The liver is an organ that performs many functions. It has large storage capacity and features and is capable of regenerating itself.
These properties provide some protection from permanent damage. However, the liver is also susceptible to damage due to its role in metabolizing, detoxifying, and storing various toxic compounds.
Signs that a dog has liver disease can vary and include loss of appetite, vomiting, stomach ulcers, diarrhea, seizures and other neurological problems, fever, blood clotting problems, and jaundice (yellowing of the skin, mucous membranes, and eyes), accumulation of fluid in the abdomen, excessive urination and
thirst, changes in liver size and weight loss.
Gastrointestinal bleeding can be seen in animals with liver disease due to ulcers or blood clotting problems.
Understanding the possible causes of each of these signs will help your veterinarian diagnose the disease and begin appropriate treatment.
Various blood tests help detect and diagnose liver disease. X-rays and ultrasounds help veterinarians determine liver size to detect abnormalities, gallstones, and gallbladder disease. Aspiration or biopsy techniques can be used to obtain samples for bacterial culture, cell and tissue analysis, and if desired, toxicological analysis. In some cases, scanning techniques such as magnetic resonance imaging can be used to identify portosystemic shunts (see below) and other vascular abnormalities.
LIVER, GALLBLADDER AND PANCREAS OF A DOG:
Early treatment is important in acute liver failure in dogs. If an underlying cause is identified, your veterinarian will prescribe specific treatments. For long-term or end-stage liver disease, and for acute liver disease with no identified underlying cause, supportive care slows disease progression, minimizes complications, and allows time for liver regeneration.
The diet normally recommended for dogs with liver disease should contain enough calories to maintain a normal weight. Protein restriction is usually only necessary for dogs at risk for hepatic encephalopathy. Follow your veterinarian’s specific advice. Frequent small meals may be best. Dogs that refuse to eat may require tube feeding.
LIVER FUNCTION: Metabolizes fats, carbohydrates, and proteins.
Metabolizes drugs (inactivates drugs or facilitates their elimination from the body)
Stores, metabolizes, and activates vitamins.
Stores minerals, glycogen and triglycerides.
It manufactures proteins that are necessary for various bodily functions such as blood clotting.
Produces bile acids necessary for digestion
It detoxifies harmful products produced in the body (such as ammonia) or ingested by animals (such as toxins/poisins).
Helps develop blood cells (extramedullary hematopoiesis)
Prescription supplements may contain B vitamins, vitamin K, and vitamin E. Low potassium and low vitamin B levels are common complications of liver disease, and supplementation is often recommended. Vitamin C deficiency does
not appear to occur in dogs with liver disease, and vitamin C supplementation is not recommended for dogs with liver disease that
accumulate copper.
Dogs with bleeding tendencies may be given vitamin K injections. Follow your veterinarian’s recommendations for vitamin supplementation, as overdosing on some vitamins can be harmful.
ACUTE LIVER FAILURE:
Acute liver failure causes sudden loss of liver function, often accompanied by neurological symptoms and coagulopathy. This can result from sudden damage to a previously healthy liver or further damage to an already diseased liver.
Immediate veterinary attention is important to support the liver until it regenerates and compensates for the damage. Any underlying cause of liver failure should be identified and treated if present. Be sure to tell your veterinarian about any medications your pet is taking or if you think your pet may have been exposed to toxins.
Treatment may include intravenous fluids, dietary changes, antibiotics,and certain liver medications.
Another goal of therapy is the prevention or treatment of neurological complications of liver failure.
COMPLICATIONS OF LIVER DISEASE
The liver has several functions, including removing many toxins from the bloodstream and producing blood-clotting proteins. Many other organs can be affected if they are not functioning properly.
HEPATIC ENCEPHALOPATHY
Hepatic encephalopathy is a syndrome of neurological problems caused by decreased liver function and occurs in many liver diseases. The origin of the disease is not fully understood, but the inability of the liver to remove toxins from the bloodstream, changes in amino acid metabolism caused by liver disease, and neurological changes may combine to cause the disease. Signs of hepatic encephalopathy include listlessness, inability to respond to basic commands, spinning, head-pushing, aimless wandering, weakness, poor coordination, blindness, excessive salivation, behavioral changes (e.g. aggression), dementia, collapse, seizures, and coma.
