Cardiomyopathy in Dogs


Dilated Cardiomyopathy in Doberman

Q: Dr. Mike Zen is a 10 year 3 month old AKC purebred Doberman Pincher who has been in great health his entire life. He had a physical not even a year ago with his new vet (his original vet retired). He was amazed of the great health and age Zen was. Ten days ago on a Friday in December we noticed some changes in Zens' health. It started with a cough. He likes to lay on his side, but when he tried to do this it caused him to cough. The cough sounded full of fluid, but he did'nt cough up any thing. He started lying straight down like the sphinx, but this is not comfortable for long periods of time. Sometimes he would try to lay on his side again but the results were the same, eventually he stop trying. My mother said he is very restless at night and is not sleeping much. His eating habits did'nt seem different, but he is drinking a lot of water. He is still very alert and playful. We also have his 5 month old grandson with us, those two would play together and that really didn't seem to bother Zen either. Saturday these symptoms continued and he seemed not to want to eat as much and he continued to drink a lot. I would lay next to Zen or he would sit between my legs to comfort him, this is when I noticed his heart. What I noticed is a very fast irregular beat with no rythem. What seemed odd to me is he did'nt have any physical activity prior to this that would speed up his heart rate. Sunday these symptoms continued and he is barely eating at all. We called the vet and made an appointment for Monday. Monday after the vets examination he told us that Zen had a galloping heart beat and that the cough probably was caused by fluid in his lunges from his heart. He also said there isn't much he felt he could do, because with a dog his age there are probably other physical problems and that treating the heart problem might cause other complications. He did not seem comfortable with doing an xray of his chest, his reasoning for this he said was he did'nt want to cause trauma to Zen by using a sedative to relax him for the xray. Which he felt would be more harmful to Zen. He suggested a low sodium diet, so we purchased some dry and wet food from him. He also said that the weight loss Zen will experience from not eating as much would actually be good for him. He said the weight loss would make it easier on his heart. We also decided to do blood work on Wednesday. Zen seemed to have good moments and not so good moments but did not seem to be in any real discomfort. He was reluctant to eat his new food though. He would eat boneless skinless grilled chicken breast, but still not with much enthusiasium. My mother started blending his low sodium diet food and fed it to him through a bottle, which he didn't seem to mind. The blood results came in on Friday at noon. Our vet told us there wasn't anything really out of line elsewhere but his nitrate and phoshate levels where high (sorry I do not know the exact numbers at this time). He said that from these results Zen probably also has liver cancer and the toxins that are being released are what started his heart to act the way it was. He didn't feel there was much he could do for Zen. He said enjoy your days with him. Zen is continuing to do the same, although he does seem to be getting weaker and will not even play with the puppy any more. He still is alert and goes outside on his own to urinate(by the way his urine is an orange color) and walks around the house. He dosn't cough as much, but he will not lay on his side either. I have noticed a decrease in the amount of water he is drinking. I know Zen has lived past what most dogs his size and pedigree do, all we want are some answers and for him to live the rest of his life as comfortably as possible. The new vet seems reluctant in giving us the straight up answers. I am not looking for a miracles, but I would like to know what you think. Is there anything we can do to make things better for him? If you need more information please let me know. Thank you for your time. James A: James- If it is possible in your area, I really think it would be best to ask for referral to a cardiologist, or if that is not possible to an internal medicine specialist. While it may be true that Zen can not be helped much, it seems worthwhile to be certain of that. Older dobermans are prone to dilated cardiomyopathy, a condition in which the heart muscles become weak. This leads to the signs that you are seeing. Other heart disease is possible, such as failure of a heart valve or an arrhyrthmia from another cause but the cardiologist should be able to help determine exactly what the problem is and be able to give you a better idea of the prognosis. There are treatments for this condition. They do not reverse the disease but they can significantly increase life span in some dogs with cardiomyopathy so it is worth considering therapy even though the eventual outcome may be the same. If you have problems locating a specialist I will be glad to try to help, but I know a limited number of specialists outside the Virginia region. Mike Richards, DVM 1/9/2001

