, and treated, the hypocalcemia and related conditions usually resolve over time.
In some cases, it may be necessary to control seizures until all of the causes of hypocalcemia have been identified and corrected. If that happens or in cases of idiopathic epilepsy, it might be necessary to use an anticonvulsant to control the seizures. While many anticonvulsants are commonly used in dog and cat medicine, we don't have solid information on dosages for birds or in some cases, what are acceptable blood levels.
While phenobarbital has been around for a long time as a treatment to control seizures, this is not what I recommend for this problem. Years ago, a colleague told me about a nutritional supplement, an antioxidant called dimethyl glycine or DMG that can be used to treat seizures in birds and other exotics. It works by increasing the threshold for seizures and is very safe. It is not a sedative so it doesn't make a bird sleepy or slow. If given at frequent intervals orally it may help prevent seizures from occurring or make them less severe. It is all that I use to treat seizure disorders in most of my avian patients. DMG is called Vetri-DMG Liquid VetriScience Labs: 20 New England Drive, Essex Junction, Vermont, 05452 (800-882-9993). This is available only to licensed veterinarians through this company. The liquid is recommended to be dosed at 1 drop per 100 grams body weight, twice a day as a loading dose, and once a day as maintenance. However, as a nutraceutical, this is very safe and I recommend titrating the dosing to effect.
In cases where a stronger anticonvulsant is necessary or when DMG is not effective, I recommend Keppra (levetiracetam) at 50 mg/kg PO q8hrs. This dosage can be increased as needed up to double the initial dosage. Unlike many other anticonvulsants, Keppra has not been identified to interact with any other known medications, making this most likely the safest anticonvulsant for avian patients. The only downside is TID dosing.
According to Building Wellness With DMG, by Rover V. Kendall, PhD with Adena Therrien, the recommended dosing for animals is 65 mg/kg PO PRN. For additional information about the benefits of DMG, please see DMG: a Nutrient for the New Millennium.
A simple way to provide DMG as well as a plethora of additional helpful nutrients, including free nucleotides, probiotics, enzymes and other trace nutrients is available from a wonderful new company, Young Again Pet Foods (www.youngagainpetfood.com) as a supplement called Immune and Digestive Support. This supplement contains therapeutic levels of DMG.
Hypocalcemia is a very complex condition in birds, in part, because of the role of secretion of the uropygial gland, a gland unique in many birds, not found in any other group of animals. Many veterinarians are unaware of the complex interaction between the uropygial gland, nutrition, full-spectrum light and hypovitaminosis A; all working in concert to maintain plasma calcium homeostasis.
Make examination of the uropygial gland a part of your routine examination of ALL parrots, especially those that are feather picking, have abnormal feathers or those with calcium issues. This overlooked gland is very important in the health and well-being of many species of birds.
Copyright © 2014 Margaret A. Wissman, D.V.M., D.A.B.V.P.
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