Heart - Cardiomyopathy


Heart - Cardiomyopathy


Vomiting with Cardizem

Question: Dear Dr. Richards,

My nine year old male cat Kitty was diagnosed a few months ago with Hypertrophic Cardiomyopathy. It was caught early before any damage to the heart developed. He was put on Cardizem 30mg capsule once a day dose. He's been on this medication for almost three weeks. I give it him one capsule every morning around 10am.

Here's the problem: Ever since he started this medication, he has been vomiting almost every morning between 4am - 6am like clockwork. If I feed him, he doesn't vomit. If I don't feed him between those hours, he vomits clear frothy liquids.This morning I fed him at 3am and he was ok until around 9am when he was chasing me for more food. When I did not comply, he vomited again. It puzzles me that he vomits 20hrs after taking the medication.

It seems that he needs food in his stomach in the early mornings or else he vomits. Could this be an Ulcer or a side effect from the medication? He has no other symptoms. Other than this, he is fine. I'm also wondering if the diet has anything to do with the vomiting. I feed him Nutro Max senior canned food.

I would appreciate your thoughts and suggestions.

Thank you, Cindy

Answer: Cindy-

I have been unable to find a specific answer to your question, or any recommendation for control of the vomiting associated with the use of diltiazem (Cardizem Rx, Cardizem CD Rx), when it is necessary to continue the diltiazem (since stopping the medication is an option only if it isn't needed). Diltiazem is a calcium channel blocker (antagonist) so its method of action is different from another group of medications that might be helpful, which are referred to as beta blockers. I am assuming that you are using the sustained release form of diltiazem (Cardizem CD Rx), since the dosage for this is usually 30mg/day per cat, versus the dosage for the non-sustained relief form which is usually given as 1/4th to 1/2 of a 30mg tablet every 8 to 12 hours (although some sources suggest using 2.5mg/kg once a day (which would be about 1/2 of a 30mg tablet once a day for a 12 pound cat).

I did find some information on the pharmocologic properties of diltiazem in cats and the peak effect of the medication occurs approximately 18 hours after administration in cats, so that does come close to correlating with the time of vomiting. In addition, vomiting is probably the most common side effect of this medication in cats, so that also correlates well with your experience. I just couldn't find much information on when vomiting occurs, or more specifically, it appears from reading clinical reports that the vomiting can occur at any time, so the specific nature of the vomiting in your cat seems unusual. I do not have enough personal experience with this medication to be sure of that, though. We have used diltiazem, so far without much problem, but our caseload for cats with hypertrophic cardiomyopathy is small.

An alternative medication that might not cause the vomiting is atenolol, which is usually dosed at 6.25 to 12.5 mg per cat per day. This medication is in the group of meds referred to as beta blockers. These have side effects in some patients, too, but it is possible that your cat might experience less problems on these medications.

There is no evidence, currently, that diltiazam or atenolol have any effect in slowing the development of hypertrophic cardiomyopathy. So their use is justified primarily by the development of clinical signs which require therapy. If there are no clinical signs it is reasonable to consider stopping the medications and monitoring carefully for signs of problems by keeping close track of respiratory rate and heart rate to be sure that you catch the development of clinical disease early. Increases in heart rate and respiratory rate occur when the damage to the heart reaches a point where it can't function properly. This is the time when the use of medication is known to be beneficial. This approach does require careful attention on your part, though. I think that some vets prefer to go ahead with medication early, hoping to protect patients whose owners may miss the signs of worsening of the disease.

I am sorry that I can't come up with any suggestions for dealing with the vomiting, other than stopping or changing the medication. What you have discovered so far is encouraging. Maybe you could change the time you administer the pills so that the timing of the need for food more closely matches Kitty's normal feeding times, too.

Mike Richards, DVM 8/3/2001

Cardiomyopathy in Cats

Cardiomyopathy is an alteration in the function of the heart muscle. It can occur for several reasons in cats and it can take several forms. When the muscle is sufficiently affected that it can not function properly, heart failure occurs.

Dilated cardiomyopathy due to taurine deficiency was common until recent years. The discovery of the relationship between taurine (an essential amino acid) deficiency and the development of dilated cardiomyopathy has nearly eliminated this condition.

Hypertrophic cardiomyopathy is now the more common form of this condition in cats. It can occur for several reasons, including hyperthyroidism, toxins, infections and genetic influences. In this disorder, the heart muscle loses elasticity and becomes thicker, making it hard for the heart to function properly. There are many apparent variations in the course of this disease in cats. At the present time, a clear understanding of the mechanism of the disease is not understood in most cases.

