What is Hepatic Encephalopathy?
The liver is critical for detoxifying blood from the digestive system. When blood fails to flow properly to the liver to be filtered or when the liver is not performing the required function of filtering toxins and harmful substances from the blood, toxins can enter the animal’s circulation system. Hepatic encephalopathy results when substances such as ammonia and other neurotoxins build up in the circulation system cause disorders of the nervous system.
Hepatic encephalopathy is potentially life-threatening and requires immediate treatment by a veterinarian.
Hepatic encephalopathy is a disorder of the nervous system that results from poor liver function.
Symptoms of Hepatic Encephalopathy in Cats
Symptoms of hepatic encephalopathy include both neurological symptoms and symptoms of liver failure.
- Unusual thirst or urination
- Vomiting and diarrhea
- Behavioral changes, including aggression
- Restlessness and pacing
- Neurological symptoms such as circling and head pressing
- Impaired balance
- Visual impairment/blindness
- Cerebral edema in severe cases
Causes of Hepatic Encephalopathy in Cats
Causes of hepatic encephalopathy may be congenital and manifest within the first 12 months of life. The condition may also be acquired, which can occur at any age.
Congenital liver impairment is usually characterized by impaired circulation to the liver. This can occur when a shunt occurs in the circulation system carrying blood from the digestive system to the liver. This results in blood from the digestive system not being filtered by the liver before re-entering the bloodstream.
An impaired liver can also be caused by or aggravated by the following factors:
- Drugs, especially anesthetics or sedatives
- Toxins in the environment
- Viral infection
- Bacterial infection, especially of the digestive system
- Dietary factors, such as low sodium, potassium or blood sugar
- Constipation leading to a buildup of bacterial flora in the gut
- Gastrointestinal bleeding
Diagnosis of Hepatic Encephalopathy in Cats
It will be critical that a complete history of the cat be provided by the pet owner to the veterinarian. This history should include information on parentage and development in a young animal to determine the likelihood of congenital factors. You should also communicate exposures and medical history to narrow down factors that may have contributed to an acquired liver disorder. Your veterinarian will want to know details about the onset of symptoms, your cat’s diet, and details of their recent urinary and fecal elimination.
Your veterinarian will order complete blood and urine tests to rule out conditions such as damaged kidneys and identify impaired liver function. In addition, x-rays and ultrasound of the liver may be ordered that will help reveal liver malfunction. In some cases, a sample of the liver by aspiration or biopsy may be taken for tissue testing. A CT scan or MRI may be used to discover shunts and structural anomalies or rule out tumors.
Treatment of Hepatic Encephalopathy in Cats
Your vet will hospitalize your cat to provide supportive care and treat the underlying liver condition.
Your veterinarian may administer intravenous (IV) fluids to counteract dehydration. In this case, your pet will be closely monitored to ensure an imbalance of electrolytes does not occur and that your cat is hydrated appropriately.
Medication to counteract neurotoxins in the circulation system will be provided as appropriate. Your veterinarian will avoid the use of sedatives and other drugs that require liver processing and will aggravate your pet’s condition.
Antibiotics may be administered to treat infection in the gastrointestinal tract and reduce harmful or excess bacteria. In addition, your veterinarian may administer enemas to remove bacteria from the colon if necessary.
Once recovered, a modified diet aimed at helping liver function and probiotic yogurt to improve gut functioning will be prescribed. The diet will balance protein requirements and minerals such as zinc, which may be a factor in impaired liver functioning.
In the case a shunt is present, surgery may be performed to correct the shunt and restore proper circulatory functioning.
Recovery of Hepatic Encephalopathy in Cats
A full recovery depends on the successful treatment of the underlying liver disorder and the extent of neurological impairment. A modified diet may be prescribed to your cat to ensure improved liver functioning. Factors that contributed to the liver disorder should be avoided. You should monitor your cat to ensure that any return of liver disorder or neurological disorder symptoms are recognized and reported immediately to your veterinarian.
Hepatic Encephalopathy Questions and Advice from Veterinary Professionals
My cat has not been eating for about 2-3 weeks now. When I initially noticed his weight loss, depression, and hiding, he had already lost about 5 pounds. My initial instinct was to have him placed on a feeding tube, but my vet never recommended this. We did full blood work to find everything looked normal, with the exception of his liver enzymes being slightly elevated. He still was not eating, and an ultrasound was done to discover that his pancreas was inflamed, so pancreatitis was suspected. I was sent home with anti-nausea and anti-depressant medications but still, no feeding tube. He had been given liquids at every vet visit. The medications have not worked and my cat is now in full liver failure with suspected hepatic encephalopathy. I am feeling that it could have been due to hepatic lipidosis and I keep reading that this is curable and treatable with proper IV nutrition and intensive care, but now I feel that it is too late, as my cat can barely walk now. I am feeling guilty that I did not know I was supposed to take him to get a feeding tube, as my vet did not mention anything about this. My question is, are the effects of HE reversible or is there permanent brain damage? Also, why wouldn’t my vet have recommended IV nutrition, as I have see that this is often a recommended treatment for liver failure? Thank you for your response.
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I have a 6 yr old male cat (always indoors) that exhibits almost every symptom of Hepatic Encephalopathy. (Head pressing, high thirst, loss of appetite, intermittent episodes that appear to be mini seizures, vomiting, weakness, unsteady and unsure on his feet, changed behaviour. I read something online stating that there are 4 grades and from the description of symptoms I would say he is between grades 2 and 3. I took him to a vet approximately 2 weeks ago. She ran blood tests but couldn't find anything and told me she suspected HE. It cost me over $250. to do this and she didn't really give me any other information. I live on $1019/mo Social Security disability income and can't afford anymore vet services. I'm hoping this disorder hasn't progressed to a point where I can't treat him with a homemade prescription cat food. All I can find are generalized descriptions of diets and no prescription diet commercial food in the US. I need a specific recipe. Do you have a specific palatable recipe that I can make for him at home? Can I add 200 mgs of milk thistle safely to his food? Can you also tell me what his life expectancy is and if it's reversible with diet or will I need to take him back to a vet for medication?
Hi Dr Turner, I just wanted to update you that Hunter is getting a LOT better. I tried easier-to-digest forms of protein (tofu and cottage cheese) mixed with rice and potatoes and chopped spinach and he wouldn't touch it. After a couple days of trying to get him to eat I went a different route. I changed his food to a local high protein (believe it or not!)dry organic pellet cat food and added 250mg of standardized milk thistle and 250 taurine amino acid in powder form to the new cat food and he ate it like he was ravenous! After a couple more days the HE symptoms began disappearing until they were gone. Now his everyday appetite is excellent and he's gaining his weight back, and he's playing more and pestering his Mama and 2 female siblings--business as usual; he's back to his silly self! In fact he seems more lively and healthier than he's been in the last 3 years. I've decided to keep him on this diet with the added herb and AA since he's doing so well. It's like he wasn't assimilating protein properly from the name brand food that I've always fed my cats. The links you sent led me on a journey to a great amount of information and research that recommended low protein diet for HE except for one study that indicated that there are a few cases where a high protein diet was successful. I know this information is outside of normal research on HE. But, Hunter appeared to be dying, so I relied on my intuition and took a chance since I knew if I didn't do something I was going to lose my little guy. It worked. I can't find the link now since I went down the rabbit hole for two days following link after link in different studies on HE, but that one particular study struck a chord in me. Anyway, I just wanted to Thank You again and let you know that Hunter is doing great now.
Thank you for the links, Dr Turner. I didn't realize this kind of help can be available to pet parents!
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