Hamsters routinely shed their fur, so some hair loss is normal. However, the fur should never appear completely bald in patches, as this signifies there could be a health or environmental issue.
Bald patches are usually a side effect of a serious issue. You mustn’t leave your hamster’s fur to grow back on its own because some conditions will kill them if left untreated.
Why Is My Hamster Losing Its Fur?
It’s natural for hamsters to lose a little fur, especially when they shed their winter coat in the warm summer months.
Long-haired hamsters are more prone to hair loss due to the amount of fur they start with. However, sudden or inexplicable bald patches must be investigated.
Fur loss and subsequent bald patches have several causes, such as:
Veterinary Practice News confirms that hamsters have scent glands on the side of the hips (flanks).
Experts believe that hamsters mark their territory through scent gland secretions, which often appear greasy, waxy, and yellow.
Pet hamsters do this by rubbing their scent glands on items within their enclosure, such as:
- Cage edges
- Separation bridges
Similarly, hamsters with access to sand in their enclosure also enjoy rubbing themselves against the rough particles to dislodge dirt and debris from their fur.
However, over-rubbing causes bald patches because of the abrasive texture.
While this is relatively normal, keep an eye on your hamster to ensure it’s not rubbing itself against objects to deal with boredom.
If so, provide more things for your hamster to do and remove any sharp or harmful objects from the cage.
2/ Metal Hamster Wheels
The overuse of hamster wheels causes them to rub on the same spots of the legs, creating sores and bald spots. If you notice your hamster losing hair on its hind legs, check how often it uses its running wheel.
Large wooden or plastic wheels aren’t as abrasive and are unlikely to cause fur loss. If you have a metal wheel, you might want to swap it out for one more suited to your hamster.
3/ Allergic Reactions
Hamsters can be allergic to certain types of bedding, especially dusty ones.
Cedar and pine bedding are unsuitable substrates because they produce too many dust particles. As well as causing respiratory issues, they can irritate your hamster’s skin.
Undyed and unbleached paper-based bedding is among the most popular substrates because it’s soft and less likely to affect the skin and fur.
Allergies are easy to treat when you know what’s causing a hamster’s fur loss. You can check by swapping the bedding out with something else to see if your hamster’s fur grows back.
If you use several substrates in a hamster’s cage, remove one type at a time to determine which one it’s allergic to. That way, you can avoid it in the future.
Food and materials on toys and hideouts can be to blame. If you’ve demined that bedding isn’t the cause of a hamster’s bald patches, eliminate certain foods or materials to see if the fur grows back.
You must also refrain from spraying anything in a hamster’s environment, such as perfumes or household fragrances. The chemicals can cause a reaction and make the skin sore.
4/ Poor Diet
Dietary deficiencies caused by a low-grain, low-iron, or low-protein diet commonly result in fur loss. Hamsters are omnivores, requiring 16% dietary protein. The best sources of protein are:
When providing your hamster with cooked meats, ensure they’ve been cooked without oils or seasonings.
Hamsters fed poor-quality seed mixes lack the nutrients needed to be healthy. One of the earliest side effects of a poor diet is fur loss.
A nutritionally-balanced diet of pellets, high-quality seeds, protein, and fresh fruits and vegetables will keep your hamster’s fur in optimal condition.
Hamsters clean their fur with their feet and saliva to remove excess oils. Once they reach maturity, you’ll notice your hamster grooms itself several times throughout the night.
This is normal, but excessive grooming can cause a hamster to get bald patches. In particular, it’ll experience hair loss behind the ears and around the hips, where its nails can reach.
Over-grooming is a sign of stress and anxiety. Things in a hamster’s environment can cause this, like:
- Other pets
- Loud noises
- Bright lights
- A cage that’s too small
- Living with another hamster
- Shallow bedding
A hamster can appear to have bald patches immediately after it has groomed itself.
The fur’s still there, but it’s wet and flattened, creating the illusion of bald patches. Once the hair dries, the hamster’s coat should return to its normal appearance.
Like most living creatures, hamsters are susceptible to mites. These tiny pests live in a hamster’s skin and fur, living off its blood and oils.
Mites cause an itchy sensation when they feed, so your hamster will scratch the affected area, causing extreme fur loss. Mites also commonly result in mange. A hamster will also develop the following:
- Inflammation of the skin
- Dry or red patches
- Redness around the tail and facial area
- Intense itching and rubbing against surfaces
- Hair loss (alopecia) on the back and rump
Mites are common, particularly if you introduce contaminated food, bedding, pets, or toys to your hamster’s environment.
According to Hautarzt, hamster-safe sprays containing pyrethrin eradicate mites from your hamster’s fur and environment.
However, you’ll need to deep clean the hamster’s enclosure and items to remove them for good.
Ringworm is a fungal infection that manifests as a ring of hair loss with flaky skin.
A humid environment causes ringworm, but it can be transferred from humans to pets. Similarly, ringworm is contagious to humans, so wear gloves whenever handling your hamster.
Many hamsters don’t exhibit signs of ringworm, but the primary symptom is bald patches. Your hamster will vigorously itch, causing worse fur loss and painful sores.
8/ Cushing’s Disease
Cushing’s disease is among the more serious causes of fur loss and bald patches. It’s uncommon, but it’s an incurable, fatal condition many hamsters develop as they age.
Cushing’s disease affects the brain’s pituitary gland, causing the body’s hormone production to become irregular. The main symptoms include:
- Bald patches or thinning fur
- Dry, flaky skin
- Weight loss
- Loose skin
- Increased thirst and urination
- Dark pigmentation on the skin
- Skeletal muscle waste
- Cuts and scabs that commonly become infected
One of the first symptoms of Cushing’s disease is fur loss. It most commonly affects male Syrian hamsters, but all species are susceptible.
9/ Old Age
Fur loss and bald patches are common side effects of aging.
Hamsters live for 2-3 years on average. Once they reach this point, they deteriorate quickly and almost without warning, which shocks many owners.
As hamsters grow older, their fur becomes sparse and patchy, so you’ll notice bald patches through the thinning coat. While this is normal, monitor your hamster’s behavior and well-being.
10/ Bar Biting
Hamsters lose fur around their nose due to bar biting. The minimum recommended cage size is 80 x 50cm. However, many hamsters need more than this, especially larger and more energetic female Syrians.
Hamsters who are stressed within their environment chew their enclosure bars for relief. The friction will cause a bald patch in one location.
Alongside fur loss around the nose, a hamster will develop painful sores from prolonged chewing.
Excessive burrowing is another cause of hair loss around the nose. They use their noses to move bedding out of the way and make holes they can move through.