Respiratory diseases in rodents and rabbits

Rodents and rabbits are often quite susceptible to many diseases. Here is some useful information on respiratory diseases in these small animals.

Factors that promote respiratory disorders

The environment is a very important factor in the development of respiratory diseases in rodents and rabbits. It is indeed at the origin of many infectious diseases. In the environment, the parameters to be taken into account are temperature, air currents, dust, irritating gases (ammonia, tobacco smoke). They are likely to irritate the nasal passages, and thus make this place conducive to the development of microbes. In case of respiratory disease, the shavings from the cage must be removed as they are a source of irritating dust for the respiratory mucous membranes and conjunctiva. Rodents and rabbits are very prone to stress and environmental changes.

They need calm and isolation. They are sensitive to high temperatures, temperature variations, cold and humidity.

Rabbits and guinea pigs are very sensitive to heat. They are prone to heatstroke, especially in hot and heavy summer weather, or as a result of direct sun exposure on balconies, behind glass or during car transportation. Heatstroke results in respiratory distress that can lead to death. For this reason, it is necessary to ensure good ventilation of the cage, provide a shaded area and leave enough water available.

Other non-infectious factors include :

  • Obesity, which in advanced cases can lead to compression of the lungs.
  • Cardiac problems that can be complicated by lung problems.
  • Tumours of the respiratory system can cause breathing problems.
  • Pollen allergies for rabbits
  • Dental problems that can develop into respiratory problems due to the proximity of the mouth and nasal passages.

Infectious agents of respiratory diseases

Pasteurellosis
It is the most common respiratory disease in rabbits. It can also affect guinea pigs, chinchilla and octodon. It is due to a bacterium (Pasteurella multocida) that is transmitted from one sick rabbit to another by contact or by contaminated environment (litter, food, water…). This disease is often expressed during stress (transport, temperature variations…) and results in nasal discharge (with sneezing and noisy breathing), conjunctivitis, pneumonia but also non respiratory signs such as ear infections or abscesses.

Myxomatosis
It is a virus that only affects rabbits (and hares). Insects are important actors in the transmission of the disease, mainly mosquitoes in summer and fleas in winter. Sick rabbits are also a source of contamination.
The disease is characterized by the appearance of nodules on the head and even on the body, but also a frequent respiratory form in winter with an important nasal discharge.
Vaccination is a way to avoid the disease.

Bordetellosis
It is a bacterial disease that can affect rodents and rabbits. It is common in rabbits and guinea pigs while rats, mice and hamsters are quite resistant to this disease. It is a zoonosis i.e. transmission between rodents/rabbits and humans is possible. The transmission takes place through contact but also through contaminated objects such as cage, water, litter…
It is a disease that is mainly expressed in stressed animals (following transport, overpopulation, inadequate living conditions…) or when another bacterial disease (Pasteurellosis) is also present.
Symptoms are runny nose, conjunctivitis and may evolve into pneumonia.

Mycoplasmosis
It is a disease caused by some of the most important pathogenic bacteria in rats and mice. This disease results in respiratory signs with secretions from the nose and eyes of red color (it is not blood) and also other more general signs such as anorexia, weakness and a poorly maintained coat. A regular change of bedding reduces the risk of catching this disease.

The Rabbit Viral Hemorrhagic Disease of Rabbits
Rabbit viral hemorrhagic disease (RVHD) is an acute infection in which the rabbit is the only known host. Transmission occurs through contact between sick rabbits. It causes respiratory damage among other symptoms and very often results in death. There is a vaccine against this disease.

The Sendai Virus
The Sendaï virus is one of the most important pathogenic viruses in rats and mice. It is the main cause of pneumonia in mice. Hamsters are also susceptible, although the infection is often asymptomatic. The gerbil is resistant. The virus may have little effect (especially in rats) but can also cause severe respiratory damage and even death in young mice. This virus can also lead to superinfections by so-called opportunistic bacteria. Other viruses, bacteria and even fungi are likely to cause respiratory disorders but are less frequent.

Tips to avoid respiratory problems

As said before, the environmental conditions are very important for these animals which are relatively fragile:

  • First of all, the cage must be easy to clean and sufficiently ventilated (cages with solid plastic walls can hold a lot of litter but are not ventilated enough).
  • Litter can be made of paper or shredded newspaper, wood shavings or hay. Litter that is too dusty should be avoided as it can irritate the mucous membranes of the nasal cavities.
  • The cage should be placed in a quiet place to avoid stress. Do not put the cage in the middle of a draught and avoid large temperature variations. The humidity level (hygrometry) must also be controlled to obtain an optimal living environment.

Optimal living room climate standards for rodents/rabbits

  • Avoid putting your pets outside in case of bad weather.
  • Do not mix sick animals with healthy animals and try to respect a quarantine period when introducing a new animal.
  • Avoid environmental factors that disrupt the respiratory system such as tobacco smoke, …
  • Regularly ventilate the living room of your animals by paying attention to draughts and change the litter regularly.
  • It is advisable to vaccinate your animals against certain respiratory diseases. Vaccines are mostly available for rabbits, including vaccines against myxomatosis and viral haemorrhagic disease.
  • Avoid unnecessary stress to your animals (overpopulation,…) as this is an important factor in the outbreak of diseases.

And above all :

It is imperative to go see a veterinarian to obtain a precise diagnosis of the disease and to have an adapted treatment.
Remember to wash your hands after each handling of a rodent/rabbit because some of these diseases are transmissible to humans (especially children).