Liver and Gall Bladder Problems in Cats 2

also see Renal failure also see Cholagiohepatitis/Hepatitis also see Triad Syndrome also see Hepatic Lipadosis also see Kidney Disease also see Urinary Problems also see Diabetes

also see Cat Liver

also see Liver and gall bladder problems in cats

Feline Liver Disease Q: We have a 16 yr. old cat with diagnosed health problems. An initial thyroid condition was recently improved to a level 1.5 reading after 3 wks. of Tapazole dosage (5mg daily). Our cat had not been active or showing much signs of an appetite prior to this and had dropped to 5.25 lbs. (vs. 8 lbs normally), but has shown imrovement as a result of the medication. The local vet would like to now do a biopsy due to elevated readings on ALP (373) and ALT (489). In light of the extreme levels of both tests and the age of the cat, we are wanting to know what the chances are for treatment and a return to a normal, painless life. What type of biopsy would you recommend, and what are the risks from anesthesia, etc.? Also, the vet wants to perform an ultasound, is this necessary in conjunction with the biopsy in your opinion? The initial thoughts are that the liver condition might be one of three things: 1)Colangeo Hepatitis, 2)Fatty liver, or 3)Tumor. What are your overall thoughts and recommendations. We love our cat very much and we are willing to do what is neccessary to help her, but we also do not want to see her suffer or be prolonging her life when it may naturally be near its end. Thanks very much for your help. -New subsciber A: Mark- There is a critical bit of information that I can't tell from your email. Were your cat's liver enzymes normal prior to the administration of methimazole (Tapazole Rx)? While it is not the most common side effect there is not much question that Tapazole can cause liver toxicity in some cats. The elevations in liver enzymes can occur very rapidly and side effects such as lack of appetite, lethargy or vomiting can follow the rise in liver enzymes pretty quickly, as well. If labwork for liver values was not done prior to administration of Tapazole or if they were normal prior to administration of Tapazole, the first thing to consider is stopping the drug. There are alternative treatments for hyperthyroidism which may be necessary to use if your cat does not tolerate Tapazole. If there is reason to believe that the liver disease is not related to the administration of Tapazole (i.e. --- there was lab work to show it might be a problem prior to administration of Tapazole), then liver biopsy makes a lot more sense at this point. If ultrasound examination is possible it can be very useful in determining if a tumor is present and if so, in helping with determining where to take the biopsy sample and in increasing the safety of biopsy techniques such as needle biopsies. It isn't possible to tell you if the Tapazole is the problem but it should be very high on the list of suspicions at this point. When Tapazole does cause liver toxicity the cat usually improves rapidly once the medication is withdrawn. (There is a good section on using Tapazole in Kirk's Current Therapy XI). Radioactive iodine therapy is considered to be the safest treatment for hyperthyroidism at this time and surgery is an acceptable option if radioactive iodine therapy isn't available or is too expensive to be an option. Please call your vet and discuss the possibility that the liver problems are related to the Tapazole. Hepatic toxicity is reported to occur in 4% of cats treated with Tapazole in the Current Therapy XI chapter. Mike Richards, DVM 3/4/99 Liver mass and renal failure in 15 year old cat - Prednesone treatment Q: Dear Dr. Mike: Last week we took our approx. 15 year old cat to Cornell for diagnostics because his appetite was poor and he was losing weight. They found chronic renal failure and a mass in the liver. We chose not to treat it aggressively--he is old and weak--and basically took him home to die. The vet gave us prednisone for him--5 mg twice a day--advised us to have him euthanized in about a week. It is now a week and he is eating well and seems comfortable. My local vet says prednisone provides a sense of well-being but that the disease will eventually be overwhelming and he will stop eating again. My question is: how long might he last? I know there is no hope for him, and we really want to do the right thing and not have him suffer. Yet it doesn't seem right to have him put to sleep when he seems to be doing fine. Can you give us any insight as to howthings might progress? Your website has given us much information; thank you. A: James- I can't give you an average lifespan for the liver mass without knowing what the mass is. But that probably isn't very important, because averages really don't apply to an individual patient very well, anyway. I think that your philosophy is just right -- while your cat feels comfortable, continue to enjoy the time that you do have and when signs of discomfort or progression of her illnesses progress, then consider euthanasia. It is important not to give up on the treatment of one life-threatening illness due to the presence of another. In this case, the renal failure is important to treat even though there may be a potentially fatal liver mass. There is a lot of information on our site on treating kidney failure. A more recent recommendation that is not on our site is consider the use of angiotensin converting enzyme inhibitors (ACE inhibitors) such as enalapril (Enacard Rx) to keep