Does Certain Dog Food Cause Elevated ALT Levels?

Whether it's a matter of keeping an eye on Pal's organ function as he ages, or he's been under the weather, blood tests are a good gauge on how things are working internally. Alanine aminotransferase, or ALT, is part of a routine blood panel and tells the vet how your pup's liver is working.

ALT is a liver enzyme caused by leaking or injured liver cells. The normal ALT level in a healthy dog is between 5 and 107 u/L. If the vet sees an elevated ALT, liver or bile duct disease will be considered the prime suspects. There are other reasons for an elevated ALT, including exposure to poisons or toxins, diabetes, hyperthyroidism, pancreatitis and severe body trauma. Dog food on its own isn't considered a culprit when it comes to causing a high ALT.

As in humans, your dog's liver processes waste. When he digests his food, the undigested portion will ferment in his gut, increasing bacteria and producing excess ammonia. The extra ammonia is absorbed into his body, and if his liver isn't functioning properly, that means toxins in his bloodstream. If his ALT level is elevated, the additional stress his liver is experiencing from his diet may contribute to his higher value.

If Pal's liver isn't functioning as it should, his diet may need to be adjusted, depending on what's ailing him. The vet may recommend a diet that gives your pup the nutrients and calories he needs without putting too many demands on his liver. A special diet often includes protein restrictions, including limiting protein and substituting high-quality, nonmeat protein sources, such as eggs and dairy products. Carbohydrates, minerals, vitamins and fats also may be regulated, and if your dog is retaining excess fluid, his sodium should be restricted.

For the dog with hepatic encephalopathy -- liver disease producing high amounts of ammonia and other toxins in the dog's blood -- high levels of protein can cause symptoms such as incoordination, behavior changes, drooling and disorientation. Restricting protein is particularly helpful for a dog with hepatic encephalopathy to help minimize ammonia.

If Pal's blood test showed an elevated ALT level, yet he hasn't been diagnosed with liver disease, don't panic. Pay attention to his behavior and look for symptoms, such as weight loss and loss of appetite, vomiting or nausea, increased thirst and urination, diarrhea, lethargy and a bloated appearance. Depending on your dog's age and medical history, the vet may order more tests to help pinpoint the cause of the higher ALT. Otherwise, it may be a matter of testing later to see if the value maintains its level.