What To Do When Your Dog Or Cat’s Liver Tests Are High

Ron Hines DVM PhD

  Liver Disease Treatments On The Horizon?

The blood test results most indicative of a potential liver problem in your pet are elevations in its ALT,   AST,   GGT, and ALP enzyme levels. It’s not that unusual for one or more of these tests to be a bit high but for your dog or cat to appear healthy. Those moderate elevations of one or two enzymes are often picked up in “wellness” checkups or yearly health checkups your veterinarian suggests.

The first thing you need to understand is that although we associate these enzymes with your dog and cat’s liver, there are many non-liver health issues that will also cause these enzyme levels to rise above normal. Things like pancreatitis in your dog or in your cat, infections like leptospirosis,   gall bladder disease,   portosystemic shunts, intestinal disease or a failing heart. Medications (such as corticosteroids), anti-seizure medications such as phenobarbital  (read here) or NSAIDs, such as Rimadyl®, that your pet might be taking can also be responsible. So can herbal supplements. (read here) Transient unidentified processes not associated with organ disease can cause moderate, temporary elevations in these tests as well. So, my approach is to retest these pets in 4–6 weeks. Many times, the second round of tests will be normal.

If your dog or cat’s liver tests are still elevated, a bile acids level test and ultrasound examination are probably in order. If the bile acids test is high, your veterinarian might place your pet on a trial course of antibiotics and most likely throw in some “liver support” products like Denamarin® or Denosyl®. They might even suggest a prescription diet such as l/d®’s Liver Care™ or Royal Canin’s Hepatic™ with the suggestion to repeat the blood test in 4–7 weeks. There is certainly no harm in giving all those unproven products a try.   

When none of those options solved your pet’s problem, your veterinarian will want to determine if your dog or cat’s underlying issue is indeed in its liver or somewhere else. Symptoms such as jaundice (icterus or yellowish skin), fluid buildup in the tummy (ascites), a mass or lump felt in the liver or seen on x-rays or any changes in the pet’s mental state (ie hepatic encephalopathy) make a primary liver problem likely. I believe that at that point most veterinarians would suggest that a fine, long needle be entered, under anesthesia, through your pet’s body wall. While guided the needle into the liver using ultrasound or a laparoscope, a tiny plug or snippet of liver tissue (a biopsy specimen) would be collected. That tissue would be sent to a veterinary pathologist to determine what abnormalities were present in the liver at a cellular level. An alternative when an abnormal liver mass (lump) is detected might be a fine needle aspirate. Cats with lymphoma involving their liver can often be diagnosed by identifying the malignant lymphocyte cells in a fine needle aspirate of its liver. see here

What Treatment Options Might Help My Dog or Cat When It’s Liver Fails?

I mentioned that veterinarians (and physicians) have no cure for chronic liver failure. Chronic liver disease is progressive and what we can attempt to do is slow the rate of decline. There is one exception. It is when your pet’s liver is not receiving enough blood due to restrictions in its hepatic artery or portal vein. Sometimes those restrictions can be corrected surgically. Sometimes they can’t. (read here) When liver failure occurs suddenly due to another underlying disease, exposure to a toxic product or unexpected reaction to a medication, the signs you see in your pet are dramatic. The most obvious ones are a lack of interest in eating and jaundice. But in more gradual liver disease, your pet’s naturally large and unused reserve of liver cells (hepatocytes), must be reduced by more than 70% before clinical signs of liver failure become apparent. Those are the cases that your veterinarian’s yearly blood tests will hopefully pick up on (detect) before you do. Unfortunately, treatment options for your pet in both those situations have not advanced significantly since the 1980s and 90s. (ask me for Hughes1995) 

Optimal Nutrition

Veterinarians have not determined what the best diet is for cats or for dogs on the road to liver failure. But for now, I would avoid feeding your pet diets that contain soybean oil or soy beans and increase your pet’s consumption of fish or krill oil rich in omega 3 fatty acids. I suggest   that you buy those product that are intended for us humans because quality control of products intended to be consumed by people tends to be considerably more rigid (better) than those distributed through veterinary channels. (read here & here) The problem is that fish oils very quickly become rancid (oxidized) and liver toxic. The bottle labels of the most trustworthy fish and krill oil supplements contain the IFOS™ logo.