Cushings and Cardiomyopathy in Boxer

Q: Dr. Mike, Thank you for answering my first email re my 9 year old boxer, Molly, who has Cushings and apparently cardio myopathy. I tried to find a certified vet cardiologist and two referral centers in Tampa, Since neither had a cardiologist on board, they suggested their board certified internist. Both centers were very familiiar with the board certified internist vet that Molly currently sees, so I am looking into going to the Small Animal Clinic at U of FL in Gainesville. Also, we are going to have Molly's lymph nodes aspirated to see if they can get a definitive diagnosis without having to remove one of the nodes. Will keep you posted on that. IF Molly does not have lymphoma, and IF her heart arrythmia is due to the Cushings, 1). How long would it take for her heart to settle down AFTER her cortisol levels are normal? (weeks, months?) 2). After her levels get normal (if they do), would continuing to take atenolol (because she hopefully would no longer need it) cause the heart arrythmias? 3). After reaching a normal cortisol level determined by the cortisol blood test, how stable is that reading (assuming we have reached a balanced lysodren maintenance dose)? (days stable, months stable, hours stable?) Thank you for your efforts on Molly's behalf. We love her so much. Michele Tampa, FL A: Michele- I don't think that I can give you as definite an answer as you would like. When dogs develop cardiomyopathy associated with Cushing's disease they do usually improve once the Cushing's disease is controlled. But I don't have enough experience with this to give you specific time periods that might be expected and I couldn't find any in a search of the databases available to me. Arrhythmias that are associated with this whole scenario should also improve and it seems to me that you could definitely hope for a time when atenolol would not be necessary but again, I don't know a specific time frame for improvement to relay to you. We have treated a lot of dogs with mitotane (Lysodren Rx) in our practice over the years. Our experience has been that once we get to the maintenance dose of mitotane that there will still be enough variations in cortisol level over the first few months that we feel monitoring on an every 2 to 4 week time period is definitely a good idea during the first few months following establishment of a maintenance dosage. After that time period, if things have gone well, we go to testing four times a year and over time we will reduce that even more but usually not less than two times a year. The cortisol levels change throughout the day (due to the diurnal cycle of the body's biorhythm) but usually stay with the established ranges. The suppression of the adrenal gland with mitotane is the stabilizing factor and that varies from pet to pet. Some can be suppressed really well and others seem to creep upwards on the dosage necessary to control their Cushing's disease throughout the treatment period. I hope that you are making progress with this. Mike Richards, DVM 7/12/99

Cardiomyopathy, Cushing's and Other Complications in Boxer

Q: Dr. Mike: I am a new subscriber to Vet Info. After reading all the emails re Cushings, Cardio Myopathy, and Addison's diseases, I still have questions. I had initially taken my 9 year old boxer, Molly, to the vet because of an enlarged lymph node under her chin. They aspirated and found that it was a reactive node and recommended biopsy to check for lymphoma. Since my own mother has been battling lymphoma for 3 years, we didn't want to put Molly through any chemo, so we decided against the biopsy, too. A few weeks later, Molly began to show symptoms of Cushings .Our vet doubted it was Cushings and that it was probably low thyroid. She was panting excessively, drinking LOTS of water, eating with a vegeance, and had gained from her usual weight of 54-56 lbs, to 67 lbs. The thyroid test showed that it was low and she was started on levrothyroxin 0.5 two times a day on March 17. After no improvement in symptoms, I requested that my vet do a Cushing's test. The test concluded that she does have Cushings and they gave her a loading dose of lysodren for 7 days. I was concerned because lysodren is a derivative of DDT and because Molly has always been so sensitive to medicines. He next blood test showed that the lysodren had supressed her adrenal system very considerably. Also, the lymph nodes were larger. My vet thought that Molly's own cortisol had probably been keeping the nodes at bay, but that since the Cushings was under control, the nodes were back to being large again. She again suggested a biopsy, which we declined (because we weren't going to treat her with chemo anyway). She asked that we see the certified internist vet and said we should see her in a few days. Molly's panting was not iimproving, although the water and food was in the normal range. I was concerned about her heart beating so fast and the fact that Molly had been so sluggish. I took her in on an emergency basis for her heart. When the internist saw Molly, she listened to her heart but said it was fine. She wasn't concerned with the lymph nodes either--said they weren't large enough to be lymphoma and that we needed to concentrate on the Cushings. We started her on a maintenance dose of lysodren (500 mg 2 x a day, twice a week) on June 10. Molly's panting seemed to increase and her heart seemed to be racing, even when she was sleeping. I called the internist and she said to bring her in immediately, that she probably had cardio myopathy and that she could just fall over dead like the basketball player and the skater did. She did an ecg and sent it to a place in NJ called CardioVet and did a ultrasound showing no fluid around the heart. The report would not be back until Monday, so she sent us home with digoxin .25mg 2x aday. Her cardiopulmonary signs were murmur, abnomal heart sounds (irregular rythum) and her rhythm was sinus with right ventricular premamture depolarizations. CardioVet's diagnostic and therapeutid advice was as follows: 'AFTER YOU GET THE ENDOCRINE IMBALANCE STRAIGHTENED OUT, IF YOU STILL DETECT THE PREMATURE BEATS, WE SHOULD PROBABLY START MOLLY ON A BETA BLOCKER, SUCH AS 25MG OF ATENOLOL 2x DAY. We stopped the digoxin that day and started her on the atenolol the next day. With no improvement in that pounding heart, I called her vet internist and she pretty much made me feel like an alarmist. I asked if Molly would ever get any better if her body would ever respond to the atenolol. She first said that this irregular heart rythum will kill her (her words). She said the atenolol would not correct the irregular beat , only slow her heart down. I then told her that my mom has heart arrythmia and that after they found which combinations of medicines worked for her, she is doing really well. Then she said just the opposite to me, that the atenolol would correct the arrythmia. So now I just don't know if Molly will ever have a better quality of life. Do you have any thoughts about it? Thank you so much.