The symptoms of this problem are similar, despite variations in why they occur. Affected cats may exhibit difficulty breathing, rapid respiratory rate, weight loss or poor condition, loss of appetite, tire easily with exercise or show signs of weakness or paralysis of the rear legs. Despite the chronic nature of the disease itself, cats often appear to develop symptoms quite suddenly, especially difficulty breathing and rear leg weakness.

Physical examination is often sufficient to produce a presumptive diagnosis of cardiomyopathy. This disease is best confirmed with ultrasonagraphy but X-rays and electrocardiograms (ECG) can be helpful. Many affected cats have heart murmurs that are audible on exam. These are not diagnostic for cardiomyopathy since they can occur with other heart disease.

Cats with sudden real leg weakness are a clinical emergency. This occurs as the result of blood clots from the damaged heart blocking circulation to to the rear legs. The resulting damage to muscle can lead to the release of sufficient levels of potassium to cause death. Immediate treatment may be necessary. Provision of oxygen to enable the damage circulatory system to do its job of delivering sufficient oxygen to the body may be necessary.

Long term management of this problem through the use of medications is possible. At the present time, there is some controversy about all methods of treating this disease but some medications do seem to be beneficial in many cases. Aspirin is used to reduce the possibility of blood clots. Due to the strong possibility of poisoning from aspirin in cats it is extremely important that this be administered under a veterinarian's supervision and at the prescribed dosages. It has not been as effective as originally hoped. Diuretics are helpful in many cats, especially when heart failure develops. A group of medications know as ACE inhibitors (captopril, enalapril) are often beneficial in the long term management of heart failure in cats. Other medications to control heart rhythm or to to try to increase the muscle strength may be indicated. Until it is established that taurine deficiency is not the problem, it is worthwhile to supplement this amino acid in all cats with signs of cardiomyopathy.

At the present time, the long term prognosis for these conditions is poor unless they are caused by either taurine deficiency or hyperthyroidism, which are treatable conditions. Work is continuing on more effective ways to diagnosis this problem and to treat it.

Mike Richards, DVM

Dilated cardiomyopathy

Question: I am writing to ask a few questions related to cardiomyopathy in cats and, more specifically, about my own cat's illness.

** Background

My cat Gus died in late June from complications of what I understand to be a rare form of cardiomyopathy. Gus was five. His vet noticed an irregular heartbeat at his annual physical in late January. After ultrasound exams here in Houston and at the A&M veterinary school (where Gus saw a cardiologist), the findings were that (1) the left ventricle of Gus's heart was enlarged and the chamber wall was very thin, (2) other areas of the heart showed thickening of the heart walls, (3) the heart was, consequently, not moving blood as efficiently as it should.

Gus was placed on a beta blocker and an ace inhibitor to decrease the strain on his heart and to help move more blood through the heart. Gus did well for five months. In mid-June, his appetite began to diminish somewhat. On June 22, Gus threw up a hair ball (which wasn't unusual), then threw up (or attempted to) several more times. We went to the vet immediately. Over the next week, Gus ate almost nothing and drank little. His vets began giving him subcutaneous fluids and force feeding a food paste. He was weak but alert for all of that time. He had one episodes of difficult breathing which was controlled with medication. On July 29, on the way home from a visit to the vet's office, Gus became very agitated, meowed loudly, and died almost instantly. The vet believes a blood clot traveled to his brain.

Gus was a foundling, so it's difficult to know his pedigree. He may have been a Maine Coon. He at least shared many traits with the breed. He was large (13.25 Lbs in good health), had a beautiful, long silky coat, a long bushy tail, and other similarities.

** My Questions

I understand Gus's disorder couldn't be properly described as the more common hypertrophic or dilative cardiomyopathies. Is anyone studying this disorder to any significant degree? I would like to support their work if it's being done and if there's an avenue for doing so. This is likely to be a naive question, since I know virtually nothing about veterinary research. (I did provide tissue samples of Gus's heart after his death to the A&M school, but was left with the impression they're not involved in significant research on this disorder.)

I also have some questions about Gus's illness. Gus appeared to be in excellent health aside from the heart problem. The illness appeared to advance very rapidly. He showed no signs of illness at previous physicals. Because he was otherwise active and healthy and because his decline was so precipitous, I'm left with the nagging fear that there might have been some cause other than Gus's genetic predisposition.

