Upper and lower respiratory diseases are very common in rats. Respiratory disease can present with a number of signs including sneezing, wheezing, nasal discharge, and unusual noises while breathing, including rattling or honking.

In this article, we outline the causes, symptoms and treatment options for respiratory diseases in rats.

Rat in hands

What Causes Respiratory Disease?

The cause is generally multifactorial and often includes a mixed infection with a range of bacteria, there are also some potential viral causes. In many cases, there is an inciting cause of stress or a risk factor in their environment that may cause the respiratory disease to progress.

Mycoplasma is one of the main players in almost all chronic respiratory disease in rats, and it can be transferred via aerosolisation, when rats breathe or sneeze on each other, or sometimes from the female rat to her babies. Mycoplasma can be a normal inhabitant of the respiratory tract, however, if your rat becomes stressed or exposed to another respiratory disease, this can trigger Mycoplasma to cause disease.

Other bacteria and viruses that can be a component of respiratory disease are usually transferred by aerosolisation.

The environment that your rat lives in can also play a factor as ammonia building up in a rat’s environment can destroy cilia inside their respiratory tract.

Cilia are small projections extending off of the cells that line the respiratory tract, which is covered with mucous. This mucous traps any dust, dirt or bacteria trying to enter the respiratory tract and the cilia move it back out of the respiratory tract. Ammonia can destroy these cilia, which then allows bacteria to enter the respiratory tract.

For this reason, we recommend well-ventilated cages with wire walls, rather than glass aquariums to house rats in. We also recommend a regular and thorough cleaning of rat cages and even litter training your rats.

Mary rat and mouse
Rat vet examination

What Are the Signs of Respiratory Disease in Rats?

Signs and symptoms that may indicate your rat has respiratory disease can include:

  • Sneezing
  • Porphyria (red discharge from the eyes and nose)
  • Increased respiratory rate or effort
  • Weight loss
  • Lethargy

How Do You Treat Respiratory Disease?

Treatment of respiratory disease is often aimed at control rather than a cure. Unfortunately, in rats, when respiratory disease occurs, it is usually present for life. Respiratory signs can clear up with the right treatment; however, in many cases, they will recur, as the organisms causing the infection can be very difficult to eliminate from the respiratory tract.

To achieve the best relief for rats, we use a combination of drugs including; antibiotics for the bacteria involved, bronchodilators to reduce the effort needed to pull oxygen into the lungs, mucolytics to help break up the mucous accumulation, and anti-inflammatories to reduce the inflammation occurring.

Treatment can include a combination of the following medications:


Antibiotics are used to control bacterial infections. Some antibiotics that are prescribed for respiratory infections can also have anti-inflammatory effects, which will further help relieve symptoms. Antibiotics commonly used include doxycycline, enrofloxacin, azithromycin and amoxycillin-clavulanic acid.

Two rats in cage
Grey rat


Anti-inflammatory drugs are used to control any inflammation that may be occurring in your rat’s airway. This is common in early respiratory disease or sometimes in relapses of clinical signs.

Bronchodilators and Mucolytics

Bronchodilators dilate the airways within your rat’s lungs, allowing more air to flow through. Mucolytics act to break up the excessive mucous build up that can occur. Both of these types of medications can help rats who are having difficulty breathing to be able to breathe better.


Using a specialised nebuliser, which turns drugs into a vapour, medications can be directly delivered to the airways. Nebulisation can also be used to help remove mucous that can build up in airways during chronic respiratory infections.

Your rat may be prescribed one or a combination of these drugs. Different combinations are picked based on the clinical signs your rat may be showing, so do not be concerned if you have not been provided with all these categories of drugs.

Rats in bed

What Does It Mean if There is a Red Discharge Around My Rat’s Nose or Eyes?

This red discharge is called porphyrin, and while it looks like blood, it is not. Increased porphyrin secretion occurs in rats due to stress or illness, which is common in rats with respiratory disease. You can clean away the discharge gently with a warm, damp cloth, as it can be irritating and often rats with chronic respiratory disease do not always clean it away.

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Should I Treat All of My Rats?

This depends on a number of factors, including how many rats you own, how many of these rats are showing clinical signs and how old your rats are. The answer is different for different scenarios, so speak to your rat vet about your situation, and they can give you a more personalised treatment plan.

What Else Can I Do to Help My Rat?

Give them lots of love! Your rat will benefit from some extra TLC, including lots of warm bedding such as polar fleece, warm food and plenty of water. If your rat lives outside, consider bringing it inside, especially during the cold winter months, as cold weather can exacerbate respiratory disease.

You can also consider providing them with a heat pack but bear in mind that rats like to nibble; therefore, supervision is required! If you are using sawdust as a substrate in your rat’s cage, try switching to something less dusty, such as shredded paper, which is less likely to irritate your rat’s airway.

If your rat is sneezing, or showing any other signs of illness, be sure to get in touch with us to make an appointment. We always recommend that rats are seen by an experienced rodent veterinarian.

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