A: Michele- There is a lot of ground to cover in replying to your note. Please bear with me if I forget to address some of the questions or create some confusion. Before I get started my number one recommendation in this case would be to ask for referral to a veterinary teaching hospital or very large referral center because I think that you need the services of an endocrinologist and a cardiologist and there aren't many internists who are really good in both these fields and who have the supporting staff to ensure good quality ultrasonic imaging outside of the teaching hospitals and big referral centers. OK, with that being said there are a few things that you should know. First, testing for hypothyroidism when there are other diseases present can be very misleading. Almost any systemic illness will lower the total thyroid hormone levels in the bloodstream. It is hard to interpret the results of thyroid testing in this situation. So if you are still supplementing thyroid hormone (I couldn't tell) there is some chance that the thyroid supplementation may be unnecessary or even that it might be contributing to some of the clinical signs seen IF it is not necessary. This is one of the reasons that I think it would help to see an endocrinologist. Secondly, when mitotane (Lysodren Rx) causes drastic decreases in plasma cortisol levels, it may be necessary to supplement corticosteroids. I couldn't tell if this had been recommended, either. Lowering plasma cortisol levels is what mitotane is supposed to do --- but it can do it too well, so it is good your vet is monitoring for that. It may be a good idea to see if the low cortisol levels and poor response to ACTH stimulation are still present. This is the second reason that having an endocrinologist in on this case may be a good idea. A good internist or general practitioner should be able to handle this, though. And they probably are, I just wasn't sure from your note. Thirdly, enlarged lymph nodes generally occur for a reason, although the reason can be very hard to elicit. It is very easy to do needle aspirations from lymph nodes, make a smear of the aspirate and send the smears to a clinical pathologist for review. In many instances, this is sufficient to provide a tentative diagnosis. THEN you can worry about whether or not to do invasive surgery to remove a lymph node to confirm the diagnosis. Even if you don't intend to treat for lymphoma it would be good to know if it was present because it would make all the other problems Molly is experiencing easier to understand and to manage. If the lymph nodes appear to be reacting to an inflammatory or infectious process then making a concerted effort to rule out the likely suspects would be a good idea. I am guessing that the internist strongly suspects cardiomyopathy based on the ultrasound (US) exam? This is a common problem in boxers so it wouldn't be unusual. This disorder often shows up at earlier ages but some boxers do seem to wait to show clinical signs. Unfortunately, this is also commonly associated with arrythmias and they can lead to sudden death. It should be possible to confirm the diagnosis and your note sounds like the diagnosis is tentative --- so that is the confusion on my part. If there is any confusion, having the ultrasound study reviewed by a cardiologist or sending Molly to a cardiologist would probably be the best course of action. At present, based on anectodal information gleaned from the Veterinary Information Network (, the medication that seems to be the best for boxers with cardiomyopathy is sotalol. In addition, carnitine supplementation MAY be helpful in boxers. It is expensive to supplement and does not always help. Plus it is helpful most often in young boxers who exhibit cardiomyopathy early, probably because these are the ones where a deficiency is part of the underlying cause. All of this is not to say that atenolol wouldn't necessarily work or be helpful but the trend seems to be towards using sotalol. Sometimes medications like enalapril (an angiotensin converting enzyme inhibitor) will help when heart failure is present as a result of the cardiomyopathy. Again, this is a reason to consider seeking referral to a cardiologist or veterinary school. They will have the latest information on this --- and it easily could have changed because cardiomyopathy is frustrating to treat and opinions on how to treat it seem to change regularly. I wish that I could get to the heart of your question, which is whether or not Molly has a chance for some good quality time in her life at this point. The problem is that there are too many things going on at once to be able to be reassuring about any one of them. When multiple problems are present in an older dog the prognosis is often worse than when a single problem is present. The best hope is that most or all of the problems are related to the treatment for Cushing's disease and the Cushing's disease itself --- and that control of that problem will help to straighten out all the other ones. The worst case scenario is that Molly was doing pretty well even though she had a weak heart that no one knew about. Then a second serious problem developed, which made the hidden heart disease apparent. It will be very hard to get back to the point that she can compensate for the heart weakness again, if that is the case. Your situation is scary and the conflicting information makes it even worse. If you have the means to consider seeking even more opinions on what is going on, please consider asking your vet about referral to a veterinary school or other referral center where a cardiologist and endocrinologist are both present to review Molly's case. If you can't get Molly to such a facility for whatever reason, consider asking that the ultrasound results and the lab results from all testing to date be sent for review to a cardiologist. And consider needle aspiration and clinical pathology examination of the lymph nodes. It shouldn't cost too much and might really help give you some idea of Molly's prognosis for getting back to a reasonable quality of life. Good luck with all of this. If this note just makes you have further questions, please send them. Mike Richards, DVM 6/29/99

