The Scar Rule, Federal Regulation 9 CFR 11.3

The scar rule applies to all horses born on or after October 1, 1975. Horses that do not meet the scar rule criteria are considered to be “sore”. That criteria is:

(a) The anterior and anterior lateral surfaces of the fore pasterns must be free of bilateral granulomas, other bilateral pathological evidence of inflammation and other bilateral evidence of abuse indicative of soring including, but not limited to, excessive hair loss.

(b) The posterior surfaces of the pasterns including the sulcus or “pocket” may show bilateral areas of uniformly thickened epithelial tissue if such areas are free of proliferating granuloma tissue, irritation, moisture, edema or other evidence of inflammation.

The Scar Rule federal regulation was enacted in 1979. When the USDA proposed this regulation in 1978, they noted that the Scar Rule refers to bilateral scarring (both feet) because in most instances soring must be accomplished in an approximately equal degree on approximately the same area of each leg. The USDA further noted that the Walking Horse industry had been utilizing a Scar Rule since the beginning of the 1974 show season, the Scar Rule had been developed by representatives of the horse industry working with the USDA and, as a result of the industry implementing this program, most Tennessee Walking Horses do not bear scars. (Again, in 1978, the USDA admitted most horses did not bear scars.) It was because the industry was proactive in implementing a Scar Rule that was working that the Department sought to adopt it as a federal regulation so violators could be prosecuted.

scar rule 1960s        scar rule 2007

A photograph taken from the 1960s depicting why the Walking Horse Industry implemented a violation system for scarring, along with a 2007 photograph depicting what the USDA calls “scar rule violation”.

The USDA further noted that the Scar Rule allows for normal changes in the skin that are due to friction; the Scar Rule allows for thickening of the epithelial layer of skin much like a callous on a workman’s hands; and moderate loss of hair caused by friction generated by an action device.

Since enacting the Scar Rule in 1979, it has been under great debate and surrounded in controversy. In 1996 (17 years after enactment) the USDA stated the Scar Rule had various interpretations and a clear enforceable scar rule was needed. That was twenty years ago and it remains shrouded in controversy to this date.

Let’s take a closer look at the Scar Rule.

Section (a) translated means the front and sides of the pastern cannot have any evidence of abuse and cannot have excessive hair loss. Based on personally witnessing thousands of inspections over the last twenty years, we do not think there is any issue with Section (a). The industry appears to be in complete compliance with Section (a).

Section (b) translated means the back of the pastern, or pocket, can have hair loss and can have tissue changes as long as proliferating granuloma and inflammation is not found.

So what is proliferating granuloma? Granulation tissue is pink to shiny red in color due and is mostly composed of new blood vessels and fibroblasts. Granulation tissue is commonly bumpy and uneven and moist to the touch. However, proliferating granuloma is an increased/excessive amount of granulation tissue or proud flesh.

It is good to remember that scars form as the body’s protection mechanism from injury. When an injury happens, the body triggers a response called “wound healing” designed to repair itself. The phases of wound healing are: (1) hemostasis or stopping the bleeding; (2) inflammation which is characterized by pain, heat, redness and loss of function; (3) proliferation and (4) remodeling

Take note here: Granulation tissue provides the early foundation necessary to promote healing. Granulation tissue can only be seen with the human eye during would healing. It does NOT mature into the epithelium, but rather granulation tissue is eventually covered by a layer of epidermal tissue (outer layer of skin).

Knowing that one cannot see granulated tissue except while a wound is healing, and knowing that granulated tissue must be proliferate (excessive) to be in violation of the Scar Rule, you would think enforcement would be simple. Surely, detecting protruding or overgrowth of tissue or seeing proud flesh wouldn’t be difficult?

The Scar Rule also prohibits irritation, moisture, edema or other evidence of inflammation in the back of the pastern, or pocket. Going back to the phases of wound healing, and keeping in mind that inflammation is characterized by pain, heat, redness and loss of function, a horse whose pastern is swollen, red, hot to the touch and results in loss of function would most likely not find success in competing and such symptoms should be rather obvious.

Is the Scar Rule bad? No. Are some of the terms difficult to understand? Yes Could enforcement be simple? Yes. Unless a horse has protruding overgrowth of tissue or has swollen, red, heated tissue, it is in compliance with the Scar Rule.

scar rule 1972a     scar rule 2017

The USDA has altered photographs they released as scar rule violations by adding a red filter to make them appear worse than they actually are. The affirming attention the USDA has received as a result of altered photographs only serves to encourage them to continue to disqualify horses for scar rule violations and has resulted in such drastic government over-reach that the true intent of the Scar Rule has been lost.

scar rule red filter

Whether the USDA needs violations for job security or for some nefarious reason, the USDA defaults to “scar rule violation” in order to disqualify horses from competition at an unacceptable rate. Some concerned horse owners who have had horses disqualified for “scar rule violation” have had their horses undergo biopsies and the results from equine pathologists, who reviewed tissue samples under a microscope, were that NO granulated tissue much less proliferate granulated tissue could be found.