Ataxia

Ataxia may be defined as the inability to coordinate the voluntary movement of muscles. Birds that are ataxic appear wobbly or clumsy and will often stand with the legs spread far apart in order to balance or hook their beak on the side of the cage. When severely ataxic, they will stumble and fall from the perch.

Ataxia may occur due to disorders of the nervous system or musculoskeletal system.

• Nervous system disorders. These are often caused by damage to the spinal cord, inner ear or brain. They often result in an inability of the brain to perceive the position of the limbs, body or head in space or an inability of the brain to coordinate movement.
• Musculoskeletal damage. Birds with musculoskeletal damage may also appear uncoordinated, as the muscles are unable to respond properly to signals from the brain.

What to Watch For

• Standing with the legs wide apart in an attempt to keep balance.
• Hanging on to the cage or objects in the cage in order to remain standing on the perch.
• Uncoordinated movements of the head, legs or wings.
• Falling from the perch.
• Lethargy, which appears as excessive sleepiness, ruffled feathers, tucking the head under the wing.
• Difficulty breathing. This includes leaning forward and stretching the neck out to breathe, open-mouthed breathing, puffing out of the cheeks with each breath, or bobbing of the tail with each breath.

Diagnosis

Your veterinarian will recommend specific diagnostic tests depending on how severely ataxic the bird is, how long the problem has been going on, and if there are other symptoms. A complete history is extremely helpful in reaching a diagnosis. Be prepared to tell your veterinarian when the problem began, if the ataxia is constant or intermittent, your birds chewing habits, the type of diet your bird is on, and of any potential exposure to other birds. Tests may include:

• A thorough physical examination
• Testing for heavy metal toxicity
• A complete blood count (CBC) and serum biochemistry panel
• Blood tests or choanal samples for Chlamydiosis (Psittacosis)
• Radiography (X-Rays) to look for evidence of metabolic disease or spinal cord damage
• Endoscopy to view the ears to look for inner ear infections, or abdominal cavity if evidence of metabolic disease is present

Treatment

• Hospitalization for intravenous or subcutaneous (under the skin) fluids and injectable medications for critically ill or dehydrated birds.
• Antibiotics or antifungal medications.
• Medications (chelating agents) for heavy metal toxicity.
• Vitamin or mineral supplementation.

Home Care

Ataxic birds generally suffer from serious disease and require veterinary attention. In the meantime, take the following precautions:

• Keep your bird in a quiet environment.
• Remove perches or swings if your bird is unable to remain perched.
• Use shallow water dishes that your bird can easily reach.
• Spread food out near your bird so that he can reach the food.
• Keep the environmental temperature warm if your bird appears fluffed up.

After veterinary examination and treatment:

• Give all medication as directed, for as long as directed, even after the symptoms appear to be gone.
• Watch for the development of other symptoms.
• Observe your bird closely. If improvement is not seen, call your veterinarian.

Ataxia may be defined as an inability to coordinate the voluntary movement of muscles. Birds that are ataxic appear wobbly or clumsy and will often stand with the legs spread far apart in order to balance or hook their beak on the side of the cage. When severely ataxic, they will stumble and fall from the perch. If ataxia is the result of nervous system disorders, other symptoms, such as trembling, head tilt, circling, star-gazing or seizures, may also occur.

Ataxia may occur due to disorders of the nervous system or musculoskeletal system. Nervous system disorders often result in an inability of the brain to perceive the position of the limbs, body or head in space or an inability of the brain to coordinate movement. This may occur as a result of damage to the spinal cord, inner ear or brain. The spinal cord carries information to the brain about the relative position or placement of the body, wings, head and legs. The fibers that carry this information are located on the surface of spinal cord, so relatively mild damage to the cord will cause ataxia.

Ataxia is usually one of the first symptoms of spinal cord or nerve damage. Birds with damage to peripheral nerves or the spinal cord usually have symptoms localized to the affected appendages and the level of mental activity is normal.

The inner ear and portions of the brain (medulla and myelencephalon) are responsible for maintaining balance and a normal body position. Damage (from infections, trauma or pressure) to the middle ear or brain will cause severe ataxia. Usually, these birds have other neurologic symptoms, such as a head tilt, circling, abnormal mental activity or seizures.

Metabolic disorders, such as diseases of the liver, kidneys, pancreas or parathyroid glands, may also affect the brain. Birds with metabolic disorders may not be able to eliminate toxic metabolites, or may be unable to regulate blood concentrations of glucose or calcium.

Birds with musculoskeletal damage may also appear uncoordinated, as the muscles are unable to respond properly to signals from the brain. This may occur with deficiencies of nutrients such as calcium, vitamin E or selenium or electrolyte disorders. Birds that are extremely weak from chronic diseases also appear ataxic. Ataxia is always a sign of serious disease warranting veterinary attention.