Treatment of hepatic encephalopathy is aimed at supportive care and rapid reduction of toxins produced in the gastrointestinal tract. Severely affected dogs may become comatose or semi-coma and should not be fed until the condition improves. Treatment may include IV fluids to correct dehydration and electrolyte (salt) imbalances. Enemas can be used to cleanse the intestines of ammonia and other toxins and introduce nutrients that help reduce toxin production. Agents that affect the bacterial population in the gut can also be used to reduce the absorption of toxic substances such as ammonia. Once the dog is stabilized, treatment is given to prevent recurrence. A restricted diet with protein adjustments may be prescribed. Signs of hepatic encephalopathy can be exacerbated by intestinal bleeding, infections, certain medications (such as corticosteroids and tranquilizers), cancer, low blood sugar, fever, kidney disease, dehydration, and constipation. Your veterinarian may prescribe additional treatments to address these concerns.
ASCITES:
Ascites is the accumulation of fluid in the abdomen. Ascites in patients with liver disease results from a combination of hepatic hypertension, low blood protein levels, and an imbalance in sodium and hydrogen metabolism. The first step in managing ascites is to limit sodium in your dog’s diet. However, a low-sodium diet alone is often not enough, and diuretics (drugs that increase fluid loss from the kidneys) may also be needed. When ascites affect breathing, appetite, and health, a long needle may be used to remove fluid from the ascites in a procedure called abdominal puncture. Routine laparocentesis can also be done if ascites does not respond to drug treatment.
CLOTTING DEFECTS:
Dogs with liver disease develop clotting disorders because the liver makes many of the proteins involved in the clotting process. In addition, the absorption of vitamins from the gastrointestinal tract that help blood clot may be reduced. Clotting problems can be treated with blood or plasma transfusions to provide the necessary clotting factors. Heparin and vitamin K can also be given to decrease or increase clotting ability. A veterinarian will prescribe the most appropriate treatment according to the pet’s general condition and blood type.
BACTERIAL INFECTION:
Dogs with acute liver failure or long-standing liver disease are susceptible to bacterial infections. The signs of liver disease itself (such as fever and hypoglycemia) can resemble those of an infection, so your veterinarian will be alert to this possibility. One or more antibiotics may be required to properly treat the type of bacteria associated with the infection.
FIBROSIS
Fibrosis, the formation of fibrous scar tissue in the liver, can eventually lead to cirrhosis. Cirrhosis is a serious condition that affects liver function. However, using appropriate drugs may reverse or reduce fibrosis. Your veterinarian may be able to determine which of the available medications will benefit your pet.
PORTOSYSTEMIC SHUNTS AND OTHER VASCULAR ABNORMALITIES:
Portosystemic shunts have already been described as congenital (congenital) defects. However, in some cases, it can also occur as part of an illness. In such cases, we are talking about acquired shunts. These can be caused by high blood pressure in the blood vessels leading to the liver. You can imagine a diseased liver resisting the flow of blood to the organ. When this happens, new blood vessels open to bypass the liver and connect to the rest of the body’s blood system, which has low blood pressure. It’s like the blood system bypasses traffic jams. Acquired shunts tend to occur in older animals and are more common in dogs than cats. Signs of acquired shunt include excessive dry mouth, vomiting, and diarrhea. Fluid accumulation in the abdomen (ascites) is common. Affected dogs may also experience coming and going neurological symptoms (due to hepatic encephalopathy).
Laboratory tests can identify abnormalities associated with underlying liver disease.
Treating the disease to minimize neurological symptoms and accumulation of ascites may improve the prognosis for some dogs.
POISONS/TOXINS THAT AFFECT THE LIVER:
Due to the liver’s role in drug metabolism, some drugs are believed to be associated with hepatic dysfunction in dogs.
Specific signs and effects depend on the drug and dosage. Often, when prescribing these medications, veterinarians are aware of possible liver disease and monitor dogs for signs of diminished or altered function.
