Recurring Respiratory Illness in Pet Rats: Causes and Prevention

Why Do Pet Rats Suffer From Repeated Respiratory Infections?

“I bought my rats from a pet store, and I’ve taken them to the vet many times for respiratory infections. I know it’s probably chronic, so how can I help my rats with this?”—Tanya

Repeated Infections Can Harm Lung Tissue

It is not unusual for pet and laboratory rats to develop respiratory infections more than once. When respiratory infections recur, a condition called atelectasis frequently develops in both humans and various animal species. This involves the collapse of part of the lung or failure of the air sacs to inflate properly, leaving the animal with less lung tissue available for oxygen exchange.

With each new respiratory infection, scarring and lung collapse tend to worsen slightly, increasing the likelihood of subsequent infections.

What Might Be Causing Your Rats’ Illness?

Numerous viruses can infect rats, and it is possible that an infection was present when you brought them home from the pet store without your knowledge. Rats can be affected by a type of coronavirus, which, similar to in humans, spreads through aerosols. While Mycoplasma is the most frequently seen bacterial infection, coronavirus is the most common viral infection in rats. (1)

Exposure to new rats can introduce these pathogens, but it is equally possible that your rats already carried the infection when you acquired them and have since contaminated their living space. The infection itself is not typically fatal, but when a secondary infection occurs—such as another virus or a bacterial infection—some animals do die.

Certain viruses and bacteria only cause illness in rats when other diseases are present. Mycoplasma is also a frequent issue in rats and becomes serious when a viral infection is involved. After treating the active infection with antibiotics, the most effective approach is to focus on prevention.

How Can You Reduce the Chance of Recurrence?

When respiratory infections are treated, we usually talk about how to prevent them from returning. For pet rats, the strongest recommendation is to eliminate bedding that can become airborne and irritate the lungs, replacing it with paper towels or materials like cardboard or paperboard. There is also a paper liner that produces minimal dust when shredded. Corn cob bedding and pine shavings should never be used, as they can grow mold and irritate your rats’ lungs, making a secondary bacterial infection more likely.

Since rats tend to chew their bedding, commercial colonies sometimes use bedding cubes that are safe to ingest. If the bedding mentioned above is not available, there are several suitable alternatives. Avoid using glossy papers, however, because they contain dyes that may bother your rats.

Make Sure There Is Enough Airflow

Another factor that can irritate the respiratory tract and lead to infection is keeping rats in a closed cage with inadequate ventilation. If you house your pets in an aquarium, this is likely contributing to the problem. This article on rat enclosures provides detailed guidance on choosing a new cage if needed.

Rats truly need a cage with wire walls to prevent ammonia fumes from their urine from building up, since even daily cleaning may not be sufficient to prevent lung irritation.

In addition to changing the bedding type, another helpful suggestion if you breed rats to sell as pets or give to friends is to separate males and females and pause breeding for roughly three months. Some viruses require a new host to multiply, and simply interrupting the breeding cycle can be enough to halt the spread of these viruses.

Sources

1. Schoeb TR. Respiratory diseases of rodents. Vet Clin North Am Exot Anim Pract. 2000 May;3(2):481-96, vii. i.nlm.nih.gov/pmc/articles/PMC7110835/

This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2024 Mark dos Anjos, DVM