Gus lived with me in a small apartment for the past two years. (Before that time we lived in a house.) Gus was an indoor cat exclusively for the four and one-half years he lived with me. The apartment environment was rather clean and, as far as I can tell, relatively free from chemicals. During his illness I searched the Web for information on possible links, but found little. (I had found your site in late June.) About a week ago, I came across some information which indicated that Lysol was fatal to cats. At some point (I *believe* after Gus developed symptoms), I used Lysol once on my kitchen floor. (It's interesting that I broke the plastic bottle while using it, spilled a good bit on the floor, rinsed it off, and never used it again, finding the fragrance very unpleasant) I don't think Gus ever had contact with the wet floor. If he had contact, though, this could have been a problem: because he was, even more than most cats, quite fastidious, he would have licked his paws clean. I saw no symptoms at the time. In addition, the apartment complex has a pest extermination contract. I spoke with the representative at length before the first application two years ago and was assured the chemicals were safe. Still somewhat doubtful, I allowed spraying less often than called for and was present on every occasion so that the apartment could be ventilated. On several occasions, I arranged for Gus to be away for the day.

Even though I believe I was careful, I was surprised to find the reference to Lysol, especially after all the reading I had done up to that point. Are you aware of any environmental links to this kind of illness? Is this product or other chemicals linked to the disorder?

** Thank You, Richard

Answer: Richard-

I am a general veterinary practitioner and I do not have special knowledge regarding heart disease in cats. However, the description that you give does sound like dilated cardiomyopathy, which was once common but is now very uncommon.

In dilated cardiomyopathy, the left muscular wall of the ventricle of the heart becomes weak, which causes the left chamber of the heart to dilate. This also interferes with the heart's ability to do its job adequately, leading to heart failure. It also allows the formation of blood clots in the heart which can then make their way into the circulation and cause problems, such sudden weakness or loss of use of the rear limbs or sudden death.

Dilated cardiomyopathy was very common until it was discovered to be the result of taurine deficiency in most cats in which it occurred. When cat food companies increased the taurine levels in their foods, this condition nearly disappeared, but not quite completely. There are still some cases, which may result from strong genetic predisposition to the problem, from toxins (chemotherapy drugs can cause cardiomyopathy), as a rare effect of hyperthyroidism and in cats who fend for themselves or are fed diets deficient in taurine. In cats in which taurine deficiency is not present, the prognosis for dilated cardiomyopathy is reported to be poor, with very few cats living longer than six months (Scherding, "The Cat: Diseases and Clinical Management).

Hypertrophic cardiomyopathy causes thickening of the heart chamber walls, which leads to restriction in blood flow due to a sort of "muscle bound" condition in the heart. The outcomes are similar but this disorder does not occur due to taurine deficiency and is more common in Maine Coon cats than in other breeds. Again, not being a cardiologist it is hard for me to be certain what the cardiologist was thinking, but perhaps the mixture of thickening in some areas and dilitation in others is the reason no clear diagnosis was possible.

The cardiology group (Dr. Mark Kittleson and associates) at the University of California at Davis have (www.morrisanimalfoundation.org) been studying cardiomyopathy in Maine Coon cats and the Morris Animal Foundation has funded research in this area.The Winn Foundation may also be funding research in this area (www.winnfelinehealth.org).

Lysol (tm) is irritating to tissues and can cause toxic damage to the lining surface of the gastrointestinal tract if ingested. I am not aware of toxic potential at low dosages, or by means other than ingestion. However, there has been a report of hypersensitive (allergy) to Lysol, causing skin disease in a cat (Rachofsky et al, Companion Animal Practice, March 1988).

You are right to be cautious about the pesticide applications. While the vast majority of pesticide companies are careful and do correctly inform customers of the risks of the products they are applying, every now and then we do see problems in pets that are the result of misunderstandings between the dog owner the pest control company.

In this particular case, it would be surprising if either the insecticide application or the Lysol actually contributed to the heart disease, though.

Both the Winn Foundation and the Morris Animal Foundation benefit many pets through funding research so they are good organizations to support, if you wish to make a memorial contribution for Gus.

Mike Richards, DVM 8/5/2000

Cardiomyopathy testing

Question: Hi Dr. Mike, I would like to know if the only way to definitely diagnosis cardiomyopathy is by an echo? Can you really diagnosis it by x ray only and/or listening to the heart? If a cat is present for a routine visit and a murmur is heard , the cat is asymtomatic at the time, would that make you think cardiomyopathy? IF you can send sites and info that would be great. Thanks, Susan

Answer: Susan-

I think that you can make a good educated guess about whether or not cardiomyopathy is present based on clinical history, the presence of a heart murmur, an evaluation of the heart murmur and heart enlargement on an X-ray or evidenced by electrocardiogram. But I think that cardiac ultrasound exam is the only really good way to be sure that cardiomyopathy is present and to evaluate how bad it is. And I think it still takes a pretty good ultrasonagrapher and/or cardiologist to make that determination, so I want to refer my patients to someone I think does a good job for this type of examination.

