Protein bumps in horses are a common problem that affects many equine athletes. These bumps, also known as nodules or granulomas, can appear on various parts of the horse’s body, including the neck, shoulders, and hindquarters. They are caused by the accumulation of protein deposits in the connective tissues and can be a result of various factors, including trauma, infection, or inflammation.
While protein bumps are generally not a serious health concern, they can cause discomfort and affect the horse’s performance. In some cases, the bumps can become infected or inflamed, leading to more severe complications. Therefore, it is essential to identify and treat protein bumps promptly to prevent any further complications. In this article, we will explore the causes, symptoms, and treatment options for protein bumps in horses, providing valuable information for horse owners and trainers.

Understanding Protein Bumps in Horses
Protein bumps are a common occurrence in horses and can range in size and location.
They present as an accumulation of collagen and connective tissue in the skin. This can occur due to a variety of reasons, including injury, infection, or even genetics. In some cases, the bumps may be benign and require no treatment. However, in other cases, they may become infected or even cancerous, which can be a cause for concern.
Diagnosis of protein bumps in horses can be done through a physical examination and biopsy. A biopsy is a procedure where a small piece of tissue is removed from the lump and examined under a microscope. This can help determine if the lump is benign or malignant.
Treatment of protein bumps in horses depends on the size and location of the lump, as well as the severity of the condition. In some cases, the lump may be surgically removed. In other cases, medication may be prescribed to help reduce inflammation and pain.
It is important to note that not all lumps or bumps on a horse are protein bumps. Other conditions, such as abscesses or tumors, can also cause lumps on the animal. Therefore, it is important to have any new lumps or bumps examined by a veterinarian to determine the underlying cause and appropriate treatment.
Causes of Protein Bumps
Protein bumps on horses are caused by a variety of factors, including allergies, insect bites, heat, trauma, and medication or vaccines. Understanding the causes of protein bumps can help horse owners take preventive measures to avoid them.
Allergies and Allergic Reactions
Allergies and allergic reactions are a common cause of protein bumps in horses. Horses can be allergic to a variety of allergens, including hay, dust mites, and other environmental factors. Additionally, horses may develop allergies to medications or vaccines.
Symptoms of allergies and allergic reactions in horses include redness, inflammation, swelling, itching, and scabs. To prevent protein bumps caused by allergies, horse owners should try to identify and eliminate potential allergens from their horse’s environment.
Insect Bites
Biting insects, such as flies and mosquitoes, can cause protein bumps on horses. Horses may also develop allergic reactions to insect bites, which can exacerbate the problem.
To prevent protein bumps caused by insect bites, horse owners should use fly control measures, such as fly masks, fly sheets, and chemical fly sprays. Additionally, owners should be vigilant about checking their horse for insect bites and treating them promptly.

Heat and Trauma
Heat and trauma can also cause protein bumps on horses. Horses may develop heat bumps in hot weather, and previous trauma to the skin can also lead to the development of protein bumps.
It’s important to try and take measures to keep your horse cool in hot weather, such as providing shade and plenty of water.
Medication and Vaccines
Medication and vaccines can also cause protein bumps in horses. Horses may develop an allergic reaction to a medication or vaccine, leading to the development of protein bumps.
To prevent protein bumps caused by medication and vaccines, horse owners should be aware of their horse’s sensitivities and allergies. Additionally, owners should work with their veterinarian to develop a vaccination and medication plan that minimizes the risk of adverse reactions.
Diagnosis and Veterinary Consultation
If you suspect your horse has protein bumps, it’s a good idea to seek veterinary consultation immediately. The veterinarian will perform a physical examination and may recommend diagnostic tests to confirm the diagnosis.
Veterinarians may also recommend blood tests to measure the horse’s immune response to certain proteins. These tests can help confirm a diagnosis and identify the severity of the allergy.

It is important to provide your veterinarian with a detailed history of the horse’s symptoms and any potential triggers. This information can help the veterinarian make an accurate diagnosis and develop an appropriate treatment plan.
Treatment and Management
Protein bumps in horses can be treated and managed in various ways. The appropriate treatment and management plan will depend on the severity of the condition, the underlying cause, and the individual needs of the horse.
Medication and Steroids
In some cases, medication and steroids may be prescribed to reduce inflammation and manage symptoms. However, it is important to note that long-term use of steroids can have negative side effects and should be used under veterinary supervision.
Surgical Intervention
Surgical intervention may be necessary in severe cases of protein bumps. Removal of the bump through cryotherapy or chemotherapy may be recommended by a veterinarian. However, it is important to note that surgical intervention can be costly and carries some risk.
Horse Care
It is important to note that some horses may be predisposed to developing protein bumps, while others may develop them due to an allergic skin reaction or infection. Rain rot and certain feedstuffs can also contribute to the development of protein bumps. Grey horses may be more prone to developing protein bumps due to their unique skin pigmentation.
Symptoms of too much protein in a horse’s diet should also be monitored and addressed promptly. Certain foods, such as those high in keratin, may contribute to the development of protein bumps.
Overall, treatment and management of protein bumps in horses should be approached on a case-by-case basis. Veterinary intervention may be necessary in severe cases, while benign neglect may be appropriate in mild cases. Proper horse care, including a balanced diet and appropriate tack, can also play a role in preventing and managing protein bumps.
Frequently Asked Questions
What causes hard bumps on a horse’s back?
Hard bumps on a horse’s back may be caused by eosinophilic granulomas or collagen granulomas. These bumps are typically caused by an allergic reaction to insect bites or other irritants.
What are collagen granulomas in horses?
Collagen granulomas in horses are firm, raised bumps that are typically caused by a reaction to a foreign substance. They are often found on the legs or back and can be treated with surgical removal or corticosteroid injections.
What causes lumps on a horse’s throat?
Lumps on a horse’s throat may be caused by an enlarged lymph node or a tumor. In some cases, the lump may be caused by an abscess or infection.
What are the possible causes of small bumps all over a horse’s body?
Small bumps all over a horse’s body may be caused by an allergic reaction to insect bites or other irritants. They may also be caused by a skin condition such as hives or rain rot. Treatment will depend on the underlying cause of the bumps.