Cardiomyopathy in Boxer

Q: I have a 9 year old female boxer (spayed). Up till about 3 weeks ago she was healthy and so active people could not believe she was 9. All of a sudden I noticed she was starting to fill out in the belly and the first 2 days thought she was finally gaining weight. I always thought she looked a little thin but was advised her weight was "normal". By the 3rd day I was pacing the floor waiting for my vet's door to open. He immediately ran a heartworm test which proved neg. Gave me Lassix 50mg. 2X a day and sent us home. I drove to the next town and asked for a second opinion. (any opinion!) This vet again ran a heartworm test and drew blood for an organ profile. (came back nothing abnormal) Then did a heart x-ray and said she had cardiomyopathy. Gave us more Lassix 50 mg 2 times a day. Instructed us to limit fluids and administer Cordoxin 1ml. 2 x a day. That was 3 weeks ago and more filled prescriptions of both meds. also k/d prescription diet. There has been NO improvement and I feel the vet has no interest in our problem or has given up. She now looks like a skeleton on top and a pregnant cow underneath (something called sideies) Her muscles are deteriorating fast and her hocks and rear feet are swollen. However the Vet still claims she is in no pain. Uncomfortable as if she has overeaten but no pain. It seems I have been given 2 options: Continue watching her die, or put her down. I am having a VERY hard time accepting either option. She is so alert and still wags her tail begs for water eats good (same amount but broke down to twice a day) she is having no problems holding her bladder and is having normal bowel movements. Can you suggest any other options that I could discuss with my Vet. What do you think about going to yet another vet? I know you can't treat animals over the "net" but I guess I need to be absolutely sure I am doing all there is. ( 9 is not that old and she has been such a dedicated loyal companion to me. She has taught obedience at my side at Vincennes University for the past 5 years, made the front page of all our local papers and has even been spotlighted on our morning television show. I just didn't see her as old! Please any suggestions would be greatly appreciated. A: I definitely would recommend asking for a referral to a veterinary cardiologist. There has been a lot of research into the causes and treatment of cardiomyopathy in the last few years and a cardiologist will be up to date on the best options. Even if it is a fairly long trip to make it would be worth it.


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...