Veterinarians sell “Liver Care” diets. I do not know of any worthy studies that show that these products increase the lifespan of dogs and cats with liver disease when compared to high-quality cat and dog diets purchased in stores or online directly by you. The only exception is the amount of copper in these “Liver Care” diets is lower. Copper is an essential nutrient. (read here) But the actual amount of copper required in a dog or a cat’s diet has never been determined. A copper deficiency has actually been associated with liver problems. (read here)

Canine “Liver Care” diets reduced their copper content based on a small subset of dogs in which elevated liver copper content due to a gene defect appeared to be the cause of their liver failure. (read here) More recently, veterinarians at Davis found that high liver copper content was associated with liver failure in dogs. (read here) However, if the high liver copper content they found was the cause – or perhaps the result of liver disease, they did not determine.

The liver is the main natural storage site in the body for copper. Any obstruction to bile flow or reduced bile production due to liver disease is known to raise liver copper levels. If these diets followed recent liver research more closely, egg white albumin, not chicken, would be their source of protein and soybeans protein & soybean oil, would be excluded. Many dogs and cats with advanced liver disease have low blood albumin levels. Unfortunately, very little albumin can be absorbed intact when eaten. (read here   or ask me for Miner-Williams2014,   here and here) However, egg whites contain all the correct amino acids to reform albumen once absorbed. (read here, &  here)  Incidentally, I would not feed egg products, or meat products for that matter, raw to dogs or cats with serious health issues. (read here)

Your Pet’s Feeding Schedule

You are always safer feeding pets with liver issues small meals throughout the day to minimize their liver workload. Entyce® might also be helpful in that respect. It is similar to a portion of the growth hormone molecule (GH). GH has positive effects on the liver. (read here)

A Fecal Bacteria Transplant

I mention on my website that “good bacteriain the intestines are thought to prevent or slow liver disease. That is at least true in humans and experimental animals. However, the commercial products that you can readily purchase in stores and from veterinarians do not contain the same bacteria that were found to be helpful. Those positive bacteria are too fragile to persist in manufactured products. The best source of those helpful bacteria that your pet might be deficient in is close contact with a healthy, and perhaps younger pet of the same species – a shared food and water bowl is sufficient. (read here)

We know that the number and types of bacteria and other microscopic inhabitants of your pet’s digestive tract change when its liver begins to fail. But as with copper, we do not know if this change is one of the causes of liver failure or if it is the result of liver failure. In any case, transferring fecal bacteria from a healthy individual to an individual with liver problems (a fecal microbiota transplant) appears to be helpful in humans and experimental animals. (read here,   here,   here,   here and   here)

Medications Based On Abnormal Laboratory Test Results

Many pets with failing livers are anemic. That can be due to a tendency toward internal bleeding (a long PT time and/or low thrombocyte count). A healthy liver produces important blood clotting hormone, thrombopoietin. Your veterinarian might suggest a hematinic, one containing iron and folic acid. If so, give it as instructed in the dose suggested. Too much oral iron is toxic. (read here) Avoid feeding vegetarian pet foods or high grain or soybean-containing diets. They contain phytins. which block the absorption of iron and other trace minerals. (read here) If the anemia is suspected to be caused by intestinal bleeding, antacids and perhaps vitamin K injections might be suggested as well.


If diagnostic tests indicate that the liver problem is due to a bacterial infection, such as leptospirosis, antibiotics, such as doxycycline or the penicillin class of antibiotics are often curative. If an underlying toxoplasma infection is suspected, the antibiotic of choice is often clindamycin or sulfamethoxazole with trimethoprim. However, both drugs must be used with caution when liver disease is present.  Even after bacteria are eliminated, lingering liver and kidney damage can remain.

Some dogs and cats with liver failure appear to be helped by other antibiotics such as amoxicillin/clavulanate or oral neomycin. If this is because of its effects on secondary infections that occur due to their immune system’s weakness due to its effect on the composition of the bacterial flora of their digestive tract is unknown. Whichever the case, improvements due to antibiotic administration can be temporary because bacteria eventually become resistant to most medications. They appear to be most effective in reducing or eliminating the signs of hepatic encephalopathy that often accompanies late stage liver disease. 

