Home » Why Is My Hamster’s Bum Bleeding? (7 Rectal Bleeding Causes)
what does it mean when a hamster is bleeding from its bum?

Why Is My Hamster’s Bum Bleeding? (7 Rectal Bleeding Causes)

If you find blood in the cage, lift the hamster and check its rear end for signs of rectal bleeding.

If a hamster bleeds from its bum, it could have anal sacculitis (blocked anal sacks), wet tail (bacterial infection), pyometra (uterine infection), rectal prolapse, or a urinary tract infection (UTI).

Some hamsters bleed from the bottom because they’ve scratched themselves.

What Does it Mean When a Hamster is Bleeding from its Bum?

If you discover that the hamster’s bum is bleeding, consider why this is the case.

Hamsters have sharp claws and fastidiously groom themselves. During this process, the hamster may have accidentally damaged the soft, delicate skin of its anus.

Alternatively, your hamster may have experienced an impact trauma.

Assuming that the hamster isn’t bleeding due to an accident, such as falling from the top of its cage while climbing, there are various explanations for rectal bleeding:

Anal Sacculitis

Anal sacculitis is a condition that occurs when the anal sacs become blocked.

A hamster’s anal sacs are two small glands on either side of the anus. They produce an oily substance that lubricates the anus.

If the sacs become blocked and infected, this can lead to pain, swelling, bleeding, and discharge.

Treatment involves flushing the anal sacs with warm water and antiseptic. For severe infections, topical antibiotics or oral antibiotics will be prescribed by a vet. Anal sacculitis clears up in 7-10 days.

Blood in the Urine

If you find blood spots in a hamster’s bedding, it may be due to a urinary tract infection (UTI) or a problem with the internal organs.

This can cause a hamster to tear its uterine lining, leading to blood leaking from the anus.

UTIs are quite common in hamsters as they urinate and defecate in their substrate. Regular spot cleaning will reduce the risk of a hamster UTI, but bacteria can still enter the urethra.

If the hamster is infected, it will pass blood into the urine.

Hamsters with a UTI will be in pain and may behave erratically. The hamster may try to pass the infection by drinking more water, so look for warning signs of polydipsia (hydrating beyond the point of thirst) and polyuria (passing excessive urine.)

Left untreated, a UTI could eventually lead to kidney disease.

According to Seminars in Avian and Exotic Pet Medicine, renal failure is common in older hamsters but can be managed with early detection and treatment.

Take the hamster to a vet if you suspect bleeding from the anus is related to a urinary tract infection, especially if it’s also losing weight. Oral antibiotics will resolve the concern; Enrofloxacin is usually prescribed under Baytril.   

Gastrointestinal Issues

If the hamster struggles to pass fecal matter, it could have a prolapsed rectum.

In some cases, the hamster will continue to behave as normal, drinking water, exercising, and eating. However, a prominent part of the hamster’s bowel and rectum will protrude outside the body.

A prolapsed rectum may begin with diarrhea, leaving the hamster straining to empty its bowels. A common cause of diarrhea is the excessive consumption of fruit and vegetables.

If a hamster is dehydrated, the opposite may apply. Stools will be too hard to pass easily, and the hamster will bleed from the rear as it eliminates. If this happens enough, the rectum will prolapse due to the strain.

Another gastrointestinal concern that could explain anal bleeding in hamsters is intussusception. This condition arises when the intestines fold into each other, causing a blockage and intense abdominal pain.

This condition can only be resolved with surgery.

what to do if your hamster’s bum is bleeding

Wet Tail (Proliferative ileitis)

Wet tail (proliferative ileitis) is a bacterial infection that impacts hamsters. Younger Syrian hamsters are most susceptible to wet tail. Unless the condition is treated urgently, it’s frequently fatal.

Wet tail manifests as diarrhea, hence the name of the condition. The hamster will have messy, watery fur around the anus. As discussed, this diarrhea can lead to rectal prolapse and anal bleeding.

Other symptoms of wet tail include weight loss, lethargy, dehydration, and sunken eyes.

At the first signs of wet tail, seek veterinary advice, as this condition will often be fatal within 48 hours. A vet will prescribe the antibiotic chlortetracycline as treatment.


So far, our explanations for rectal bleeding in hamsters haven’t been gender specific.

If you’re asking, “Why is my male hamster bleeding from its bottom?” you can skip this section. Pyometra is a condition that only applies to female hamsters.

Pyometra is most frequently found in senior hamsters, especially ones who’ve mated multiple times and produced several litters of pups.

Pyometra is caused by pus building within the uterus, often due to excess bacteria. This pus results in a discharge of blood.

There are two types of pyometra: open and closed.

Veterinary Quarterly explains that a foul-smelling white discharge accompanies bleeding in the case of open pyometra. A vet will drain this form of pyometra.

Closed pyometra unfolds inside the hamster’s body, making it hard to spot symptoms. This means that close pyometra is often fatal. As symptoms aren’t recognized until the latter stages, the bacteria can spread throughout the hamster’s body and cause sepsis. 

Other warning signs are a distended, swollen belly, excessive thirst, and lethargy.


Hamsters are prone to tumors, which come in these forms:

  • Benign tumors are non-cancerous.
  • Pre-malignant tumors start benign but increase in risk as the hamster ages.
  • Malignant tumors are cancerous and likely to be fatal.

Aside from a physical lump on the hamster’s skin, the symptoms of a cancerous tumor include lethargy, excessive thirst, and fur loss. Anal bleeding can be the final warning sign.


If a hamster is carrying pups, she may start spotting and bleeding. This can look like bleeding from the anus at first glance. Equally, as with UTIs, the uterine lining may be torn.

Female hamsters are fertile after 6 weeks, with males becoming sexually active after 4 weeks. Ordinarily, a licensed breeder or pet store will separate hamsters into solo habitats or single-sex groups by this age. However, mistakes sometimes happen.

Hamsters only gestate for around 3 weeks, or less in the case of a Syrian, so pregnancy can only explain bleeding for a short time.

A hamster bleeding from the bottom is always serious, but it needn’t be terminal. If you find blood around a hamster’s bottom, a veterinarian should examine it.