Heart and Blood Vessel Disorders
Older Syrian hamsters can develop blood clots in the heart, called atrial thrombosis. This is often linked to congestive heart failure and sometimes to a condition called amyloidosis in which abnormal proteins build up in the liver and kidneys, interfering with their function. Signs of atrial thrombosis can include fast breathing, an uneven heartbeat, and a bluish tint to the skin or gums. There is no effective cure, though a veterinarian can help manage the condition for a short time.
Digestive Disorders
Diarrhea
Digestive problems are common in hamsters. Diarrhea, often called “wet tail," is seen often.
Bacterial Causes of Diarrhea
A serious cause of diarrhea in young hamsters is proliferative ileitis, a disease caused by Lawsonia intracellularis bacteria. Stress from travel, crowding, surgery, illness, or diet changes can make diarrhea more likely. Signs include wet fur around the tail, low energy, poor appetite, and weight loss. Treatment might include fluids and antibiotics, and sick hamsters should be kept away from healthy ones.
Tyzzer disease, caused by Clostridium piliforme bacteria, is an illness with similar signs, including diarrhea, dehydration, weight loss, and sudden death. It spreads through contaminated feces. The cage and all supplies must be cleaned very well.
Salmonella infection is uncommon but can cause diarrhea, dehydration, weight loss, and a rough coat. The infection can also spread to people. Even if a hamster looks better after treatment, it can still carry the bacteria.
E coli infections can also cause diarrhea, especially in young or stressed hamsters. A vet can diagnose these infections with lab tests and prescribe treatment.
Diarrhea can also be caused by antibiotics given to hamsters. Some antibiotics can be deadly to hamsters because they upset the normal bacteria in the intestines, leading to severe diarrhea and death. Never give antibiotics unless a veterinarian prescribes them.
Parasitic Causes of Diarrhea
Pinworms are rare in hamsters, but tapeworms are more common than in mice and rats. Many infected hamsters show no signs of parasites. Heavy infections can affect the intestines and might be seen in the feces. Some rodent tapeworms can infect people, so as always, wash your hands after handling your hamster or cleaning the cage.
Protozoa can also cause diarrhea in young or stressed animals.
A vet can identify all of these parasites from a fecal sample.
Obstruction
Obstruction of the intestines can happen because of parasites, ingestion of foreign material like bedding, or a condition called intussusception, in which part of the intestine folds into another part. This can occur because of straining from diarrhea, and can also cause rectal prolapse, where part of the intestine sticks out from the anus. This is an emergency and calls for immediate veterinary care.
Eye and Ear Disorders
Conjunctivitis, or pinkeye, can be caused by injury, infection, or dust. It can also occur with facial swelling caused by dental problems. Warm water can help remove crusts, and a vet can flush the eye and prescribe medicine.
Hamsters sometimes have an eyeball bulge out of the socket because of injury, infection, or rough restraint. This is an emergency and requires quick veterinary care for the best chance of saving the eye.
Bone, Joint, and Muscle Disorders
Limping can be caused by strains or broken bones. Injuries often happen when a hamster's leg gets caught in a wire wheel or wire cage, which is why solid surfaces are safer. Falls can also cause broken bones or back injuries. If your hamster seems to be in pain or doesn't want to move, get veterinary help right away.
Nutritional Disorders
If a pregnant hamster doesn't get enough vitamin E, her babies can be born weak or stillborn, and she might eat them. Adult hamsters low in vitamin E can also have weakness or even paralysis (inability to move). A balanced diet helps prevent this problem.
Lung and Airway Disorders
Like people and other animals, hamsters can develop respiratory infections from viruses and bacteria. Breathing problems can become serious quickly in hamsters. If your hamster wheezes or has trouble breathing, see a vet promptly.
Pneumonia
Pneumonia (infection of the lungs) is uncommon but can happen after stress weakens a hamster’s body. It is usually caused by bacteria, sometimes in combination with viruses or other causes. Signs include secretions from the nose or eyes, trouble breathing, loss of appetite, and low activity. Mild cases can improve with antibiotics and supportive care.
Sendai Virus (Parainfluenza Virus 1) Infection
This virus is rare but spreads easily between hamsters. Newborn hamsters sometimes have secretions from the nose, breathing trouble, or pneumonia, and can die. Adults often show no signs. No direct cure exists, but your vet can treat dehydration, poor nutrition, or bacterial infections to help your hamster survive this illness. Keep sick hamsters away from others and keep cages clean.
Reproductive Disorders
Breeding females can have fertility problems because of age, poor diet, cold temperatures, too little nesting material, or problems with their breeding cycle. Pregnant females can lose or eat their young if stressed, poorly fed, overcrowded, handled too much, or if the pups are sick or deformed.
Milk gland infections are caused by bacterial infections of female hamsters' breasts and can happen about 7 to 10 days after they give birth. The glands can swell and leak pus or mucus. A vet can diagnose the infection and prescribe antibiotics.
