causes of rabbit heart attacks
Health and Wellness

Rabbit Heart Attack Signs, Symptoms, Causes, and Treatment

The rise in the life expectancy of domesticated rabbits increases their chances of developing cardiovascular disease. Signs of heart disease in rabbits present themselves gradually. Unfortunately, this means heart attacks are often detected at advanced stages, where the risk of complications and death is significantly higher.

Heart disease is difficult to detect as some rabbits may be asymptomatic (no symptoms). But some rabbits may show fatigue, have different breathing patterns, or experience physical changes. Your rabbit may struggle to breathe, lose weight, or have deteriorating coordination.

However, rabbits can have a good quality of life even after they have a heart attack. Treatment for heart disease includes eliminating the cause, such as pneumonia or lung disease, medication, and special care from the owner. Stress reduction, a nutritious diet, and weight management (if your rabbit is obese) are also crucial for preventing the advancement of heart disease.

Heart Attacks in Rabbits

Cardiovascular disease is a major health concern that is mainly seen in rabbits older than 4 years. However, it can affect younger rabbits as well, depending on the cause.

The life expectancy of domestic rabbits is around 10-12 years for smaller breeds. The higher life expectancy comes with an increased risk of circulatory disease, arteriosclerosis, and heart issues.

You may not notice any signs or symptoms during the early stages of heart disease in your rabbit. There might be subtle changes, such as lethargy, reluctance to play, a mild decrease in appetite, or weight loss. However, these can be easily brushed off as they’re not specific to heart disease.

As heart disease in your rabbit progresses, you may notice changes in your rabbit’s breathing. In more advanced stages, your rabbit will show significant signs, such as labored breathing, occasional fainting, and complete loss of appetite.

Your rabbit will show severe signs of heart disease when it’s heart isn’t able to circulate blood around the body effectively. This causes fluid to back up in the abdomen and/or the lungs. At this stage, your rabbit has congestive heart failure.

Causes of a heart attack in rabbits vary. While a diet rich in fat or a lifestyle lacking exercise is a common cause of heart disease, some active rabbits have been shown to suffer from heart issues as well. Infectious disease, a diet lacking nutrients, living in a small cage without exercise, or dysfunction of the left ventricle are among the principal explanations.

If you suspect your rabbit may have heart disease, bring it to your vet for an examination. Rabbits suffering from heart disease should have annual exams, even if they seem healthy. Your vet will check your rabbit’s heartbeat for a heart murmur, or abnormal heart rhythm. A rabbit’s normal heart rate is 120 to 150 beats per minute, and a normal respiration rate is 30 to 60 breaths per minute.

Note that not all rabbits with cardiovascular disease have a detectable heart murmur. However, if it is present, it will alert your vet, even if outward signs are absent. Severe signs, such as difficulty breathing, should be counted as an emergency. Immediate hospitalization with oxygen support will be needed until symptoms improve.

How to tell if your Rabbit is having a Heart Attack

A heart attack, or heart disease, often presents itself through changes in breathing and physical changes, such as lethargy. Unfortunately, signs and symptoms of heart attacks in rabbits can resemble other conditions, making the condition look less serious than it actually is.

Signs of Heart Disease in Rabbits

Many rabbits are asymptomatic when they have heart disease until their condition progresses to a severe, and sometimes life-threatening stage. The most common visible symptoms of an oncoming heart attack include:

  • Breathing irregularities or difficulty breathing
  • Generalized weakness
  • Intolerance to exercise
  • Tachycardia (heart rate that is too fast)
  • Dyspnea (shortness of breath)
  • Heart murmur
  • Weight loss
  • Loss of appetite

Clinical signs develop slowly in case of heart disease and are often non-specific of the condition. Symptoms such as refusal to eat, loss of appetite, and lethargy can mimic other health concerns. Your rabbit may also have digestive disorders, such as diarrhea, hard and dry feces, and a distended belly.

Your Rabbit’s Eating Patterns

Changes in your rabbit’s eating patterns can be a significant sign of an impending heart attack. If your rabbit has stopped eating altogether, keep an eye on its bowel movements. Lack of appetite is a potential symptom of heart issues associated with a heart attack; however, not eating altogether can lead to gastrointestinal stasis (GI stasis).

GI stasis is a painful and fatal condition in rabbits that occurs when there is an obstruction in your rabbit’s digestive system. If your rabbit stops eating or doesn’t have any bowel movements, seek immediate veterinary attention.

Recognizing the signs and symptoms of a heart attack can be difficult in rabbits. Frequently, obvious signs are vague and resemble those of other conditions. Furthermore, rabbits are skilled at hiding signs of weakness, including pain and illness. This helps protect them from prey animals.

