Symptoms of myocarditis in dogs:

1. Acute myocarditis often begins with symptoms of myocardial excitement, manifesting as rapid and substantial pulse, hyperpalpitations, and enhanced heart sounds.

2. After a little exercise, the dog's heartbeat increases rapidly and can continue for a long time even if the exercise stops.

3. When canine myocardial dystrophy and degeneration occur, the main symptoms are heart failure.

4. When the heart loses its compensatory adaptability, the sick dog's mucous membrane becomes cyanotic, it is highly difficult to breathe, the superficial veins are dilated, and the limbs, chest and abdomen are edematous.

5. Dogs with severe myocarditis have loss of appetite, lethargy, loss of consciousness, and eventually die suddenly due to heart failure.

Causes of myocarditis in dogs:

1. Some parasitic diseases (such as Toxoplasma gondii, canine nausea filariasis) can also be secondary to myocarditis.

2. Toxic diseases (such as carbon monoxide, heavy metals, phenols, organophosphorus, narcotics, etc.) can directly damage the myocardium, leading to myocarditis or myocardial degeneration.

3. Septicemia, allergies, rheumatism, anemia, etc. can all cause myocarditis.