- Etiology of heart failure in dogs
- Symptoms of Heart Failure in Dogs
- Diagnosis of heart failure in dogs
- Treatment of heart failure in dogs
- Prevention of heart failure in dogs
Heart failure in dogs is a whole complex of heart pathologies, each of which has its own name.
But they all mean the inability of the heart to pump a certain volume of blood, adding to this the accompanying changes. One of the main functions of blood is the transport of oxygen and various nutrients to all organs and tissues, as well as the removal of breakdown products from the body as a result of metabolism. Blood also has many complex functions that directly depend on the work of the heart muscle: maintaining blood pressure, body temperature, etc. There are two types of heart failure:
- Acute - occurs very quickly, within a few hours, has no clinical signs, and often ends in death for the dog.
- Chronic – develops over time, has clinical signs.
Heart failure - what is it?
Heart failure in dogs is a condition in which the heart loses its ability to pump enough blood and can no longer meet the body's oxygen needs. The result is a decrease in the intensity of blood circulation, a slowdown in metabolic processes and disruption of the functioning of internal organs.
Some dog breeds are predisposed to this disease, so their owners need to be especially careful. Among them:
- collie,
- shepherd,
- English bulldog,
- schnauzer,
- boxer,
- spaniel,
- fox terrier.
Causes of heart failure
Stress, long-term use of certain medications, obesity combined with physical inactivity, as well as kidney disease are factors that provoke the development of heart failure in dogs. Symptoms of this condition are usually seen in dogs over 7 years of age. With improper care, the clinical picture appears much earlier.
In dogs of toy breeds (for example, toy terriers), the most common cause of heart failure is emotional overload.
Other reasons that provoke the development of heart muscle failure:
- Congenital anomalies of the myocardium.
Gastric septal defect, patent ductus arteriosus and other defects of the heart valve apparatus can lead to impaired circulation of the heart muscle. As a rule, they appear within 4-6 months after the birth of the pet.
- Inflammatory processes affecting the myocardium.
Damage to the serous membrane of the heart (pericarditis), the heart muscle (myocarditis) or the inner lining of the heart (endocarditis) are the most common inflammatory diseases found in dogs of different ages.
- Damage to blood vessels.
Various diseases of the vascular system (for example, hypertension and atherosclerosis) significantly increase the load placed on the heart muscle. As a result, cardiac diseases develop, one of which may be heart failure.
- Cardiomyopathy.
Structural and functional changes in the heart muscle can trigger infections (eg, viral, fungal, bacterial) suffered by the dog. If they provoke the proliferation of connective tissue, then myocardial hypoxia gradually develops.
- Intense physical activity.
Improperly planned or excessive physical activity (for example, long runs over long distances, strength exercises, etc.) often lead to premature wear of the heart muscle in large breed dogs.
- Endocrine system disorders.
Diseases provoked by hormonal imbalances in the body, pathologies of the thyroid gland and diabetes mellitus lead to the development of congestion in the heart muscle, which is chronic.
Is cardiac decompensation associated with heart valve disease?
The cause of CHF in dogs of dwarf and small breeds is most often insufficiency of the atrioventricular valves. It is estimated that 80% of cases of CHF in dogs are caused by mitral valve endocardiosis. However, there are many other reasons. Disease of the heart muscle (cardiomyopathy), rhythm disturbances, and narrowing of certain major blood vessels (the aorta and pulmonary artery) can also cause CHF. Initially, mitral valve endocardiosis leads to left-sided CHF. If left untreated, heart failure can progress to involve both sides of the heart (total or biventricular heart failure).
Clinical picture: main symptoms of the disease
With heart failure, the dog experiences chills, drowsiness and constant weakness. If a pet develops cerebral hypoxia as a result of the disease, fainting often occurs. All mucous membranes (for example, gums and tongue) acquire signs of cyanosis, that is, they change their color to violet-bluish.
What happens in dogs with heart failure?
- Decreased activity.
The dog gets tired quickly, avoids physical activity (for example, training and walking), and increasingly refuses active games. The pet begins to move with caution: walks slowly, does not jump on stairs, etc.
- Heavy breathing, shortness of breath.
The first thing many owners pay attention to is breathing problems. If in the initial stages they occur only after intense physical exertion, then over time shortness of breath appears even in a calm state.
- Decreased appetite.
The animal quickly loses muscle mass, rapidly loses weight, and anorexia develops. In the initial stages of the disease, severe thirst is observed. Subsequently, problems with appetite arise. Animals even refuse their favorite food.
- Cough.
If your dog has heart failure, he or she may cough. At first - rare attacks. As the disease progresses, the cough becomes more frequent and debilitating. This is caused by enlargement of the hypertrophied heart muscle and compression of the trachea.
- Strange poses.
The pet changes its gait, as well as its posture when lying down or sitting. Typically, in case of heart failure, the animal sits down with its front legs spread wide. In this case, the chest area protrudes greatly and becomes tense.
- Ascites.
The abdominal area increases as a result of the accumulation of fluid in the peritoneum. This is an important signal indicating a severe circulatory disorder. The manifestation of this symptom indicates the last stages of the development of heart failure.
Heartworm (dirofilariasis)
Heartworm or dirofilariasis is a fairly common parasitic disease today. Previously, it was believed that this disease was a disease of more southern regions, but statistics have changed greatly in recent years, and dirofilariasis began to be recorded in Moscow and the region, and even St. Petersburg.
Symptoms can be hidden or obvious. With obvious symptoms, the pet owner will observe a picture of heart failure:
- fast fatiguability;
- dyspnea;
- pallor of the mucous membranes.