The ability to conceal symptoms is an advantageous characteristic to have in the wild. However, in domestic rabbits, this can prove to be fatal. You must distinguish your rabbit’s normal behavior from unusual behaviors, such as lack of appetite, lethargy, and irregular bowel movements.

heart attack symptoms in rabbits

Symptoms of a Heart Attack in Rabbits

As the disease progresses, your rabbit may show other signs such as persistent cough, accompanied by signs of pain or aggressiveness. Your rabbit’s heart rate increases because its heart has to work harder to pump blood throughout its body and supply its vitals with enough oxygen.

Detecting symptoms such as irregularities in heartbeat is more challenging in rabbits than it is in other animals. Therefore, you must look out for vague symptoms, such as behavioral changes, changes in mood, changes in eating patterns, and so on.

The following signs are typically seen when the rabbit’s heart is no longer capable of keeping up with circulating blood throughout the body. This causes fluid to back up in the abdomen and lungs, resulting in a heart attack or congestive heart failure.

Labored Breathing

During advanced stages of the disease, your rabbit may take long, deep, and labored breaths and/or have a blue discoloration on its tongue. This is a sign that it is not getting enough oxygen. Your rabbit will start mouth breathing as respiratory rate increases.

Audible Inhalation

Breathing in air is noisier and more difficult than exhaling air. This is because the heart is incapable of pumping enough blood throughout your rabbit’s body at this stage. Your rabbit’s nostrils will be dilated and breathing may become diaphragmatic (from the belly).

Fluids may accumulate in the lungs and the heart, indicating your rabbit is suffering from congestive heart failure.

Raised Head and Neck

Breathing problems linked to a heart attack will cause your rabbit to take a characteristic position at rest. Your rabbit will sit with its head and neck tilted slightly upward, keeping the front part in a raised position.

If your rabbit shows signs of breathing difficulties, it may be having a heart attack. Immediate medical attention should be sought at this point to stabilize your rabbit’s condition.

In acute stages of heart failure, your rabbit gets syncope. This is a temporary loss of consciousness often related to poor blood flow to the brain. This will be followed by collapse and death.

Causes of Heart Attack in Rabbits

Numerous factors can contribute to heart disease and cause heart attacks in rabbits. One major cause of heart attack in rabbits is stress. Rabbits are highly vulnerable to stress, and being in an environment that causes frequent stress in rabbits can lead to cardiovascular issues. A nutrient-poor diet and not enough exercise can also be contributing factors to heart attacks.

A High-Fat Diet

A diet rich in fat, too many treats, and sugar can contribute to heart problems in rabbits. Pellets that aren’t entirely hay-based or contain unwanted ingredients, and even heavy hay, such as Alfalfa hay during adulthood can affect the digestive systems of rabbits.

To maintain a healthy digestive tract, rabbits should be given a steady supply of high-quality grass hay. Your rabbit’s diet should be 80 to 90% hay because it contains the right balance of nutrients adult rabbits requires to be healthy.

In addition to grass hay, you can also supplement your rabbit’s diet with leafy greens, such as lettuce, spinach, kale, and carrot tops. Sweet or starchy vegetables, such as potatoes, and high-sugar foods, such as fruits should only be offered as treats to rabbits.

Your rabbit may enjoy the taste of certain treat foods, such as apples, but in excess, such foods can impair your rabbit’s digestion and cause severe complications in the long-term.

Nutrient Deficiencies

Deficiencies in nutrients, especially vitamins and minerals, such as calcium and phosphorus can cause heart disease. Too little calcium in the body can also lead to bone loss, thereby affecting your rabbit’s bone strength. Vitamins D or E deficiencies can cause abnormal mineralization of the blood vessels or muscle weakness, which can contribute to a heart attack.

Vegetables, pellets, and some fruits are excellent sources of vitamins and minerals for rabbits. Feed your rabbit leafy greens every day and fruits and starchy vegetables only as treats.

Lack of Exercise

In addition to a healthy diet, rabbits require daily exercise to reduce their risk of heart attack associated with weight gain. Your rabbit needs to have enough room to run around and exercise.

Spending too much time in a cage without any exercise can cause your rabbit to gain weight rapidly. Your rabbit should be let out of its enclosure daily. Allow your rabbit to roam around, jump, and play in an open space. It’s an excellent way for it to release its pent-up energy.

Make sure that your rabbit’s play space has been rabbit-proofed. If you’re letting your rabbit play outside, ensure that it is safe from predators, pets, and children as they may stress your rabbit.

