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Did your vet recently run routine bloodwork on your furry friend and find elevated liver enzymes? What does this mean? In many cases, increased liver enzyme levels in dogs are mild and tend to resolve on their own. Unfortunately, that’s not always the case. Raised liver enzymes are not a standalone condition. However, they can indicate liver damage or disease or several other underlying health issues.
Be patient with your veterinarian because it can take some time for them to determine what’s causing these abnormal blood test results. And not all vets explain this well when delivering results. So, I’ll help you understand what elevated liver enzymes could indicate, what further diagnostic tests may be needed, and what possible treatments are available.
What Does The Liver Do?
First, knowing the liver’s role is essential to understand why elevated enzymes could be a potential warning sign. A dog’s liver works much the same way as it does in humans. In a nutshell, it does a lot to keep the body healthy. The liver is a vital organ, and when healthy, it’s responsible for:
- Removing toxins from the body
- Storing vitamins
- Metabolizing energy
- Creating bile to aid digestion
- Breaking down medications for the body to absorb them properly
- Producing certain proteins that enable blood clotting
Increased liver enzymes can sometimes indicate that the liver isn’t functioning as it should. However, this doesn’t automatically mean there’s a specific liver disease present. Rather, it highlights a potential problem within the liver that requires further investigation to determine the underlying cause.
Raised liver enzymes are like a flag or warning from the liver that something is going on. They are not all that specific and only indicate that some cell damage has occurred. Further investigations are required to work out the underlying cause of this. The exact tests recommended will often depend on the rest of your pet’s initial blood work, physical exam, and history.
– Dr. Rebecca MacMillan, BVetMed, BSAVA, PGCertSAM, MRCVS, a veterinarian and surgeon at a small animal clinic in the United Kingdom
What Causes Elevated Liver Enzymes In Dogs?
Many factors can cause elevated liver enzymes in dogs. It doesn’t necessarily mean that your pup has liver disease or liver failure. Sometimes, it’s a one-off of a random blood test. In other cases, it’s due to infections, medications, toxins, and underlying health conditions. Identifying the underlying cause is key to developing an effective treatment plan. According to the Merck Veterinary Manual, here are the many causes.
Diseases
Several diseases or developmental abnormalities can cause elevated liver enzymes in dogs, indicating signs of early-stage liver problems. These include:
- Diabetes mellitus: occurs when the pancreas fails to produce enough insulin to regulate glucose (sugar) in the blood
- Cushing’s disease: occurs when the adrenal glands produce too much of the hormone cortisol, which can damage organs
- Pancreatitis: an inflammation of the pancreas that can result in the release of enzymes and toxins into the bloodstream, which can then affect other organs, including the liver
- Hyperthyroidism: occurs when the thyroid gland overproduces thyroid hormones, which increases the metabolism and puts stress on the liver and other organs
- Liver cancer: Although liver cancer only affects 1% of dogs, it can be a cause of increased liver enzymes
Medications
Certain medications, such as steroids like prednisone and some antiseizure drugs like phenobarbital, can lead to increased liver enzyme levels. Nevertheless, your veterinarian will take into account the risk of liver damage when prescribing these medications and will keep an eye on your dog for any indications of reduced or changed liver function.
Toxins
Various toxins can lead to elevated liver enzyme levels and may also result in severe liver damage or failure. Among these harmful substances are heavy metals, specific herbicides, fungicides, insecticides, rodent poisons, aflatoxins produced by mold, amanita mushrooms, Sago palm ornamental plants, blue-green algae, and acetaminophen.
Infections
Various infections can lead to an increase in a dog’s liver enzymes, and if not addressed appropriately, some of these infections may result in liver disease or even failure. Unfortunately, dogs can be susceptible to a range of infections that impact liver health. These include:
- Viral: Infectious canine hepatitis, also called canine adenovirus (CAV-1), is a highly contagious virus affecting your dog’s liver, kidneys, spleen, lungs, and eyes.
- Bacterial: Leptospirosis* is caused by a dog ingesting or coming in direct contact with the bacteria Leptospira, which is spread in the urine of infected animals and can survive in soil or water for weeks to months. Other types of bacterial infections that can affect the liver include Tyzzer’s disease (caused by Clostridium piliforme) and tuberculosis (caused by Mycobacterium species).
- Fungal: The most common fungal infections associated with liver dysfunction are coccidioidomycosis (Valley Fever), caused by the inhalation of fungal spores from contaminated soil, and histoplasmosis, caused by ingesting or inhaling the fungus Histoplasma capsulatum, which is found in soil contaminated with bird or bat droppings.
- Parasitic: Toxoplasmosis is caused by a parasite called Toxoplasma gondii (T. gondii). Dogs can become infected by eating affected cat feces, contact with soil or litter containing the parasite, and ingesting infected raw or undercooked meat (especially from pigs, rodents, or birds).
