Respiratory diseases are highly prevalent among rats, affecting both their upper and lower respiratory systems. The manifestations of these diseases can include sneezing, wheezing, nasal discharge, and peculiar breathing sounds such as rattling or honking.

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

Rat in hands

What Causes Respiratory Disease?

Respiratory diseases in rats usually have multifactorial causes, often involving a combination of bacterial infections and potential viral factors. Stress or environmental risk factors can also serve as triggers for the progression of respiratory diseases.

Among the significant contributors to chronic respiratory diseases in rats is Mycoplasma, a bacterium that commonly plays a key role. Mycoplasma can be transmitted through aerosolisation, which occurs when rats breathe or sneeze on each other, and sometimes from the female rat to her offspring. While Mycoplasma can normally reside in the respiratory tract without causing harm, stress or exposure, other respiratory diseases can activate it, leading to illness.

Apart from Mycoplasma, other bacteria and viruses can contribute to respiratory diseases, typically through aerosol transmission. Additionally, the environment in which your rat resides can significantly impact their respiratory health. The accumulation of ammonia in a rat’s living environment can cause damage to the cilia lining the respiratory tract.

Cilia are small projections extending from the cells that line the respiratory tract, covered in mucus. These cilia play a crucial role in trapping dust, dirt, and bacteria, preventing their entry into the respiratory system. However, ammonia can destroy these cilia, compromising their defence mechanism and allowing bacteria to enter the respiratory tract more easily. To mitigate this risk, we recommend housing rats in well-ventilated cages with wire walls rather than glass aquariums. Additionally, it is essential to regularly clean rat cages thoroughly and consider litter training your rats to maintain a clean environment.

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 around a rat’s nose or eyes 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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