Regular exercise is essential, but too much can cause more harm than good. So how much is too much exercise for a rabbit? Rabbits that are forced to lead overly active lifestyles, such as those training to jump in shows, have a high risk of heart attack as well.

Too much exercise can strain a rabbit’s heart. On the other hand, too little exercise will not work your rabbit’s heart enough. Finding the right balance that suits your rabbit best is vital in preventing disease and stress.

why is my rabbit's heart beating so fast?

Stress

An environment where your rabbit is constantly prone to stress can increase its chances of heart disease or a heart attack. Rabbits lie at the bottom of the food chain and are known to die of shock or heart attack during high-stress situations. According to research published in the journal, Pathophysiology, heart failures, hypotension, and arterial hypertension are common in animals that are sensitive to stress, including rabbits.

Stress caused by an overpopulation of rabbits in a limited space increases levels of a neurotransmitter called catecholamines in the blood. Elevated levels of this neurotransmitter can stimulate dysfunctions of the left ventricle of the heart.

Rabbits are incredibly timid and afraid of loud noises. If loud noises are frequent in your home, chances are your rabbit is continuously under stress. Sudden loud noises, such as lightning, thunder, or fireworks can cause severe distress in rabbits as well. If you cannot control the noise entering your rabbit’s cage, taking it inside your house can help calm your rabbit.

Stress can also be caused by the fear of a predator lurking around your rabbit’s hutch. Your rabbit doesn’t know that the predator cannot get inside its cage. The more anxious your rabbit gets, the more it responds with a rapid heartbeat. If this happens too often, your rabbit’s heart and body will not be able to keep up with stress.

Too much stress can kill a rabbit. If you aren’t able to relocate your rabbit’s hutch to an area free of stress, consider moving your rabbit indoors. The ASPCA, recommends that owners house their rabbits indoors as not only does it keep rabbits safe from environmental stressors, temperature changes, and predation, it also reduces their exposure to frequent stress.

Infections

Heart problems can also result from infections. Common culprits include toxin-producing bacteria and protozoa, and viruses such as coronavirus. These infections affect the heart by causing myopathy (muscle disease), cardiomyopathy (disease of the heart muscle), and endocarditis (inflammation of the inner lining of the heart).

These infections damage the heart muscle, making infected rabbits more susceptible to heart disease and heart attacks.

Certain Drugs

The administration of anesthetic agents or certain drugs can damage or kill heart tissue. These include frequent use of ketamine-xylazine mixture, agonist detomidine, and doxorubicin.

Risk Factors for Heart Attack in Rabbits

We’ll now look at how age, sex, and breed play a role in increasing a rabbit’s susceptibility to heart disease and heart attacks.

Age

  • Rabbits under the age of 4 are rarely diagnosed with cardiac disease
  • According to many reports, heart disease is most common in older rabbits

Sex

Your rabbit’s gender does not predispose it to any type of heart disease. Neutering or spaying or rabbit doesn’t affect your rabbit’s vulnerability to a heart attack either.

Breed

  • Larger breeds have a higher incidence of heart disease than small or dwarf breeds. There aren’t any diseases (including heart disease) that are specific to dwarf rabbit breeds. In fact, smaller rabbits live much longer than larger rabbits.
  • The most common breeds reported to suffer from heart disease include the New Zealand White Rabbit and the French Lop Rabbit.

Types of Heart Diseases in Rabbits

Heart disease can occur in any stage of a rabbit’s life, as a result of infections, administration of certain medications, stress, lack of exercise, and unhealthy eating habits. Heart disease can be classified into many categories. These include:

  • Congenital Heart Disease. This means that the disease or physical abnormality is present from birth. Congenital cardiac abnormalities found in many rabbits include defects of the ventricular or inter-auricular septa of the heart.
  • Myopathies. Diseases of the muscular middle layer of the wall of the heart (the myocardium) can increase the volume of the heart and decrease heart function. In rabbits, myopathies associated with the enlargement of the heart are more common than other types of cardiomyopathies.
  • Congestive Heart Failure. This relates to a decreased level of oxygen in the blood. Heart failures often occur as a result of conditions that have weakened the heart muscle, preventing it from pumping blood as effectively as it normally should.
  • Pulmonary Congestion. When excessive amounts of fluids accumulate in the lungs, lung disease can occur. This is often caused by congestive heart failure when the heart is incapable of pumping blood properly.
  • Tachycardia. This refers to an abnormal heart rate or a heart rate that is too fast. The rapid heartbeat prevents the heart from filling up completely (with blood), thus compromising blood flow to the rest of the body.
rabbit having heart attack

Heart Attack Treatment for Rabbits

Your vet will perform a series of scans and tests, looking for any abnormalities that you may have missed. Some of these tests include ultrasounds, radiographs, ECGs, and blood tests.