Causes

There are many causes of ataxia in birds. Ataxia can be caused by diseases of the nervous systems (brain and spinal cord) and can occur due to toxicities, metabolic diseases or systemic weakness. There are many contagious diseases that cause ataxia, so it is important to inform your veterinarian of any potential contact – direct or indirect – with other birds. Possible causes of ataxia in birds include:

• Trauma. Trauma to the brain or spinal cord commonly occurs when birds fly into objects such as windows or mirrors.
• Toxins. Heavy metal toxicity, caused by ingestion of objects containing lead or zinc, is one of the most common diseases seen in pet birds. Other toxins, such as insecticides, mycotoxins (from mold) and salt poisoning can also cause ataxia.
• Nutritional deficiencies. Thiamine (Vitamin B1), vitamin E, selenium and calcium are all nutrients required for proper functioning of the nervous system.
• Bacterial infection. Bacteria may infect the brain, causing encephalitis or abscesses or may infect the inner ear. Bacterial septicemia will also cause severe weakness and ataxia.
• Viral infection. Several different avian viruses may cause neurologic signs, especially ataxia. Proventricular dilatation disease is caused by a virus that tends to target the nervous system. Many of these birds will also have symptoms of intestinal tract disease. Other viruses, such as Newcastle's disease virus (paramyxovirus), reovirus, togaviruses (eastern and western equine encephalomyelitis) and polyoma virus may also cause ataxia. With these viruses, however, ataxia is usually only one of several symptoms. Viruses can be transmitted by direct exposure to another bird, shared food or water dishes, or on your hands or clothing, depending on the type of virus.
• Chlamydiosis. Chlamydia may affect the nervous system in addition to other organ systems. Generally, birds will have other symptoms in addition to ataxia.
• Fungal infection. Aspergillus or cryptococcus may invade the brain or spinal cord.
• Neoplasia (cancer). These include tumors in the brain or spinal cord.
• Parasites. Toxoplasma and sarcocystis are microscopic parasites that can form cysts in the brain. These parasites are acquired by ingestion of cat, raccoon or opossum feces or by eating cockroaches.
• Metabolic disorders. These include liver disease, diabetes mellitus and renal disease.

Diagnosis In-depth

A thorough history is extremely important in the diagnosis of ataxia. Be prepared to tell your veterinarian:

• When the problem began and if other symptoms preceded the ataxia. Is the ataxia intermittent or constant? Has it become worse?
• Are other neurologic signs, such as abnormal mental activity, seizures, star-gazing or circling present?
• Has there been any exposure to flea products or other insecticides?
• What is your bird's diet?
• What are your bird's chewing habits?
• Are any other symptoms, such as lethargy, gastrointestinal or respiratory signs present?
• Has your bird been exposed to other birds?

Your veterinarian will recommend specific diagnostic tests depending on the duration and severity of ataxia and physical examination findings. To find the cause of ataxia, extensive diagnostic testing is usually required. Any combination of the following may be recommended:

• A complete blood count (CBC). The number of circulating white blood cells may be helpful in distinguishing between infectious and non-infectious causes of ataxia. Anemia (decrease in the number of red blood cells) may cause severe weakness and ataxia.
• Serum biochemistry panel. This test is needed to look for evidence of electrolyte abnormalities, calcium concentration or metabolic problems, such as diseases of the liver, kidney or pancreas.
• Plasma protein electrophoresis. This blood test looks at the types of proteins present in the circulation. For example, birds with chronic diseases, especially infectious or inflammatory diseases, will produce antibodies and an increase in one class of proteins (gammaglobulins) will occur. Birds with liver disease or severe intestinal disease usually have low concentrations of another class of protein (albumin).
• Blood tests or other samples for Chlamydiosis (Psittacosis)
• Blood tests for Aspergillosis
• Testing cloacal swabs for polyomavirus, paramyxovirus or other viruses
• Blood tests that measure the concentration of heavy metals, such as lead or zinc in circulation
• Radiography (X-Rays) to look at the size and density of the liver, kidneys or other organs or for the presence of heavy metal densities in the intestinal tract.
• X-rays of the skull to look for damage to the inner ear
• Fluoroscopy. This is a video or moving X-ray that is performed by a specialist and used to determine if the coordination of peristaltic waves is normal. It is useful in the diagnosis of toxicity (lead or zinc), foreign bodies or viral diseases (proventricular dilatation disease).
• CT scan or MRI to look for disease of the brain or inner ear
• Endoscopy. This test is viewing the ear canal or body cavity directly with an endoscope to collect samples for biopsy or culture. A specialist usually performs this test.
• Crop biopsy. If proventricular dilatation disease is suspected, characteristic lesions are sometimes found on biopsy specimens from the crop. At this time, the only way of definitively diagnosing proventricular dilatation disease is through the observation of characteristic lesions on biopsy specimens from the gastrointestinal tract or nervous system.

Treatment In-depth

Your veterinarian may recommend one or more of the diagnostic tests described above. In the meantime, treatment of the symptoms might be needed, especially if the problem is severe. The following treatments may be applicable to some, but not all, birds with ataxia. Therapy is not a substitute for definite treatment of the underlying disease responsible for your bird's condition.

• Birds with ataxia and other symptoms such as lethargy and anorexia usually require hospitalization and 24-hour care.
• Fluid therapy. Birds that are not eating are usually moderately to severely dehydrated and require fluids. Fluids may be given by an intravenous catheter, an interosseous catheter (into the bone marrow) or subcutaneously (under the skin). The route of administration will depend on how severe the level of dehydration is.
• Forced feeding if your bird is anorexic. This is usually accomplished by placing a tube into the crop and instilling a liquid gruel.
• Antibiotics or antifungal medications. Drug therapy may be needed to treat or prevent an overgrowth of bacteria or yeast.
• Chelating agents for heavy metals
• Calcium or vitamin supplementation
• Soft bedding and a quiet environment