hypertension under control and improve circulation in the kidneys. The rest of the recommendations on our site --- subcutaneous or intravenous fluid therapy as needed, potassium supplementation, phosphate binders if necessary, appetite stimulants if necessary and good supportive care still hold. I am pretty sure that the Cornell veterinarians have given you their best estimation of the time that they thought your cat had left for a comfortable life but often these estimates turn out to be wrong. You should feel confident in your ability to judge your cat's general well being after living with her for 15 years. Trust your instincts and ask your vet for advice when you have questions about how well she is doing. I do not want to give you false hope but there are two or three patients in my practice who I thought would surely die within a few days --- more than six months ago. Take this one day at a time, spoil your cat a little and trust your instincts. You almost certainly will know when the time has come to consider euthanasia. Good luck with this. Mike Richards, DVM 2/28/99 Feline Liver Disease - prognosis and treatment Q: Dear Vet Mike. Our cat, Kali, is an 8 year old, fixed, mixed breed, female. A few weeks ago she got very ill and the diagnosis was liver disease. That diagnosis was based on interpretation of x-rays (the liver appears swollen), a blood test (which shows abnormal liver function), and palpitation (liver feels swollen). Though Kali's acute problems are gone and her liver feels normally sized, she's not quite back to normal yet-not quite as active as she used to be. Also a recent blood test showed improved liver function, but her liver enzymes are still quite high. If she continues to improve we're considering a liver biopsy. Our question is, if we do a biopsy exposing Kali to its risks, is it likely we'll find out anything which will change either her prognosis or treatment? Her current prognosis is rather unsure. She may live another 2 weeks, 2 years, or more. It just depends on how long her liver is able to adequately function. Her treatment consists of a special diet-Hills Prescription Diet c/d-s. We do have one additional question: Do you have any other suggestions with respect to treatment? Thank you very much. Sincerely, Brian and Heidi A: Brian and Heidi- I think that the best way to help you with this problem is to briefly describe most common liver diseases and hope that will help you to figure out the best approach to Kali's problem. I do have a couple of specific questions and suggestions which I'll put at the end of the note. There are five conditions that affect cat livers which could be called reasonably common. The first is toxic injury -- which may be due a poisonous substance, to injury from bacterial toxins or from lack of blood supply to the the liver. The second is hepatic lipidosis. This is a metabolic condition that occurs when cats do not eat. There are two problems when this condition occurs, the one that caused the cat not to eat in the first place and the liver failure that results from it. It helps if both conditions can be identified and treated but that is not always possible to do. This condition can appear to come on rather suddenly, much like toxic injury. The third condition that affects cat livers is cholangiohepatitis, which can show up in several different variations and is a chronic condition. The fourth condition is a group of conditions in which the liver circulation is not functioning correctly, known as portosystemic shunts. The last condition is cancer of the liver. There are several cancers which affect cats which have a tendency to spread to the liver. Figuring out which of these conditions is present involves understanding each of them a little more and also understanding the limitations of lab values and diagnostic techniques which can be used to determine what is happening to the liver. Lab tests that are commonly used to evaluate liver condition include the ALT (alanine aminotransferase), AST (aspartate aminotransferase) and ALKP (ALP, SAP, serum alkaline phosphatase). These tests do not indicate how the liver is functioning at the present time. They are associated with specific types of damage to the liver and help to determine if these types of damage are a current problem. Liver function can be evaluated using bile acid response testing, which does give an indication of the liver's ability to do its job at the time the test is done. X-rays and ultrasound can give indications of the liver's size and ultrasound can sometimes pinpoint specific lesions in the liver or the gall bladder. Liver biopsy is currently the only sure way to identify many of the liver conditions that affect cats. Liver biopsy can sometimes be done simply by inserting a hypodermic needle into the liver and aspirating contents, a relatively safe procedure or it may involve specialized biopsy needles or exploratory surgery to remove a small wedge of tissue from the liver. Each method of biopsy has its advantages in specific circumstances. The ALT value is specific to the liver, almost, in cats. A rise in the ALT occurs when the hepatocytes (liver cells) are damaged enough to leak through the cell membrane and release this enzyme. This can occur due to toxins, bacterial infection, blood supply deficiencies, bile duct obstruction and hepatic lipidosis. When an acute injury to the liver occurs the ALT rises rapidly as it is released from damaged cells. In general the level will rise for the first few days and then