* Vaccinations are available for both CAV-1 and leptospirosis.
Genetic Predisposition For Liver Disease
Certain breeds have a genetic predisposition for different forms of liver disease. If your pup has increased levels of liver enzymes and is a breed prone to liver disease, your veterinarian will take this genetic factor into account.
Copper-Associated Hepatopathy (CAH)
Copper storage disease is a condition where excessive copper accumulates in the liver, leading to liver damage. It is one of the most common causes of chronic hepatitis. Adding zinc to the diet may help to protect the liver by preventing the absorption of copper from the gut in these cases. Copper storage disease is a known problem in Bedlington Terriers, Dalmatians, Doberman Pinschers, Skye Terriers, and West Highland White Terriers.
Chronic Hepatitis
Chronic hepatitis is a long-term inflammation of the liver and has other causes than copper storage disease. In addition to the breeds affected by copper, other breeds of dogs predisposed to this chronic hepatitis include Chihuahuas, Cocker Spaniels, Labrador Retrievers, Maltese, Springer Spaniels, and Standard Poodles.
Portosystemic Shunt
A portosystemic (liver) shunt involves an abnormal blood vessel (or vessels) that causes the blood to bypass the liver when it should be going through it. Nearly 80% of cases are due to a congenital (birth) defect, and breeds most prone to this developmental disorder include Australian Cattle Dogs, Cairn Terriers, Golden Retrievers, Irish Wolfhounds, Labrador Retrievers, Maltese, Miniature Schnauzers, Old English Sheepdogs, and Yorkshire Terriers.
Other Breed-Specific Liver Conditions
- Shar-Peis are prone to amyloidosis, a disease caused by the buildup of abnormal protein deposits (amyloid) in the liver.
- Scottish Terriers are predisposed to a breed-specific form of vacuolar hepatopathy, a liver condition characterized by the presence of small fluid-filled spaces within the liver cells.
- Miniature Schnauzers and Beagles are commonly affected by familial hypertriglyceridemia (FHTG), a genetic disorder characterized by elevated levels of triglycerides in the blood.
- Shetland Sheepdogs, Cocker Spaniels, and Miniature Schnauzers have a genetic predisposition to gallbladder mucocele (GBM), an abnormal accumulation of bile within the bile ducts leading to liver inflammation, elevated liver enzymes, and other problems.
What Foods Can Cause Elevated Liver Enzymes In Dogs?
A dog’s daily diet of a complete and balanced dog food isn’t a common cause of elevated levels of liver enzymes, but it can occur. For example, if your pup eats something high in fat before getting their blood tested, this could cause levels to temporarily rise.
However, some human foods are toxic for dogs and can cause moderate to severe liver problems. These include anything with xylitol, a sweetener found in peanut butter and baked goods, grapes, raisins, chocolate, pistachios, almonds, walnuts, and more. If you share peanut butter with your pup, be sure it’s dog-friendly.
It’s also important to note that over-supplementing some vitamins and minerals, like iron, vitamins A and D, and copper, can cause liver problems. For this reason, you should always consult your veterinarian before giving your pup any supplement, even something as simple as a multivitamin for dogs.
Symptoms Of Elevated Liver Enzymes In Dogs
Elevated liver enzymes don’t have signs per se; it’s the underlying condition that causes symptoms. Many dogs don’t show signs of liver problems in the early stages, or they’re very nonspecific (minor weight loss, reduced appetite, occasional vomiting). Once liver problems progress, the most common symptoms include:
- Lethargy
- Loss of appetite
- Vomiting and/or diarrhea
- Increased thirst and urination
- Jaundice (yellowish coloring to appear in a dog’s eyes, gums, skin, and ears)
- Confusion
- Seizures
Early detection and intervention are key to helping your pet’s liver recover and function properly. If you notice any signs that your pup doesn’t seem like themselves, contact your veterinarian to fully assess your furry friend’s liver health. With early diagnosis and treatment, liver disease is manageable. After all, the liver has the amazing ability to repair and regenerate itself.
Diagnosis: Determining The Cause Of High Liver Enzymes In Dogs
Finding elevated or high liver enzymes in dogs is as simple as a blood test measuring specific liver enzyme levels in the bloodstream. While not always a standard part of every routine vet visit, vets can and often do check liver enzymes ALT (alanine aminotransferase) and ALP (alkaline phosphatase). However, some also check AST (aspartate transferase) and GGT (gamma-glutamyl transferase) liver enzymes, particularly if a dog exhibits signs of illness.
If your pup isn’t showing any symptoms, a veterinarian may prescribe a trial of antibiotics in case of infection, antioxidants (e.g., vitamin E, Denamarin), or ursodiol (a medication that has anti-inflammatory, antioxidant, and liver protectant properties) for a few weeks, according to Veterinary Partner. If levels don’t improve after a re-check, further diagnostics are needed.
