Polyneuropathy in Cats

Feline polyneuropathy is an uncommon disease of the peripheral nerves, which changes the cell body of nerves. Polyneuropathy is the term used to broadly characterize autonomic neuropathies, sensory neuropathies, mixed motor neuropathies and neuron disease. The primary clinical sign of polyneuropathy in cats is related to progressive neurological deficits, requiring high quality care. The prognosis for polyneuropathy in cats is generally poor, as polyneuropathy is a disease that progressively worsens over time. 

Polyneuropathy in cats is characterized by a group of diseases affecting the nervous system. Polyneuropathy can be inherited from the parents or is a condition acquired later in life. Inherited polyneuropathy is a progressive disease that may not be noted by a cat owner until later in life, whereas acquired polyneuropathy can occur suddenly. An owner my notice clinical signs of this condition associated with the feline’s neurological system including muscle tremors, head tilt, seizures and overall weakness. Polyneuropathy in cats can be caused by a number of underlying causes from metabolic disease to toxicity, which requires veterinary diagnosis. Polyneuropathy in cats can be fatal and once a feline is diagnosed, lifelong supportive therapy is often required.

Symptoms of inherited polyneuropathy and acquired polyneuropathy vary in felines. Inherited polyneuropathy in cats is a slowly progressive condition, as symptoms appear as the feline ages, whereas acquired polyneuropathy can occur rapidly. 

Inherited Polyneuropathy Symptoms:

• Depression 
• Blindness
• Seizures
• Head tremors 
• Ataxia (unsteady gait)
• Muscle atrophy 
• Muscle tremors
• Generalized weakness 

Acquired Polyneuropathy Symptoms: 

• Depression
• Anorexia 
• Muscle atrophy 
• Weakness
• Paralysis 

Polyneuropathy in cats can be either inherited or acquired. Inherited Polyneuropathy is usually seen starting at age six and progressively worsens as the feline ages. Both types of polyneuropathy affect numerous feline breeds, but purebred felines are at a greater risk of contracting the neurological disease than mixed breeds. 

Inherited Feline Polyneuropathy 

• Lysosomal storage disease: an inherited deficiency defined by the inability to create and store enzymes.  
• Demyelination: nerve covering destruction
• Spinal muscular atrophy: the shrinkage of spinal muscles 

Acquired Feline Polyneuropathy 

• Glomerulonephritis: inflammation of a portion of the kidneys
• Polyarthritis: joint inflammation 
• Polymyositis: muscle inflammation
• Systemic lupus erythematosus: immune disease of multiple organs 
• Immune-mediated or hyperactive immune system
• Infectious causes (e.g. feline leukemia)
• Metabolic causes (e.g. diabetes mellitus)
• Paraneoplastic syndrome: a broad term used for disorders arising from immune response to cancers such as myeloma, osteosarcoma, lymphosarcoma, mast cell tumors, carcinoma, insulinoma  
• Drugs and toxicity: effects of chemotherapy (cisplatin, vinblastine, vincristine), chemicals (lindane, carbon tetrachloride, organophosphates), or metals (zinc, copper, mercury lead, thallium) 

Due to the vast number of possible underlying reasons a cat could develop polyneuropathy, the veterinarian will diagnose your cat’s condition through differential diagnosis, the act of testing the feline for possible disease causes that match the symptoms the feline is displaying. Baseline exams the veterinarian may start with include blood work, specifically a complete blood cell count and biochemistry profile. A urine sample will also be requested to conduct a urinalysis. Even these baseline tests could reveal cancer or a metabolic disorder. In order to detect disease of the immune system, your veterinarian may request a serum antinuclear antibody titer (ANA). Additional testing that the vet may request to diagnose polyneuropathy in cats may include: 

• Blood tests screening for infectious organisms
• Radiographs: x-rays of the feline may find evidence of cancer or other abnormalities
• Electrophysiology 
• Electromyography evaluation (EMG): condition test of motor and sensory nerves
• Biopsy of muscle and nerve tissue: indicate nerve function defects and degeneration, as well as progressive disease. 

Some felines suffering from polyneuropathy require hospital care including supportive therapy of nutritional support and electrolyte therapy. If your cat’s polyneuropathy has been pinpointed to a specific underlying disorder, your veterinarian will prescribe specific therapy for the disorder at hand. If the condition is caused by toxicity or reaction to a drug, the element will be removed from the feline’s regimen. Allergic reactions and immune mediated diseases are managed using immunosuppressant drugs, such as a form of corticosteroid. The majority of felines with polyneuropathy are treated as an outpatient, but inherited polyneuropathy in cats are not generally treated. 

Follow veterinary care as directed including change in diet and medications. Always consult your cat’s doctor if you notice improvement or an adverse reaction to the prescribed therapeutic treatment for polyneuropathy. Lifelong therapeutic treatment is often required. The prognosis for a feline with polyneuropathy is guarded, as it depends on the underlying cause of the condition. Felines with inherited polyneuropathy, have a rather poor prognosis, and a short lifespan or euthanasia is usually the end result.