decrease gradually over two to three weeks if no further injury occurs. This makes the ALT useful in determining if a liver condition is due to an acute injury or due to ongoing damage, making it a chronic condition. There are times when other systemic illnesses, such as hyperthyroidism or feline leukemia virus infection, can cause enough liver damage to slightly elevate the ALT chronically. Aspartate aminotransferase (AST) is found in the liver and other organs, including the muscle and brain tissue. Rises in the AST can indicate a problem in any of the organs it is common in, so it is not as specific to the liver. However, when it rises in conjunction with the ALT it can help to confirm that liver disease is present. It may rise faster and to higher levels than the ALT when obstruction to bile flow is present, which can also help to differentiate one cause of liver disease. In order for aspartate aminotransferase to be released, the liver cell usually has to die. Due to this, there can be situations in which the ALT rises because cells are damaged, but the AST remains low because they are still alive. A rise in ALT without any rise in AST would normally be a good prognostic sign since it would indicate damage without cell death. Alkaline phosphatase (ALP) is found in many tissues but in cats the majority of this enzyme in the bloodstream comes from the liver. This enzyme is excreted in response to bile duct obstruction, making it pretty specific for this problem in cats. It can take awhile for production of the enzyme to start and it will be produced as long as the condition persists, so levels tend to start out low and then rise over the course of an illness in which bile flow is obstructed. Large rises in the ALP level tend to indicate pretty severe obstruction to bile flow which has been present for some time. These tests show the amount of damage to the liver cells which are present. The reason that they can not be considered "liver function tests" is that a liver with only a few normal cells, such as one in which cancer is widespread or cirrhosis has occurred, may have little or no cell damage in the remaining cells --- but almost no ability to function. Conversely, a large number of liver cells can suddenly die due to a blood clot or toxin and the rest of the liver can function normally. A large rise in ALT, AST or ALP may occur even though the liver is able to do its job. The test that is currently used to assess the functional ability of the liver is the bile acid response test. Bile acids are removed from the circulation by the liver. If this does not occur, it is a good indication that the liver is not able to function. Bile acid response testing can help to determine if disorders have damaged the liver's ability to do its job and are useful in finding conditions, such as portosystemic blood shunts, in which the functional amount of liver tissue is decreased. In our practice, hepatic lipidosis seems to be the the most common liver disorder that we encounter. Typically, cats with this condition are refusing to eat. Many of them approach food as if they want it but then refuse to eat at the last minute. If they do eat they may vomit immediately. Some cats do eat and manage not to vomit but only eat small amounts each day, not enough to meet their caloric needs. Cats with this condition appear to be depressed. Often, they are heavy cats prior to the onset of the illness but lose weight rapidly once it starts. As time goes on cats with this condition may develop severe neurologic signs such as head pressing, seizures or coma. Jaundice develops pretty quickly in cats affected by hepatic lipidosis. The best treatment for this condition is aggressive force feeding, often requiring placement of a stomach tube to allow for adequate caloric intake. Hepatic lipidosis is usually fatal if untreated but approximately 80% of cats will recover with aggressive nutritional support. Cats with this condition respond better to high protein, high carbohydrate diets (like kitten foods), which is the opposite of diets prescribed for most other liver conditions. Hepatic lipidosis can often be diagnosed using a fine needle aspirate of the liver, a relatively safe form of biopsy that most veterinary practices are capable of. We see a fair number of cats that appear to have had toxic insults to their liver for reasons we rarely discover. They are often depressed, often vomiting, sometimes have jaundice and sometimes don't. They also are reluctant to eat. We tend to suspect this problem when the fine needle aspirate doesn't look like hepatic lipidosis but we suspect liver disease based on the lab values and clinical appearance. We look for an underlying cause we can identify and then usually try antibiotic therapy and nutritional support for a few days prior to looking for definite cause because cats with toxic insults often improve fairly rapidly. If the cat is seems to be getting worse we may progress to further diagnostic testing more quickly. It takes a week or two for rises in liver enzyme levels to start to drop towards normal levels in these cats but their attitude and clinical condition seems to improve more rapidly than the lab values. We also see a fair number of cats with cholangiohepatitis of some sort. There are several types of these disorders. Cholangitis is inflammation or infection of the bile ducts. This is sometimes the first stage of cholangiohepatitis, which is inflammation of the bile ducts and liver tissue. Suppurative cholangiohepatitis