As with humans, the liver is also essential for dogs for dogs. What are liver diseases in dogs, and how can they be treated?
The liver is an important organ for our dog. It helps digestion and blood clotting and removes toxins from its system. If it doesn’t work properly, it can make our furry friend sick. But liver disease in dogs can often be cured and managed. The important thing is to notice the symptoms of the disease, and to act promptly to solve the problems of our four-legged friend. Let’s find out the best ways to recognize these problems and how to intervene on time.
The dog’s liver
The liver is an organ that performs many functions. It has a large memory capacity and functional reserve, and is capable of regenerating itself. These properties offer some protection against permanent damage. However, the liver is also susceptible to injury due to its role in metabolizing, detoxifying and storing various toxic compounds.
Liver functions include:
- Metabolizes fats, carbohydrates and proteins
- Metabolizes drugs (inactivates or facilitates body excretion)
- Stores, metabolizes and activates vitamins
- Preserves minerals, glycogen and triglycerides
- It produces proteins necessary for various body functions, such as blood clotting
- It produces bile acids necessary for digestion
- Detoxifies harmful products manufactured inside the body (such as ammonia) or consumed by the animal (such as poisons)
- Influences immune responses
- Helps develop blood cells (extramedullary erythropoiesis)
Acute liver failure causes a sudden loss of liver function, which is often associated with neurological signs and clotting abnormalities. It can occur due to a sudden injury of a previously healthy liver or an additional insult to an already sick liver. It is important to seek immediate veterinary care for liver support treatment until it can regenerate and compensate for damage.
Recognize the signs of a disease
The signs that a dog has liver disease can vary and include loss of appetite, vomiting, stomach ulcers, diarrhea, convulsions or other neurological problems, fever, blood clotting problems, jaundice (a yellow tinge noticeable in the skin, mucous membranes and eyes), fluid collection 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 problems with blood clotting.
Blood tests can detect and diagnose liver disease, and with an ultrasound the vet can determine any irregularities, gallstones and gallbladder diseases. Early treatment is critical for dogs with acute liver failure. The veterinarian will prescribe specific treatment if an underlying cause is identified. In the case of long-term or end-stage liver disease, supportive treatment is aimed at slowing the progression of the disease, minimizing complications and allowing the liver time to regenerate and compensate.
The generally recommended diet for dogs with liver disease should include enough calories to maintain a normal weight. Just follow the specific advice provided by the vet, and it may be better to feed small frequent meals. Dogs who refuse to eat can request tube feeding.
Prescribed supplements may include B vitamins, vitamin K and vitamin E. Low potassium levels and low levels of B vitamins are common complications with liver disease and supplementation is often recommended. Vitamin C does not appear to run out in dogs with liver disease and supplementation is not recommended in dogs with copper storage liver disease. Vitamin K injections are sometimes given to dogs with a tendency to bleed.
Complications of liver disease
The liver has multiple functions, including the removal of many toxins from the bloodstream and the production of blood clotting proteins. When it is not functioning properly, many other organs can be affected. Let’s see what are the main liver diseases in dogs.
Hepatic encephalopathy, a syndrome of neurological problems caused by poor liver function, has been observed in several liver diseases. While the development of this condition is not fully understood, the inability of the liver to eliminate poisons from the bloodstream, changes in amino acid metabolism caused by liver disease and neurological changes can work together to cause this disorder. Signs of hepatic encephalopathy include dullness, inability to respond to basic commands, circle, head pressing, aimless wandering, weakness, poor coordination, blindness, excessive burring, behavior changes (e.g. aggression), dementia, collapse, seizures and coma.
The treatment of hepatic encephalopathy aims to provide supportive care and quickly reduce the poisons produced by the digestive tract. A limited protein-modified diet may be prescribed. Signs of hepatic encephalopathy can be aggravated by intestinal bleeding, infections, certain medications (such as corticosteroids and sedatives), cancer, hypoglycaemia, fever, kidney disease, dehydration and constipation. The vet may prescribe additional treatments to address these concerns.
Ascites is a condition in which fluid collects in the abdomen. In patients with liver disease, ascites is caused by a combination of high blood pressure in the liver, low levels of protein in the blood and an imbalance in the metabolism of sodium and water. The first step in controlling ascites is the restriction of sodium in the dog’s diet.
Clotting defects occur in dogs with liver disease because the liver produces many of the proteins responsible for the clotting process. In addition, there may be a reduced absorption of vitamins that help clot from the digestive tract. Clotting problems can be treated using blood or plasma transfusions to provide the necessary clotting factors.
Dogs with acute liver failure and long-standing liver disease are sensitive to bacterial infections. The veterinarian will be alert to this possibility because the signs of the liver disease itself (e.g. fever, or low blood sugar levels) may be similar to those of the infection. One or more antibiotics may be needed to adequately treat the types of bacteria associated with the infection.
Fibrosis, the formation of fibrous scar tissue in the liver, can eventually lead to liver cirrhosis. Cirrhosis is a serious disease that disrupts liver function. However, fibrosis can sometimes be reversed or reduced through the use of appropriate drugs. The vet can determine which, if any, available medications would be helpful for our pet.
Portosystemic shunts have already been described as a congenital (congenital) defect. However, in some cases they can develop as part of the disease. In these cases they are called acquired shunts. They can be caused by hypertension in the vessels that enter the liver. It can be thought that the diseased liver resists blood flow in the organ. Acquired shunts are usually observed in older animals and are more frequent in dogs than in cats.
