Hepatic Encephalopathy in Dogs

Due to the build-up of ammonia and other toxins in the brain, your canine’s mental function may be altered causing symptoms such as head pressing, wandering, and fatigue. The severity of the hepatic encephalopathy can be classified in stages which are based on the level of brain abnormality and damage.

This lack of filtering and detoxification by the body will cause the build-up and subsequent changes in the liver and kidney function. Testing by your veterinarian will reveal the stage of hepatic encephalopathy that your dog has, determining treatment ranging from hospitalization to stabilize your pet, dietary changes, and possibly surgery, depending on the initial diagnosis and the cause of the condition.

Hepatic encephalopathy is a condition characterized by the inability of the liver to filter toxins. The lack of filtering leads to an accumulation of toxins (particularly ammonia), causing symptoms indicative of central nervous system issues.

Hepatic encephalopathy occurs gradually in its initial stage. The first warning sign is generally a lack of interest or fixation as if in contemplation. Other signs to look for are:

• Seizures and convulsions
• Hysteria
• Pacing
• Aggression
• Staggering
• Tremors
• Walking in circles
• Sudden blindness
• Diarrhea
• Drooling
• Weight Loss
• Sleepiness
• Apathy
• Compulsive behavior
• Vomiting

As the liver gets worse and progresses through the stages, there are dogs that will be extremely unsteady while walking, disoriented and disturbed. You may find your pet pressing the head against the wall and wandering around in confusion. In the final stages, coma and collapse can occur.

Illnesses like kidney disease can precipitate hepatic encephalopathy, as can toxicity due to poisonous substance ingestion, infection, and cirrhosis of the liver. Other causes for this condition are:

• Portosystemic shunts (a congenital condition)
• Concurrent metabolic disease
• Hypoglycemia
• Thyroid conditions
• Dehydration
• High dietary protein
• Certain medications (such as barbiturates, antihistamines)
• Hepatitis

Not all liver problems are related to hepatic encephalopathy. Your veterinarian may recommend tests that rule out other diseases. The veterinary specialist will require pertinent information such as symptoms your pet typically displays at home, his daily dietary schedule and what type of food he eats, his urinary habits, and which, if any, supplements or vitamins you may be giving your pet. Laboratory tests may include:

• Blood ammonia
• Blood clotting
• Urinalysis
• X-rays and ultrasound of the abdomen

If further investigation is needed, a liver biopsy could be suggested. The veterinarian will want to determine at what stage of hepatic encephalopathy your pet has reached as the treatment will vary accordingly.

Depending on clinical signs, your pet may need hospitalization as part of his therapy. In this case, supportive care will be necessary to slow down the progression of the condition. This disease cannot be cured, but with proper therapy your pet can be stabilized and can return home. To begin, intravenous will be administered and will include vitamins (particularly vitamin B), electrolytes, and antibiotics. The antibiotic treatment will be given with careful monitoring of the natural intestinal flora of your pet, which could be compromised somewhat due to the hepatic encephalopathy. 

Often, a cleansing enema will be done in order to prepare the gastrointestinal tract for recovery. If your pet has a congenital shunt, surgery will be required to correct it.

Canines who have been treated for hepatic encephalopathy will need continued care once home. The veterinarian will give specific instructions based on your pet’s case and the cause for the condition. A dietary recommendation will be prescribed and must be followed in order to prevent a recurrence of the neurological signs that your pet may have experienced. Often, probiotic yogurt is part of the dietary change, as is a protein modified diet. Studies show that a feeding regimen with a monitored (not necessarily restricted) protein allowance has given pets with liver disease quality of life after diagnosis; yogurt, cheddar cheese, and cottage cheese are often the recommended choices.

A canine who has undergone surgery will have exercise restrictions and will need a quiet restful corner in which to convalesce. Monitor your pet for several days after he returns home from the clinic and adhere to the instructions provided by the veterinary team, continuing the course of all medications even if your pet seems to be feeling fine.