And fair warning – there are some questionably gross photos below. Just scroll fast!

Exuberant Granulation Tissue (EGT) is Proud Flesh

• Granulation tissue is what your horse’s skin makes to heal a wound, a new type of connective tissue. It’s a collection of new blood vessels, inflammatory cells, and fibroblasts, the specialty cells that help create connective tissues. This new tissue serves to bring the edges of wounds together.

• During a horse’s wound healing process, their body may go into “overachiever mode,” and the new tissues grow out of hand. You could say the new growth is exuberant, hence exuberant granulation tissue formation.

This is granulation tissue.

The Wound Healing Process in Horses

• Backing up from the EGT situation, let’s look at the whole wound healing process. The process has a few stages, three or four, depending on what you read online. And they all overlap; it’s not a relay race where one stage passes off to the other.

Hemostasis

After an injury, the blood flow will eventually stop and form a blood clot. This clot may happen on its own, or you must apply first aid to help stop the bleeding for more severe injuries.

• The initial injury triggers blood vessels to tighten, which stops the bleeding and makes that blood clot with fibrin. This blocks bacteria from entering and creating a wound infection, although this can still happen.

Inflammation

• The wound is angry, no matter the size of the wound, during the inflammatory response stage of wound healing. The area fills with blood, fibrin, platelets, and white blood cells (WBCs). The WBCs are immune cells and clean the wound environment, removing foreign material like bacteria and other pathogens that may decide to take a chance on invading the body.

• The WBCs also direct traffic, telling the fibrin to start the clotting process.

• For about seven days after the incident, the blood vessels begin to dilate again, acting as roads for the WBCs to pick up debris like dead tissue and invaders and then get rid of it.

• The area will be painful as the traffic mixes with the actual damage.

Complications related to inflammation during debridement

• As the WBCs clean up the debris, there may be an abundance of neutrophils as part of immune function. These specialized WBCs will overpopulate the area, creating pus. This is a clear indication of infection and will slow healing.

Proliferation

• This stage sees granulation tissue forming, and the skin will start to cover the wound during epithelialization. This is a fancy way to say that new skin starts moving over the wound to cover it completely.

• The balance a horse must achieve is tricky – there needs to be enough granulation to heal, but not so much that the skin can’t connect over the top of it.

• Here is a fun fact about skin healing. The skin over body wounds can heal at the rate of .2 mm a day, while leg wounds take longer, about .09 mm a day. This rate does contribute to proud flesh, as the skin is too slow to cover the granulation tissue, which starts to ignore the normal healing process.

Maturation

• This stage occurs as the granulation tissue settles, the area contracts back into the wound bed, and the scar becomes smaller. Maturation can take months or longer. Scarring is possible; some hair may grow back without pigment if the pigment-producing cells cannot repair.

• This stage is when the skin returns to normal and can take months – or longer. Sometimes, there is scarring; sometimes, your horse’s hair coat grows back with white hairs.

This is the same horse as above, just further along in the healing process.

What Causes This Hypergranulation Tissue?

• A few factors contribute to EGT, and these come from all directions. Limb wounds are the usual source of proud flesh.

Epithelialization

• When a horse’s wound is inflamed for too long, proud flesh is likely. Too much irritation, possible infection, re-injury, irritations, and the already slow epithelialization process let the granulation tissue run away. And because the skin can’t connect over the wound, the proud flesh keeps growing outward, creating a lower-leg cauliflower full of blood vessels. The more it grows, the harder it is for the skin to cover it, and healing delays repeatedly.

Movement and muscles

• Cuts and scrapes over joints have a challenging time healing, as anytime a horse moves, that joint moves and may tear open any healing. Pressure on wounds, like bed sores, also slow healing and invites proud flesh to grow.

• Ever notice that your horse can twitch his skin to shake a fly? The muscle responsible for this, the panniculus carnosus, twitches the skin and is absent in a horse’s legs. This muscle is considered a part of the wound-healing process, and its absence on the limbs may contribute to proud flesh.

Infection

• Dirt, debris, bacteria, bone fragments, and foreign substances can delay healing and create more inflammation and pus. Severe infections can lead to fevers, which are dangerous by themselves. Dirty shavings, muddy paddocks, and horses being horses make infection likely, especially on lower legs, which tend to step in things that may not be so clean.

Blood supply

• While proud flesh is vascular, the lower legs are not particularly full of tissue and blood as the body. Oxygen is vital to the healing process, and the blood may not be able to reach the affected areas easily. Oxygen helps the WBCs take out the trash.

