Ferret Heart Disease FAQ


  1. Cardiomyopathy in the Ferret (Dr. Williams)
  2. Cardiomyopathy (Dr. Brown)
  3. Caring for a ferret with heart disease
  4. Living with a ferret with congestive heart failure

Cardiomyopathy in the Ferret (Dr. Williams)

Dr. Bruce Williams, DVM, writes:

In short, CMP is a congenital problem in some lines of ferrets that manifests as ferrets get older. CMP means that the muscle of the heart becomes progressively weaker, and the heart is no longer strong enough to pump all of the blood. As the muscle weakens, it stretches, and the heart gradually enlarges, sort of like a balloon.

As the blood begins to back up, it will accumulate both within the lung and around the lung (often also in the abdominal cavity), resulting in coughing, which is the most commonly noticed sign. Actually, most animals have decreases in activity first, as they tire easily.

CMP can be treated with some drugs, including diuretics which help it manage the load, but the damage is progressive and cannot be reversed.

Concerning CMP - the vast majority of cases are probably due to genetics. CMP is seen in Boxers, Great Danes, and Dobermans - each of these breeds has their own specific type. CMP also runs in family lines in humans. While viruses have been incriminated in humans, I have not seen lesions resembling pre-existent viral infections in the ferrets with CMP that I have seen.

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Cardiomyopathy is a common cause of heart disease in a number of companion animals, including dogs, cats, and as many owners and breeders know, our little friend, the ferret. The word cardiomyopathy comes from three Greek words meaning, literally, "a disease of the heart muscle", and that, unfortunately, sums up much of what we know of this disease.

The cause of cardiomyopathy in the ferret, as well as in the dog and the cat, is unknown. In humans, where cardiomyopathy was first diagnosed and has been studied most extensively, this is also largely the case, although some types of cardiomyopathy may occur as a result of pre-existing endocrine diseases, viral disease, toxicities (including alcoholism), and nutritional deficiency (Robbins, 1989). There is one cause of cardiomyopathy that has been elucidated in the cat, and although it has not been definitely linked in the ferret, may be of importance - taurine deficiency. (This is just another reason why you should make sure that your ferrets food includes taurine - make sure to check those labels on the bag of food.)

Cardiomyopathy in the ferret is an insidious disease - the majority of the damage to the heart occurs long before the owner ever realizes that the animal is ill. The general defect in all types of cardiomyopathy is the same - death of cardiac muscle fibers, which are then replaced with scar tissue. Scar tissue does not have the ability to conduct electrical impulse or to contract like heart muscle fibers can. As more and more myofibers are lost, the heart weakens and can no longer pump blood efficiently. This results in the two clinical findings which are the hallmark of diagnosis of heart disease in the ferret: a) an enlarged heart, and b) a "backing up" of the blood due to the weakened heart's inability to pump it effectively (resulting in a syndrome known as "congestive heart failure" - explained below.)

When the blood backs up in the ferret it may go to a number of places - it may back up into the abdomen, resulting in a swollen, fluid-filled belly. Additionally, it may back up into the space around the lungs or into the lungs themselves. If fluid backs up into the lungs, the ferret may initially show a soft cough. As the fluid buildup progresses, the cough may worsen, and the owner will generally notice a sharp decrease in the animal's energy. In the end stages of the disease, ferrets have marked difficulty in breathing, often as a combination of the fluid in the lungs and the fluid in the abdomen (which presses on the diaphragm, impeding the ferrets' breathing even further). This is what is known as congestive heart failure.

I have also seen cases of a different type of cardiomyopathy in a handful of ferrets, a type of cardiomyopathy which is also seen in cats and is known as "hypertrophic cardiomyopathy". In this disease, there is an overgrowth of fibers in the heart, which encroach upon the inside diameter of the heart, and in this manner, decrease the heart's effectiveness in pumping the blood presented to it. The clinical signs of this type of cardiomyopathy are identical to the congestive type which has already been discussed.

Diagnosis of the disease is difficult in the early stages, but becomes progressively easier as the disease goes along. All of the signs (enlarged heart, fluid in the abdomen or around the lungs) can be seen on a radiograph (or "x-ray"), and this is the primary method by which affected animals are diagnosed. Specialized tests, such as echocardiography, are available at some veterinary hospitals, and can help pinpoint cases earlier in the disease's progression.

We have discussed that cardiomyopathy is an insidious, progressive disease; there is no cure for cardiomyopathy, only treatment. The hallmark of treatment of this type of heart disease is two-fold: you must first decrease the amount of fluid built up in abnormal locations, and second, increase the strength of contraction of the heart. Diuretics are used to mobilize the excess fluid from the abdomen and lungs, and to keep the blood volume at a level which the weakened heart can pump it. Digitalis and related drugs help increase the strength of contraction of the remaining heart muscle to help it pump more effectively. In early cases, management of fluid volume with diuretics may be the only treatment necessary, with digitalis and like drugs held in reserve for the time when the heart becomes weaker.

