Like humans, the liver is a vital organ for a canine too, which performs a number of functions. It detoxifies and eliminates toxins that enter the bloodstream. The liver also produces bile to break down fat, and plays a vital role in maintaining the immune system. If the liver is in any way affected, whether by disease or diet, it can cause serious health problems for your pet. One reliable indicator of liver trouble in canines is an increase in levels of liver enzymes. ALT (Alanine aminotransferase) or SGPT (Serum glutamic pyruvic transaminase) is an enzyme found in the liver and its levels often rise due to liver infections. Another such key enzyme is AST (Aspartate aminotransferase)

Symptoms
Some of the symptoms of elevated liver enzymes in dogs are:
  • Vomiting: Dogs can vomit to remove undigested foods, or if they eat something they shouldn't. However, a pet owner must be careful to distinguish between these natural vomiting bouts and something more serious, like a stomach infection.
  • Diarrhea: This can be a symptom of a serious disorder, and the dog must be given immediate medical attention.
  • Anorexia: Dogs may occasionally skip meals or act up at the sight of food. This may be due to stress or other socio-environmental factors, yet if it continues to do so over a period of time and loses weight, it is a cause for concern, and may point toward liver diseases such as jaundice.
  • Bleeding disorders: Blood disorders in dogs, such as Von Willebrand's Disease, can hamper the process of blood clotting, and even small cuts and bruises may bleed copiously.
  • Lethargy and sluggishness: If your dog breaks from its normal routine of physical activity and begins to laze around the house, this may be a symptom of liver disease. Insomnia is another warning sign that your dog is facing health issues.
Causes
There are several reasons why liver enzymes in dogs shoot beyond normal levels. The most common causes are diseases, but the levels can also increase due to steroids or other anti-inflamatory drugs.
  • Jaundice: Bilirubin is a waste product formed due to the breakdown of hemoglobin. A weak liver is unable to remove this compound and it accumulates in the body, becoming toxic to a dog's health. A result of this malfunction of the liver is jaundice. The accumulated bilirubin causes yellowing around the whites of the eyes and the gums.
  • Pancreatitis: Tests for enzyme levels may indicate elevated levels of Gamma-glutamyltransferase (GGT). This enzyme is mostly concentrated in the pancreas and the kidneys. Pancreatitis or obstruction in the bile duct, can lead to an increase in the levels of GGT in the liver.
  • Infectious Hepatitis: This is a contagious disease of dogs caused by a DNA virus known as canine adenovirus 1 (CAV-1). This virus is transmitted to a healthy dog through saliva, urine or feces of an infected dog. Even after a dog has been cured of the disease, it may retain the virus for 6 months.
  • Cushing's Disease: More accurately referred to as Hyperadrenocorticism, it causes an increase in production of the adrenal hormone in the body. There are two types of Cushing's disease, Pituitary-dependent and Adrenal-dependent Cushing's. In the former, there is a tumor in the adrenal gland leading to the overproduction of the hormone cortisol, while the latter is caused by a malfunction of the pituitary gland. Dogs afflicted by this condition often experience hair-loss, increased appetite, and a distinct pot-bellied appearance. In such dogs the enzyme ALT (Alanine aminotransferase) can be elevated, because the liver is trying to purge the excess cortisol from the system.
Dietary Remedies
Medication for treating symptoms due to elevated liver enzymes will be prescribed by the veterinarian after diagnosing the problem. The vet may also suggest modifications to your dog's diet. The medicines and changes in dog's food aim at helping the liver to recover from damage caused due to the disease. As far as diet is concerned, a dog should be given less of proteins and fats, since they increase the liver's workload. Ensure that the canine eats food with low levels of sodium, as to lower the risk of fluid buildup in the abdomen due to high blood pressure in the blood vessels of the liver.
  • Protein intake: Make sure that the protein intake is of high quality. Although protein is difficult to digest for the liver, it is important for building new healthy liver tissue. High quality protein is easy to digest as compared to low quality proteins that produce ammonia when digested, which the liver can't filter easily. Plant-based proteins (soy) and dairy-based proteins are recommended. Tofu, yogurt and non-fat cheeses are also recommended sources of protein. They are easy to digest and help the liver fight infection.
  • Vegetables: Some good sources of vitamin and protein are vegetables such as spinach, green peas, broccoli and beans. Fiber present in vegetables can enhance elimination of toxins from the dog's system.
  • Carbohydrates: Along with proteins, feed your dog high quality carbohydrates that are, again, easy to digest. Some sources of good carbs are brown rice, kidney beans, potatoes and oatmeal.
  • Dietary supplements: Milk thistle can be given to a dog as a dietary supplement. Milk thistle performs the dual task of aiding in liver cell regeneration and protecting the liver by eliminating toxins. Standard dosage of milk thistle is 200 mg twice or thrice daily. Milk thistle can be obtained in the form of capsules or liquid that could be mixed with the pet's food. However, alcohol-based milk thistle should be avoided. The vet will usually prescribe a course of antibiotics along with supplements of vitamin K.
As the liver functions in coordination with the other organs of the body, high liver enzymes in dogs can be caused by problems of the liver or even due to natural cell death in the liver. The liver has strong regenerative capacity. So, dog illnesses caused due to disease or damage to the liver can be cured with prompt and proper medical attention.