Abscesses in Hamsters

Causes, Treatment, and Prevention

Brown and white hamster on a white background

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Hamsters are fairly low-maintenance pets when it comes to health concerns, but that doesn't mean they aren't prone to certain problems. Abscesses are one such problem that hamster owners may need to address. These infections occur in wounds from minor accidents or fights with other hamsters, and they can be life-threatening without treatment. Knowing how to recognize abscesses and administer first aid can help you keep your hamster healthy.

What Are Abscesses?

Abscesses are pockets of infection that form at the site of an injury. They are generally filled with pus, which is fluid composed of white blood cells, blood, and bacteria. These pockets swell to form lumps that are tender to the touch. Abscesses are most often found under hamsters' skin but can occur internally, on organs, in a cheek pouch, or the mouth.

Symptoms of Abscesses in Hamsters

A lump or swelling is usually the most obvious indication of an abscess, but other signs of infection may accompany the swelling, such as:


  • A foul smell coming from the lump
  • Pus and blood on the fur
  • Lethargy
  • Lack of appetite

Food in the cheek pouches can look similar to an abscess but an abscess will not decrease in size as a cheek pouch will when the food inside it is removed or consumed.

If an abscess ruptures, pus and blood may be seen on the fur in the surrounding area. This may also have a very foul smell due to the bacteria that is present. Hamsters are usually fastidious cleaners but the amount of infected fluid an abscess can produce may not be easily cleaned up or may be unreachable if it is on the hamster's neck or head.

Finally, if an abscess causes systemic infection in a hamster, lethargy and a decrease in appetite are likely to occur.

Causes of Abscesses

Pet hamsters develop abscesses when bacteria cause infection at the location of an injury. Common causes of hamster injuries include:

  • Bite wounds from other hamsters
  • Bite wounds from a cat
  • Scrapes or punctures from sharp objects in a hamster's cage

Diagnosing Abscesses in Hamsters

To differentiate an abscess from a tumor, it's necessary to find out what is inside the lump. Your veterinarian may feel the lump and suspect it is an abscess. The first step may be to carefully lance the lump using a scalpel blade. If pus drains out, then it will be obvious it is not a tumor. To definitively diagnose it, though, the contents must be analyzed.

A sample of the abscess may be withdrawn with a syringe and observed under a microscope for bacteria so that a targeted antibiotic treatment plan can be established.


A hamster's abscess must first be drained. Your veterinarian may have already done this as part of the diagnostic process. The abscess will then need to be flushed with a saline solution or other antibacterial agents. Antibiotics will be prescribed for you to administer at home.

Prognosis for Hamsters with Abscesses

When caught and treated promptly, abscesses usually heal quickly, and hamsters regain their health. If, however, the infection has spread or entered the hamster's bloodstream, the prognosis is poor. Antibiotics may not be able to stop the infection, and the hamster may die.

How to Prevent Abscesses in Hamsters

A bite wound is one of the most common causes of a hamster abscess. To prevent fighting, house your hamster alone. Most hamster species are best kept as single rather than multiple pets anyway.

Another thing you can do to help prevent abscesses is to ensure there are no sharp edges in its cage. Wire cages may have sharp spots on the corners and doors. Ladders, wheels, and other toys in the cage can also be problematic. Check these things regularly to help keep your hamster safe.