The signs of an acquired shunt include excessive thirst, vomiting and diarrhea. The accumulation of fluids in the abdomen (ascites) is common. Affected dogs may also have neurological signs (due to liver encephalopathy) that come and go. Laboratory tests can identify abnormalities associated with the underlying liver disease.
Poisons affecting the liver
Due to the liver’s function in metabolizing medications, some medications have been associated with liver dysfunction in dogs. The specific signs and effects depend on the drug and dosage. In many cases the vet will be aware of the potential for liver disease when prescribing these drugs and will monitor the dog for signs of impaired or impaired function.
Other liver toxic substances include heavy metals, some herbicides, fungicides, insecticides, rodent poisons, aflatoxins (produced by mold), amanita mushrooms, cycad plants (ornamental plants) and blue-green algae. These can cause life-threatening liver damage.
Infectious liver disease
Different types of infections can affect the liver, including viral, bacterial, fungal and parasitic diseases. Viral liver diseases in dogs associated with liver dysfunction include infectious canine hepatitis and canine herpes virus. Infectious canine hepatitis, caused by canine adenovirus 1, can cause long-term inflammation and scarring of the liver as well as causing liver tissue death. Canine herpes virus causes severe fatal liver disease in puppies.
Leptospirosis is a bacterial infection caused by Leptospira interrogans, which can cause liver disease. The diagnosis is usually made with a blood test or identification of the organism in the urine or blood samples. Treatment includes supportive care and treatment with appropriate antibiotics. Special precautions are recommended when handling dogs suspected of leptospirosis, as this organism can also infect humans. The most common fungal infections associated with liver dysfunction are coccidioidomycosis and histoplasmosis. Signs of liver dysfunction include fluid build-up in the abdomen (ascites), jaundice and enlarged liver.
Toxoplasmosis is a parasitic disease that can kill liver cells and cause sudden liver failure. Jaundice, fever, lethargy, vomiting, increased abdominal fluid and diarrhea are seen as well as signs of central, pulmonary or ocular nervous system involvement. Liver diseases associated with toxoplasmosis in dogs are often observed in young dogs or those with a suppressed immune system. Some dogs with toxoplasmosis are also infected with the canine distemper virus, in which case the disease is sudden onset and rapidly fatal. Diagnosis can be difficult. Treatment usually involves appropriate antibiotics. The prospects for recovery depend on the severity of the disease.
Leishmaniasis is a potentially fatal disease caused by protozoan species Leishmania. The disease affects multiple organs, including the liver. There are several medications available for treatment, but they rarely cure the disease. Permanent therapy may be needed. The disease can pass to people, especially those with compromised immune systems. The outlook for severely affected dogs is poor.
Chronic canine hepatitis
Chronic hepatitis is a long-term inflammation of the liver. It is more common in dogs than in cats. Different breeds of dogs are predisposed to this condition. Although the cause can be determined in some cases of chronic hepatitis, in many cases the cause remains unknown. The accumulation of copper and iron is often observed in dogs with chronic hepatitis.
Other liver diseases in dogs associated with chronic hepatitis include viral infection (such as infectious canine hepatitis), leptospirosis, exposure to certain chemicals or poisons and drug toxicity. Abnormal accumulations of copper can lead to copper-associated liver disease, one of the most common causes of chronic hepatitis. The addition of zinc to the diet can help protect the liver by preventing the absorption of copper from the intestine in these cases.
Liver inflammation can also occur due to infections around the biliary tract, which transports bile from inside the liver to the small intestine. These infections go back to the intestinal tract, often due to the slow movement of bile, gallstones or other biliary tract disorders. The condition, called cholangiohepatitis, is rare in dogs. Antibiotics are needed to treat the infection and surgery may be required, depending on the cause.
Endocrine diseases affecting the liver
Several liver diseases in dogs involving the endocrine glands can cause problems in this organ. These diseases include diabetes mellitus, Cushing’s disease and hyperthyroidism.
Liver cysts can be acquired (usually single cysts) or present at birth (usually multiple cysts). Occasionally, the cysts can become large and cause abdominal bloating and other signs such as lethargy, vomiting and excessive thirst. The vet may be able to feel masses in the abdomen which are usually not painful.
The liver produces and stores energy in the form of glycogen, which is released to maintain blood sugar levels. However, in dogs with vacuolar liver disease, abnormal quantities of glycogen accumulate inside the liver cells, removing them. It is a common liver syndrome that is generally revealed with the results of a liver tissue biopsy. The syndrome is often associated with an excessive function of the adrenal gland (hyperadrenocorticism) or with stress, disease, inflammation or long-term cancer.
Nodular hyperplasia is an uncommon, age-related condition in dogs. It usually does not cause disease or affect liver function. If it is detected, a biopsy may be needed to distinguish these changes from those caused by other serious liver diseases.
Among liver diseases in dogs, there are also tumors. THE tumors that originate in the liver (called primary tumors) are less common than those caused by spreading to another part of the body. Primary tumors are most often observed in animals over 9 years of age. These tumors can be malignant or benign and can spread (metastasize) to other locations such as lymph nodes, the abdominal wall and the lungs.
Tumors that can spread to the liver include lymphoma, pancreatic cancer, breast cancer and many others. Metastatic tumors usually occur on multiple sites. The signs may include decreased appetite, lethargy, fever, excessive urination and thirst, vomiting, weight loss, jaundice, bleeding problems, hepatic encephalopathy (see above), liver enlargement and fluid build-up in the abdomen. Seizures can develop due to liver encephalopathy, low blood sugar levels or the spread of brain cancer.