Hypertrophic Cardiomyopathy in Macaws: Thickened Heart Muscle and Risk Signs

Hypertrophic cardiomyopathy, often shortened to HCM, is a disease where the heart muscle becomes thicker than normal. In a macaw, that thickened muscle can become stiff and less efficient, so the heart may not fill or pump as well as it should. Over time, this can reduce oxygen delivery to the body and increase the risk of fluid buildup, abnormal heart rhythms, weakness, or sudden collapse.

In birds, heart disease can be hard to spot early because many signs overlap with respiratory illness. A macaw with heart disease may seem tired, breathe harder, lose balance, or avoid flying long before anyone hears a murmur. Merck notes that pet birds with heart disease may show weakness, lethargy, increased breathing effort, tremors, or fainting-like episodes, and that advanced imaging such as radiographs, ECG, CT, and echocardiography has improved avian diagnosis.

HCM is not the only heart problem seen in parrots, and in macaws it may occur alongside other cardiovascular issues such as atherosclerosis, pulmonary hypertension, or age-related heart changes. That is why your vet usually focuses on identifying the type of heart disease, how severe it is, and whether your bird is stable enough for testing before discussing treatment options.

In many birds, hypertrophic changes in the heart are thought to develop secondary to other problems rather than from a single known inherited cause. Avian cardiology references describe hypertrophic cardiomyopathy as thickening and stiffening of the heart muscle that can occur with increased cardiac afterload. Reported contributors include arterial narrowing, atherosclerosis, chronic pulmonary disease, systemic hypertension, pulmonary hypertension, congenital vascular problems, and some metabolic or toxic conditions.

For macaws, one important background risk is broader cardiovascular disease. Merck notes that macaws are among the psittacine birds considered particularly susceptible to heart disease associated with atherosclerosis, with risk factors including sedentary lifestyle, high-fat diet, and high blood cholesterol. IVIS also describes atherosclerosis as increasingly recognized in parrots and links it to high-fat, high-cholesterol diets, lack of exercise, age, and species susceptibility.

Not every macaw with a thickened heart muscle has the same underlying trigger. Some birds may have chronic respiratory disease that increases strain on the heart. Others may have obesity, vascular disease, iron-related metabolic disease, toxin exposure, or inflammatory heart damage. In some cases, the exact cause is never fully confirmed unless a necropsy is performed after death.

That uncertainty is frustrating for pet parents, but it also means your vet should avoid assumptions. The most helpful next step is usually a careful search for contributing conditions that can be managed, even if the heart muscle change itself cannot be reversed.

Diagnosis starts with a hands-on avian exam, but many macaws with heart disease need more than auscultation alone. Birds can have serious cardiac disease without an obvious murmur, and stress can make both breathing and heart rate harder to interpret. Your vet will usually assess breathing effort, body condition, hydration, mucous membrane color, and whether your bird is stable enough for testing.

Common first-line tests include radiographs, bloodwork, and sometimes ECG. Merck states that avian heart disease is increasingly diagnosed with the same broad tools used in people, including x-rays, CT scans, electrocardiograms, and echocardiograms. Avian cardiology references also note that radiographs or CT can show heart size and shape changes or fluid, while echocardiography helps evaluate heart motion and pumping function.

If HCM is suspected, echocardiography is the most useful test for confirming thickened heart muscle and assessing chamber size and function. Additional testing may include blood pressure measurement, cholesterol and triglyceride evaluation, oxygen support during workup, or referral to an exotics or cardiology service. Because fragile birds can decompensate with handling, some diagnostics may be staged over time rather than done all at once.

A realistic 2026 US cost range for a macaw cardiac workup is often $300-$1,200 for the exam, imaging, and baseline lab testing. A medical exam at one avian-exclusive clinic is listed at $135, and pet bird necropsy fees at one state diagnostic lab are listed at $150-$300, which helps anchor common avian specialty costs. Advanced imaging, emergency oxygen care, hospitalization, or referral echocardiography can increase the total substantially.

Not every case can be prevented, but you can lower cardiovascular risk by supporting your macaw’s overall heart and vessel health. One of the biggest steps is feeding a balanced diet and avoiding long-term reliance on high-fat seed-heavy feeding patterns. Merck identifies high-fat diet, sedentary lifestyle, and high cholesterol as important risk factors for heart disease in susceptible pet birds, including macaws.

Daily movement matters too. Safe climbing, flapping, foraging, and species-appropriate activity can help reduce inactivity-related risk. Weight management is important because obesity and poor conditioning can add strain to both the cardiovascular and respiratory systems. If your macaw has chronic breathing issues, treating those early may also help reduce long-term stress on the heart.

Routine avian wellness visits are one of the best prevention tools. Your vet may catch subtle weight changes, exercise intolerance, abnormal breathing, or lab changes before a crisis happens. Older macaws and birds with a history of poor diet, limited exercise, or chronic respiratory disease may benefit from more proactive screening.

Prevention also includes environment. Keep your macaw away from smoke, aerosol irritants, and other toxins, and ask your vet before using supplements or medications. While prevention cannot guarantee that HCM will never occur, it can reduce modifiable risk factors and improve the chance of finding heart disease earlier, when more care options are still on the table.