Other hepatotoxicants include heavy metals, certain herbicides, fungicides, insecticides, rodent venoms, aflatoxins (produced by fungi), amanita, and cycads (for ornamental use in sago palms for gardens and homes). plants), and cyanobacteria. These can cause life-threatening liver damage.
If your dog accidentally overdoses on medication, has side effects from medication (even at the prescribed dose), or has ingested poison, it should be seen by a veterinarian immediately. If necessary, your veterinarian can take steps to minimize the absorption of drugs and poisons. Depending on the situation, the veterinarian may induce vomiting, administer activated charcoal, pump the animal’s stomach, or administer appropriate antidotes.
LIVER INFECTION:
Many types of infections can affect the liver, including viruses, bacteria, fungi, and invasions.
Viral diseases in dogs with liver dysfunction include infectious canine hepatitis and canine herpes virus. Infectious canine hepatitis caused by canine adenovirus 1 can cause not only the death of liver tissue but also long-term inflammation and scarring of the liver. Canine herpesvirus causes severe, often fatal liver disease in puppies.
Accidental intranasal injection of Bordetella vaccine into the skin instead of through the nose can cause liver damage in some dogs.
Leptospirosis is a bacterial infection caused by Leptospira bacteria, which can lead to liver disease. Diagnosis is usually by blood tests or detection of the pathogen in urine or blood samples.
Treatment includes supportive care and treatment with appropriate antibiotics. This pathogen can also infect humans, so special care should be taken when handling dogs with suspected leptospirosis.
Other types of bacterial infections can also cause liver damage, such as infections caused by Clostridium piliforme and Mycobacterium species.
Infections in other parts of the body can invade liver tissue and cause damage and malfunction. Dogs with liver failure or long-term liver disease are more susceptible to various types of bacterial infections, as the liver is the body’s defense against bacterial infections. The most common fungal infections associated with liver dysfunction are coccidioidomycosis and histoplasmosis. Signs of liver dysfunction include accumulation of fluid in the abdomen (ascites), jaundice, and an enlarged liver. Histoplasmosis is usually treated with one or more prescription antifungal drugs. Depending on the severity of symptoms, recovery may be poor. Coccidioidomycosis can be treated with long-term (6 to 12 months) antifungal drugs. However, recurrences occur occasionally, and some dogs require lifelong treatment.
Toxoplasmosis is a parasitic disease that destroys liver cells and can cause sudden liver failure. Jaundice, fever, lethargy, vomiting, increased ascites, and diarrhea occur in addition to signs of central nervous system, pulmonary, or ocular involvement. Canine toxoplasmosis-related liver disease is most common in young dogs and dogs with weakened immune systems. Some dogs with toxoplasmosis are also infected with the distemper virus. In this case, the disease begins suddenly and quickly becomes fatal. Diagnosis can be difficult. Treatment usually includes appropriate antibiotics. Chances of recovery depend on the severity of the disease.
Leishmaniasis is a potentially fatal disease caused by protozoa of the Leishmania species. The disease affects multiple organs, including the liver. Several drugs are available for treatment, but they rarely cure the disease. Lifelong treatment may be required. The disease can be transmitted to people, especially those with weakened immune systems. The outlook for severely affected dogs is poor.
CHRONIC HEPATITIS IN DOGS:
Chronic hepatitis is long-term inflammation of the liver. It is more common in dogs than in cats.
Several dog breeds are susceptible to this condition, including Bedlington Terriers, Labrador Retrievers, Cocker Spaniels, Doberman Pinschers, Skye Terriers, Standard Poodles, Springer Spaniels, Chihuahuas, Maltese and West Highland White Terriers.
In chronic hepatitis, the cause may be identifiable but often remains unknown. Copper and iron accumulation are common in dogs with chronic hepatitis. Other conditions associated with chronic hepatitis include viral infections (eg, infectious canine hepatitis), leptospirosis, exposure to certain chemicals or toxins, and drug toxicity.
Abnormal accumulation of copper can lead to copper-related liver damage, one of the most common causes of chronic hepatitis. Adding zinc to the diet in these cases can help prevent absorption of copper from the intestine and protect the liver. For more information on copper-related liver disease, see Liver. Your veterinarian will determine the appropriate chronic hepatitis management and treatment regimen depending on your dog’s symptoms, cause (if known), breed and medical history.
