Kanfer’s Answers – Heart Disease

We just had a newly rescued foster bun die on us suddenly. We’d only had her for 1 week. She was an intact female, estimated age 9 months -1 year. Caught outside in an area where rabbits have been getting dumped at for decades. She had a facial trauma on the left side of her face that was badly infected. A vet cleaned out the infection the day we caught her. He did not find any part of her eye left. She went back for a recheck 5 days later and the infection was persisting so the eye area was cleaned out again. Less than 2 days later, she passed away during the night.

We had a necropsy performed and this is what she found:

“Her chest is where I believe we can find cause of death. Her heart was surprisingly enlarged. Particularly her right atrium and ventricle. I was not able to pinpoint a specific congenital defect, although I suspect that based on her appearance of being a younger rabbit. We can see myocarditis (infection of the heart and valves) when there is an infection elsewhere in the body (like her eye), but I would not have expected to see the substantial enlargement of the heart itself with that. Her lung tissue appeared congested, but that is likely secondary to her heart.”

Can you give any further insight as what may have happened to this poor girl? Is inbreeding a possible cause of an enlarged heart? We’ve not had experience with heart issues here so any knowledge you can offer would be appreciated.

I am sorry for your loss. It is more likely that the bite wound and severe infection was the cause of her passing away, she probably was septic. Yes, inbreeding can lead to a rabbit being born with an abnormal heart. Infection can also affect the heart.

We just had a newly rescued foster bun die on us suddenly. We’d only had her for 1 week. She was an intact female, estimated age 9 months -1 year. Caught outside in an area where rabbits have been getting dumped at for decades. She had a facial trauma on the left side of her face that was badly infected. A vet cleaned out the infection the day we caught her. He did not find any part of her eye left. She went back for a recheck 5 days later and the infection was persisting so the eye area was cleaned out again. Less than 2 days later, she passed away during the night.

We had a necropsy performed and this is what she found:

“Her chest is where I believe we can find cause of death. Her heart was surprisingly enlarged. Particularly her right atrium and ventricle. I was not able to pinpoint a specific congenital defect, although I suspect that based on her appearance of being a younger rabbit. We can see myocarditis (infection of the heart and valves) when there is an infection elsewhere in the body (like her eye), but I would not have expected to see the substantial enlargement of the heart itself with that. Her lung tissue appeared congested, but that is likely secondary to her heart.”

Can you give any further insight as what may have happened to this poor girl? Is inbreeding a possible cause of an enlarged heart? We’ve not had experience with heart issues here so any knowledge you can offer would be appreciated.

I am sorry for your loss. It is more likely that the bite wound and severe infection was the cause of her passing away, she probably was septic. Yes, inbreeding can lead to a rabbit being born with an abnormal heart. Infection can also affect the heart.

“THIS ONE IS NOT A HEART DISEASE QUESTIONS BUT IF YOU CAN ANSWER THIS ONE PLEASE. 

 

hello, 

I have a question for Dr. Kanfer regarding bunnies molting and getting bald patches. 

Recently my bunny was molting and suddenly I saw a bald patch on his behind. It was pretty red and I took him to the exotic vet near me who suggested it was due to molting. We grabbed a sample of the skin to look under microscope and it was negative for fungal infection etc. I was given some antiseptic wipes to use and make sure the wound doesn’t change. A week later, the same patch looks dark purple and skin is scabby. The bunnny is eating fine and active and not scratching or biting the scab. 

My question is- is this bald patch during molting normal? Is the skin color changing to purple and getting hard/scabby normal? And will hair grow back? 

I couldn’t find anything about this online so curious if Dr. Kanfer can shed some light on this. 

Thank you in advance! 

Rashi Bhatnagar

When rabbits molt they sometimes lose hair in patches. Sometimes when rabbits are overgroomed they may develop bald patches. When the hair grows back in the skin can initially look very dark, black or purple, before you actually see the hair itself coming out of the skin. If the area formed a scab then that means there was some trauma to the skin, and it is healing.

Questions about heart disease in rabbits…

  1. The terms “congestive heart failure” and “heart disease” both sound scary as a diagnosis. Is there anything you can share that might offer some comfort for those of us whose rabbits have this condition?

Heart disease is a general term meaning any abnormality of the heart. As heart disease progresses and becomes severe then the heart is not able to pump the blood through the heart normally. This causes fluid to build up in the lungs or liver. When fluid is building up this is called Congestive Heart Failure. This condition can be treated, but the response to treatment depends on how bad the heart disease is. The main treatment for Congestive Heart Failure is a diuretic like Furosemide to pull out the excess fluid.

Heart disease of all stages as well as Congestive Heart Failure can be treated with additional medications to help the heart function better. X-rays and a heart ultrasound (echocardiogram) are necessary to determine the type of heart disease as well as how advanced the heart disease is. Rabbits frequently develop Dilated Cardiomyopathy. Cardiomyopathy means heart muscle disease. Dilated means the heart muscle gets thin and stretched out, and the heart chambers become enlarged. The heart muscle can get so weak that it cannot contract normally. Rabbits may also develop Hypertrophic Cardiomyopathy. With this disease the heart muscle gets thickened and cannot contract as well. Rabbits can also get abnormalities of the heart valves.