However, not all animals respond well to treatment. Dr. James Fox, in his book Biology and Diseases of the Ferret, reports that even when treated, the clinical course is fairly rapid, and treatment failures are common. This enforces the need to monitor your pets closely and bring any suspicions that you may have to the attention of your veterinarian immediately.

1. Robbins SL, Cotran RS and Kumar V. Pathologic Basis of Disease. W.B. Saunders and Co., Philadelphia, 1989. p. 634-638.

2. Fox, JL. Biology and Diseases of the Ferret. Lea and Febiger, Philadelphia, 1988, pp 268-269.

3. Jubb, Kennedy, and Palmer. Pathology of Domestic Animals, vol 3. Academic Press, San Diego, 1985, pp. 26- 29.

Bruce Williams, DVM
Dr. Williams is available to help with diagnoses and answer questions.

Cardiomyopathy (Dr. Brown)

Dr. Susan Brown, DVM, writes:

We see far less cardiomyopathy than we used to before the started adding taurine to the cat food diets. Taurine deficiency was implicated in dilatative cardiomyopathy in cats.

However, we see both dilatative (where the heart muscle is weak and gets dilated) and hypertrophic (where the heart muscle gets thickened and the ventricle space gets very small). Diagnosis is based on signs, survey x-ray, ECG and ultrasound...you need to differentiate the dilatative form from the hypertrophic form, they use some different medications. One should also test the ferret for heartworms in heartworm susceptible areas (although, hopefully they will be seen on ultrasound), because this disease can also cause serious heart disease.

We use diuretics for all cases and Vasotech and then other drugs as needed depending on the type of disease it is. It is worth treating and we have had ferrets go on for up to two years past the initial diagnosis even with some fluid in the lungs initially. Of course it all depends on how much damage the heart has sustained in the first place.

Caring for a ferret with heart disease

[The following information comes from Sukie Crandall, who generously sent an account of her experiences with Meltdown and Ruffle, two of her ferrets with heart disease.]

Fat does not present a problem for ferrets with heart disease as far as anyone has so far seen, but in some cases of non-cardiomyopathic or pre-cardiomyopathic heart disease salt might pose difficulties. There are NO ferret or cat foods with levels low enough; the ones with the lowest levels also have the least nutrition so ferrets would have had to eat more of the food and therefore more salt. Many baby foods also have too much salt. Instead, if your vet recommends a low-salt diet, cook a plain meat from your grocer without adding salt, puree it, add a few hard boiled egg yolks, and some Nu-Salt salt substitute to ferret's taste. Nu-Salt is potassium chloride so it is also useful when diuretics or dehydration cause electrolyte problems for ferrets with ascites. For storage purposes you can make convenient cubes by freezing most of it in ice trays and later transferring them to a sealed container or wrap.

Never give a ferret with heart disease any treats, herbs, or foods which can upset the careful balance you have achieved. Some of these include licorice, caffeinated or depressant-containing beverages, fibrous treats which can impair the uptake of Lanoxin, and perhaps chocolate since these animals are more sensitive to even slight perturbations.

Stress may be fatal to a ferret with heart disease. Give the individual her or his own cage or space such as a bathroom with a barrier across the portal (sanctuary) and allow play or sleep periods with good friends only while you supervise. Never let the ferret have a tantrum; pick it up immediately. Keep heat below 80 F and try to not let the temperature vary widely in your home. Remove very large or heavy toys your ferret is in the habit of moving and substitute small, light ones. Because the litter pan is used often look into some of the ones with shallow ramps or lower entry ways which can be found in ferret catalogs. Punishment is never a good training tool for ferrets anyway since they learn better by striving to do the things which earn them praise; for a ferret with cardiomyopathy it can be extremely dangerous. Let your sick one get away with things you would not normally have tolerated.

Since your ferret will very likely eventually have to use a piece of newspaper set on the floor of the cage when he or she can no longer deal comfortably with a litter pan add shredded newspaper to your litter to get it used to the concept while saving money you'll need for vet bills and pharmacy payments. (Our $80 shredder paid for itself in six months through reduced litter costs.)

Living with a ferret with congestive heart failure

[This article was contributed by Jan and Don Boyle.]

Eventually you may have a ferret who suffers from CHF or congestive heart failure. I am not a vet and do not offer advice. What I can offer are our experiences and hope by sharing them with you that it may in some way help you to deal with it as your little fuzzy goes through it. We still have our "big boy".

