Rats make great pets, but sadly they are prone to several health conditions in their short lives that vets see all too frequently. One of these is a head tilt, where the rat appears to have its head permanently cocked to the side. Although it can look comical, it is a sign that something is not right with their centre of balance.

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The Balance Centre

An animal’s ability to stay upright and balanced is controlled by the body’s balance centre. This is composed of structures in the inner ear known as the vestibular apparatus and the part of the brain that receives and interprets the signals sent via nerves. Collectively they are referred to as the vestibular system. Any disease or abnormality that affects the vestibular system can cause an animal to feel unsteady on its feet, stumble or develop a tilt to the head.

Diseases of the Inner Ear

The most common cause of a head tilt in pet rats is an inner ear infection. Although outer ear infections may result in discharge coming out of the ear, this may not be the case with an inner ear infection. It is possible that a head tilt may be the first or only symptom present. Other things you may notice include scratching of the ear, an unpleasant aroma coming from the rat’s ear, or a red stain around the eyes called porphyrin. Porphyrin is a natural stain that rats produce from a gland behind the eye when they are under stress or are unwell.

Ear infections (otitis) in rats typically involve bacteria

They can occur in the absence of other health conditions; however, otitis is often a complication of a very common disease in rats called Murine Respiratory Mycoplasmosis. This airway disease is a chronic and life-shortening infection caused by Mycoplasma pulmonis, a bacterium that likes to grow in the airways, nose, and sinuses of rats. The inner ear structures are connected to the sinuses by the Eustachian Tube. This tube allows infection in the sinuses to spread to the ear.

If a rat has a Mycoplasma infection, the head tilt may follow or be accompanied by changes in breathing such as more rapid or laboured breathing. They may have a discharge from the nose or appear generally unwell with lethargy and a reduced appetite. If the infection is severe, you may even hear unusual sounds when your rat breathes.

Other Causes of Head Tilt

Rats are inquisitive animals that like to explore, investigate, and climb their surroundings. An accidental fall or knock to the head could cause trauma to the vestibular apparatus or the nerves in this part of the body. Likewise, if there has been in-fighting within a group of rats, a bite around the ear and face could damage nerves or introduce bacteria into the skin and deeper tissues, creating an abscess.

In these cases, trauma creates inflammation 

This, with or without infection, can alter how the vestibular system perceives the animal’s own body position. If you have concerns that your rat has fallen from something, or there is fighting and biting between your rats, your vet can help with medical and behavioural management as needed, to minimise the likelihood of more serious health effects occurring.

Another cause of a head tilt is a physical and structural change such as a tumour

This is more likely to occur in the brain tissue than the ear. Attached to the lower brain is the Pituitary Gland which is the second most common site for tumours in female rats. Although Pituitary Gland tumours are usually benign, they can severely impact an affected rat’s life. Depending on the size of the tumour, a head tilt could occur alongside more concerning neurological symptoms such as weakness, circling or seizures.

Treatment of a Head Tilt

Whether a head tilt is the only symptom or one of many, prompt veterinary care gives the best chance of improving your pet’s quality of life. As a prey animal, rats can hide some symptoms of disease. Knowing what is normal for your rat as well as regular health checks can help both you and your vet recognise when something is wrong.

Treatment and its success, depend on the underlying cause but may include antibiotics and anti-inflammatories. If your rat has an ear infection in the absence of Murine Respiratory Mycoplasmosis, treatment and recovery may be straightforward. Sometimes the infection clears up, but the head tilt can remain. Your rat can usually adapt to this, although you may need to alter its housing to lower the risk of injury from being uncoordinated.

Unfortunately, Mycoplasma pulmonis infection typically persists despite medical therapy, and often worsens over time. Symptoms commonly become less responsive to medication as the disease progresses. Treatment of tumours are generally aimed at reducing symptoms to improve your rat’s comfort and welfare. Your vet can discuss appropriate treatment options and advise when a decision may need to be made to help end any suffering.

Conclusion

There are several reasons why your rat may develop a head tilt. The presence of other symptoms may influence the success of treatment. As it can be difficult to recognise disease in prey species due to their ability to hide symptoms, regular health checks and seeking veterinary advice whenever your rat seems unwell, is key to optimising the health of these delightful pets.

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