African Grey parrots living indoors are known to have problems with seizures, most commonly related to hypocalcemia. However, as calcium levels dip and rise according to circadian rhythm, one should not rule out hypocalcemia based on a single blood test having a calcium concentration in the normal range for psittacines (8.0-13.0 mg/dlL). Determining ionized calcium concentration may be helpful, but reference ranges for the many psittacine species are not yet established.

If a grey parrot is feather picking, appears clumsy, or has had a seizure, suggest adding calcium to the drinking water (Neo-Calglucon™ Sanzoz, calcium glubionate 23 mg/30 mL drinking water or 23 mg/kg PO q24h), supplementing with Tums™ (calcium carbonate) and having the owner offer more high calcium food (cottage cheese, cheese, yogurt and almonds).

Often, though, calcium supplementation alone does not control seizures in these parrots, because several factors control calcium homeostasis, namely, the uropygial gland, vitamin D₃ levels, possible concurrent hypovitaminosis A, ultraviolet light exposure, and secretions from the parathyroid and ultimobranchial glands. African Grey parrots living outdoors and exposed to natural sunlight rarely suffer from seizures, so it seems clear that the interrelation between the uropygial gland, ultraviolet light and vitamin D₃ is responsible for their normal calcium homeostasis.

Evaluation of the uropygial gland should be a routine part of the physical examination of every feather-picking and seizuring bird. To ensure that the uropygial gland is functioning properly, gently roll the bird's wick through your fingers, and then check your fingers for a greasy spot. If no secretion is seen, gently massage the gland (bilobed, heart-shaped) and then check the wick again. The normal uropygial gland produces vitamin D₃ precursors that are preened onto the feathers. Upon exposure to ultraviolet light (particularly UVB), the precursors are converted to active D₃, which is then be ingested when the bird preens again.

Some birds with hypovitaminosis A will have squamous metaplasia of the uropygial gland, and it will not be secreting properly. Those birds should receive supplementation with beta-carotene to correct the squamous metaplasia. Beta-carotene capsules contain a red liquid, which is accessed by poking a hole in the end of the capsule, and giving the bird a drop orally twice per week, or as indicated. Red palm oil is another source of beta-carotene. Since beta-carotene is converted to active vitamin A, it is safe and non-toxic; any excess is excreted unchanged. In contrast, supplementation with vitamin A can result in overdose, which can be dangerous or even life-threatening. In some cases, other birds may have plucked out the wick feathers, making extraction of the secretion difficult or impossible.

For activation of the uropygial gland secretion, a bird needs exposure to natural, unfiltered sunlight (not through glass or plastic), or exposure to full-spectrum fluorescent light (changed regularly as recommended by the manufacturer and placed within 18 inches of the cage). While formulated diets should contain adequate amounts of vitamin D₃, all birds with calcium problems, especially grey parrots, should have the uropygial gland evaluated, and they should receive some sunlight or full-spectrum artificial lighting. Note that some species of psittacines do not possess an uropygial gland (e.g. Amazon parrots, hyacinth macaws), nor do emus, ostriches, cassowaries, bustards, frogmouths, many pigeons and woodpeckers.

Instead of treating the seizures initially with an anticonvulsant, the nutritional supplement dimethylglycine (DMG) [Vetri-Science Lab] is recommended due to the positive effects of DMG on the brain and CNS. This supplement works by providing a methyl group, which acts in a similar manner as an antioxidant. However, DMG also raises the threshold for seizures, and has other benefits for avian and exotic patients, including use for proventricular dilatation disease (PDD) in birds, and E. cuniculi in rabbits. Some seizuring animals may still require anticonvulsant therapy, although there are no published therapeutic reference ranges for phenobarbital in avian species. Using DMG will most likely reduce the dosage of anticonvulsants needed, and may even preclude their use, which is much safer for avian and exotic patients.

[Contributed by Margaret A. Wissman, DVM, DABVP, Avian Practice]