If any cardiovascular problems are detected, your vet will recommend lifestyle changes and medication to stabilize the condition. Cardiovascular issues cannot be cured, but following your vet’s advice can help your rabbit to live a good quality life, even if it rests often and is less active.

Treating the Underlying Disease

Heart attacks can be caused by underlying diseases, such as pneumonia or other lung diseases. In such cases, stabilizing the heart condition will rely on controlling the disease.

For lung diseases, a procedure pleurocentesis can be beneficial for rabbits suffering from severe dyspnea (shortness of breath) and pleural effusion (fluid in the lungs). This technique allows the practitioner to remove excess fluid from the lungs so that your rabbit can breathe easier.

Lifestyle Changes

After your rabbit has a heart attack, you must monitor your rabbit daily. Lifestyle changes following a heart attack include environmental changes and dietary changes.

Poor nutrition is a common contributor to heart disease. Ensure that your rabbit has access to plenty of high-quality grass hay, leafy greens, and a moderate amount of pellets. You’ll have to limit the number of treats you offer your pet, including fruit, starchy veggies, and sweet veggies.

Environmental changes primarily involve controlling stress. Reduce stress to a minimum in your rabbit’s living environment. Ideally, your rabbit should be housed indoors, away from loud noises, harsh weather conditions, potential predators, and annoying pets.

You may have to keep your rabbit in a separate, rabbit-proofed room where you can offer special care to your pet and carefully monitor its progress.

Medication

Meds will not cure your rabbit’s heart condition, but it will stabilize its heart. Your vet may prescribe drugs to improve your pet’s heart function and reduce pulmonary edema.

Diuretics can help mitigate fluid and sodium retention and offer some relief. Your vet may also recommend nitrate-based medication to alleviate pressure on the heart.

Monitor your rabbit regularly while administering these drugs. This will allow you to confirm the state of your rabbit’s body weight, hydration level, and serum levels of creatinine, electrolytes, and urea nitrogen.

Anatomy of a Rabbit’s Heart

A rabbit’s heart is pretty small in relation to its body size. The heart is located high in the sternum between the two lungs.

A double-walled sac called the pericardium protects the rabbit’s heart. The pericardium consists of a deep layer and a superficial layer. The pericardial cavity lies between these layers, and it is filled with fluid. This fluid acts as a shock absorber, protecting the heart against trauma.

The rabbit’s heart has four chambers, two on the left and two on the right. These include:

  • Two auricles (left and right auricles). These chambers have fine walls.
  • Two ventricles (left and right ventricles). These have thick, muscular walls.

The ventricles pump blood out of the heart and into the bloodstream. Walls and valves separate the auricles and ventricles.

Heart issues can occur in many ways. For example, if the right ventricle stops working normally, your rabbit’s blood pressure will increase. This causes the accumulation of fluid in the abdomen and lower limbs. If the left ventricle isn’t able to pump blood, blood will pool in the lungs, resulting in respiratory distress, fatigue, and oxygen uptake.

Heartbeat in rabbits has two significant steps, the contraction phase, and the relaxation phase. The contraction phase is called systole, and the relaxation phase of a heartbeat is called diastole.

A rabbit’s heart rhythm originates from a group of highly specialized muscle cells found in the wall of the right auricle. The muscles generate an electrical impulse that is transmitted to the auricles and the ventricles via the atrioventricular bundle and Purkinje fibers. This allows the heart muscle to contract. Abnormalities in a rabbit’s heart rhythm is often a telltale sign for heart disease or an oncoming heart attack.

Although conditions such as heart disease and heart attacks have measures to prevent them and improve them, there is nothing that can be done to cure heart disease altogether. Following veterinary treatment, your goal should be to prevent another cardiac episode. This can be done with a proper diet, eliminating nutritional deficiencies, building a healthy exercise routine, and stress management.

Avoid locking up your rabbit in a confined space and allow it to roam around and play freely at least once a day. Stress management is just as vital as a healthy diet in preventing heart attacks. Rabbits are known to get scared to death, or at least have a heart attack, in severely stressful situations.

If your rabbit already has heart disease, lifestyle adjustments, and medications can help prolong your pet’s life. Your rabbit may not be as jumpy and active as it used to be following a heart attack, but special care from its owner can ensure it lives a happy and comfortable life.

Be aware of signs that you can detect, such as changes in eating habits, litterbox habits, and lethargy. Keeping warning signs in mind can help save your pet before its condition gets worse.