Some lesions are readily apparent and others may be hidden under areas of plaque or swollen gums. They can also occur in the canine teeth and incisors. The cause of these resorption lesions is unknown. Other possible causes include autoimmune disorders, viral diseases or a nutritional deficiency. Cats with EORLs may show pain when their jaws are touched and may also have increased salivation or oral bleeding.
Lesion extends into the pulp canal, but good tooth structure remains.
Lesion extends into the pulp canal and there is extensive loss of tooth structure. However a dental explorer should be used to examine each tooth above and below the surface of the gum. Any calculus on the teeth needs to be removed before a complete examination can be performed. Dental radiographs are helpful in diagnosing this condition and evaluating the extent of disease. I being mild and Grade V being severe.