Heart disease is not cured. It can be managed. If it is discovered in the early stages then medicines can help the heart function better and give the rabbit a longer life. If it is not discovered until the rabbit is in Congestive Heart Failure, and the lungs are filled with fluid then sometimes those cases will not improve much. I recommend performing x-rays annually starting at age 7 yrs of age. This will allow you to catch heart disease in the early stages.

  1. I understand it is rare to discover a rabbit has heart disease before conditions may be quite serious. What defines early diagnosis or recognition of heart disease, and how might early treatment offer an advantage?

I recommend performing x-rays annually starting at age 7 yrs of age. The x-rays need to be read by a veterinarian that is experienced with rabbits and knows normal heart sizes. If the heart appears mildly enlarged on x-rays then an echocardiogram can be performed to see if there is heart disease and if so, how serious.

There are also cases where we discover heart disease in young animals. So you may want to get x-rays done even if your rabbit is young. Plus it is good to have baseline x-rays to compare to.

Some veterinarians do not believe in using heart meds until heart disease is advanced. In rabbits heart disease can sometimes progress quickly. I like to start a low dose of heart meds as soon as I discover mild heart disease. This helps the heart continue to work better and slows down the progression of heart disease.

  1. Assuming heart disease is progressive and not curable, how do the variety of medications available for treatment still really benefit an animal?

Commonly used heart medications include:

–Benazepril/Enalapril: dilates the blood vessels, and make it easier for the heart to pump the blood out

–Pimobendan: helps the heart muscle contract and dilates blood vessels

–Furosemide: pulls out excess fluid

By using these meds I have had hundreds of rabbits whose heart function improved, determined by rechecking x-rays and echocardiograms.  I have also been able to reverse some cases of Congestive Heart Failure and have the rabbits live a few more years.

  1. Are some forms of heart disease more treatable than others? Can any forms be reversed?

Dilated Cardiomyopathy is more treatable than Hypertrophic Cardiomyopathy. Heart disease cannot be cured but the heart can improve on medications, usually there is significant improvement. When I see an enlarged, dilated heart on x-rays or echocardiogram, I start heart meds and after a few weeks I usually see the heart contracting better and the heart is not as enlarged. Eventually the heart will start to get enlarged again, and when that happens I increase the heart medicine doses.

  1. Is it true that some rabbit breeds and sizes (ie. New Zealand white rabbits, dwarf breeds, and larger size rabbits in general) are more prone to heart disease compared with others?

In my experience Flemish Giant and large New Zealand Whites tend to have hearts that appear large on x-rays, compared to their body size. In some cases they truly do have heart disease, but sometimes they don’t actually have heart disease, their heart just looks big. An echocardiogram is required for diagnosis. Personally I have not seen a higher percentage of heart disease in larger or dwarf rabbits. But large breed rabbits do tend to live shorter lives.

  1. Are there any recommended nutritional supplements or diet changes that could offer significant benefit to rabbits with heart disease? For example, I have read that some medications meant to treat this condition can also have a depletion effect of some nutrients or electrolytes perhaps within their bodies.

Dietary causes of heart disease can occur in cats and dogs. There has not been evidence of dietary issues causing heart disease in rabbits fed a normal diet.

The diuretic medication Furosemide can affect electrolytes, mostly seen in cats, and can worsen kidney disease.  

Nutritional supplements that may help: Omega fatty acids, L- carnitine.

  1. My senior rabbit was recently diagnosed with a significant heart arrhythmia and cardiomyopathy. He has since been placed on 3 medications: pimobendan, benazepril and furosemide. Since beginning the medications, I have noticed some unusual movements of him that weren’t particularly visible before. While resting, I have seen him sometimes nod his head upright ever so slightly and quickly…almost as if he were burping or had a hiccup. Sometimes this will happen in succession for 3 or 4 times. Less frequently, I may see almost like a flutter of movement along his sides…also very quick and short. My vet suggested this wouldn’t likely be heart-related. She did not suggest it was reason for great concern, but maybe digestive-related. He is otherwise behaving relatively normally and eating. Could this be a side-effect of any of these medications? Do you think I should still be concerned? My vet is experienced in exotic animal care.

Rabbits with heart disease may breathe a little harder or deeper. This can cause their head to rock or nod when resting. But some rabbits without heart disease do this as well. The flutter movement along the sides could just be the intestines moving. These do not sound concerning, and do not occur secondary to these heart meds.

  1. Finally, can you offer any words that might help me not to worry so much about seeing him decline…perhaps suddenly or dramatically so? I do not want him to suffer for any prolonged time and not recognize when it may be right to let him go peacefully. I wonder if his treatment will help prevent anything dramatic from occurring, or anything that may be particularly upsetting…as I know losing him will be hard enough.

You can have x-rays rechecked every 2-3 months and ultrasound rechecked every 4-6months, to monitor for worsening of the heart disease. After I start heart meds I usually see the heart go back down to a more normal size on recheck x-rays, as it gets less stretched out. Often the arrhythmia will go away. Then after time passes the heart will start to get enlarged again, and/or the arrhythmia returns. When that happens the meds would need to be increased.

When rabbits molt they sometimes lose hair in patches. Sometimes when rabbits are overgroomed they may develop bald patches. When the hair grows back in the skin can initially look very dark, black or purple, before you actually see the hair itself coming out of the skin. If the area formed a scab then that means there was some trauma to the skin, and it is healing.