Poor wound management

• When first aid comes too late, or the affected area is not adequately cared for, the probability of EGT increases. When the area is treated, the likelihood of complications increases without care of the wound site.

Collagen and cytokines

• The protein collagen helps hold the skin together. It’s also vital for nails, hair, bones, and connective tissue. Collagen also helps form the scaffolding for the granulation issue. If the collagen production and breakdown are off-kilter, proud flesh can begin.

• And then there are cytokines, small proteins that help cells communicate during immune responses. They guide cells to areas of inflammation, infection, or injury, ensuring the body can respond quickly and effectively. TGF‐β1 is one such cytokine and usually has finished its job after the inflammatory stage of wound healing. But- in horse legs, TGF‐β1 hangs around, telling the horse that inflammation is still happening, triggering proud flesh in horses.

Read some science about collagen here.

Read some amazing, in-depth information about proud flesh and healing here. This is a more scientific article with photos.

Horse socks can be helpful when trying to keep dirt and bacteria and “stuff” out as your horse’s leg heals.

How to Support Healthy Granulation Tissue

• Any wound you find needs to be cleaned and treated. You can clip the area, too, to help keep it clean. Clipping also allows you to apply topical medications and track healing more easily. It is handy to take pictures or measurements to track the healing process. Here are some first-aid tips:

• Loop your vet in. Even minor, seemingly harmless wounds can develop exuberant granulation tissue, especially near joints. Punctures can create joint infections, and the smallest of minor scrapes can trigger cellulitis or lymphangitis.

• Clean wounds with a balanced saline solution or water. Peroxides, alcohol, and other harsh cleaners damage tissue further.

• Prep the area with clippers. Clipping the surrounding hair, dap some KY jelly over the area to prevent hair from poking the sore. Then rinse.

This horse is perfectly happy and sound with his proud flesh. It’s under constant vet care, and it’s just part of this horse’s process.

Get Your Vet’s Input

Should you wrap the wound?

• Perhaps. Some wounds need some support and stability so the tissues can come together. Some wounds are irritated by wraps, which might complicate the wound.

• Wraps can also interfere with the formation of scabs, which may help with the natural wound contraction. Sometimes, the scab needs to come off.

• There’s also some evidence that proud flesh is more likely to form when wounds are bandaged for extended periods.

Should your horse have stitches?

• The wound’s size, depth, and location all play a role here. Some tissue damage fares much better without sutures; others need them. There’s also the chance that sutures will pull and tug when the leg joints flex and extend, which may create more damage.

• In puncture wounds, closing the wound is not the way to go. Puncture wounds act like Petri dishes for bacteria to fester into infection deep in the area.

When Proud Flesh Develops – Diagnosis and Treatment Options

• If you suspect your horse is starting to grow pink cauliflower, get your veterinarian out pronto. Management of exuberant granulation tissue is best before it grows too much.

• Your vet should be able to discern the beginnings of proud flesh by visual exam. Proud flesh looks pink or red and is usually lumpy. Your vet may be able to gauge how vascular the area is and how deep it might be.

• As with many things horses, there are many other reasons for healing to go sideways. It’s always a good idea to rule out infection, summer sores (so gross!), tumors like sarcoids or melanoma, a mystery growth, or inflammation due to a foreign body. There are many vital structures in the lower legs, and a clear understanding of the depth and severity of the granulated tissue is critical.

• X-rays or other diagnostic imaging may be needed, too.

• Your vet can also piggyback on your measurements and documentation of the area to track healing over time.

There are a few things for your vet to consider to determine an appropriate treatment:

• Is an infection making this injury swirl around in the inflammation stage instead of healing?

• Does the area need bandaging? Or air?

• Do prescription meds like antibiotics and steroids like cortisone make sense? Sometimes, healing has progressed too far, and other options need exploration.

• Is it necessary to send a tissue sample to the lab for biopsy?

• Does this area need debridement?

Surgical removal of proud flesh

• Your vet can surgically remove the proud flesh. In most cases, your horse remains standing, although general anesthesia may be best in severe cases.

• The goal of debridement is to literally level the playing field by removing the exuberant granulation tissue to allow the skin to come together and the area to contract.

• Luckily for horses, proud flesh is not innervated – there is no nerve supply, so pain is not an issue.

• It’s also possible for your veterinarian to perform skin grafts, taking skin from another part of the body to cover the leg wound.

Bandaging, casting

• Every horse will react differently to wraps, casts, and topical treatments. There is science about what works the best, and each method of wound care has pros and cons.