Skin Disorders
Many skin problems in hamsters are caused by infection or parasites. Check your hamster’s skin often, and if you notice changes, have your hamster checked by a vet.
Skin Abscesses
Abscesses are pockets of pus under the skin. They usually form after bites, fighting, or cuts from sharp cage items. They are often found around the head. In males, the scent glands on their sides can also become infected. Treatment includes draining the abscess, cleaning it, and giving antibiotics. Fighting hamsters should be separated.
Actinomycosis
Actinomycosis is a rare bacterial infection that can affect the glands around the mouth that produce saliva, causing pus to drain. A veterinarian can diagnose it by taking a sample of the pus. The infection can be treated by draining the area and giving antibiotics.
Hair Loss (Alopecia)
Hair loss can happen from rubbing on the cage, too little protein in the diet, or other hamsters chewing the fur. It can also be linked to infection with mites or ringworm (fungus), hormone problems, kidney disease, or a type of cancer called lymphoma. A vet might need skin tests or blood tests to find the cause.
Ringworm
Ringworm is a fungal skin infection, not a worm. It can cause bald, flaky, crusty, or red patches, though some hamsters show no signs. Ringworm can spread to other animals and people. A veterinarian can diagnose it and might prescribe antifungal treatment. Wear gloves when cleaning the cage and wash your hands well.
Skin and Fur Mites
Mites are common in hamsters, especially in older males. Heavy infestations can cause dry, scaly skin and hair loss, often over the back and rear end. Other mites affect the ears, nose, face, feet, or tail. Mites that affect hamsters generally do not affect humans. To treat mites, a vet usually prescribes medicine you can apply to your hamster's skin, along with frequent cage cleaning.
Liver, Kidney and Urinary Tract Disorders
Inflammation and Scarring of the Liver (Cholangiofibrosis)
Older hamsters, especially females, can develop long-term liver disease. Blood tests can show liver changes. The cause is unknown, and no effective treatment exists.
Affected hamsters can also develop kidney inflammation that gets worse over time. Signs include weight loss, extra thirst, and increased urination (or a wetter cage). A veterinarian might use blood tests, urine tests, or imaging to look for the cause and suggest treatment.
Diseases Affecting Multiple Body Systems
Some illnesses affect more than one body system, like the digestive system, the circulatory system, and so on.
Lymphocytic Choriomeningitis Virus (Arenavirus) Infection
Lymphocytic choriomeningitis virus usually affects wild mice but can sometimes infect hamsters. Hamsters can get it through contact with infected wild rodents or their droppings. Hamsters often do not appear sick, but they can spread the virus to people. Some hamsters lose weight, have seizures, become lethargic, or reproduce less.
No effective treatment exists, but keeping your pets away from wild rodents will prevent spread of the virus. Infected animals should be euthanized, and their cages should be thoroughly cleaned. This virus can be very dangerous to people, especially during pregnancy, so use gloves and wash carefully after handling anything contaminated.
Amyloidosis
Amyloidosis results when a protein called amyloid builds up in organs such as the liver and kidneys. It is more common in hamsters over 1 year old and in females. Signs often appear when the kidneys begin to fail and include poor appetite, rough coat, hunched back, fluid buildup, and lethargy. There is no cure, and treatment is mainly supportive.
Polycystic Disease
Polycystic disease, which is hereditary, causes fluid-filled cysts to form in organs of the body and is common in hamsters over 1 year old. The liver is often affected, but other organs can be involved too. Surgery is the only cure, and it only works in some cases. However, depending on location, some cysts can be drained for the comfort of the hamster.
Pseudotuberculosis
Pseudotuberculosis is a rare bacterial disease that spreads when food or water is contaminated by wild birds or rodents. It can cause severe illness, including blood infection and major weight loss. There is no treatment. Pseudotuberculosis can also spread to people, so infected hamsters and those hamsters that have been exposed must be euthanized, and cages must be cleaned very carefully.
Tularemia
Tularemia is a rare but severe bacterial infection with Francisella tularensis bacteria. Hamsters can catch it from infected ticks or mites. Sick hamsters usually die within 48 hours. There is no treatment, and the disease can spread to people. Infected or exposed hamsters must be euthanized, and their cages must be disinfected. Prevent contact with ticks and treat mite problems quickly.
Cancers and Tumors
Cancer is not common in hamsters, and many growths are benign (not cancerous). Benign tumors often form in organs involved in hormones or digestion, especially the adrenal gland.
Lymphoma can appear in older hamsters and affect the lymph nodes and many other organs, including the liver. One form of lymphoma affects the skin and can cause low energy, weight loss, hair loss, and skin inflammation.
Other tumors form in the uterus, intestines, brain, skin, mammary glands (breasts), hair follicles, fat, or eyes. If you notice any lump, have your vet check it as soon as possible. Some tumors can be treated with surgery, medicine, or both if caught early enough.
For More Information
Also see professional content regarding disorders and diseases of hamsters.
