Rat Care
Rats are social, inquisitive animals that make great companions. They very rarely bite so they are often great pets for children. Rats should be kept together in at least a pair although sometimes they may fight and need to be separated whereas spaying and neutering usually helps. Males should not be kept with females unless they are neutered because they breed readily and have large amounts of babies.
Housing
Rats need a solid bottom cage at least three feet long and two feet wide. Time outside of the cage to explore a safe area is great enrichment. They will chew wood and plastic so only ceramic or metal dishes should be used. Water bowls get very dirty so must be cleaned frequently and water bottles attached to the side of the cage should be used. Carefresh (recycled shredded paper) bedding or layers of fleece bedding are the best options to use at the bottom of the cage. There should be several hides that your rat can get completely under to hide and sleep. Cardboard boxes offer great hiding places and rats enjoy destroying them as well. Toilet paper rolls, wooden chews, grass hay, newspaper, and other destructible toys (avoid plastic) provide good enrichment and chewing opportunities.
Rats urinate and defecate a lot so their cage should be cleaned frequently (at least 1-2 times weekly) to reduce waste odor and contamination.
Diet and Nutrition
Rodent blocks and rat pellets are fortified with excellent nutrition and are much healthier than seed mixes. Avoid mixes with nuts, corn, seeds, and fruit as these will be favored and can lead to obesity. Small amounts of table scraps can be offered such as greens, whole grains, rice, nut butters, some fruit, healthy cereals, and pasta. You should not offer human junk food despite the fact they might like it.
Health
Spaying female rats before 16 weeks old is recommended to decrease the incidence of mammary tumor development. With good care the average lifespan is about 2-2.5 years.
Rat Spay
If you decide to get a female rat as a pet in the future, it is very important to have it spayed when it is around 3 to 4 months of age. This eliminates the chance of ovarian disease and greatly reduces the chance of other reproductive diseases. This also greatly reduces the chance of a rat developing a mammary tumor develop as she ages. It is one of the most important things you can do to extend her life.
Rat Bite Fever
Rat bite fever is an infectious disease in people caused by the bacteria Streptobacillus moniliformis. People become infected either by being bitten by a rodent carrying the bacteria. While any person who comes into contact with the bacteria is at risk of developing the disease, children under 5 years of age, adults over 65 years of age, and immunocompromised people are at higher risk.
Rats who carry this bacteria will not show any signs of illness. There is a test that involves a swab of their mouth which is used to look for the DNA of the bacteria. There is no treatment that is 100% effective is removing this bacteria from positive rats. If a rat is positive, it should be considered positive for life.
If your rat is positive, take important steps to protect yourself by practicing good hygiene. Always wash your hands thoroughly after handling your pet or its cage furnishings. Do not let your rat lick you. Avoid touching your face or mouth while handling your pet. Do not kiss your rat. Keep pet rats out of the kitchen or anywhere food is prepared or consumed.
Symptoms of Rat Bite Fever in people include fever, vomiting, headache, muscle pain, joint pain or swelling, and rash. Symptoms can start as early as 3 days after exposure to the bacteria but sometimes can be delayed for up to 3 weeks. It is important that your physician knows you have pet rodents. If our feel ill or your rat bites or scratches you, inform your physician promptly so you can be placed on antibiotics. Untreated Rat Bite Fever infection in people can be deadly.
Upper Respiratory Disease in Rats
A rat that sneezes a lot, has more tears than normal or has crusty eyes, or has an audible wheeze or crackle, is showing signs of a respiratory infection.
Respiratory infections in rats are often caused by viruses. Many times the viruses are harbored in older rats that aren’t showing any outward signs of infection yet they are still capable of infecting younger rats. This is one reason why it is important to avoid mixing rats of different ages and different origins together.
One of the common causes in young rats is Sialodacryoadenitis virus/SDA virus which usually causes nasal discharge, red tears, and congestion for about 3 weeks. There are many other viruses that can cause disease.
This young rat has red nasal discharge and a small amount of red crust in the corners of the eyes. It has a distinct clicking sound when it breathes. It is most likely infected with SDA virus.
Another common cause of respiratory infection is Mycoplasma pulmonis. Mycoplasma often responds well to antibiotics but in some cases it may go on to cause pneumonia despite appropriate treatment.
There are a variety of bacteria that are “secondary invaders”. This means they do not cause disease on their own but can make infections caused by viruses or mycoplasma more serious. If left untreated, these bacterial infections quickly develop into pneumonia.
