Hyperviscosity is a rare syndrome that typically occurs as a result of a tumor or cancer. In order to treat hyperviscosity, the primary disease or cancer that is causing the excess plasma proteins to form will first have to be treated.

Excess plasma proteins in the bloodstream can lead to a condition called hyperviscosity, or high blood viscosity. In rare occasions, hyperviscosity can occur due to an excess amount of red blood cells. Hyperviscosity isn't a condition or disease, but is rather a syndrome or symptom of another disease or condition in the cat's body.

Because hyperviscosity can adversely affect several organ systems, such as the heart, kidneys and liver, a variety of different symptoms may present. These symptoms include:

As different symptoms of hyperviscosity can point to different causes, it's important to note any abnormal symptoms that the cat is experiencing in order for the veterinarian to make a proper diagnosis. These causes may include:

The veterinarian will ask for the cat's health history, what the symptoms are and when the symptoms first began. The veterinarian will examine the cat, listening to its lungs and heart with a stethoscope and looking into its eyes for any signs of retinal detachment or hemorrhaging.

Labs will need to be run, which will include a complete blood count, biochemical profile and a urinalysis. The veterinarian will use the blood tests to look at the total plasma protein count and any abnormalities in the blood. The urinalysis will indicate how the kidneys are functioning and if the hyperviscosity is affecting them. The veterinarian may also look for the presence of Bence-Jones proteins in the urine, which will indicate if the cat has multiple myeloma. If a monoclonal gammopathy is suspected, the veterinarian may run a specialized test called a serum electrophoresis to look for the abnormal blood protein.

Because hyperviscosity is a syndrome, it's essential to treat the primary cause in order to reduce the high count of plasma cells in the blood.

If the cat has hyperviscosity due to cancer, chemotherapy may be administered to the cat. Chemotherapy kills the cancer cells in the body with the goal of prolonging the cat's life or removing all of the cancer cells in the cat's body, placing the cat in remission. If the cat has hyperviscosity due to an autoimmune disorder, immunosuppressants may be prescribed to the cat in order to reduce the immune system's reaction.

Cats with cancer may receive radiation. During radiation, high-energy waves are used to kill the cancer cells. Radiation therapy may be used in conjunction with surgery and chemotherapy.

In some cases, surgery may be necessary to remove the tumor that is causing the hyperviscosity to occur. The cat will be placed under general anesthesia while the veterinarian performs the surgery.

In order to reduce the plasma protein count while the primary condition is being treated, the veterinarian may recommend a procedure called plasmapheresis. During plasmapheresis, the cat's blood will be removed from its body. The blood will be centrifuged and separated while an electrolyte solution is flushed through the cat's body. The separated red blood cells will be washed before being returned to the cat's body, removing the excess plasma proteins. Plasmapheresis can prevent complications from hyperviscosity from occurring, such as heart failure, while other treatments are taking place.

The cat will need to remain hospitalized until its condition is under control. After the cat has been released from the hospital, follow-up appointments with the veterinarian will be necessary in order for the monitoring of plasma cell protein levels and medication effectiveness. Treatments for the primary condition will also need to be followed-up with the veterinarian. It's important to follow all of the instructions from the veterinarian and keep the cat comfortable at home in order to encourage healing.