I treat a lot of cats for cardiomyopathy, sometimes with good success, despite the fact that I don't have an ultrasound machine and can just barely read an ultrasound image, though. Many of my clients won't travel to a specialist or won't spend the money for the specialized testing and if there is enough reason to suspect cardiomyopathy we will treat for it based on the rest of the findings in a case. Lots and lots of cats were successful diagnosed and treated for this condition prior to the availability of ultrasound imaging.

Heart murmurs in cats that occur in the early adult years are highly suggestive of cardiomyopathy but not conclusive for it. Listening carefully to the murmur and determining the location and type of murmur can help in the determination of whether it is likely to be due to cardiomyopathy. A "gallop rhythm" is very suggestive of cardiomyopathy in cats but this may only occur very late in cardiomyopathy.

The problem is that there are other causes of heart failure that can produce similar clinical signs and so it is difficult to be sure of the diagnosis. In some respects this isn't too bad since treatment for heart failure is similar for most conditions causing it but there are sometimes important differences and a few cats get shortchanged if there is not an accurate diagnosis.

I don't know of a good web site devoted to feline cardiomyopathy but I suspect it is mentioned on many of the sites devoted to cats and cat medicine and wouldn't be surprised if there is a site for feline cardiomyopathy that I am not aware of. There is some information in the PubMed database and you can get some leads on journal references that your vet might have in his or her library. The Vet Clinics of North America have had a couple of issues in which this topic was discussed.

If you have more specific questions about ultrasound exam or cardiomyopathy I would be glad to try to answer them.

Mike Richards, DVM 3/13/2000

Hypertrophic cardiomyopathy and Corticosteroids

Question: Dear Dr. Mike:

I just read your articles related to cats with hypertrophic cardiomyopathy. I have a 17 month old male cat who has just been diagnosed with this disorder. I had brought him to numerous vets with the complaint that Storm appeared to be having episodes of increased shortness of breath. Storm is an indoor, active, 16 pound cat who after repeated tests always came back the picture of health. I had been told Storm had everything from a hairball to asthma. My lovely cat is now in the ICU ward, where he was brought after being found on the floor cyanotic, foaming, with rapid respiration's. It has been 4 days of hell but I have seen Storm and been told he is slowly getting better. He is now breathing on his own, without oxygen assistance, and is out of failure. My question to you is, Storm was given a shot of Cortisone on Tuesday, exactly 2 days before I woke up to him in failure. Do you think the Cortisone shot affected him? Nobody will give me a straight answer, but I feel that I have failed my beautiful kitten and need to know. I love my cat deeply and pray every minute for his return. Please help, your response is eagerly awaited. Thanks...D.

Answer: Dawn-

Corticosteroids can cause just enough extra work for the heart to push a weak heart into failure. In this situation the corticosteroid isn't causing the underlying problem (cardiomyopathy) but it does cause the final insult that leads to failure.

Unfortunately, lots of people discover that their cats have cardiomyopathy because something that wouldn't ordinarily cause problems does cause problems for their cat because of a weakened heart. Anesthesia, heat, forced exercise, corticosteroids, other diseases and anything else that can make the heart have to work hard can lead to the sudden appearance of clinical signs in a cat with previously undiagnosed cardiomyopathy.

So it isn't really a matter of you letting him down --- you didn't know this problem existed and neither did your vet. Perhaps you could have been a little more observant, or your vet could have been a little more observant -- but this is a situation in which hindsight is a HUGE advantage. The truth is that many cats with cardiomyopathy are hiding it well enough that it is very hard to diagnose it based on observable clinical signs.

Hopefully the Medical Center will be able to get Storm through this crisis and then help you to keep him stabilized afterwards. His progress so far is a good sign.