Unfortunately, there is no rapid test that can tell if a rat has a virus, mycoplasma, a bacteria, or some combination. Mycoplasma and bacteria respond to antibiotic treatment and usually improve after 7 days of antibiotics. Viruses do not respond to antibiotic treatment and a rat may continue to have a clear to pink nasal discharge, sneezing, and watery eyes for about 3 weeks.
If a rat is on antibiotics for 7 days and is not getting better but is not getting worse, it often has a viral infection. If a rat on antibiotics starts to have more trouble breathing, or has a change in the color of its nasal discharge, it needs to be re-examined to determine if it has developed pneumonia, a very serious infection that requires more intensive therapy.
Hygiene is very important to limit the spread of this disease. If your rat is sick, wash and disinfect your hands before handling any other rats. Clean the cage and wash and disinfect the cage and food bowls and water bottles every day until the upper respiratory infection resolves.
Other rats that have been exposed to an infected rat may come down with the disease within 2 weeks.
Tumors, Abscesses, Cysts in Rats
Rats are prone to a variety of lumps and growths beneath their skin. Many times these are abscesses or infections that accumulate pus beneath the skin. In older rats, typically 18 months or older, cancerous tumors are more common as the cause of bumps. The tumors may be benign ones such as adenomas or lipomas, or they may be more serious ones classified as adenocarcinomas. Most tumors are readily removed at a small size and many of them do not return if the surgery was able to completely remove the growth. If you see a bump on your rat, don’t wait until it gets big to get it checked. The sooner we see your pet, the better the chances are that we can help!
Mammary Tumors
Mammary tumors are very common in unspayed female rats over 18 months old and in rats that were more than 4 to 6 months old at the time of spay. About 10% of male rats can develop mammary tumors. Depending on the genetic strain of rat, around 90% of mammary tumors are benign which means they do not spread. Tumor removal does not guarantee that another tumor will not develop, but tumor removal in combination with a spay tends to significantly reduce the risk of new tumors developing. A rat that has a benign tumor and tumor removal and spay will typically live a full life. Many younger rats have lived up to an additional 2 years following surgery.
Surgery is not the right choice for some rats. Many rats do well without surgery and have a normal quality of life until the tumor is so large it interferes with movement or it develops scabs or ulcers, at which time humane euthanasia should be considered.
If you decide to get a female rat as a pet in the future, it is very important to have it spayed when it is around 3 to 4 months of age. This eliminates the chance of reproductive disease. This also greatly reduces the chance of a rat developing a mammary tumor as she ages. It is one of the most important things you can do to extend her life.
Rat Pituitary Tumors
A pituitary tumor is an abnormal growth of the pituitary gland, which sits just under the brain. It is one of the more common tumor types that rats are at risk for as they age. A majority of pituitary tumors in rats are pituitary adenomas. These are benign, meaning the cells do not spread to other parts of the body. However, because of the location of the pituitary gland, excessive growth can place pressure on the brain and brainstem. This can lead to neurological signs that worsen as the tumor grows.
The most common sign of a pituitary tumor in a rat is difficulty performing normal movements. Owners may notice that their rat is having trouble climbing, sitting at the bottom of their cage, and may appear off-balance while walking. A rat may also have difficulty using their front paws for grooming and grasping food. In lighter colored rats, owners may notice pink or red staining around the face and head from porphyrin that is not completely cleaned away. Signs can progress to a rat being unable to eat or drink on their own. A CT scan may be used to confirm a diagnosis of pituitary tumor, but unfortunately, there is no way to remove a pituitary tumor in a rat safely.
There are two medications (cabergoline and bromocriptine) that can be used to slow tumor growth and delay the progression of symptoms. These medications work by inhibiting tumor cells from producing hormones. The efficacy of these medications is variable; some rats respond very well, and some not at all. Other medications that can be used to ease swelling and inflammation are steroids. Because long-term use of steroids can suppress the immune system, they may be prescribed alongside a long-term course of antibiotics depending on the case.
The most important part of caring for a rat with a pituitary tumor is supportive care and monitoring quality of life. Owners should keep track of how well their rat is able to eat, drink, walk, and groom on their own. Additionally, keeping a log of an individual rat’s favorite things to do and how well they can still do those things can help to monitor quality of life.
Abscesses and Cysts
Abscesses may be simple to treat after they have been surgically drained. A course of antibiotics and anti-inflammatory medication may be all that is needed after a minor surgical procedure. Some abscesses are resistant to treatment and may require multiple surgeries and more intensive medical therapy.
Cysts are accumulations of material in the glands of the skin. Some cysts will rupture and ooze gray to white material. Other cysts will need to be surgically removed.
Further Reading
