Canine cardiomyopathy refers to a group of conditions related to a weakening of the heart muscles. Cardiomyopathy symptoms are used to diagnose the condition, but often appear only when the pet is in late-stage heart failure. The body is able to compensate for the gradual weakening that occurs in the heart for months and years until a certain point, at which the condition may seem to escalate very quickly. It's not uncommon to see the first outward signs of cardiomyopathy in your dog only when he is very close to death. Still, recognizing the symptoms of cardiomyopathy quickly will afford you the best chance of seeing your pet through this disease with a vet's assistance.
Coughing
The single most common sign and most important outward identifier of canine cardiomyopathy is coughing. As the heart loses function, blood collects in your dog's blood vessels around the lungs. This eventually pushes small amounts of fluid into the lungs, and your dog begins to gag or cough frequently. This is one of many signs of fluid collection in pets that are experiencing loss of heart function or heart failure.
Swelling
As a result of additional fluid buildup throughout his body, a dog with cardiomyopathy may have a distended stomach or swelling in other places around his body. Because this fluid builds up gradually, it can be difficult to notice the changes unless you are aware of them. For this reason, it is useful to photograph your pet periodically and compare pictures of him across different months. This will allow you to better see whether he has any fluid buildup and resultant body swelling over the course of time.
Loss of Stamina
Dogs with cardiomyopathy seem to tire very easily. If you notice that your pet has suddenly lost his interest in running around outside or going for walks, or if he sits down and refuses to move after just a few minutes of either of these activities, heart problems may be the cause. As a result of a weakened heart muscle, certain chambers in your pet's heart become enlarged. This disrupts the normal flow of blood and oxygen throughout his body, which in turn causes your pet to tire easily.
Late Stage Symptoms
There are several symptoms that are unique to late stage heart failure as a result of cardiomyopathy. If your dog begins to breathe heavily and drool without having had any exercise or motion whatsoever, he may be experiencing the first signs of heart failure. Check his tongue; if it appears blue, that's a sign that he's not receiving the proper oxygen throughout his body. Dogs can also lose consciousness or collapse as a result of late stage cardiomyopathy.
If you notice any of the symptoms listed above, take your pet to an emergency medical center immediately. Heart failure is often fatal, and immediate action is necessary in order to restore your pet's health, if it's still possible.