• Wraps may interfere with healing by limiting oxygen and stimulating granulation tissue to grow. On the other hand, bandaging seals moisture in the area, which helps skin cells grow. Both bandages and cases are a physical barrier for microbial infections, too.

• However, occlusive dressings that don’t allow air, water, or anything else into the area have goopy coatings to fully seal the area. They won’t absorb anything. This stone wall approach to covering an area will also trap any serum or exudate from the wound and may inflame it further and inhibit new skin cells from growing.

• In the case of casts, the more rigid structure limits movement that might keep a wound more open.

• There is some evidence that silicone-based gel dressings are the best for EGT. A small study compared dressings and the silicone model holds some promise.

Read this study here.

Topical treatments

• Another small study tracked the efficacy of different types of topical treatments. The researchers examined silver sulfadiazine cream, a triple antibiotic topical, and a hyperosmolar nanoemulsion. There was another control group that did not receive any treatment.

• The outcome was the same for all horses, with the same healing time. The researchers also noted that treatment with the silver or emulsion needed debridement more often.

You can read this study here.

New Advances With a Leaf Extract

• Researchers in India have discovered that a leaf extract from the Aerva jananica herb will squash granulation tissue growth in horses. There are MANY exciting things about his particular study.

Causes of EGT in the study

• The horses involved in this study had previous injuries that developed proud flesh. The authors noted that another primary cause of proud flesh is an infestation of the habronema worm larvae in wounds, also called summer sores.

• Summer sores, like proud flesh, can take months and months to heal and require daily attention and often topical and oral medications.

Why plants?

• Many plants have components called flavonoids. These plant chemicals often have antioxidant, anti-inflammatory, antiviral, and blood flow boosting properties with medical potential.

• In the case of proud flesh, the flavonoids in Aerva jananica appear to stop the proliferation of granulation tissue.

Implications for humans

• In India, this plant is a nuisance weed. However, for farmers, developing this herb for medicinal applications could yield another valuable crop that was once discarded.

• This research could pave the way for studies into human keloids, which are similar skin disturbances. It’s a win-win for horses and people.

Read more about this study here.

Prevention of EGT

• The best way to prevent EGT is to bubble wrap your horse and never let them do anything. Barring that highly unrealistic option, taking care of a cut, scrape, or open wound quickly is best.

• Keep tabs on the area daily after cleaning, clipping, and a quick vet consult. Look for excessive growth that is moving outward and impedes wound closure.

• Monitor the wound surface and color. Look for that apparent cauliflower texture that shows the formation of granulation tissue. The goal is to avoid this area turning into a chronic wound.

• Keep the area clean and follow your vet’s suggestions about topical over-the-counter products, or perhaps a prescription is best, like a topical steroid.

• The same holds for wrapping. Topical application of meds under wraps may be an option and might depend on the stage of healing.

• Feel and observe the surrounding tissue. Heat, excessive redness, soreness, or strange swelling are signs of infection. Your vet will have to determine the likely culprit. Bacterial infections can happen, as can fungal infections.

• Check your horse’s vital signs. Fevers indicate an infection that the whole body is fighting. Infected skin wounds can trigger a fever.

• Depending on the extent of tissue overgrowth, your vet may need to trim back excessive tissue.

Dietary Support for Proper Wound Healing in Horses

• Equine nutrition supports the health of your entire horse – inside and out. The best place to start is an equine nutritionist to help you find the best balance of nutrients for your horse’s age, weight, exercise routine, health conditions, and metabolic disorders. This is a complicated process, at best.

• An excellent place to start is to consider your horse’s skin, coat, and connective tissue health and ensure the diet has enough nutrients targeting the skin and soft tissues.

• That means a diet balanced with Omega-3 fatty acids, Vitamin C, and various ingredients like biotin, zinc, and iodine.

• Most vitamin and mineral supplements or ration balancers will round out a forage-based diet. But, you will likely need to add Omega-3 fatty acids via flax, fish oil, or chia.

Science about Granulation Tissue – Horses vs. Ponies

• Researchers have found some evidence that ponies are less likely to develop proud flesh related to the TGF‐β1 growth factor.

• Horses have less of this signal protein, therefore not influencing the inflammatory phase of wound healing and the contraction of injuries as much as ponies.

• Essentially, horses respond slower, whereas ponies get the job done faster, thus not allowing as much time for granulation tissue to overtake the healing process.

This study has more about the horses and ponies and how they develop proud flesh.

Some horses end up with proud flesh, no matter what we do or how much the vet is involved. The earlier you can care for and carefully manage a wound, the better the odds are in your horse’s favor.