Mike Richards, DVM 12/2/99


Q: I am interested in finding out as much as possible about cardiomyopathy disease, causes and treatment. I have just had a kitty diagnosed with this condition. My reason for concern is, my vet was less than optimistic about Pink’s longevity. He said most cats only live 12 to 18 months after being diagnosed with cardiomyopathy, even with treatment Pinky is 3½ years old, male, red tabby with a calm, loving personality. He is slightly overweight at 14 lbs. He gets ¾ cup Science Diet Light, split feeding twice a day. He chose to live with us when he was 5 months (after being a regular visitor for several weeks). He was neutered and tested Felv/Fiv negative when he was 6 months and has always been current on his vaccinations (5 in 1 + FIP). He leads a carefree playful life indoors with 3 other healthy neutered male cats. His health has been excellent (so has his mother’s, she lives next door). Around Christmastime he developed an occasional cough, 2 to 10 coughs every 4 to 7 days and vomiting, small amount of clear liquid, every 10 to 14 days. I also noticed his gums were more inflamed then usual. He has always had slightly redder gums and a different breath smell then my other cats but clean teeth. On Feb. 10th I took Pink to the Drs. He suspected asthma and suggested an x-ray and redoing the Felv/Fiv test (which was neg. again). The x-ray showed vague bronchial congestion with possible evidence for asthma. What surprised us both was Pinky’s heart looked enlarged, which the vet said could be caused by asthma but after the x-ray he listened more carefully to Pink’s heart and heard a slight murmur. To get a better idea he suggested an ultrasound exam from a specialist that would come to the vet's office. The exam showed the heart valve on the left side was not closing completely, and the septum chamber wall was slightly thickened, 16 mm. However, there did not appear to be any evidence of asthma in the lungs. The diagnosis of the consulting vet and the 2 doctors in the clinic was cardiomyopathy, cause unknown, with the caveat that gum disease and bacteria can contribute to heart and kidney problems. Suggested treatment was Clamamox for gum inflammation and Dilacon for heart disease, although he had reservations about the effectiveness of Dilacon at this early stage of cardiomyopathy. And a follow up ultrasound exam in 2 or 3 months. After reading your articles at vetinfo.com I am wondering if Pinky should have a complete blood work-up to check kidney and thyroid function. Are there any other tests or treatments that you can suggest? What about his diet? I don’t want to incur any more expense then is necessary but Pink is like my second son and I am willing to go into debt to take care of him. Again, thank you so much for the service that you provide to animals and their care givers.

A: A study was recently published in the February 15th issue of the Journal of the American Veterinary Medical Association by Atkins, et. al. on pages 517 to 520. It reviews the diagnosis of 100 cats seen for cardiorespiratory abnormalities at North Carolina State University and Texas A&M University. The authors report that 51% of cats seen in this study had cardiomyopathy, 12% had other cardiac problems, 9% had heartworms, 8% had asthma, 8% had metabolic illnesses (hypertension, hyperthyroidism), 3% had noncardiogenic pleural effusion and the remaining 9% had other miscellaneous illnesses or a diagnosis was not possible.

So the odds are really good that a cat with coughing and other cardiac or respiratory signs has hypertrophic cardiomyopathy, just based on the prevalence of the disease. On the other hand, I think that most cardiologists agree that a single ultrasound exam showing some signs of hypertrophy can be misleading and that it is best to confirm this diagnosis by repeating the ultrasound exam. If the specialist was not a cardiologist you might want to consider asking for referral to a veterinary cardiologist for a second opinion. I know that this is often not financially or even physically possible but if it is a reasonable option where you live I'd consider it. If you need to conserve funds to treat the condition it is certainly reasonable to accept the diagnosis since it is very likely to be correct.

I don't know what Dilacon is (I do think I may have requested this information in an email. If it was 18 pages long then I must have sent something else accidentally or else copied the entire file I was working from to the email somehow. If I did that you have a lot of extraneous information).

Anyway, the basic question you are seeking information on is prognosis and I haven't supplied much information.

Here goes:

If a cat has no clinical signs when the disease is diagnosed the prognosis is often very good for a reasonably normal lifespan. Some cats live a long time with no treatment at all in this case. I know of several cats who have lived at least 5 or 6 years after diagnosis and are still alive. Many vets feel it is best to treat with enalapril (Enacard Rx) or diltiazem (Cardizem Rx) at this stage.

If a cat has some clinical signs, such as coughing, shortness of breath or weight loss and the left atrium is not enlarged then the prognosis is still reasonable. The above medications may be used, or beta blockers may be added if the heart rate is very fast.

If the cat has the above clinical signs and an enlarged left atrium the prognosis is not as good (probably closer to the 12 to 18 months your vet has predicted) because many cats with this set of conditions will develop blood clots that cause sudden death or rear leg paralysis at some point. Aspirin therapy is sometimes advocated in addition to treatment for heart failure. If blood clotting potential seems very high warfarin type medications may be used.