Intestinal Protectants

When your veterinarian suspects that hepatic failure has allowed blood ammonia levels to become too high, your vet might prescribe lactulose. It has no direct effect on the pet’s liver, but is often effective in reducing body ammonia levels. If secondary intestinal ulcerations leading to anemia or lack of appetite is present, sucrafate is often prescribed to reduce digestive tract acidity. There are more effective antacids, the ones ending in *****zole   or ***dine, but all of them can have negative effects on the liver.

Silibinin, AKA Silybin, AKA Silymarin, AKA Milk Thistle Extract

These “Liver Health” products go by many names. I’ll call the first silymarin because that’s the name under which it is marketed to pet owners. Wikipedia calls it silibinin. In their sub-page on the plant it is extracted from, they mention that silymarin has never shown clinical evidence that it has any medicinal effect and that medical articles that claim that it does are of poor quality. (read here) Silymarin is said to be an antioxidant. Physicians in the underdeveloped world tout and dispense this product considerably more frequently and for a wider variety of illnesses than physicians located in areas where more sophisticated medical options are widely available. In areas of the world that rely on (liver failure, gallbladder disorders, diabetes, high LDL cholesterol, high blood sugar, increase breast milk flow, prevent cancer, treat cancer, treat snake bites, prevent sour stomach, slow aging, prevent Alzheimer’s disease, treat Parkinson’s disease, treat trichotillomania, reduce inflammation, “neuroprotection”, prevent osteoporosis, treat acne, prevent skin cancer, dark spots, wrinkles, lines and skin discoloration, treat hangovers, treat pathological gambling and other compulsive disorders) There is no agreed upon what a standard dose should be. Silymarin has been consumed for medical purposes for a long time, at least since the time of Pliny the Elder.

SAM, AKA SAMe, AKA S-Adenosylmethionine

SAMe or S-Adenosylmethionine is a derivative of an essential amino acid, methionine produced in the body with the aid of folic acid (folate). Animals, including dogs, cats and humans cannot form methionine, they must consume it in their diets. SAMe takes part in a wide variety of metabolic activities (read here)

Some that market the product refer to it as a “neuroprotector”. They suggest people consume it to treat mood, joint and liver problems, depression, anxiety, fibromyalgia, schizophrenia, and dementia and for general “brain health”. Despite its widespread use, no well-designed scientific studies confirm its effectiveness in treating any of these conditions, nor that consuming large amounts of it are without risk. (read here)   Despite SAMe being heavily marketed, a 2001 Cochrane study of the usefulness of SAMe concluded with: “We could not find evidence supporting or refuting the use of SAMe for patients with alcoholic liver diseases”. (read hereA repeat analysis of SAMe’s usefulness in 2006 came to the same conclusion. (read here) Now your dog or cat did not have alcohol consumption as the underlying cause of its liver issues. But hepatocytes destroyed by any disease all lead to the same results – a lack of functional hepatocyte liver cells.

These products are sold under various names. The companies marketing them tend to give them glowing reviews and unique names and often make the generic names of their ingredients difficult to quickly locate on their labels or advertisements. Most include somewhere in their advertisements that their products are scientifically proved and in one way or another better than their competitor’s products.

I see no harm in giving any of these products when used as directed. But I have doubts as to their effectiveness. If your pet’s blood bilirubin (direct bilirubin = conjugated bilirubin = liver-processed bilirubin) level drops after consuming them. Or if its blood albumin level rises toward normal. Or if prothrombin time decreases, or if its total blood protein content rises toward normal. Of if its jaundice resolves, Please let me know, and I will let other readers know by adding your report to this page. 

Dealing With Excess Ammonia Buildup In Your Pet’s Blood Stream

Hepatic encephalopathy and cognitive dysfunction often accompany advanced liver disease. You can read about treatment options for your dog and cat here.

Neurological Issues

Seizures sometimes occur in liver failure. They can be the result of high ammonia levels or low blood sugar. When they are an issue, pets are often given levetiracetam.

When people develop sudden liver failure, it is often the result of consuming large quantities of acetaminophen/aka paracetamol (Tylenol™). The specific treatment for them when caught early is N-acetyl cystine (NAC).  Should that be suspected to have happened in your cat or your dog, an emetic to induce vomiting, a gastric lavage,   activated charcoal and perhaps large volume high enemas; as well as NAC would be the treatments of choice.

You are on the Vetspace animal health website

Visiting the products that you see displayed on this website help pay the cost of keeping these articles on the Internet.