is inflammation with pus production. It can be acute or chronic. Cats with this condition tend to have unexplained weight loss, sometimes fevers, decreased appetite, sometimes vomiting and sometimes just a "not doing right" appearance. Antibiotics and medications to stimulate bile flow may be helpful. Surgery can sometimes aid in the treatment of this disease, if a way can be increase bile flow. Another form of this condition is nonsuppurative cholangiohepatitis. This may be the chronic form of the suppurative condition or it may occur without evidence that suppuration ever occurred. Cats with this condition often are losing weight but have normal attitudes. They may have occasional vomiting or may not. Often, the first sign that owners notice is yellow discoloration of the white portion of the eyes or the oral tissue. This condition tends to occur in middle aged or older cats but can occur at any age. There are cats with this condition whose liver enzyme levels stay almost normal or only show slight increases. Anemia is often present and as the disease progresses protein levels may decrease in the serum. Even though there is a decrease in protein production by the liver this condition seems to respond better to a low protein (but high quality protein sources) diet than to higher protein. Chronically administered medications are used more commonly in treatment of this condition than in the other liver diseases. Corticosteroids may be helpful. In the end, cirrhosis may occur with either suppurative or nonsuppurative cholangiohepatitis. Diagnosis of the type of cholangiohepatitis and even whether cholangiohepatitis is present often requires biopsy of the liver. Suppurative cholangiohepatitis may be apparent on surgical exploration of the liver area but it usually is a diagnosis made after examination of a biopsy sample. For this condition biopsy normally requires at least the use of specialized biopsy needles and may require surgical removal of a small section of the liver. Portosystemic shunts are connections between the arterial and venous blood flow in areas in which that shouldn't occur. This condition is usually congenital and occurs when fetal circulation does not change after birth properly, leading to portions of the liver not receiving adequate blood supply and therefore not functioning properly. Since this occurs at birth most cats with this condition are diagnosed when they are young but cats may not show sufficient clinical signs to make a diagnosis until they are young adults. It has to be considered in cats less than 4 or 5 years old which have unexplained liver disease. Lab values for ALT, AST and ALP are often close to normal or slightly elevated but bile acid response testing shows a severe deficiency in liver function in most cases. Poor growth and neurologic problems such as incoordination, head pressing, blindness and seizures usually are the reasons this condition is brought to the veterinarian's attention. Liver cancer is not especially common in cats and is usually the result of metastasis of lymphoma or pancreatic tumors to the liver. Some tumors do grow directly from liver tissue. Tumors may show up on X-rays and ultrasound exams or may be discovered during surgical exploration of the abdomen during a biopsy procedure. Liver disease of any origin can lead to blood clotting problems because the liver makes most of the clotting elements. Even though this is always theoretically possible with liver disease actual problems from uncontrolled bleeding after biopsy are not very common. It is still a good idea to test blood clotting prior to doing any type of biopsy other than a fine needle aspirate, though. OK, that is the background information. If Kali is eating well -- eating at least a normal amount of food and if her liver enzymes levels (ALT, AST, ALP) drop to normal levels, then biopsy may or may not be necessary. I tend not to do it when I am reasonably convinced that some sort of acute liver insult occurred and the cat is eating well and acting normally. If the liver enzymes are even a little elevated over normal or if liver function testing revealed significant decreases in liver function, then I think that liver biopsy is a lot more useful. The long term management of the liver disease present is much easier when it is clear which disorder is present. With cholangiohepatitis it is important to know which form of the problem is present, too. I am not sure why the c/d-s diet is being used. There may be a reason that I am not aware of for using that particular diet but it is not low protein/high quality protein and it is not high protein, so it doesn't fit either of the dietary scenarios I am familiar with using. It may be worthwhile to ask your vet what his or her reasoning is in prescribing this particular diet. A liver biopsy would give more information for obtaining a prognosis, so that you would be more sure what sort of future scenario you are dealing with and also in guiding treatment. However, if Kali is eating well and feeling well, it is reasonable to wait a bit and see if the liver enzyme levels return to normal levels prior to making the decision to biopsy. Hope this helps and doesn't just add to the confusion. Mike Richards, DVM Liver Disease Q: Hello Dr Mike, I was hoping you may have a suggestion for my cat. On wednesday my cat (approx. 