Do you have a swelling under the skin and you are unsure what it is? This is the place to start.

Swellings are a very common problem in horses with many causes, as a result we have a number of different articles on this subject. This article is designed to explain the causes of swelling, help differentiate the various types, and then direct you to more specific topics on the specific swelling. Note that bumps, lumps, and tumors of the skin itself are discussed elsewhere. Some swellings are obviously part of the skin but if you are uncertain try moving the skin around the swelling. Does the swelling move with the skin or does the skin move over the top of it? If it moves with the skin most likely it is associated intimately with the skin and discussed in the article on skin bumps and tumors, ...more.

In this article swellings and tumors of the tissues under the skin are discussed. The differences between non-inflammatory and inflammatory swellings are outlined and the common swellings that occur in horses are identified by their characteristics and location. Links to more specific articles on further diagnostics, treatment, and prognosis are provided.

Article Summary

• By knowing whether your swelling is inflammatory and/or edematous you can greatly reduce the number of possible causes.
• Once the cause is known more effective treatment can be instituted.
• There are a number of common swellings that can be diagnosed by their location and characteristics. Images and descriptions of the common swellings and tumors of horses are provided.

The common swellings of the horse are often best understood by separating them into inflammatory and noninflammatory processes. So what is inflammation? It is the body's response to physical insults like trauma, infection, allergies, and autoimmune diseases. Inflammation is recognized by redness, heat, swelling, and pain. It is difficult to detect the redness of inflammation with the highly pigmented skin of most horses so swelling, heat, and pain are the hallmarks in horses. Swelling is associated with inflammation because inflammation makes the blood vessels "leaky" and results in serum (the liquid part of the blood) leaking out and collecting in and around the tissues. But this is not the only type of swelling there is.

Noninflammatory swellings, as you will soon see, has many causes and may be do to local or systemic conditions, acute or chronic in nature, persist or be recurring under certain conditions. They are the same temperature as the surrounding non-swollen areas and are not painful when palpated. Very mild inflammation or early in the inflammatory disease process there may be minimal heat and pain so frequent reassessment is a good practice if uncertainty about the nature of the swelling exists. You should also note that hematomas can be a warm, noninflammatory swelling in the case of a ruptured subcutaneous vessel.

The presence or absence of heat and pain are detected by careful exploration of the swelling. This is best done in a quiet and relaxed atmosphere. Horses often react when you touch and squeeze them even when not painful so first carefully evaluate for reaction by palpating non-effected similar areas. This gives you several benefits:

• You can observe the horses normal reaction to such an exam.
• You can observe the normal temperature of the area.
• It allows the horse to get use to this type examination.

After careful and thorough exploration you should make a judgement whether your swelling has inflammation associated with it or not. After deciding whether your swelling is associated with inflammation the next step is to determine is it caused by edema?