Hyperviscosity Syndrome in Cats: cause, symptoms, treatment

Hyperviscosity syndrome in cats is a pathological condition affecting the blood flow. We know the causes, symptoms and treatment.

Hyperviscosity syndrome in cats is a clinical picture characterized by the slowing of blood flow through the vessels.

The subjects most affected are elderly cats but generally there is no gender or breed predisposition, in the same cat it is a rather rare condition.

Causes of hyperviscosity syndrome in cats

Hyperviscosity is generally caused by a considerably high concentration of blood plasma proteins.

However, it can also occur (rarely) due to a noticeably high number of red blood cells.

The main causes can therefore be:

  • Chronic atypical inflammation with monoclonal gammapathy (in which an abnormal protein has been detected in the blood)
  • Lymphocytic leukemia or lymphoma
  • Multiple myeloma and plasma cell tumors
  • Marked polycythemia ( a net increase in the total number of blood cells)
  • Chronic autoimmune disease (systemic lupus, rheumatoid arthritis )


The hyperviscosity syndrome in cats involves the appearance of symptoms that are sometimes not consistent and precise signals to be able to identify the pathology.

The following are the symptoms that can occur in the animal suffering from this particular condition:

  • rapid heartbeat;
  • convulsions
  • depression
  • disorientation
  • instability
  • congestive heart failure ( caused by volume overload)
  • lethargy
  • excessive urination
  • loss of appetite in cats
  • rapid breathing
  • nosebleeds
  • excessive thirst
  • bleeding tendencies
  • visual impairment
  • haemorrhage or retinal detachment
  • optic swelling

Diagnosis and treatment of hyperviscosity syndrome in cats

In order to define a diagnosis, the veterinarian will need to know when the symptoms occurred , the previous health history of the animal and any accidents that have occurred.

In any case, this is not an easy assessment as hyperviscosity is a syndrome, not a definitive diagnosis.

The veterinarian will then proceed with the execution of:

  • a thorough physical examination on the cat
  • complete blood profile 
  • chemical blood profile 
  • a complete blood count
  • the total count of plasma proteins, evidence of blood disorders
  • a urinalysis of the cat

Once the results from the laboratory have been obtained and the diagnosis of hyperviscosity syndrome in cats has been established, the doctor will be able to establish an adequate therapy that will be performed in hospital.

What the vet will need to treat, first and foremost, is the main disease, which is a treatment aimed at resolving the symptoms caused by cancer or an inflammatory condition.

Once the hospitalization phase is over and the values ​​have been re-established, the cat can go home and be followed carefully.

Follow-up should include blood tests, urinalysis from time to time, and monitoring of the cat ‘s serum or plasma proteins to assess the effectiveness of the treatment.

Cat BreedsCat Food and Nutrition
Tips for Cat OwnersCat Training
Cat BehaviorKittens
Cat HealthCat Grooming
Cat AdoptionTravel with Cat
Holiday Season- Cat

Leave a Comment