5 yr. old) seemed depressed and not herself. On Thursday I took her in for a blood panel and Friday the results were back. On examination, my vet was able to feel her liver easily and when the results came back it was apparent that something is wrong with her liver. All the levels pertaining to her liver were elevated. She spent the weekend on fluids and antibiotics to flush this out of her, but she doesn't seem to be responding to treatment. There is nothing toxic in the house that is accessible to her. She used to be an indoor/outdoor cat before we took her in, but she hasn't been outside for at least 5 months. On Monday she will be getting an x-ray and we may have something else to go on. At this point we don't know what's going on, whether it's a congenital problem, a shunt issue, or ??? Her liver isn't functioning and she is running out of time and I don't know what, if anything, can be done. My vet suggested other options after the x-ray such as a biopsy or ultrasound. I know this may be premature and you don't have the test results in front of you, but can you offer any suggestions about any treatments -- conventional or not? Thanks, Marc A: Marc- I will try to think about this more later but I wanted to let you know that I think it is pretty important to get a liver biopsy in a cat with liver disease that isn't doing well. It is a good idea (almost imperative) to check blood clotting times prior to doing a liver biopsy, except perhaps a fine needle aspirate, because the liver makes some of the clotting factors. We do fine needle aspirate biopsies first, looking for signs of hepatic lipidosis. If we find none, then we look further. If we had ready access to ultrasound and someone good at reading them, we might lean in that direction prior to doing a more involved biopsy after the fine needle aspirate. We don't, so we usually do the biopsy and then arrange for ultrasound since it usually takes us a few days to arrange that. Bile acid response testing is not invasive and gives a good idea of how well the liver is actually functioning so that is another thing to consider. If she starts to feel better then there is not as much reason to rush from one test to the other but it is still a good idea to try to get a diagnosis if the condition seems as if it will remain chronic (and since her liver seems to be enlarged) because the long term goals are different depending on what liver disease is present. Good luck with this. I hope she is doing better by now. Mike Richards, DVM Liver Disease and vomiting Q: My kitty was diagnosed with fatty liver 2-1/2 weeks ago. He's now got a stomach tube through which I'm feeding him as he's lost so much weight and is not interested in eating on his own. After a week in the hospital, I've had him home for a week and he's vomited food up every day. The time of day varies and sometimes it's right after eating; other times it's an hour or two later. I was feeding prescription a/d food and have now switched over to baby food hoping it would help. He's on regulan to help with the nausea but I'm not sure how much difference that is making. A few days ago someone suggested to not microwave the food but rather put it in very warm water in a cup. This worked great for a day but yesterday the vomiting was back. I'm sorry this is so long, but I'm really in despair. Any thoughts on how I can control the vomiting? Thank you! Joyce A: Joyce- It is not uncommon for cats with hepatic lipidosis to vomit after feeding through a stomach tube is begun. There doesn't appear to be a clear consensus on medications to help with this condition but cimetidine (Tagamet Rx), cisapride (Propulsid Rx), metoclopramide (Reglan Rx), and other medications similar in effect to cimetidine are most often recommended. There is a clear consensus that feeding small quantities very frequently will often help. For hospitalized cats the use of gravity or pump controlled feeding from a reservoir such as an IV bag is utilized to ensure continuous small quantities of liquid food. At home it may be necessary to just use very frequent small meals for a week or so to gain control of this situation. I hope that everything is already looking a lot better by now. Mike Richards, DVM Liver Disease and diet Q: I just discovered your web page today after returning from our vet. Our 8 year old cat, Amnesty hasn't been eating well for two days so I thought we'd best get him checked out. Apparently his physical exam was unremarkable so I brought in a urine sample. It showed elevated bilirubin and protein. Subsequent bloodwork revealed an alk phos of 670. I was told the normal high range was 200! He was put on Clavamox 125 mg bid and Metronidazole 250 mg od. I was told to check in with the vet in a week and let him know if his appetite has improved. I'm wondering what the prognosis might be and if there's anything else I should be doing. He normally eats Medical-W wet and dry food but I found a web site that suggests we might try Hill's Prescription Diet k/d. Any suggestions would be greatly appreciate. Thank you. Sheila A: It is pretty important in cats to determine the nature of the liver disease prior to choosing a diet. Cats most commonly have either cholangiohepatitis or hepatic lipidosis. These diseases require an entirely different approach to dietary management. Cats with cholangiohepatitis probably do better on a diet that has very good quality protein in limited amounts. Cats with hepatic lipidosis probably do better on diets that are high in protein since their problems tend to relate more to fat deposition in the liver cells from not eating well. The higher protein diets are more attractive to cats and the excessive protein