If a cat has already had an embolic episode (clinical signs of having had blood clots, such as temporary paralysis of the rear legs) the prognosis is grave and the prognosis for lifespan is probably several months in most cases. The same medications are used in these cases, they just aren't as likely to help at this point.

I think I'd want to run a heartworm test here in coastal Virginia but I am not sure of the necessity of that where you live.

I'd find out whether or not there was any evidence of atrial enlargement, too. It may help to clarify how serious the situation is.

Good luck with this.

Mike Richards, DVM

Pulmonary edema and cardiomyopathy

Q: Please help me to understand exactly what has happened to our two male persians; In Feb.1998, our oldest male (age6) needed to be sedated for a dental cleaning,immediately after the procedure,our vet informed us "Sammy" developed acute pulmonary edema most likely caused from the anesthesia. Sammy was placed on oxygen therapy and given steroids I.V. After several days we were able to bring Sammy home although he was extremely short of breath and weak. Time passed and Sammy regained his appetite but remained short of breath and lethargic,our vet did not prescribe any medication for him but instructed us to avoid using any aerosol sprays around him. On June 23,1998 everyone was gone from our home except our daughter who called us at work and said Sammy was scratching on her bedroom door,when she opened the door Sammy was very short of breath and had "frothing pink fluid" draining from his mouth. She rushed him to the vet but he died en route and we have been devastated since. Our vet said he died from acute pulmonary edema.

On June 22,1998 our year and a half male "Spanky" developed pneumonia and he was placed on amoxi drops and sent home. On July 1,1998 Spanky had a follow up chest x-ray and EKG which revealed atelectasis,we started him on Lasix,that night Spanky developed rapid resp (80 per minute) At 5:30 A.M. he was in severe distress and I rushed him to the vet and he diagnosed him with pulmonary edema.Our vet administered I.V. steriods and placed Oxygen on Spanky but he showed no improvement.At 11:00 A.M. the vet recommended he euthanize Spanky since there was no improvement. I have buried two of my "children" within 9 days of each other and I keep thinking there was something more that could have been done to save them-such as preventive medicine using steroids, diuretics or cardiac meds.I have searched our home for any possible cause but there have been no major changes. Please help me determine the cause of their illness (they were unrelated cats) and tell me if there was anything which could have prevented their deaths.

Thank you

A: Dear D.-

For a long time I have heard reports of episodes of pulmonary edema and/or heart failure following anesthesia in cats. There has been some concern among veterinarians over the potential for ketamine, a commonly used anesthetic agent, to cause episodes of pulmonary edema. No one seems to be certain why this occurs, nor how frequently. We use ketamine in our practice and have not had an anesthetic death in several years. Ketamine appears to cause hypertension during the recovery period in many cats. If the cat has pre-existing cardiomyopathy this could lead to a sudden worsening of the cardiomyopathy leading to pulmonary edema and death, if the cardiomyopathy can not be brought under control with medications. There is some possibility that this effect could occur even without cardiomyopathy being present. I have only seen reports of this condition in association with ketamine but it may occur with other anesthetic agents. Despite this risk, ketamine appears to be a lot safer than other injectable anesthetic agents in cats, especially when compared with barbituates.

Cardiomyopathy is the most common cause of pulmonary edema or in young male cats and this syndrome definitely can occur without anesthesia to facilitate it. Cardiomyopathy may produce a heart murmur but it can occur without any audible murmur or noticeable clinical signs. Murmurs associated with cardiomyopathy seem to be easiest to hear by placing the stethescope directly on the sternum of affected cats and this is not the place a lot of vets were taught to listen to pet's hearts so a vet who is following the protocol taught in their veterinary school may never listen there. With atelectasis it may be more likely that Spanky had pleural effusion (fluid collecting around the lungs) but this can occur with cardiomyopathy as well.

There are other possible causes of acute pulmonary edema and pleural effusion, including cancer, feline leukemia virus infection and heartworm disease. We just treated a patient who died from a thymus tumor even though she was only 1.5 years old. She had a great deal of fluid in her chest and we could not even control it well enough to allow us to proceed with a good diagnostic effort prior to her death.

We use high dosages of diuretics, withdrawal of fluid from the chest if the problem is pleural effusion rather than pulmonary edema, oxygen therapy and nitrogylcerine ointment sometimes to help control the fluid. Many times we succeed in getting cats stabilized. Sometimes this leads to long term control of the problem if cardiomyopathy is present. Sometimes it just prolongs a patient's life for a few hours or days. I wish we knew which cases were going to respond in advance but all we can do is try to treat and then wait to see what happens. It is very frustrating for us and even more frustrating for our clients.

