Pneumonia is one of the most common bacterial diseases of pet guinea pigs. A number of potential disease-causing bacteria may inhabit the respiratory tracts of otherwise normal guinea pigs.

Stress, inadequate diet, and improper home care often predispose a pet guinea pig to respiratory infection, although many well looked after guinea pigs can develop pneumonia.

Signs of pneumonia may include laboured or rapid breathing, discharge from eyes and nostrils, lethargy and inappetence. Some animals show no signs at all before dying suddenly.

Middle and inner ear infections occasionally result from respiratory disease in guinea pigs. Additional signs may include incoordination, tilting of the head, circling to one side, and rolling.

A bacteria called Bordetella which is often carried by rabbits (without showing any respiratory signs) can often cause fatal pneumonia in guinea pigs.

Diagnosis of pneumonia is usually done by taking an x-ray or CT scan of your guinea pigs chest to look at the lungs. Infection causes changes in the lungs, which can be seen on this type of imaging. Your vet may take a deep nasal swap to culture the bacteria if it is affecting the upper airway too to identify the cause of the infection and select an appropriate antibiotic to treat it.

You should consult your vet if you think your guinea pig has this serious bacterial infection. Aggressive antibiotic therapy by injection and appropriate supportive care, including oxygen are sometime necessary. Bacterial culture and antibiotic sensitivity testing help your vet select an appropriate antibiotic.

Often, guinea pigs will require a long course of antibiotics which you will need to give at home for several weeks. Nebulising is useful in some cases; this involves the use of a drug delivery device (inhaler) used to administer medication in the form of a mist inhaled into the lungs.

Unfortunately, even though the signs of infection can be relieved, the causative bacteria cannot always be eliminated. Some guinea pigs unfortunately have long-term scarring in their lungs and will be more prone to picking up an infection again in the future.