There are a number of diseases that can affect the functioning of a dog’s liver and lead to enlargement. An enlarged liver in dogs can often be accompanied by ascites, or fluid accumulation in the abdomen. Those with ascites will have an abnormally swollen belly. An enlarged liver is most commonly found in older dogs. It is important to identify and diagnose the cause of an enlarged liver early, so an attempt can be made to treat the underlying cause.

Hepatomegaly is clinical state of abnormal liver enlargement. Because the liver serves to filter toxins from the bloodstream, it can be affected by a number of diseases. An enlarged liver is a finding which should prompt a detailed clinical work-up for primary and secondary liver disease.

Because an enlarged liver may be caused by various diseases, the symptoms may vary as well. However, some common symptoms are below:

An enlarged liver can be a symptom of one of the following diseases:

Diagnosis is helped by an owner reporting a detailed history; listing the symptoms there dog is exhibiting, as well as any recent incidents that may have been abnormal or they suspect may have led to their dog’s change in health. The veterinarian will conduct a thorough exam, starting with weighing and comparing your dog’s weight to its normal weight, followed by a physical examination of your dog, seeking any abnormalities or signs of liver enlargement. Unless your dog is very overweight, at this stage the veterinarian will have been able to detect an enlarged liver by feeling the abdomen.

The veterinarian will then conduct a comprehensive round of tests in order to identify the cause of the enlarged liver. These include a blood sample to be analyzed for a complete blood count, which checks for anemia, signs of infection, and presence of Heinz bodies, or spotted red blood cells caused by hemoglobin accumulation; and a blood biochemistry profile, which measures liver enzymes, albumin, bilirubin and cholesterol level. Additional tests will include a heartworm examination, blood coagulation test, and a bile acid test, which requires 12 hours of fasting in preparation.

More-than-likely, the veterinarian will then conduct a urinalysis, which will be analyzed to determine kidney function. Depending upon the initial findings, x-rays may be taken to determine the size of the liver and gallbladder and the presence of metastisis, or a cancer having spread to another area of the body such as the chest cavity, as well as ultrasounds that detect the density of the liver and the presence of gallstones in the gallbladder. In cases where a tumor is found or a severe liver disease is suspected, the veterinarian may require a liver biopsy in order to obtain a sample and determine if the tumor is benign or malignant. In the case of suspected heart disease, advanced tests such as echocardiography and electrocardiography may be conducted.

If ascitic fluid is present it may be sampled and analysed. This can mean sending the fluid to an external lab for analysis.

As many different diseases may cause an enlarged liver in dogs, the treatment varies widely. When possible, any underlying disease will be treated. Depending upon the severity, your dog may require a period of hospitalization, in the case of heart complications or advanced liver disease, or even surgery, in the case of cysts, abscesses, or tumors. Surgery may be used to remove the affected mass. A risk of surgical removal is hemorrhage, so the veterinarian will be ready in case a transfusion is needed. Additionally, liver surgery is considered an anesthetic risk, as anesthesia is processed in the liver.

Many treatments involve rehydration therapy, antibiotics and regular doses of multivitamins to promote recovery and overall liver health. Zinc and vitamins A, B, C, D, E and K will help to promote liver detoxification and health. Liver supplements such as SamE and Milk Thistle can also play a role.

Your dog’s recovery will depend upon diagnosis and treatment, but your role in the recovery will regardless be to follow all veterinarian instructions and closely monitor your dog’s health and behavior.

Your dog’s prognosis depends upon the cause of the enlarged liver; however, in any case, keep in mind that the liver is the site of drug metabolism in dogs, and do not give your dog any new medication without consulting your veterinarian first. Your veterinarian may prescribe a specific diet, such as low protein diet with added liver supplements. In any case, changing the  feeding pattern to small and frequent meals may be helpful for recovery.

Your dog may have an enlarged liver for any number of reasons. As a result, the total cost will vary greatly. However, multivitamins (especially those that contain zinc, A, B, C, D, E and K) and liver supplements are essential for liver detox and overall health of your dog. Multivitamins and supplements can be bought at most pet stores and can cost between $12 and $34. The veterinarian may suggest an antibiotic to treat (or avoid) infection. Antibiotics usually cost between $15 and $53. The veterinarian may want to remove any mass surgically. Uncommonly, this may require a blood transfusion. The blood transfusion may cost $150 to $380 per unit on average. The surgery itself can cost between $2,000 and $4,000 depending on the cause of the enlargement. Your dog will likely require hospitalization that can cost between $67 and $112 per night, with intravenous fluids. The total cost with what has been mentioned here would be between $2,237 and $4,425. The overall cost could even be greater than the total mentioned here, if the underlying issue requires ongoing treatment. 

The underlying cause of the enlarged liver can mean any number of tests which can add substantial cost to the total.