Pneumonia refers to severe inflammation of the lungs caused by bacteria, viruses, or fungal infections. Also, coma, dental disease, inability to swallow and other environmental factors such as inhalation of foreign bodies into the lung, smoke or chemicals can cause this inflammation.
The condition can be both infectious when caused by pathogenic microorganisms or noninfectious if it related to other factors including environmental factors including allergies and air pollutants such as aerosols and dust.
Also, a weakened immune system, some underlying diseases, regional factors such as if in places where temperatures vary greatly, and you have outdoor rabbits including those on direct draughts can contribute to this condition. Indoor rabbits can also be affected by pneumonia.
Here are some of the microorganisms that can cause severe lung inflammation disease.
- Viruses causing pneumonia – Common viruses include myxoma virus, coronavirus, and herpesvirus. They also make your pet to be vulnerable to bacterial caused pneumonia.
- Bacteria - The most common viruses that cause pneumonia in rabbits are P. multocida (most common)and Bordetella bronchiseptica. Others include Staphylococcus aureus, Pseudomonas spp. Streptococcus sp. Escherichia coli, Klebsiella pneumoniae, Moraxella bovis, Vibrio vulnificus  among others.
- Fungal – occurs mainly when spores are inhaled to the lungs or through the bloodstream.
- Parasites – inhaled or enter the lungs through the skin.
The diverse causes, especially by the many bacteria and some viruses indicates that the use of the term ‘Pasteurellosis’ in place of pneumonia inconsistent.
Symptoms may depend on the exact cause, severity, duration of illness, immunocompetence of the affected rabbit as well as age. . In most instances, symptoms are only an indication advance stage of respiratory system compromise.
Some of the frequently noted symptoms include the following:
- Anorexia or decreased appetite
- Labored breathing (dyspnea) and abnormally rapid breathing (tachypnea)
- Sneezing and coughing (coughing is not so common in rabbits)
- Nasal and eye discharge
- Facial abscesses
- Congested mucous membrane (cyanosis)
- Malaise and the affect rabbits will not tolerate exercises
- Albino rabbits will have bluish eye color
Since rabbits can hide some of the symptoms that this condition causes, it is advisable to take any lower respiratory disease seriously, even if it is mild, unless competent diagnosis by a qualified vet proves otherwise. Severe symptoms may include
- Noisy and severe labored breathing
- Coughing blood
- Anorexia and weight loss
- Hypothermia shock (fever)
- Your rabbit will lie down and be unable to rise or move
- Mouth breathing with the neck extended, i.e., head positioned up and backward position.
Note that a bacterial infection may spread to other organs to cause conjunctivitis (eyes), to the middle ear, pericarditis, pleuritis or cause a testicular abscess. If it infiltrates to the blood, septicemia may develop which will require immediate and aggressive treatments.
In case of any symptoms, see your veterinarian at the earliest opportunity for diagnosis and treatment.
Diagnosis will involve examination of the clinical signs, history of your pet ( such as diet and stressors including change of environment, pollution, living conditions, and so on) as well as lung auscultation.
Afterward, your vet may conduct the following procedures to help in verification the exact cause of pneumonia in your rabbits as well as its severity:
Bloodwork (complete blood examination) to detect any hematologic changes
- Thoracoscopy for tissue biopsy. Lung wash and biopsies require sedation
- Radiography to detect whether it is the lower or upper respiratory tract affected as well as the presence of edema or abscesses.
- Bacterial cultures to identify strains of bacteria involved and hence medications to use
- Lab analysis of discharges from the nose
Pneumonia in rabbit’s treatment and care
Treatment options will largely depend on the cause detected during diagnosis. Also, there will be support care to reduce some of the symptoms your pet may be having. You vet may consider the following:
- Hospitalization, fluid and electrolyte therapy if your rabbit suffers from fever, weight loss, lethargy or anorexia.
- Painkillers may also be prescribed in case of pain as well as anti-inflammatory medications.
- Depending on what diagnosis reveals, he or she may prescribe antivirals, antimicrobials, antibiotics (including ophthalmologic antibiotics) or antifungals.
- Oxygen therapy to decongest the lung or chest if they are congested.
- In the case of abscesses, surgery may be recommended
Prognosis will depend on the responsible microorganism, nature, and presence of other complications including peritonitis, septicemia, bacteremia, and pericarditis.
A high mortality rate has been noted in cases caused by Pasteurella multocida, Staphylococcus aureus or Pseudomonas.
Once treated, further reinfections can be prevented by strategies such as isolation, good husbandry (proper hygiene, not overcrowding your rabbits, proper ventilation) and proper disposal of any dead bunny.
Furthermore, avoid allergens (dust and chemicals), provide proper diet (to provide necessary nutrients and booth immunity), proper housing to shield rabbits from temperature variation or draughts and so on. On diet, include leafy greens such as romaine lettuce, carrot tops, parsley, cilantro as they contain moisture and will in rehydration.
Finally, do not force your rabbit to exercise will still recovery. Restrict its activity.