Q: I have a 3.5 year-old, male ferret. The only illness he has had was a possible ulcer eight months ago, but he responded to treatment and was fine. About three weeks ago all he would do is sleep. He was very lethargic. He would get up, eat a little, take a few sips of water and then go back to sleep again. I took him to the veterinarian and he was tested for insulinoma, but it was negative. His blood test showed elevated liver enzymes. We redid the test last week and it shows the liver enzymes have risen again. My vet is stumped. He is considering an ultrasound and a procedure that uses a needle to take a few cells from the liver. Since last week, though, my ferret is completely back to normal. He is playing, eating, drinking and going to the bathroom like he did before. It is like he had a bug and is now over it. The only worry is the elevated liver enzymes. Do you have any idea what my vet should look for or what we should do?
A: Your veterinarian has made some excellent suggestions for your ferret. The liver has many functions and can be affected by numerous conditions including infections, toxins and cancer. Many of these conditions cause different degrees of liver dysfunction that vary from mild changes to fatal liver failure.
In the early stages of liver disease, there may be no way to discern which type of condition is present in your ferret without some slightly invasive diagnostic testing. Liver analytes (sometimes called enzymes) on the biochemistry panel can alert us that the liver is not healthy, but this cannot tell us exactly what is causing the liver dysfunction. Radiographs can tell us if the liver is enlarged but not what is causing the enlargement.
In extremely severe liver dysfunction, the liver is unable to remove and eliminate contaminates from the bloodstream. When these contaminates reach a high enough level in the bloodstream, a ferret becomes very sick and the skin and membranes take on a yellowish hue. At that point, the liver is so unhealthy that it can be difficult to reverse the course of illness. Therefore, the goal of veterinarians is to make a diagnosis during the early stages of liver disease and begin treatment so the liver can regain most, if not all, of its previous function.
An abdominal ultrasound reveals much about the changes to the appearance of the liver but not exactly what is causing those changes. By inserting a very thin needle into the liver, using ultrasound to guide its placement, it is possible to remove hundreds of thousands of liver cells and view them under a microscope to aid in making a diagnosis.
Your question, though, is a very good one. If your ferret is improving, should you do this test? A needle, albeit a very thin one, will be inserted into your anesthetized ferret, which is a risk, although a very small one. The easy way to answer your question is that ferrets have a remarkable ability to adapt to illness and they can appear to be well even if they are still sick. I suggest that you revisit your veterinarian and if he/she feels there is still a danger of liver disease, then it makes sense to do the liver test to make sure the disease is not still present or has progressed.