In-depth Information on Diagnosis
- Complete history and physical exam. A thorough history is important to ascertain the possibility of exposure to raccoons, ticks and toxins. A thorough physical exam will assist in choosing the appropriate diagnostics.
- Neurologic exam. Careful assessment of the nervous system is imperative to determine the nature of the nervous system disorder. Animals with a peripheral nerve disease have weak muscles with diminished tone and decreased to absent reflexes. Those that are still able to walk may appear lame and have a stilted gait, although they are aware of where they are placing their feet. Dogs with central nervous system disease may have behavior changes, walk with a drunken appearance and have stiff limbs. A neurologic evaluation not only pinpoints the part of the nervous system involved, but also assesses how widespread the problem is.
- Complete blood count. A CBC evaluates the red and white blood cells as well as the platelets. These would all likely be normal with polyradiculoneuritis, but the test may help rule out other disease processes.
- A biochemical profile. This test evaluates blood sugar, blood proteins and electrolytes, and provides information about liver and kidney function. This is useful to get an overall idea about metabolic function. Animals with profound electrolyte disturbances (potassium and calcium in particular) or low blood sugar may also show signs of severe weakness.
- Urinalysis. Evaluation of the urine is part of a complete laboratory assessment and gives a better indication of kidney function than the biochemical profile alone.
- Electrodiagnostic testing. Tests in this category include electromyography (EMG) and nerve conduction studies. These are specialized tests that examine the electrical activity in nerves and muscles and allow an accurate assessment of nerve and muscle function. They may be helpful in supporting the diagnosis of polyradiculoneuritis. However, abnormalities in these tests don’t occur until about 6 to 7 days after the animal begins showing signs of weakness. These tests must be performed by a neurologist with specialty training.
- Cerebrospinal fluid tap. A CSF tap involves collecting the CSF fluid by inserting a small needle into the space around the spinal cord. This requires that the patient be under anesthesia. Analysis of this fluid in dogs with polyradiculoneuritis often reveals elevated levels of protein. Evaluation of the fluid may help rule out other causes of the clinical signs.
- Arterial blood gas. An ABG provides information about how well the animal is breathing and if there are appropriate oxygen levels in the blood. In patients that appear to be demonstrating weakness of the respiratory muscles, this test is a useful way to assess the need for a respirator to assist breathing.
In-depth Information on Therapy
There is no specific treatment for polyradiculoneuritis. Most dogs recover over a period of 3 to 6 weeks, but some animals may take many months to recover, or may never recover completely. The most important aspect of treating these patients is to provide ample supportive care. Treatment consists of:
- Soft bedding or a waterbed is necessary to prevent bed sores since animals are generally paralyzed when the disease is at its worst point. Additionally, it is important to turn the animals onto their opposite side several times a day. This insures that the lungs are not being constantly compressed on one side, which may make them more prone to infection.
- Physical therapy is an important component of care. Paralyzed muscles atrophy or shrink and then develop contracture (muscle shortening) secondary to lack of use. Massaging the muscles and moving the limbs manually, including flexing and extending the joints several times a day help limit the secondary muscle damage. Hydrotherapy with whirlpool baths is also appropriate, if available.
- Ventilation. Mechanical ventilation, or assisted breathing on a respirator, may be required in cases that develop respiratory muscle paralysis. In these cases, the animals die without a respirator. This can only be performed at specialty practices or university veterinary hospitals and is an extremely labor intensive and expensive procedure.
- Dogs generally maintain their ability to urinate and defecate, but they can develop urine scalding and secondary skin infections if they are not kept very clean, as they cannot get up to eliminate. Very careful hygiene is important.
Follow-up Care for Dogs with Acute Polyradiculoneuritis
Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not improve over the expected time frame.
This disease generally follows a long course. Once the dog is stable, much of the supportive care will be done at home. This can be a real challenge, especially in large dogs. If supported in an upright position, most dogs can drink and eat on their own. To avoid the risk of inhaling their meals, it’s imperative to keep your pet upright while eating and drinking. Additionally, offering water frequently is important to prevent dehydration.