An abscess is pus-filled localized capsules or pockets often due to bacterial infection. In rabbits, these abscesses are surrounded by a thick fibrous tissue that can be soft or slightly firm and the pus is made up of “neutrophils (a type of white blood cell involved in infection and inflammation), fluid, and cellular debris”  as well as some bacteria.
Abscesses are common in these pets and they can affect them anywhere on their body including on their teeth, jaw, cheeks, chin, dewlap, feet or even their brains, among other places.
However, they are common on the head, face (especially for the tooth abscesses) and limbs.
Rabbit abscess picture
Also, abscesses can be internal or develop under the skin. Those under the skin will form a bump-like appearance that is tender to touch, or it can be relatively painless. Note that they can grow over time when on the skin, but they can also occur on face, jaw or joints.
On the other hand, internal abscesses are common behind the eye, in the chest and abdomen cavities, lungs, in the nasal passage and in the ear among other places. Some of the internal masses might not be abscesses but tumors.
Finally, they affect rabbits of all ages, and they are common in pet rabbits. Furthermore, they may occur over a long period of time or rapidly. Some breeds, especially “dwarf and lop-eared rabbits are predisposed to abscesses that are caused by dental disease.” 
- How are they formed?
- Signs and symptoms
- Treatment of abscesses in rabbits
How are they formed?
The invasion and multiplication of bacteria trigger the immunity cells to form a wall to stop further spread of the bacteria. The bacteria may continue to multiply but soon will be cut off food and oxygen supply.
The immunity cells will then invade the bacteria and pus will be formed consisting of immunity cells, dead bacteria, and debris of nearby cells. A few bacteria may survive, adapt, remain dormant inside the encircled cocoon.
Fluid buildup and pressure may make the abscess to rupture letting out pus and those that do not burst may remain for several months. For those that do not burst, other factors such as poor diet and a weakening immunity may cause the bacteria to overpower the defensive immunity cells, multiply and this will lead to widespread infection.
Sometimes, when this occurs, some of the escaped bacteria my seed, i.e., cause new or multiple abscesses to form.
Signs and symptoms
The signs and symptoms will depend on the affected areas. For instance, those on the superficially on the skin may not show any signs while those that are deep, or on teeth or oral cavity may be accompanied by several symptoms. Some of the common symptoms include the following:
- Presence of swellings that may have pus or not and they are often tender to touch.
- A discrete mass that may feel like just a mass or be fluid-filled (have pus).
- Superficial abscesses that have ruptured might have discharges and be inflamed
- Those on teeth and oral cavity may make your furry friend prefer soft food, be unable to chew, lose appetite, and so on.
- Reluctance to move and limping especially if your rabbit has feet abscesses
- Signs of pain may also be noticed such as a hunched position, hiding, being less active, and so on.
We have mentioned that they are primarily caused by a bacterial infection. However, they can secondarily be formed due to things such as cancer, foreign body, dental disease or problems.
Also, the infection may spread from the original site of infection to other body parts via blood. Common causes include the following:
Abscesses are caused by both aerobic and anaerobic bacterial organisms which include Pasteurella multocida, Pseudomonas aeruginosa, Fusobacterium nucleatum, Bacteroides spp., Staphylococcus aureus, Peptostreptococcus pp., Proteus spp., Prevotella spp., other Pasteurella species, among other pus-producing bacteria.
Dental disease and problem
Issues such as overgrown teeth, malocclusion, trauma, tooth decay, and other dental diseases may predispose these pets to develop tooth abscesses (on the face, upper jaw or lower jaw and rarely on the nasal cavity and behind eyes).
Trauma or wounds
Bites from fighting, injuries, wound or surgery could open a way for the various bacterial organisms to enter their body.
They help bacteria go through the skin or oral cavity and they include sutures following a surgical operation, feed material, and so on.
Diagnosis is by looking at any of the clinical signs that your rabbit may have and your vet may also do physical examination and palpation depending on where the abscess is.
The use of radiographs especially in cases of dental or jaw abscesses might reveal their location as well as whether they have affected any bone and to what extent or not.
Ultrasound to examine the “ocular and periocular tissues will help identify a retrobulbar abscess.”
Finally, aspiration using a fine needle can help rule out other conditions such as neoplasia (abnormal tissue growth.
During treatment, sample pus should be collected and used in cytology and be cultured to help determine the exact microorganisms involved.
Treatment of abscesses in rabbits
Treating or curing them is often challenging. They need aggressive treatment and they have a high tendency of recurring even after treatment by a rabbit savvy vet. Here are the reasons why treatment may present challenges.
- Their pus is often very thick making draining them completely a daunting if not an impossible task. Their pus is often consistent like cottage cheese, is thick and creamy. This is due to the low level of enzyme myeloperoxidase that bunnies have as opposed to other animals such as dogs and cats making the digestion and liquefaction of material contained in the capsule hard.
- They have thickened walls that are fibrous making it very difficult for antibiotics to penetrate these walls and kill the bacteria causing them.