About 2 or 3 weeks prior to the critical events I am about to describe, Poto had a "slow-down". It was subtle, but noticeable. I did not know what was going on but noticed less playfulness and activity from him. Then one night I awoke at about 2:30 am and saw Poto, our oldest male ferret (probably almost 7 yrs old now) lying on the bathroom rug and looking "different". Sort of extra "flat" and limpish. I got up and usually he would perk up and watch me, but this time he just laid there and when I tried to stir him, he wouldn't get active. It is different than just being sleepy and I find it a bit difficult to relate in words, but you would know if you are close to your ferret.

Being a nurse, I have a stethescope so I listened to his heart and it was really frightening to hear his hear beat too slowly, then stop, start again and at times race very fast. I thought he was dying and later I realized of course that he indeed could have. I might say at this point that you can put your ear to your ferret's chest and hear their heartbeat also and don't necessarily need a stethescope. My husband got up and got him to stir and he seemed a bit better sort of but I was on the phone to a local vet by now. After describing his symptoms, the (ferret illiterate) vet said it could wait till morning.

Well, morning brought a heart that was racing to almost 400 beats per minute and then down to 200 beats, according to the local vet and an x-ray that wasn't read until late afternoon despite several calls by me to the clinic. It was 6pm before Poto was given his first dose of lasix (2mg). What the x-ray had revealed was that Poto's lungs and abdominal cavity was filling with fluid. There was a problem, however, in that the vet did not know for sure what he was seeing on the x-ray. The lasix was indeed what Poto needed but it came almost too late (almost 30 hours from the time we discovered Poto's symptoms) and perhaps a larger dose would have gotten faster results. We left the clinic with no diagnosis given, despite the symptoms and an x-ray.

Anyway, that night brought even worse symptoms of his condition. He struggled to breathe and at times experienced a "soft wet sounding cough". Only a couple or three during the night, but here again, I could distinguish that there was something different about this cough compred to the usual cough I have heard from my ferrets. Also, Poto had not had a cough prior to this episode.

Early the next morning we took Poto to a specialist vet a few hours away. I am pleases to say that the sonagram of his heart revealed that his heart valves were working normally. There was a pad of fat by his heart. That added to his problems according to his doctor. He did have two water-filled cysts in his kidneys but I do not think the doctors connect that condition with his CHF.

At home we continued the lasix doses and at the advice of his specialist vet, gradually reduced the amount of lasix to its lowest possible effective level, which is for Poto, a 1/2 mg dose given two times a day, 12 hours apart. In addition, Poto recieves a very small dose of a 1 mg tablet of enecard (animal medication) and that is one eighth of one tab daily. I use liquid lasix since his dose is small and I mix it with 5 teaspoons of liquid and the liquid consists of 1 teaspoon Sustecal and 4 teaspoons of water. I add the enecard (finely ground) to the evening dose of Ststecal/water with the lasix (1/2 mg) in it. So Poto recieves 1/2 mg of lasix am and 1/2 mg lasix pm with the 1/8th piece of a 1 mg tablet of enecard finely ground up and added to the liquid which has been slightly warmed. Oh yes, I also put a sprinkle of brewer's yeast in to help disguise the taste of the liquid lasix which is terrible. Lasix also comes in a tablet form.

Poto is overweight. It puts more strain on his heart because he is overweight. It is easier to keep your ferret from getting fat than it is to get the weight off of him/her. Obesity in ferrets shortens ferrets lives just like it does humans. When the weather was milder, we took walks and that helped some.

Right now and for several months, Poto has been doing wonderfully well and plays like his old self which is vigorously at times and seems as good as before, but that is because he has always been a very strong ferret. We have worked hard to try to get his weight down slowly. It is very difficult. Restricted calorie Eukanuba (only buy at some vet's clinics) has helped some. Now, I mix it with the regular Eukanuba since the restricted formula is not primarily a meat based formula like the regular lamb and rice is. I also plan to try reduced calorie Totally Ferret since our ferrets like the regular kind.

CHF in ferrets is a progressive disease just like it is in humans. According to the literature I have read, ferrets have been known to live up to 2 years after onset of symptoms. We are about 8 months down the road now. In the future, I expect to have to increase the lasix dosage.

I do recommend that you read all you can get your hands on CHF and ferrets. There is not a lot out there and your vet may not be skilled in treating ferrets who have it. It is different than treating cats or dogs and you may be able to shed some light on your fuzzie's best course of treatment for your vet and yourself.

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Copyright© 1994-1998 by Pamela Greene <pamg@rice.edu>.
Last modified: 27 Feb 1998. Comments and suggestions are welcome!
I am not a ferret expert and cannot guarantee the accuracy of this information.