Heart attacks are often associated with humans, but birds can also suffer from cardiac events and heart conditions. One species of bird that is particularly prone to heart attacks is the cassowary.
Cassowaries and Heart Attacks
Cassowaries are large, flightless birds that live in the forests of Australia and New Guinea. They are part of the ratite family, along with ostriches, emus, and rheas. Cassowaries are the third tallest and second heaviest living bird species, reaching up to 6 feet tall and weighing up to 130 pounds.
These big birds have muscular bodies, strong legs with dagger-like claws, and hard, bony head casques. Their dark feathers help camouflage them in the rainforests where they live. Despite their imposing size, cassowaries are usually shy, reclusive birds that forage alone or in pairs.
Cassowaries have very low metabolic rates compared to other birds, which allows them to survive on limited food sources in their habitats. However, this also makes them more susceptible to heart problems. Their hearts beat more slowly, at around 32 beats per minute compared to smaller birds whose hearts beat 200-600 times per minute.
The vascular system of cassowaries differs from other birds as well. The Purkinje fibers that transmit electrical signals in the heart are fewer in number and less branched. Due to these anatomical factors, cassowaries are prone to arrhythmias, irregular heartbeat, cardiomyopathy, cardiac fibrosis, and eventually heart failure.
Stressors That Can Trigger Heart Attacks
There are several factors that are believed to increase the risk of heart attacks and cardiac events in cassowaries:
- Age – Older cassowaries are more prone to heart conditions.
- Obesity – Excess body fat puts strain on the cardiovascular system.
- Poor diet – Malnutrition and mineral deficiencies can affect heart health.
- Dehydration – Being deprived of water taxes the circulatory system.
- Stress – Cassowaries are very territorial and stress exacerbates heart issues.
- Capture myopathy – Muscle damage from restraint can lead to heart failure.
- Injuries – Traumatic wounds increase strain on the heart.
- Diseases – Bacterial and viral infections affect cardiac function.
Veterinarians have noted that the single biggest risk factor for heart attacks in cassowaries is stress. Their heart rates accelerate when they encounter human activity near their territory, hear unfamiliar noises, or experience other alarming events. This fight-or-flight response taxes the cardiovascular system.
Signs and Symptoms
Cassowaries that are suffering heart conditions may display an array of symptoms and warning signs. These include:
- Labored breathing
- Open-mouth breathing
- Wheezing
- Panting
- Lethargy and weakness
- Loss of appetite
- Cyanosis (blue tinge to skin)
- Pale or white mucous membranes
- Inability to stand
- Collapse
- Sudden death
Owners of cassowaries as pets or in private collections need to monitor their birds closely for any of these signs of potential heart issues. Changes in normal behavior like reduced activity and disinterest in food are often the first indicators.
A cassowary suffering heart strain may spend more time sitting or lying down and avoid walking around. They are likely to breathe heavily with open beaks as their bodies struggle to deliver enough oxygenated blood.
In severe cases, the birds may lose consciousness and be unable to stand or support their own weight. A bluish coloration of the head area results from inadequate circulation. Without emergency treatment, death can occur rapidly in cassowaries experiencing cardiac distress.
Diagnosis
Several diagnostic tests can be performed on cassowaries suspected of having heart disease or cardiomyopathy issues:
- Physical exam – Listening to the heart and lungs with a stethoscope, checking mucous membranes, feeling the pulse.
- Blood tests – Assessing cardiac enzyme levels that indicate damage or stress.
- Electrocardiogram (ECG) – Measuring electrical signals in the heart to identify arrhythmias.
- Echocardiogram – Using ultrasound to visualize the structure and function of the heart.
- Radiographs – Taking X-rays to examine heart size and shape.
These tests require capturing, restraining, and sedating the cassowary to obtain readings. This is challenging given the massive size and dangerous claws of these birds. It also introduces additional stress that could further exacerbate cardiac issues. Veterinary experts skilled in handling and treating cassowaries are required.
Common Diagnnoses
Some of the specific heart conditions and problems commonly seen in cassowaries include:
Arrhythmias
Abnormal heart rhythms like atrial fibrillation are common in cassowaries. This is often caused by damage to the Purkinje fibers of the heart’s electrical system.
Cardiomyopathy
Enlargement, thickening, or stiffening of the heart muscle impairs its ability to pump blood efficiently.
Valvular Heart Disease
Leaky or narrowed valves prevent proper blood flow through the heart chambers.
Heart Failure
The heart is too weak to supply the oxygen demands of the body. Fluid can back up into the lungs causing difficulty breathing.
Myocardial Infarction
A partial or complete blockage of blood flow causes damage or death to parts of the heart muscle – a heart attack.
Treatment
Several treatment options are available for cassowaries with heart conditions, although outcomes can be poor in severe cases:
- Supportive care – Providing rest, fluids, and nutritional support.
- Oxygen therapy – Assisting breathing with supplemental oxygen.
- Medications – Administering drugs like diuretics, ACE inhibitors, beta blockers, antiarrhythmics.
- Surgery – Repairing damaged heart valves or installing pacemakers in some cases.
The best strategy is trying to prevent heart problems in cassowaries before they occur. This involves maintaining low-stress captive environments, ensuring proper nutrition, and limiting obesity. Catching cardiac issues early improves the chances of successful treatment.
Cassowaries with advanced heart disease or chronic conditions like cardiomyopathy have a grave prognosis. These big birds do not do well with intensive care or being handled for frequent medical treatments. Euthanasia may be the most humane option if their quality of life is greatly diminished.
Interesting Facts About Cassowaries
Here are some additional interesting facts about these huge flightless birds prone to heart problems:
- Cassowaries are the only members of the cassowary genus Casuarius. There are three extant species – the southern cassowary, northern cassowary, and dwarf cassowary.
- They are an ancient lineage related to emus, kiwis, and ostriches. Cassowaries date back at least 15 million years.
- Cassowaries have three-toed feet with a dagger-like inner claw up to 4 inches long used for defense.
- Their hard casques on top of the head may assist in pushing through dense rainforest vegetation.
- The skin and feathers of cassowaries have a coarse, hair-like appearance unique among birds.
- Cassowaries are important distributors of seeds that help regenerate rainforest plants.
- The southern cassowary is recognized as an endangered species due to habitat loss.
- Cassowaries are solitary, territorial birds that only come together briefly for breeding.
- Females lay 3-5 large green eggs in a nest on the forest floor.
- Males incubate the eggs for 50 days and raise the chicks alone for 9 months.
These unusual traits make cassowaries fascinating birds. Their tendency for heart problems requires attentive care in captivity to keep them healthy.
Key Facts Summary
- Cassowaries are large flightless birds prone to heart attacks and cardiac disease.
- Their low metabolism and vascular anatomy make them susceptible to arrhythmias, cardiomyopathy, and heart failure.
- Stress is the biggest trigger for heart attacks in cassowaries.
- Labored breathing, weakness, and collapse can signify a cassowary heart attack.
- Tests like ECG and echocardiogram diagnose their heart problems.
- Supportive care, oxygen, meds, and surgery can be used, but prevention is ideal.
- Cassowaries have interesting traits like dagger claws, hard casques, and solitary habits.
Conclusion
The cassowary is an unusual and amazing bird that is unfortunately prone to serious heart conditions. Their anatomy and stress responses leave them susceptible to arrhythmias, cardiomyopathy, heart attacks, and sudden death. Careful management and prompt veterinary care give them the best chance of surviving and recovering from heart problems. These endangered giants of the rainforest deserve special attention to keep their remarkable hearts beating strong.