These properties provide some protection from permanent damage. However, the liver is also susceptible to damage due to its role in metabolizing, detoxifying, and storing various toxic compounds.
Signs that a dog has liver disease can vary and include loss of appetite, vomiting, stomach ulcers, diarrhea, seizures and other neurological problems, fever, blood clotting problems, and jaundice (yellowing of the skin, mucous membranes, and eyes), accumulation of fluid in the abdomen, excessive urination and
thirst, changes in liver size and weight loss.
Gastrointestinal bleeding can be seen in animals with liver disease due to ulcers or blood clotting problems.
Understanding the possible causes of each of these signs will help your veterinarian diagnose the disease and begin appropriate treatment.
Various blood tests help detect and diagnose liver disease. X-rays and ultrasounds help veterinarians determine liver size to detect abnormalities, gallstones, and gallbladder disease. Aspiration or biopsy techniques can be used to obtain samples for bacterial culture, cell and tissue analysis, and if desired, toxicological analysis. In some cases, scanning techniques such as magnetic resonance imaging can be used to identify portosystemic shunts (see below) and other vascular abnormalities.
Hepatitis can also result from infection of the bile ducts that carry bile from within the liver to the small intestine. These infections often spread from the intestinal tract due to the slow movement of bile, gallstones, or other biliary tract disorders. This condition, known as cholangiohepatitis, is rare in dogs. Antibiotics are needed to treat infections, and surgery may be needed depending on the cause.
ENDOCRINE DISORDERS OF THE LIVER:
Several diseases of the endocrine glands can cause liver problems in dogs. These diseases include diabetes, Cushing’s disease, and hyperthyroidism.
Diabetic dogs rarely develop disease-related liver dysfunction. Dogs with diabetes are at increased risk of inflammation of the pancreas (pancreatitis), which can lead to certain types of liver disease. Some diabetic dogs develop hepatocutaneous syndrome, which is often fatal. Diabetes may also increase metabolism and lipid mobilization, increasing the risk of developing fatty liver. Lipids include all water-soluble fats and fat-like chemicals that the body uses as fuel. However, excessive accumulation of lipids in the liver impairs organ function. Insulin replacement may or may not solve this memory problem.
Dogs with hyperadrenocorticism may experience changes in the liver similar to those seen with corticosteroid overdose. These problems are controlled when the underlying disease is treated. Liver changes are also seen in dogs with hypothyroidism.
LIVER CYSTS AND NODULAR HYPERPLASIA:
Liver cysts may be acquired (usually a single cyst) or present at birth (usually multiple cysts). Congenital polycystic liver disease has been reported in Cairn Terriers, Bull Terriers, Beagles, and West Highland White Terriers.
In some cases, the cyst may grow and cause symptoms such as abdominal swelling, fatigue, vomiting, and excessive dry mouth. A veterinarian may be able to feel a mass in the abdomen that is usually painless. Fluid may accumulate in the abdomen. The problem can be identified using x-rays or ultrasound, but the definitive diagnosis is made with a biopsy.
Surgical removal of the cyst usually cures the symptoms.
CANINE VACUOLAR LIVER INJURY:
The liver produces and stores energy in the form of glycogen. Glycogen is released to maintain blood sugar levels throughout the day. However, in dogs with vacuolar liver disease, abnormal amounts of glycogen accumulate and swell within the liver cells.
This is a common liver syndrome and is usually revealed by the results of a liver tissue biopsy. This syndrome is often associated with excessive adrenal function (hyperadrenocorticism) or long-term stress, disease, inflammation, or cancer. Certain medications can also stimulate this syndrome. The presence of glycogen-enriched hepatocytes can also occur in dogs with nodular hyperplasia and certain types of liver cancer. A veterinarian will identify and treat the underlying cause of these liver changes. They may also change the dog’s food, add vitamin supplements, or recommend other treatments. A variant of this syndrome is common in Scottish Terriers. Dogs affected by this breed can slowly or rapidly develop serious liver diseases such as cirrhosis, liver cancer and liver failure.
