The fainting will happen for a few seconds to a few minutes depending on how fast the dog’s heart corrects itself.
It should be noted, that for young puppies, particularly under the age of 6 months, fainting can be the sign of hypoglycemia...a rapid, dangerous drop in blood sugar levels (treated by rubbing Karo syrup directly onto the pup's gums for rapid transport into the bloodstream and then bringing him or her to the closest vet or animal hospital)....Therefore, any collapse or fainting must be treated immediately.
Each case is different. However some Boxer dogs with cardiomyopathy will reach a point where the ventricles of the heart expand. This causes the walls of the heart to become too thin and the heart itself will decline in strength.
Coughing may occur at this point. Owners should not panic if coughing occurs, as it may be something as simple as allergies...However, it is important to have it checked out as soon as possible.
How is this Diagnosed?
Because the Boxer breed is prone to two different heart conditions (see also, Aortic Stenosis
) , it is important for owners to bring their Boxer for wellness checks (once per year for adults and twice per year for seniors). It is during a vet check that an irregular heartbeat will be detected via a stethoscope.
If your Boxer has symptoms of cardiomyopathy, an ECG may be done, however an ECG tends to only pick up arrhythmias if they are very frequent. For this reason, you will want to ask for a Holter monitor test, which involves a device about the size of a deck of cards to be attached to the Boxer for a 24 hour time period, which is a much better diagnostic tool. This will show if a dog has infrequent skips and how often this occurs.