Q: My pet hamster seems to have gotten the flu! His breathing is a lot heavier than normal, there’s a bit of discharge at his nose, and he’s less active. I just recovered from a cold, so could I have passed it on to him?

A: While hamsters can get ill and display symptoms very similar to a human flu, including nasal discharge, wheezing, sneezing, and panting, it is unlikely that you passed your cold to him. The viruses that attack people are mostly human-specific, just as hamster viruses attack rodents only. Although it is possible for bacterial infections to infect across species, if your hamster is in good health and has strong immunity, the chances are very low.

Regardless of whether you’re sick or not, pet owners should always remember to maintain strict personal hygiene. If you are ill, avoid handling your pet. If you need to, wear a mask and if possible, gloves. Wash your hands thoroughly with soap and water before and after handling your pet (and especially before eating), as certain pathogens can be spread from human to hamsters and vice versa. Although it is rare, it is still a possibility, so it is best to make a habit to practice hygienic handling of your hamster.

When a hamster breathes heavily, it can mean an upper respiratory (mouth-throat), or lower respiratory (lung) inflammation or infection. The respiratory tract may be swollen and thickened, and congested with mucus, pus and other body fluids. The increased mucus in the tract may be an allergy caused by irritants or other allergens, an inflammation caused by trauma, or a viral, bacterial, fungal or parasitic infection.

As a response to this, your hamster’sbody is naturally producing fluids to “stick” onto these foreign bodies to flush them out of his system. However, these fluids narrow the respiratory passageway, causing your hamster’s breathing to be more laboured. The “wheezing” sound you hear is actually air travelling through the narrowed passage.

Since your hamster is in respiratory distress, has mucus dripping from his nose, and is lethargic, he is very likely sick. As a guide, any change of body weight by 10 percent over a short span of days warrants further investigation, so be sure to pop your hamster on the scale regularly. Prompt veterinary attention is required to diagnose the root of the problem, and for appropriate medication to be prescribed. There is little to be done at home.

As hamsters are “fragile” due to their size, their condition can deteriorate rapidly when they stop eating and lose weight. An otherwise active hamster can very quickly become a severely sick one in a matter of hours or days. Also, try not to wait too long as treatment is always easier and more successful when done in the earlier stages of an illness. While waiting to take him to the vet, keep your hammy’s stress levels low by housing him in a dark and quiet area.