Nodular hyperplasia is a non-prevalent age-related disease of dogs. It does not usually cause illness and does not affect liver function. If found, a biopsy may be required to distinguish these changes from those caused by other serious liver diseases.
CANINE HEPATOCUTANEOUS SYNDROME:
Hepatocutaneous syndrome is a rare long-term progressive disease that affects both the liver and skin. Affected dogs develop crusty sores around the lips, nose, toes, ears, elbows, and eyes. Other signs include loss of appetite, weight loss, fatigue, increased thirst and increased urination. This condition can occur in dogs with certain long-term medical conditions, such as diabetes or certain tumors, or on long-term use of certain medications, such as phenobarbital. Your veterinarian may recommend dietary changes and treatment for dermatitis. Some affected dogs may also benefit from other medications and may require treatment of the underlying disease. Unfortunately, dogs often die from this disease.
LIVER CANCER
Tumors that originate in the liver (called primary tumors) are less common than those caused by metastases from other parts of the body.
Primary tumors are most common in animals aged 9 years and older. These tumors are either malignant or benign and can spread (metastasize) to other sites such as lymph nodes, abdomen, or lungs.
Cancers that can spread to the liver include lymphoma, pancreatic cancer, and breast cancer.
METASTATIC TUMORS USUALLY OCCUR IN SEVERAL PLACES:
Signs include loss of appetite, lethargy, fever, excessive urination and dry mouth, vomiting, weight loss, jaundice, bleeding problems, hepatic encephalopathy (see above), enlarged liver, and fluid accumulation in the abdomen.
Attacks may result from hepatic encephalopathy, low blood sugar, or cancer that has spread to the brain.
Abdominal tumors may be discovered during a veterinarian’s examination or abdominal ultrasound. In many cases, a biopsy is required for a definitive diagnosis. In some cases, liver tumors can rupture, causing life-threatening internal bleeding. If a single lobe of the liver is affected, surgical excision of the affected liver lobe is often recommended. For other types of cancer, chemotherapy may be effective. The outlook for primary liver tumors affecting multiple lobes is bleak, as there is still no effective therapy.
Several other non-infectious chronic diseases can also affect the liver.
GLYCOGEN STORAGE DISEASE
Glycogen is a type of storage sugar found in animals. When the body needs energy it is converted to glucose. Glycogen storage diseases are caused by deficiencies in certain enzymes, resulting in the inability of cells to release glycogen. When this happens, glycogen accumulates in the liver and other organs and can no longer be converted to glucose. This condition is inherited in certain dog breeds such as Maltese, German Shepherds, and Curly Coated Retrievers. Signs of this disorder include an enlarged liver, slow growth, and weakness due to hypoglycemia. Liver biopsy or genetic testing is used for diagnosis. Treatment is symptomatic and involves eating frequent, small meals containing carbohydrate-rich foods. In most cases, the prognosis is poor and most dogs with these diseases die young. hepatic amyloidosis
Amyloid is a protein that is not properly folded. Misfolded proteins aggregate and cause damage by crowding out normal cells. Amyloidosis is a genetic disease of Chinese Shar Pei. However, the liver is not always affected. Long-term exposure to antigens can be associated with long-term infections and can lead to amyloidosis in the liver. Some dogs are asymptomatic, but typical symptoms include loss of appetite, excessive thirst and urination, fever, vomiting, jaundice, and an enlarged liver. Affected animals may collapse and have pale mucous membranes due to ruptured livers and subsequent internal bleeding. Diagnosis is by identifying amyloid deposits in liver biopsy specimens. Drugs are available to slow the progression of amyloidosis, but the prospects are bleak, especially if diagnosed late in the course of the disease.
DISEASES OF THE GALLBLADDER AND BILE DUCTS
The liver secretes bile, a substance that helps digest and absorb fats and remove certain waste products from the body. Bile is stored in the gallbladder and released through the bile ducts into the small intestine. Jaundice (yellowing of the skin, mucous membranes, and eyes) is often the main symptom of gallbladder and bile duct disease. Gallbladder cancer is an exception and should not cause jaundice.
