Respiratory disease in rats: mycoplasma, bedding and warning signs

According to the veterinary edition of the MSD Veterinary Manual, chronic respiratory disease in rats is caused mainly by a bacterium, Mycoplasma pulmonis, often together with other bacteria and viruses. Most pet rats are affected to some degree. The infection can stay quiet for a long time, then flare up and spread to the lungs.

It spreads through direct contact, through the air, during mating, and from mother to young at birth, according to the MSD Manual. The RVC adds that the infection lasts for the rat’s whole life.

Behind each eye, rats have a gland, the Harderian gland, that produces a red pigment called porphyrin. According to the MSD Manual, it is secreted in larger amounts when the rat is stressed or ill: the tears turn red and dry into crusts around the eyes and nose that look like blood.

It isn’t a disease in itself but a signal: pain, acute stress or an underlying illness, often respiratory. RSPCA Australia advises having a rat with red tears checked promptly.

According to the MSD Manual, how severe the disease becomes depends heavily on the level of ammonia in the cage, produced as urine breaks down, and on any other viruses or bacteria present. A lack of vitamin A or E also plays a part, according to the MSD Manual and the RVC.

• Remove urine-soaked bedding every day, and change all the bedding at least twice a week, according to the MSD Manual.
• Choose absorbent, low-dust paper bedding; avoid pine and cedar shavings and scented bedding.
• No glass tanks or wooden cages: air circulates poorly or urine soaks into the wood, and ammonia builds up.
• A well-ventilated cage, in a room kept at around 18 to 26 °C (64 to 79 °F), according to the MSD Manual.

• Sneezing, snuffling, little clicking sounds when breathing.
• Nasal discharge, red tears or red crusts around the eyes and nose.
• Ruffled coat, hunched posture, tiredness, weight loss.
• Head tilt: the infection can spread to the middle ear.

Separate a rat showing respiratory signs from its companions until you have your vet’s advice, as the MSD Manual for owners recommends.

Diagnosis is based mainly on the examination and the rat’s history; X-rays are sometimes useful. Treatment often combines several medicines given over several weeks: it relieves the signs without clearing the infection, and relapses are common.

According to the RVC, early, well-followed treatment gives the best chance, and many rats with chronic respiratory disease keep a good quality of life with the right care.

Respiratory treatment often lasts for weeks, and relapses come back. In MyArk, every prescribed dose becomes a shared reminder: whoever gives the medicine ticks it off, and the whole household can see it’s done.

• A reminder for every dose, on the schedule your vet prescribed
• Respiratory episodes noted and dated in the health record
• Weight followed in the weight tracker, to spot a relapse
• A shared reminder for cleaning the bedding