- They often have ‘finger-like extensions’  making them larger than assumed and their total removal challenging.
- There are relatively fewer antibiotics that have been cleared for use in treating rabbits. This limits the choice of antibiotics to use, unlike other pets.
The treatment option will depend on where the abscess is as well as its size. Surgical removal is the most common treatment unless they are located near vital organs (such as near heart, lungs, windpipe) or on a place difficult to surgically remove them.
In general, those involving the face, joints and plantar are much difficult to treat and require long post-operative care and hospitalization.
Small and superficial ones can be surgically removed under sedation or general anesthesia without the need for hospitalization. Large ones may need hospitalization and care for some time until your rabbit begins to heal.
During the surgical process, all debris (dead tissue), pus, and everything must be removed, and a sample of the pus taken for culture and sensitivity test to identify the exact bacteria and hence recommend the right antibiotics.
Afterward, the wound will be thoroughly cleaned and your vet may also consider packing and cleaning the area daily to ensure no bacteria remains. Otherwise, the cases of bacteria being trapped inside and causing another abscess may happen.
Also, antibiotics may be placed inside the cavity left behind, and there might be systemic antibiotics to kill any bacteria that may have escaped. Additionally, the use of analgesia to reduce pain may be recommended.
Finally, your vet will decide on the best way to pack the wound depending on the location as well as if flushing or cleaning is required daily.
Other treatments and home remedy for rabbit abscess
The most recommended treatment is surgical excision. However, some factors such as location may necessitate the use of some treatments which include the following:
This remedy uses strong or high sugar concentration. Although these bacteria do they feed on sugar, a reason why abscesses are common in diabetic animals. The high concentration will suck water from these organisms thus killing them as well as inhibit their growth.
Soak a gauze in dextrose and pack it into the wound. Let it say for only a day and change it to avoid it being diluted by the fluid coming from the wound or it may be absorbed into the body.
Manuka honey such as Raw Manuka Honey Certified MGO has a strong sugar concentration like dextrose as well as antibacterial properties. It will promote “the formation of clean, healthy granulation tissue, and acidifies the wound, promoting healing” .
It should be used after draining and removing any dead tissues. Use a syringe to ensure honey reaches the cavity. Do this twice and ensure your rabbit does not lick the honey.
Soak antibiotic solution into a gauze and pack it inside the wound. This method allows you to use antibiotics that would have been toxic or harmful if given systemically. However, ensure absorption does not cause issues including gut problems by killing the good bacteria. This can cause dysbiosis and enterotoxemia
It involves packing polymethylmethacrylate (PMMA) beads impregnated with antibiotics into the abscess wound. The wound can then be stitched. These beads are ideal where the abscess is deep, hard to clean or is in place that cannot be accessed easily.
However, ensure the antibiotic is safe as it may get absorbed and alter intestinal normal flora balance by killing the good bacteria.
The use of calcium hydroxide has shown some success in treating abscesses, especially the facial ones and it is normally put inside a drained and cleaned abscess. One possible downside is being caustic, it can cause necrosis as well as damage muscles, nerves, and blood vessels severely.
N-acetylcysteine - Parvolex
It can help breakdown pus, inhibit some bacterial activities as well as stimulate some functions of the immunity cells. However, it has a strong detestable smell.
It may help break down the thick pus and make it remove easy
Rabbit abscess surgery cost
The cost of abscess surgery will depend on the location where the abscess is, its severity and whether your pet will be hospitalized or outpatient. Also, the packaging and aftercare as well as medications that are required will have an impact on the total cost.
On average expect the cost of severe abscess surgery to be about $250 -$500. Additional costs for medications, hospitalization, aftercare, and treatment, may apply, among other costs. However, this cost may be much lower for a simple incision.
Recovery and prognosis are tied to where the abscess is and how severe it is. For instance, those on the abdomen or legs will take longer to heal since they are under pressure as your bunny lies down or walks. In such a case, consider confining this pet to a small area that you clean regularly.
Those near the tail, anus or any other place that leaks may get contaminated and this can stop the wound from healing.
Finally, those on the face and involving oral cavity and teeth may cause bone infection making prognosis to be poor and require more aggressive treatments.
Prevention will include dealing with the various risk factors that can lead to the formation of following abscesses
- Tooth or dental - Diets with enough hay such as timothy hay, leafy greens, trimming of overgrown teeth, and so on.
- Skin abscess – Prevent fighting, remove any abrasive objects and treat any skin wounds
- Brain and ears (perioral abscesses if on the base of the ear) – Treat any middle ear infections, chronic sinus or any other nasal infection
- Feet especially on sore hocks – provide a dry, soft solid ground and treat any wounds and pain that may cause immobility. Avoid urine scalding, soiled bedding and sharp objects on the surface of their cages, hutches or run. Control obesity in rabbits too.
- Lung abscesses – Treat bacterial pneumonia, infections that affect this organ and lower respiratory problems.
- Rabbit lumps – have any lumps examined by your vet to be certain what causes them.