Gallbladder agenesis is the absence of a gallbladder at birth. It doesn’t matter if you don’t have a gallbladder as long as your liver doesn’t have bile ducts.
Biliary atresia is underdevelopment of the bile ducts of the liver and is rare. Affected dogs become jaundiced and uneconomical at an early age. The outlook is poor.
Cystic mucosal hyperplasia of the gallbladder is also known as cystic mucosal hyperplasia, cystic mucosal hyperplasia, and mucous cholecystitis. This involves the development and growth of mucus-filled cysts within the gallbladder. It can be caused by treatment with steroid hormones, such as female reproductive hormones. The early stages of this disorder can be a condition known as gallbladder dysmotility.
BILE DUCT OBSTRUCTION
Bile duct obstruction is associated with many conditions, including inflammation of the pancreas, gallbladder, and small intestine. Foreign bodies in the intestine. cancer; and parasitic infections. Tissue swelling, inflammation, and fibrosis can compress the bile ducts. Diagnosis is based on laboratory tests, x-rays, and ultrasound. Diagnosis and treatment of obstructions often require abdominal surgery. However, for dogs with pancreatitis, treatment often relieves the blockage. Otherwise, surgery may be required. If gallstones are the cause of the blockage, the gallbladder may need to be removed. If cancer is present, surgery relieves some symptoms but is not a cure.
INFLAMMATION OF THE GALLBLADDER (CHOLECYSTITIS)
Inflammation of the gallbladder (cholecystitis) can be caused by bacterial infection, cancer, liver injury, gallbladder obstruction, or blood clots. In some cases, the wall of the gallbladder is damaged, allowing bile to leak into the abdomen, causing serious abdominal infection and inflammation, and even death. Anorexia, abdominal pain, jaundice, fever, and vomiting are common symptoms. A dog may be in shock due to an abdominal infection.
Inflammation can also spread to the bile ducts and surrounding branches of the liver. Diagnosis is based on blood tests and ultrasound findings and can be confirmed by biopsy bacterial culture and tissue analysis. Treatment usually consists of removing the gallbladder and giving the appropriate antibiotics to treat the infection. Prognosis is good if surgery and appropriate antibiotics are started early, but poor if diagnosis and treatment are delayed.
GALLBLADDER MUCOCELE IN DOGS
A gallbladder mucocele is an abnormal buildup of bile in the bile ducts, causing bile duct obstruction. Enlarged mucus sacs can cause inflammation, tissue death, or rupture of the gallbladder. This condition can be inherited in some breeds, such as the Cocker Spaniel, Miniature Schnauzer and Shetland Sheepdog. Underlying medical conditions can also predispose dogs to this condition. Some dogs with mild symptoms may improve with medication alone. However, most people require surgery to remove the gallbladder. A liver biopsy is often done during surgery. Antibiotics are usually required 4 to 6 weeks after surgery. Dogs with ruptured gallbladders and sepsis may not survive surgery.
GALLSTONES
Gallstones rarely cause disease. When the disease does occur, it usually occurs in middle-aged to older dogs and can be more common in small dogs. Symptoms include vomiting, jaundice, loss of appetite, abdominal pain, fever, and discomfort after eating, but many dogs have no symptoms. Gallstones are diagnosed using ultrasound. Gallstones are being diagnosed more frequently in recent years as abdominal ultrasonography becomes more common. Drug therapy, including antibiotics, can be used to treat uncomplicated dogs. Surgery is needed to remove the stone if it blocks bile or causes cholecystitis. Removal of the gallbladder may be necessary.
RUPTURE OF THE GALLBLADDER OR BILE DUCT
A ruptured gallbladder or bile duct is most often caused by a gallstone blockage, inflammation of the gallbladder, or blunt trauma.
Ruptured bile ducts can also occur as a result of cancer or certain parasites. A rupture can leak bile into the abdomen, causing a serious condition called biliary peritonitis, which can be fatal if the rupture is not repaired.
Treatment may include surgery to place a stent in the bile duct, surgery to remove the gallbladder, or surgery to connect the gallbladder to the small intestine.
For more information See also specialized content on liver and gallbladder diseases.
