Lump Under the Skin in Rabbits

Abscesses in rabbits are caused by the introduction of bacteria and the resulting accumulation of pus (dead white blood cells). Illnesses, bite wounds, dental problems, and unsanitary cage conditions can all lead to abscesses under the skin. To give your rabbit the best chance of full recovery, it is vital that you contact your veterinarian immediately if you notice your rabbit has a lump under his skin.

Lumps under the skin in rabbits are often caused by abscesses which commonly occur on the face and limbs. These masses are formed by inflamed tissue containing thick, purulent discharge. This can lead to discomfort, sepsis, and skin necrosis for your rabbit.

As a rabbit’s skin can form a thick capsule around the abscess inflammation, and discharge may not be visible, most often it is the palpable mass that owners notice first. Although your rabbit may not present with discomfort or pain, other symptoms which may indicate an abscess are:

• Lethargy
• Fever
• Thick, purulent discharge in cases of rupture
• Aggression when handling due to discomfort
• Anorexia

Types

Rabbits can suffer from many types of abscesses in different organs of their bodies. These include:

• Subcutaneous masses which are common in the head and may be large and solid
• Internal abscesses such as thoracic, abdominal or uterine (pyometra) 
• Dental abscesses which are the result of tooth root infections and can lead to tear duct abscesses

There are some conditions that may predispose your pet to developing abscesses, such as;

• Recurring cases of rhinitis and sinusitis
• Dental disease
• Fighting and bite wounds
• Pododermatitis due to bare or unhygienic cage floor
• Cramped living conditions

Abscesses occur due to the introduction of bacteria into the tissue. Although it can be possible to locate the point of entry in cases of bite wounds or dental disease, in many cases the cause of introduction is not known. The bacteria often found to be responsible for abscess in rabbits are:

• Staphylococcus aureus
• Proteus 
• Bacteroides 
• Pasteurella multocida

Your veterinarian will perform a full physical examination on your pet. They will discuss your pet’s clinical history with you and ask if there is a known history of fighting or bite wounds. 

Your veterinarian will be able to palpate the abscess and may be able to visualise discharge. They will carefully examine your pet for other abscesses, wounds or underlying conditions such as dental disease. As abscesses can cause osteomyelitis, the infection of the bone, your veterinarian may choose to perform radiographs to check for this.

Your veterinarian will likely take a sample of exudate to perform a culture and sensitivity test to identify the causative bacteria and most effective antibiotic treatment.

As their physiology is quite different to cats and dogs, rabbit abscesses require much more invasive treatment than most pets. This is due to numerous factors. In rabbits the pus is thick and difficult to remove, meaning often traces of bacteria are left behind after flushing. Rabbit abscesses are also known to form finger-like projections in the surrounding tissue, causing further abscesses to form. 

Due to these factors, the best practice  is considered complete surgical excision of the abscess under general anesthetic. Although there are risks involved with anesthesia your rabbit will be carefully monitored throughout. The procedure will involve clipping the fur around the abscess, washing the area with a surgical preparation and then removing the abscess, carefully debriding all affected tissue and thoroughly flushing the area with an antiseptic solution. 

Medication

Ideally your veterinarian would await the results of the bacterial culture test prior to commencing antibiotic treatment, however, as the prognosis for rabbits is drastically improved by early treatment, your veterinarian will most likely give enrofloxacin while waiting for results. When culture results become available your veterinarian may choose to change antibiotic treatment.

Analgesia

Your veterinarian will likely give either NSAIDS or opiates for analgesia.

Diet

It is vital that your pet eat during his illness. Anorexia in rabbits can become dangerous in as little as 4 hours, and can cause gastric stasis, hepatic lipidosis and intestinal ileus. 

Appetite stimulants such as parsley, carrot tops and kale may be recommended, along with any of your rabbit’s favorite foods, hay and fresh vegetables and pellets. 

If your pet is still refusing food, syringe feeding a complete diet may be necessary. Your veterinarian may choose to give pellets moistened with water, pureed vegetables or banana on top of this.

Fluid therapy

Fluid therapy may be given to decrease the risk of anorexia or gastric stasis occurring following the surgery.

The prognosis following an abscess in a rabbit may be guarded due to the risk of recurrence. Your veterinarian will likely prescribe a 2-6 week systemic antibiotic treatment following surgery with revisit appointments to monitor recovery. 

Following the surgery your pet may be drowsy; provide him with a soft, warm recovery area. Research has shown medical grade honey to assist in recovery due to it’s healing and antibacterial properties, this may be a supportive option for your pet. In order to give your pet’s immune system the support it needs to recover, provide your pet with a clean, warm environment and excellent nutrition. As abscesses are commonly known to reoccur, regularly check your rabbit for the development of masses and contact your veterinarian if one is found.