Effects of Heart Failure – From the Dog’s Point of View
Respiratory distress is the most consistent and recognizable symptom of heart failure. As the dog’s condition progresses, it will have increasing difficulty breathing; this is called “dyspnea.” Affected animals may breathe shallowly and rapidly, which is known as “tachypnea,” or being “tachypnic.” Dogs in heart failure often have breathing problems even when they are asleep or resting, as their body tries to get enough oxygen into its blood supply to support its vital organs and tissues. Like other animals, dogs that are having trouble breathing are extremely uncomfortable and usually in a great deal of distress. They may be restless and fidgety, or tired and lethargic. Heart failure also frequently causes pain.
Symptoms of Heart Failure – What the Owner Sees
The onset of heart disease is often accompanied by subtle behavioral changes in the affected animal. Depending on why its heart is failing, the dog may develop signs of disease very suddenly or very slowly. Early on, most of the symptoms of heart failure are fairly nonspecific, but they certainly can be recognized by attentive owners. They include:
- Difficulty breathing; shortness of breath (even at rest and during sleep)
- Reduced activity level; exercise intolerance
- Tiring easily
- Panting more than usual; gasping for breath
- Loss of appetite
- Loss of weight
- Intermittent cough (worse with exercise, exertion or excitement; frequently happens at night, several hours after the dog falls asleep; may cough up a bubbly red fluid from pulmonary edema/fluid build-up)
- Fluid retention in the abdomen and chest; “pot-bellied” appearance (ascites)
- Swelling of the lower legs (dependent edema)
- Pale, cool tongue, gums, lips
- Rapid, irregular, thready pulse
Most owners of dogs in heart failure report that their pets seem to be uncomfortable, act restless and aren’t behaving normally. As the dog’s condition progresses, its respiratory difficulties will worsen. It will become fatigued, and its mucous membranes will turn pale or even become blue. Ultimately, the dog will become recumbent and unable to rise. A weak, rapid heart rate and coughing is also common.
Dogs at Increased Risk
Doberman Pinschers, Boxers, Great Danes, Irish Wolfhounds and other large- and giant-breed dogs are predisposed to developing dilated cardiomyopathy, a condition in which the heart becomes enlarged and usually eventually fails. Older small and toy breeds, such as Cavalier King Charles Spaniels and Dachshunds, have an increased chance of developing heart failure from a disease or defect in one or more of their heart valves.