Dirofilariasis is transmitted from mosquitoes to animals and people. Dirofilariae live, multiply and circulate constantly in the bloodstream, heart, subcutaneous tissue and muscles. These are viviparous organisms; their larvae, stage 1 microfilariae, can circulate in the blood of an infected dog for up to 2.5 years without causing any symptoms. If such a dog is bitten by a mosquito, the larva in it goes through the following stages of development in 2-3 weeks and becomes invasive, that is, capable of infecting the next organism. When bitten by an infected mosquito, the infective larvae enter the dog's subcutaneous tissue, where they mature further. The larvae of the 5th stage penetrate the blood vessels, are carried by the blood flow into the heart and large vessels, and after 6 months they become adult, sexually mature helminths and can reach 35 cm in length, causing harm to organs and tissues. The danger of this disease lies in thromboembolism by adult helminths in the heart and instant death of the animal.
Types of disease: characteristic features
Left-sided heart failure (LSF ). It affects the left half of the heart more, so it most often manifests itself in the form of pulmonary edema. In this case, the pressure in the left atrium increases, and the pumping function of the myocardium decreases. All this is caused by the fact that the left ventricle does not push the required volume of blood into the systemic circulation.
Characteristic features:
- rapid breathing,
- accumulation of fluid in the lung tissue,
- dry cough,
- short-term disturbance of consciousness,
- fast fatiguability.
Right-sided heart failure (RSF) . Impaired pumping function of the right ventricle, which does not push the required volume of blood through the lungs. More often, right-sided heart failure leads to edema of peripheral tissues and the intermaxillary space, with fluid leaking into the chest, pericardial and abdominal cavities.
Characteristic features:
- sagging abdominal area,
- breathing complication
- X-shaped paw placement,
- neck stretching,
- swelling of the limbs.
Acute and chronic heart failure: differences
Acute heart failure (AHF) . Its main difference is its high speed of development. In dogs, it develops against the background of large blood loss, severe infectious diseases, etc. In addition, it can occur at some stages of chronic heart failure (CHF). In case of AHF, emergency first aid by professionals is required. Only in a veterinary clinic will it be possible to relieve the pet’s acute condition.
Chronic heart failure (CHF) . Among the most common reasons: hormonal imbalances and excessive physical activity that does not correspond in intensity to the animal’s body weight. The main difference is the slow and constant increase in clinical signs over several months or even years. All symptoms manifest themselves in stages: from breathing problems to ascites. In addition, chronic heart failure is characterized by severe exhaustion of the pet.
Myocarditis
Inflammatory and infectious diseases can cause another type of heart defect in dogs - myocarditis, or inflammation of the heart muscle.
The development of myocarditis can be triggered by certain infections, intoxication of the body with poisons or excess medications, or injury to the heart by broken ribs.
The disease can manifest itself with the following symptoms:
- heart rhythm disturbance;
- dry cough;
- weakness of the dog;
- hard breath;
- temperature increase.
Treatment is prescribed in accordance with the cause of myocarditis
Diagnosis of the disease in dogs
The first thing experienced veterinarians begin with is an initial examination. During a visual examination and obtaining data from the dog owner, the specialist diagnoses shortness of breath, cyanosis of the mucous membranes, peripheral edema, as well as other signs characteristic of acute or chronic heart failure.
Diagnostic methods used:
- X-ray examination . It allows you to identify congestion in the pulmonary circulation, as well as the presence of fluid in the chest cavity;
- Electrocardiography (ECG). It is aimed at recording and studying the electric fields arising during the functioning of the heart muscle;
- Echocardiography . It allows you to identify compensated disorders of myocardial function, therefore it is always used to diagnose heart failure.
If necessary, additional diagnostic methods are used (for example, tissue Doppler sonography). The main thing is to contact a veterinary clinic that has all the necessary equipment for a quick and accurate diagnosis of heart failure in dogs.
Treatment of heart failure
Timely contact with veterinarians is the key to effective treatment. When an animal arrives, the veterinarian first assesses the condition of its body. If urgent stabilization is required for acute heart failure, then emergency measures are taken.
Treatment tactics are based on eliminating the cause that provokes the development of the disease (for example, heartworms, congenital heart muscle defects, etc.), as well as controlling emerging clinical signs.
To carry out effective drug therapy, experts prescribe:
- Angiotensin-converting enzyme (ACE) inhibitors. They eliminate spasms, normalize blood pressure, improve the supply of oxygen to the myocardium, and also dilate the heart arteries;
- Beta blockers . They are prescribed to achieve hypotensive and antiarrhythmic effects. Drugs in this group improve myocardial perfusion. They are prescribed to pets when sinus rhythm is detected;
- Symptomatic drugs . Their intake is necessary to eliminate the clinical manifestations of heart failure. Veterinarians prescribe diuretics, cardiotropics, painkillers and other medications.
Heart valve disease: diagnosis and monitoring
The correct diagnosis of any disease begins with a thorough medical examination and medical history. A presumptive diagnosis of heart valve disease can often be made this way, but a definitive diagnosis requires another test, such as an echocardiogram.
Dogs diagnosed with degenerative heart valve disease should be monitored for development or worsening of the disease.
While your veterinarian will want to continue monitoring your dog with periodic exams and chest x-rays, you should also monitor your dog at home for symptoms such as coughing, rapid breathing at rest, and exercise intolerance.
Proper care at home
The task of experienced veterinarians is to prevent irreversible consequences in the dog’s health, normalize its condition and eliminate the clinical manifestations of heart failure. However, in addition to drug treatment, your pet requires proper care at home.
If your pet is diagnosed with acute or chronic heart failure, you will need to follow a set of measures:
- dose physical activity,
- provide emotional peace
- eliminate stressful situations,
- change your pet's diet by adding foods high in thiamine, magnesium, selenium and vitamin E.
Remember: the sooner you seek professional veterinary help, the greater the chance of your pet returning to a healthy life!