It is extremely hard to lose two good friends in such a short period of time. You have my sympathy.

Mike Richards, DVM

Hypertrophic Cardiomyopathy of cats - Dilacor

Q: My nine year old cat was diagnosed with idiopathic hypertrophic cardiomyopathy a year ago. He is on Dilacor, 60 mg (I open the 120 mg. caspsule and give him one of the tiny tablets) once a day, at night, and half a baby aspirin Monday, Wednesday and Friday a.m. He has good days and bad days, understandably. He vomits a lot. Not every day, and sometimes goes several days without vomiting, but still a lot. I've been searching the internet this evening trying to find out if this is a side effect of the medicine, or of the disease, and came across this WebSite. He is well-combed and doesn't seem to have hairballs. We live in an area where people use snail pellets, and pesticides, in their yards...we don't, and Brandon doesn't travel too far from home. I've considered this as a source, but it seemd like too much of a repetitive coincidence. His appetite is good on some days, and not on others. He has lost a small amount of weight, and another thing I've noticed, his fur seems a little oilier than normal...can you offer any suggestions?


A: It is my understanding that Dilacor XR (Rx) is usually used in the following manner for hypertrophic cardiomyopathy of cats: Dilacor is a capsule that contains three small tablets. Each tablet is 60mg. The tablets are split in half and the cat receives 1/2 tablet every 8 hours.

Dilacor is not approved for cats and there is not a "label dosage" to go by. Your vet may have information that suggests once daily dosing is satisfactory, which I am unaware of. This also means that there isn't a convenient list of noted side effects but I do not think that vomiting is a very likely side effect of the medication, based on the limited information I can find on it. I do think that almost any medication can cause almost any side effect in a given patient but you still have to consider it unlikely when it isn't being widely reported.

Vomiting is not normally considered to be a clinical sign of hypertrophic cardiomyopathy. It is possible to confuse coughing and vomiting in cats pretty easily. If this seems as if it might be possible in your cat's case, then you may be seeing coughing. That could be a sign of hypertrophic cardiomyopathy if it is severe enough. Vomiting is very common in older cats in association with inflammatory bowel disease, hyperthyroidism and sometimes kidney failure. It may be worthwhile to make an effort to rule out these other causes of vomiting, if possible.

It is not too likely that the vomiting is from insecticides. But it would still be a good idea to keep Brandon out of the neighbor's yards if they are using an insecticide.

You might want to check with your vet about the dosing schedule for Dilacor, just in case there is a misunderstanding. It would be a good idea to discuss the vomiting at that time with your vet, too. It really may be beneficial for Brandon to consider testing for other possible causes of vomiting.

I hope you find some relief for Brandon's vomiting.

Mike Richards, DVM


Q: Dear Dr Mike, I may be asking you a question that's already in your archives, if so, please redirect me. I'm an American living in France and I have my cat with me. I have been to a vet here about a health problem of her's, but my French Vet Vocabulary isn't that great, so maybe you can help explain her malady to me in my native language. My 6 year old Siamese cat started limping a week ago and I took her to a reputable vet. He performed a cardiac ultrasound and believes that she is having some artery blockage which is causing paralysis in her hind legs. He prescribed a sort of cat asprin (aFelagyl) and an antibiotic (Synulox 50) to treat her until he gets more lab results back. Have you heard of this? It sounds extreme to me. I would greatly appreciate an answer as I'm far from home and scared for my kitty. Thanks, leslie

A: Leslie-It is not highly unusual for cardiomyopathy in cats to lead to blood clotting in the heart. When these blood clots get into the circulation they travel down the aorta. If they are large enough, they will be stopped at the point the aorta divides in order to provide circulation to the rear legs. A blockage at this point leads to paralysis of the rear legs. This is a serious problem and cats can die from the circulatory disturbance and its side effects as well as from the cardiomyopathy that causes the problem in the first place.

While there are other possibilities I suspect your vet is competent and that he will probably do the best that he can to help your cat. I hope this is working out OK.

Mike Richards, DVM

Ultrasound exam (echocardiography) for Cardiomyopathy

Q: My cat was just diagnosed as having stress-induced heart failure, with possible cardiomypathy. It was suggested that I get an echocardiogram done. What will this show me? Will it lead to a possible treatment and prolonged life for my cat, or will it just tell me what exactly is wrong? Please give me any info you can, and also the likelihood that this was stress induced. Thank you.

A: Cheryl- Ultrasound exam (echocardiography) is the only way I know of to definitively diagnose cardiomyopathy. If this is present, treatment is possible and treatment will usually extend the lifespan of affected cats. If it is not present and some other cardiac disorder is causing the symptoms it may be possible to diagnose that as well. I really do think it is worthwhile to have an ultrasound exam.

