Canker Sore Overview. Canker sores, also known as aphthous ulcers, are among the most common causes of painful sores in the mouth. 1  The classic lesion is a small (less than 1 centimeter) oval to round ulcer with a erythematous (red) border.2  They occur on the mucous membranes inside the mouth.anker Sore Overview. Canker sores, also known as aphthous ulcers, are among the most common causes of painful sores in the mouth. 1  The classic lesion is a small (less than 1 centimeter) oval to round ulcer with a erythematous (red) border.
Other Causes of Heavy Panting in Dogs. Heavy breathing or deep, intense panting can also be a symptom of eclampsia, also called milk fever. Eclampsia is a dangerous condition that affects nursing mothers; low blood calcium levels lead to an inability to stand or walk and tremors.
Dogs tend to pant a great deal. Because they don't sweat the way humans do, panting is their way of cooling down when they are overheated, in a particularly warm climate, after exerting themselves. This is not, however, the only reason why dogs pant.Panting is also an important way for dogs to oxygenate their blood.ogs tend to pant a great deal. Because they don't sweat the way humans do, panting is their way of cooling down when they are overheated, in a particularly warm climate, after exerting themselves. This is not, however, the only reason why dogs pant. Panting is also an important way for dogs to oxygenate their blood.