Liver Failure in Dogs

Hepatitis is inflammation of the liver tissue, which can have various causes. The specific cause needs to be identified in order to set up proper treatment, though in some cases the prognosis will be guarded.

Running tests to reach a diagnosis is essential, since there are so many possible causes for this inflammation — the most important thing is knowing what the problem is and to what extent the liver has been affected. Let's look at all the details.

Symptoms in a dog with hepatitis

The liver carries out important functions in the body, such as regulating the metabolism of carbohydrates, fats, proteins, vitamins, and endocrine hormones, along with immune, detoxifying, digestive, and storage functions.

When it fails, we can see changes such as inflammation, tissue death, fibrosis, and degeneration. These end up triggering certain symptoms. In an early stage, these are:

1. Loss of appetite.
2. Vomiting and diarrhea/constipation.
3. Weight loss.
4. Polydipsia/polyuria (drinking more water and urinating more than normal).
5. Fever.

In cases of severe liver failure, we'll see:

1. Green stool.
2. Ascites and edema (with low albumin and portal hypertension).
3. Hepatic encephalopathy.
4. Elevated ammonia.

What causes hepatitis?

The liver is an organ very sensitive to metabolic, toxic, infectious, cancerous, and circulatory disturbances. Since bile production is one of the liver's most sophisticated functions, it's one of the first to be disrupted. Jaundice (yellowish mucous membranes) is the clinical sign of this disruption.

The causes of hepatitis, and therefore of abnormal liver enzymes (transaminases), include:

• Corticosteroids — mainly raising ALP.
• Antifungals such as ketoconazole.
• Anticonvulsants: phenobarbital raises liver enzymes, mainly ALP and, to a lesser extent, ALT, AST, and GGT.
• Congestive heart failure.
• Chemical substances: aflatoxins, heavy metals, Amanita mushrooms (a type of toxic mushroom).
• Viral and bacterial agents such as leptospirosis, liver abscesses...
• Liver tumors (primary or secondary).
• Others such as diabetes mellitus, hypothyroidism, pancreatitis, sepsis, thromboembolism, sepsis.

Diagnosis

An accurate diagnosis requires properly interpreting the lab tests and imaging tests run by the vet. Besides taking a medical history and doing a general physical exam of the animal, full bloodwork will need to be run, with the chemistry panel providing the most information (elevated liver enzymes).

Changes in liver chemistry values can result from direct liver cell damage, impaired blood flow, or reduced liver mass.

An ultrasound will be essential. This non-invasive technique lets the vet see the organs, bile ducts, gallbladder, and liver blood vessels, showing the liver's outline and any changes it's undergone. A liver biopsy will be recommended. The simplest technique is a percutaneous biopsy under local anesthesia (from the left flank).

Treatment for liver failure

This will depend on the cause and how deteriorated the liver is. There are several options depending on the prognosis, listed below.

Treatment for acute hepatitis

If we've identified the disease behind the liver inflammation, treatment is aimed at it. In cases of infection, treatment will be fluid therapy (preferably saline solution) and antibiotics (amoxicillin-clavulanic acid, metronidazole, ampicillin, or whatever's appropriate based on a culture). Symptoms will also be treated. If this acute liver failure is drug-induced, the medication needs to be stopped immediately. Or if it's due to poisoning, that needs to be treated too.

Surgical treatment

When hepatitis is due to bile duct obstruction (cholestasis) or tumors that have developed in the liver itself, surgery may be the treatment of choice. In cases of hepatic or extrahepatic shunts, surgical resolution by an expert surgeon will also be attempted.

Treatment for chronic active hepatitis and cirrhosis

In these cases, corticosteroids and immunosuppressants are used, since the dog's immune system produces antibodies against their own liver. These will be prednisone or prednisolone for several months, combined or not with azathioprine. A high-fiber, low-fat, low-protein diet supplemented with zinc should be followed.

The medication aims to slow this progressive degeneration, though the disease can progress to cirrhosis, a condition in which liver tissue is irreversibly damaged. So, the prognosis is guarded. Treatment in cases of cirrhosis will be symptomatic, with a low-fat, low-protein diet.

Supportive treatment

Besides treating the underlying cause of the liver problem, it's very important to pay attention to symptoms, to prevent complications as much as possible.

To do this, as mentioned above, special low-protein, low-fat diets specifically formulated for these cases are prescribed, along with medication to control blood ammonia levels, maintain clotting, or prevent seizures and gastrointestinal ulcers.

It's also worth supplementing the diet with zinc, since it binds to copper and prevents its absorption in the intestine. Liver protectants such as SAMe, vitamins K and B12 (cobalamin), and ursodeoxycholic acid to clear biliary sludge (if detected via ultrasound) can be used. Traditional Chinese medicine can optionally be used as a complementary therapy.

What can dogs with liver failure eat?

Always under veterinary supervision, since it's part of their treatment, we should feed our dog food made with high-quality ingredients but low in fat and protein, to ease digestion and avoid overworking the liver.

There are two options: making a homemade diet ourselves, formulated by a veterinary nutritionist, or choosing a product already made specifically for dogs with this condition, such as Special Care by NFNatcane, a low-fat, low-protein product made with quality ingredients and healthy fruits and vegetables.

Whichever option you choose, remember that your vet will tell you the right amounts and number of feedings based on your dog's health status.