“When I find raised liver enzymes in a patient, I need to start doing some detective work,” says Dr. MacMillan. “The cause could be primary liver disease, but it could also be the liver’s reaction to other things going on in the body, such as heart disease or endocrine disease (hormonal issues). Each case is different. Over the years, I have seen the initial finding that raised liver enzymes lead to the diagnosis of a whole variety of conditions.”
Further Diagnostic Testing
Based on your pup’s medical history, liver enzyme results, and any clinical symptoms, veterinarians have many diagnostic tools they use to get to the bottom of what’s occurring with your dog. Further tests could include a dynamic blood test called a bile acid stimulation test. This involves taking a fasted blood sample and then another sample a couple of hours after the dog has eaten to see if the liver is functioning effectively.
“Sometimes I need to run other blood tests if I’m suspicious of infectious diseases, pancreatitis, or endocrine disorders such as Cushing’s disease,” Dr. MacMillan shares. “I also ask owners careful questions about a dog’s care if their symptoms make toxicity likely. This is why you must tell your vet immediately if you suspect your dog has eaten something they shouldn’t have.”
Dr. MacMillan says diagnostic imaging is also valuable for determining liver disease. “X-rays can give us an idea as to liver shape and size, but in my experience, ultrasound scans are often more useful, particularly when we want to look at the liver tissue and the gallbladder in more detail,” she explains. “Some conditions can only be diagnosed through a liver biopsy. This may be done at the same time as an ultrasound scan. A sample of liver tissue is obtained and sent to the lab for analysis. This can help to diagnose conditions such as copper-associated hepatopathy (CAH) and chronic hepatitis.”
Treatment Of Elevated Liver Enzymes In Dogs
The approach to treating elevated liver enzymes in dogs varies based on the root cause of the issue. For example, treating endocrine diseases, infections, toxicity, and a liver shunt may require different approaches than treating ongoing liver disease. Your veterinarian will discuss your dog’s treatment options based on their findings. Below, I’ve highlighted some common treatment protocols for liver disease.
Treatment of chronic hepatitis can be complicated to explain; it’s determined by the severity, type of disease process, and clinical symptoms. In severe situations, hospitalization, intravenous fluid therapy, and supportive care might be required. Anti-inflammatory drugs are most frequently prescribed, but other medications may be necessary depending on the existence of concurrent problems. Certain patients may require dietary changes.
For dogs diagnosed with copper-associated hepatopathy, treatment options include d-Penicillamine, a medication that binds excess copper in a dog’s body so it can be excreted in the urine, zinc therapy before meals, and/or a prescription diet that’s low in copper and high in zinc, such as Hill’s Prescription Diet l/d Liver Care or Royal Canin Veterinary Hepatic.
Supplementation
Veterinarians may also recommend supplementation, depending on the case. However, it’s crucial to follow your vet’s treatment plan. In some cases, liver supplements may be harmful to certain dogs. Always get your vet’s approval before giving your pup any supplement. Common liver supplements include:
- S-adenosyl methionine (SAMe) — an antioxidant that supports healthy liver function
- Silybin (milk thistle extract) — helps reduce inflammation and prevent liver damage
- Denamarin — includes s-adenosyl methionine (SAMe) and silybin
- S-acetyl-glutathione (SAG) — another antioxidant that supports healthy liver function
Prevention
Not all causes of high liver enzymes can be prevented. However, the best things you can do for your pup are to ensure they’re getting a complete and balanced diet that meets AAFCO guidelines, sufficient exercise, and regular vet checkups.
- Consider an all-natural dog food that contains no artificial ingredients or preservatives and nutrient-rich foods such as lean proteins, whole grains, fruits, vegetables, and omega-3 fatty acids.
- Be sure to vaccinate your dog against diseases such as infectious canine hepatitis and leptospirosis.
- Avoid any human foods that are toxic to dogs.
- Make sure any toxic plants in your garden are fenced off, or houseplants are kept out of reach of your dog.
How Pet Insurance Can Help
Our furry friends can develop unexpected illnesses or encounter accidents (like ingesting something toxic) at any time. Obviously, this isn’t limited to liver problems. Many of these health problems can cause pet parents significant worries about their pet’s health, and how they will afford necessary vet care. Liver disease and many other chronic health issues can cost thousands of dollars over your dog’s lifetime.
This is why pet insurance is a sound investment for your finances and your pup’s health. By covering a significant portion of your vet bills when things go wrong, pet insurance can save you from deciding between your budget and your dog’s health care needs. See our article about whether pet insurance is worth it to learn more. We also have a dedicated article recommending the best pet insurance providers.
Why Trust Canine Journal?
Sally has over 20 years of experience in human health sciences communications, including 10 years as an expert on pet health conditions and treatment. She’s also spent over a decade researching pet insurance as part of an expert team at Canine Journal. As dedicated canine professionals and long-time dog owners, we test and research the best pet products, not only for our own pups but for all of our readers.