I do not think that anyone really knows why hypertrophic cardiomyopathy occurs except when it is caused by hyperthyroidism or hypertension. So stress is as good a guess as any but I think it is a guess. Dilated cardiomyopathy is almost exclusively caused by taurine deficiency. This form of cardiomyopathy is rare since cat foods have been supplemented with taurine ever since the discovery of that problem.

Mike Richards, DVM

Cardiomyopathy in young cat

Q: Dear Dr. Mike, We have had some distressing news. We took my mothers cat to the vet to be spayed but after pre-surgery exam they informed us that they would not undertake the operation because of fluid around the lungs seen on her xrays with which the vet gave a presumptive diagnosis of cardiomyopathy. The kitten is 9 months old. My mother, age 81, was very upset, needless to say. The treatment prescribed was lasix and potassium (which we requested). Would you recommend a ECG? Also, is there medication that can help the kitten to lead a longer and more comfortable life? I have your article on Cardiomyopathy in Cats. Thank you for making such information available to us! Marilyn

A: Marilyn= This information may be too late to help in making a decision, but in cats ultrasound exam is more likely to be helpful than an electrocardiogram. If you have to chose between tests due to expense or other reasons, it would be best to to ultrasonagraphy (echocardiography). If you don't have to choose it is best to consider chest X-rays, ECG and ultrasonagraphy, especially in a cat this young. Having all of these results would make it easier to form a treatment plan.

Mike Richards, DVM


Q: Dear Dr. Mike, I am soooo embarrassed! I have been having so much trouble with my mail program...I know I received a message from you regarding the question below, but now it is no where to be found on my computer. Would it be possible to re-send? So sorry for extra trouble but we were so excited to hear from you! Thank you for caring about people and pets! M. Dear Dr. Mike , We have had some distressing news. We took my mothers cat to the vet to be spayed but after pre-surgery exam they informed us that they would not undertake the operation because of fluid around the lungs seen on her xrays with which the vet gave a presumptive diagnosis of cardiomyopathy. The kitten is 9 months old. My mother, age 81, was very upset, needless to say. The treatment prescribed was lasix and potassium (which we requested). Would you recommend a ECG? Also, is there medication that can help the kitten to lead a longer and more comfortable life? I have your article on Cardiomyopathy in Cats. Thank you for making such information available to us! Marilyn

A: Marilyn- Your timing is not very good, unfortunately. I just purchased a new computer and archived the old mail in files rather than copying the old data to my new computer. I am hoping Michal recognizes the mail and knows if it was put online where you might be able to find it.

Just in case we don't find the original reply (which may be more detailed), the basic answers to your questions are this:

Echocardiography (ultrasound exam) is MUCH more likely to provide a diagnosis of heart problems in a cat and I would choose it over an ECG if you have to make a choice. If not, do both.

Diltiazem (Cardizem Rx) seems to help cats with cardiomyopathy based on our clinical experience. This is the standard therapy, to the best of my knowledge, but I seem to remember seeing somewhere that some vets are questioning its effectiveness now. Furosemide (Lasix Rx) can be beneficial and sometimes enalapril (Enacard Rx) is recommended as well. Many cats can be stabilized and live reasonably normal lives.

Mike Richards, DVM

Cardiomyopathy in Kitten

Q: Dear Doc: My girlfriend has a six month old kitten which was a stray that she adopted. Her boyfriend noticed about a week ago that when Madison runs around the house, she pants and her tongue hangs out. She was showing difficulty breathing and in the past was diagnosed as having a heart murmur. She took Madison to the vet yesterday and was told she had an inflamed heart and would need an ultrasound. The technician does not come to his office for another week(unless emergency is requested). Can you explain what a possible diagnosis could be for an inflamed heart , and whether an inflamed condition is treatable? Your fast response would be greatly appreciated as we are very worried!!! Thank you

A: The most likely problem is cardiomyopathy. This is a weakness of the heart muscle that is probably the most common cause of heart murmurs in cats. It is important to get an ultrasound examination to be sure that is the problem. In many cases this condition will respond to treatment well enough for cats to live a pretty normal life for some time -- or else our patients have been very lucky. I don't have my references here (have been out of town) but I don't think that the cause of this condition is known unless it is due to dietary deficiency of taurine, which is pretty rare if a cat is fed good quality commercially available cat foods.

Mike Richards, DVM

Last edited 05/06/02


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...