Due to certain diseases and conditions that can either directly or indirectly affect the liver's ability to function, the organ may increase in size, which is referred to as hepatomegaly.
Kittens normally have larger livers in regard to their actual body mass, as compared to adult cats. However, hepatomegaly is most commonly diagnosed in older cats. Depending on the underlying cause, the enlargement may involve the whole liver or only part of the liver. For example, infections and/or inflammation may lead to a generalized symmetrical enlargement of the liver, whereas tumors, hemorrhages, cysts, or rotation of the liver lobe may lead to asymmetrical or focal enlargement. That is, only a part of the liver may be enlarged.
Symptoms can vary depending on the cause. Enlargement of the abdomen is the most commonly observed symptom. On examination your veterinarian will find an enlarged liver or a palpable mass in the abdominal area. The mass is usually observed behind the rib cage and may even be visible with naked eye. However, in obese animals it is difficult to detect an enlarged liver on physical examination.
You will need to give a detailed history of your cat’s health, onset and nature of symptoms, and possible incidents that might have led to this condition. Your veterinarian will perform a thorough physical exam to evaluate all body systems, and a complete blood profile will be conducted, including a chemical blood profile, a complete blood count, and a urinalysis. The results of the routine laboratory tests are highly variable depending on the underlying cause of the liver enlargement. The complete blood count may reveal anemia, abnormal spherical red blood cells (spherocytes), disrupted red blood cells (schistocytes), red blood cells with spots due to hemoglobin accumulation (Heinz bodies), presence of parasites with red blood cells, immature white blood cells (blast cells) in the blood, red blood cells with nucleus, and abnormally low or high number of platelets (tiny cells used in blood clotting). The biochemistry profile may show abnormally high levels of liver enzymes, and a high cholesterol level. Further testing may include blood clotting profile as blood clotting abnormalities are common in patients with liver involvement. Your cat may also be tested for presence of heartworm disease.
The abdominal X-rays may show an enlarged liver with rounded margins, or a displaced stomach and kidneys. The chest X-rays may help in determining any metastasis of a tumor to the chest cavity, and will also show diseases involving the heart and lungs. Abdominal ultrasonography can be used to view further details in the abdominal cavity, revealing changes in liver size and surface contour, as well as the presence of concurrent diseases. Abdominal ultrasound will also help in discriminating diffuse or localized types of liver enlargement. More advanced diagnostic tests, like electrocardiography and echocardiography, can be used to evaluate the structure and functions of heart.
If tumors are seen or suspected, your veterinarian will want to take a sample of liver tissue in order to confirm either its benign or malignant nature, but even without a tumor present, a tissue sample can be helpful for determining the cause, severity and stage of the liver disease. The samples will be sent to laboratory for microbial cultures, and in case of infection, the culturing of the sample will help in determining the type of microorganism that is involved so that suitable drugs can be prescribed.
The growth of pathogens away from the original site of the disease
The group of processes that involve the use of nutrients by the body
Something that becomes worse or life threatening as it spreads
A gland that aids in both digestive and insulin functions
The prediction of a disease’s outcome in advance
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
A procedure of imaging internal body structures by exposing film
The condition of having a part of a body part protruding through the tissue that would normally cover it
The protein that moves oxygen in the blood
Out of proportion or unbalanced; may also be referred to as unsymmetrical.
A condition of the blood in which normal red blood cell counts or hemoglobin are lacking.
A localized infection, usually a lesion filled with pus. Can be large or small in size.
Not being able to cause harm; the opposite of malignant.
The muscle in the abdomen that aids in breathing
The space in the abdomen that holds the major digestive organs in an animal. Normally referred to as the area between the diaphragm and the pelvis. Also referred to as the peritoneal cavity.
A procedure that is used to evaluate the health and structures of the heart
An enlargement of the liver to an abnormal size