Many rat owners will, at some point, find that their rat has a skin lump. Often, a frightened rat owner will assume that the rat's skin bump is malignant cancer, but this is not always the case. In some cases, rats can develop potentially-deadly cancer, but on many occasions, the rats has grown a non-cancerous growth that's often identified as a cyst.
How and Why do Cysts and Abscesses Form in Rats
Cysts and abscesses are by far, the most common type of dermal lump or bump seen in rats. Cysts and abscesses can form in rats of all breeds, all ages and in both sexes. Notably, cysts and abscesses - a pocket of infection below the skin's surface - are very common in hairless rats.
Cysts can form in the hair follicle, creating a follicular cyst, or in the skin's pores, creating a sebaceous cyst. Excess oils (commonly seen on the backs of male rats in the form of a yellow tint to the skin), dirt, and dead skin cells can form a blockage in the skin's pores or follicles, causing sebum, pus and fluid to accumulate beneath the skin's surface.
In many cases, a rat's dermal bump will start out as a sebaceous cyst, but the rat's scratching or an owner's picking at the bump can lead to infection. A pocket of infection can then form beneath the surface of the rat's skin, creating an abscess.
Characteristics of Cysts and Abscesses in Rats
Cysts and abscesses can grow very large, very quickly. A rat can develop a skin lump the size of a cherry tomato or large grape in a matter of a day or two. Tumors, on the other hand, do not typically grow at such a fast rate.
Unlike tumors, which tend to be hard like a rock beneath the rat's skin, cysts and abscesses are generally firm but softer since they're filled with sebum (a toothpaste-like paste), pus or fluid.
Cysts are also located at the level of the skin, while tumors tend to be situated below the skin's surface. One easy way to determine whether the rat's bump is at skin level involves placing a finger on either side of the lump and pulling the skin between the fingers taught. Then, move the entire hand back and forth. If the lump is at the skin level, the lump will move with the skin. If the lump is below the level of the skin, the lump will appear stationary as the skin moves over the rat's growth.
Cysts and abscesses will sometimes begin draining naturally, so discharge is not uncommon. Redness and slight swelling in the immediate vicinity of the rat's skin growth is also not uncommon.
Treating Cysts and Abscesses
Cysts and abscesses will often rupture and drain without intervention, but this can be painful and messy. In other cases, lancing and draining the lump on the rat's skin is required, often multiple times before healing is complete. Oral antibiotics are often prescribed for rats who are suffering from a cyst or abscess.
Some rat owners can opt to lance and drain the rat's cyst at home by applying a heat pack wrapped with a moist wash cloth. After applying the moist, warm compress for 20 minutes, the skin will be softened and the contents of the cyst will rise to the surface. A sterilized needle can then be used to lance the rat's cyst, allowing for drainage. Once drainage is complete, the site should be washed with an anti-bacterial soap, sterilized with betadine twice daily until the rat's skin has completely healed. A dab of antibiotic ointment can help promote healing.
Whatever the case, a rat with a lump or bump must be examined by a veterinarian. This is the only way to determine the exact nature of the skin bump or tumor - and remember, not all tumors are cancerous. And even in the case of a cancerous tumor, early removal of the rat's mass can allow the pet to live a full, happy life.
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Mia Carter - Mia Carter - Journalist, Producer/Editor & Web Writer. Carter's work has appeared on CBS and CNN.com.
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