What Causes Hypergranulation Tissue on a Dog's Lips?

The formation of granulation tissue is a necessary step in healing process of any type of physical wound. The granulation process produces new tissue, such as skin, after a short period of inflammation. Normally the granulation of a wound is not a detrimental process, but some injuries lead to the over-granulation of tissue. Tissue composed of excess granulated tissue, called hypergranulation tissue, can interfere with the normal healing process of your dog and leave protruding scars. The precise causes of hypergranulation tissue are not entirely understood, but medical researchers have identified several factors that contribute to this problem.

  1. Pathogens

    • The presence of pathogens, microbes or poisonous chemicals in a wound increases the likelihood of the development of hypergranulation tissue. Dogs that chase wild animals or fight with other dogs, even if it̵7;s just play fighting, are at higher risk for this type of injury. Wounds from the claws or teeth of a strange animal have a high chance of becoming infected with harmful bacteria. Your dog's immune system will also respond to the microbial infestation by releasing biological chemicals that slow the healing process of the infected wound. This delay can increase the chances of your dog developing hypergranulation tissue.

    Allergies

    • The presence of allergens or irritants can also contribute to the growth of over-granulated tissues. Some products designed for wound treatment can actually produce allergic reactions that inflame the tissue on and around a wound. General irritants, such as silver nitrate, can also inflame an existing wound, even though they may not have any impact on healthy skin. Allergic reactions are associated with collagen production, which has been linked with the development of hypergranulation tissue.

    Wound Management

    • Wounds require proper care and vigilance to heal properly. It is difficult to monitor a dog all the time, and a wound on his lip is even harder to keep clean than an injury elsewhere on his body. If the wound is too moist or too dry at the wrong times, then the tissue has a higher chance of over-granulating. A moist bandage should cover the entire injury until the granulation bed has formed. After the formation of the bed, use a dry bandage on the wound. Flush deep or open wounds with non-irritant antiseptic solution daily to kill pathogens.

    Other Causes

    • Topical steroids and surgical excisions can damage an already wounded area, greatly increasing the chances of over-granulation. Repeated surgery can disrupt the wound, causing the healing process to start over from the beginning. Steroids slow the healing of the wound, creating additional opportunities for the formation of excess granulation.