is used as an alternative energy source to fat metabolism. If your cat is doing well at this point it may not be necessary to worry over this issue. Hope that is the case. If not, working with your vet to establish the cause of the liver disease and using the correct diet along with other appropriate treatment could make a big difference. Mike Richards, DVM Poor liver values - treatment and diagnostic tools Q: My cat is about 16 years old and has had poor liver values over the last couple of years, during these episodes he would refuse any food offered. He has been receiving injections to boost his liver values, but his episodes of poor liver values seem to get more frequent. Do you have any diet or treatment recommendations !? Thanks a lot ! Alexa A: Alexa- It would be a good idea to try to identify the cause of the liver enzyme increases if possible. Cats get two liver conditions most frequently, cholangiohepatitis and hepatic lipidosis. They can be affected by other liver problems and it is also possible to get elevations in liver enzymes that are related to other conditions that are only indirectly affecting the liver. An example of this would be a rise in alkaline phosphatase enzyme levels in response to administration of cortisones or rises in liver enzymes due to circulatory problems. Liver biopsy is the most reliable test for differentiating between liver diseases. It is always a good idea to make sure there isn't a contributing problem by taking bloodwork and possibly X-rays prior to biopsy. Also, it can be important to confirm that the blood clotting system is working properly prior to doing a liver biopsy. Cholangiohepatitis is the most likely diagnosis when the condition seems to wax and wane. There are several possible causes of this problem and they have to be treated appropriately. It is often possible to tell from a liver biopsy which is the most likely cause. Infections need to be treated with antibiotics and supportive therapy such as dehydrocholic acid (Decholin Rx) if bilirubin levels are high. Appetite stimulants may be necessary. Immune mediated cholangiohepatitis may respond to administration of corticosteroids or other immunosuppressive medications. Dietary changes may be beneficial depending on the exact cause. Many vets are uncomfortable about performing liver biopsies. If your vet doesn't want to do this and you do want to pursue a diagnosis ask about referral to an internal medicine specialist. Mike Richards, DVM Polycystic renal disease/ liver disease Q: Dear Dr. Mike, What can you tell me about poly cystic liver disease in cats. Also can you refer me to any references or journals on this subject. Any help that you can provide would be greatly appreciated. Thank You A: I can not tell you much about this disease except that it seems to be mostly a problem of Persian cats and that it is probably the same disease as polycystic renal disease. The cysts seem to occur in either organ system but cause problems earlier when they develop in the kidney. I haven't even seen any conjecture about why these cysts occur, except mention that they can be associated with cancer in some cases. At present, it appears that draining the cysts by guiding a needle into them using ultrasound may make the cat more comfortable and may help to preserve kidney or liver function. It doesn't appear to be a long term solution but there doesn't appear to be a better approach at present. I wish we all knew more about this problem. Mike Richards, DVM Lactic Dehydrogenase Q: My cat had some blood tests done recently as since she is overweight (although she is losing weight on a Feline RD diet prescribed by my vet) I was afraid she might be becoming diabetic. She has gone from 16.8 lbs. to 14.2 lbs in 10 months. When her blood tests came back, her lactic dehydrogenase was 1065, almost twice the normal level. In speaking to my vet he says it is difficult to tell what this means, since lactic dehydrogenase is produced by almost every organ in the body and prior efforts he has made with labs in other cases to break this down has not provided much useful info. Any thoughts on how I can get more info. into what this test result means? By the way, her ALT(SCPT) and AST(SGPT) were slightly elevated also. A: I think that it is important to take any rise in liver enzymes seriously in a cat that is losing weight, even if it is on a dietary program. Cats that are losing weight are prone to hepatic lipidosis. If your cat becomes anorexic (doesn't want to eat) it is much more important to keep this particular disorder in mind. I would recommend rechecking these particular values again in a week or so, if possible. Your vet is absolutely correct about the value of lactic dehydrogenase (LDH) testing. It is found in a great number of body tissues and it is difficult to assign much meaning to a rise in LDH. I think that we would not choose to run this test if it weren't included in many laboratory profiles in which all of the tests chosen by the testing lab are included. However, there are a few instances in which increases in this enzyme level are meaningful. When no other lab values are elevated it is possible that the increase is due to malignant cancers and LDH increases do occur with liver disease and this helps to point out liver disease when other liver enzymes like the ALT and alkaline phosphatase levels are increasing. Please have all of these values rechecked in one to two weeks - or sooner if your vet advises that. Michael Richards, DVM Last edited 12/05/02