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Rat FAQ


The goal of this Rat FAQ is to educate the general public about the proper care of domesticated pet rats. Suggestions may be sent to RatNMouse1@aol.com regarding possible updates to this FAQ. All of the information contained within this FAQ is based on the experience of the authors. This FAQ is in no way meant to supersede or replace veterinary advice. The text of this FAQ may be reproduced and distributed as long as nothing is altered, edited, or removed. It must be distributed in its entirety and full credit to the authors must be given. The authors of this FAQ are Mary Ann Isaksen and Diane Newburg.


LIFE SPAN

Q: How long will my pet rat live?
A:
The average lifespan of a pet rat is between 2 and 3 years. However, genetics, husbandry and love will ultimately determine how long your pets live. Animals bred from healthy parents will live longer than those bred from weak and sickly animals, and animals fed a healthy diet and kept in clean cages using the proper bedding will live longer than those fed junk food who live in dirty cages on pine or cedar.

Love and attention can sometimes play a big role in how long your rat will live. A neglected animal will be depressed and sometimes just wither away, while an animal given lots of attention and love will live months beyond its life expectancy because it is happy and has a much stronger will to live.

ACQUIRING A RAT

Q: Where is the best place to obtain a rat?
A:
A breeder of rats is usually the safest place to obtain a rat as most are concerned about their breeding animals being healthy. They also handle the babies from birth so the rat is very socialized when you get him. You may also be able to obtain the lineage of your rat if you get him from a breeder. To find a breeder in your area, contact your local rat and mouse club.

Pet store rats can make wonderful pets, but you should examine them closely for any health problems. Many pet store rats (especially if from the “feeder” section) have not been handled so can possibly take weeks to become accustomed to being handled. Be sure you examine the rat to verify if it is male or female as many pet store employees are unable to do this accurately. (The large testicles of a male rat should be apparent by the age of three weeks.) Whichever sex, consider getting pairs or trios since rats are very social animals and do not do as well if kept singly.

We also strongly recommend visiting your local humane society or animal shelter when looking for pets. Homeless pet rats and mice are euthanized daily simply because people don't think to go there to adopt small friends.

MALE OR FEMALE

Q: Is there any difference in disposition between a male and female?
A:
Both sexes make wonderful pets. Females are smaller and considerably more active than males and their fur is softer. On the other hand, males are normally happier sitting on your lap and having you scratch their head.

QUARANTINING

Q: I want to buy some new rats, but how can I be sure I don’t bring home a deadly virus to my existing pet rats.
A:
Any new rat should be quarantined from two weeks to a month. The rat should be housed in a separate cage in a separate room, although air-borne viruses can be transmitted from room to room. Unless you can quarantine your new rats from your old rats in a separate building, there are no guarantees. To ensure that you are doing all you can, be sure to wash and disinfect your hands after handling the new rat and handle the new rat last. Change your clothes if you happen to put the new rat on your clothing while handling it prior to handling your old rats. Watch the new rat closely for any signs of illness, and also watch your old rats for signs of illness. If any symptoms appear, be sure to treat immediately.

HOUSING

Q: What kind of cage is best for rats?
A:
Both wire cages and aquariums are suitable for rats and each has advantages and disadvantages. However, any type of cage must be large enough for the number of rats to be housed in it. When purchasing a cage for a baby rat, be sure to allow plenty of room for the rat to grow. Most cages manufactured for hamsters do not allow this necessary room and are therefore unsuitable for rats.

An aquarium will protect the rat from drafts, but has poor air circulation which makes it warmer and more humid than a wire cage. An aquarium is also more difficult than a wire cage to decorate and to provide levels for climbing. A 20-gallon tank will house one or two females or males and would need to be cleaned twice a week since the rats are living in their litter, unlike in a wire cage where they can climb up onto shelves. Tanks make it difficult for the owner to interact with their pets. Rats housed in aquariums need daily out time to provide necessary exercise unless the rat happens to be a wheel runner.

Wire cages should be powder coated, not galvanized, as galvanized wire will corrode in time as rat urine burns it away. The cage floor should be solid, not wire, and shelves should be solid. The often-seen wire on shelves or ramps that is 1/2” x 1” is frequently the cause of a rat’s foot or leg getting caught and breaking or being seriously sprained. Rat & Mouse Gazette recommends FernCage by Sierra cages (562/696-5969 or write 11830 Wakeman Street, Santa Fe Springs, CA 90670).

Cages made with wood are totally unacceptable for rats as their urine will soak into the wood, causing ammonia buildup, which can lead to or exacerbate respiratory disease. They may also chew through the wood allowing them to escape. The wood may also splinter making it unsafe to tender rat flesh.

CLEANING

Q: What should I use to clean my cages?
A:
Cages can be disinfected with Parvosol, a germicidal, virucidal, veterinary cleaner-disinfectant. (Other brands available are Spectra-Sol and Roccal-D) Bleach is also fine, diluted 1 part bleach to 10 parts hot water. Be sure all residue is thoroughly rinsed off and the cage is well dried.

LITTER AND BEDDING

Q: I've heard that cedar shavings are bad for rats. Is this true?
A:
Yes! Both cedar and pine shavings contain phenols, the oils in the wood that give them their fresh and woodsy smell. Phenols are poisonous, caustic, acidic compounds present in soft woods, and are routinely diluted for use in disinfectants (such as Pine-Sol and Lysol) and cover the smell of animal urine. Because phenols are caustic, they constantly irritate the nasal passages, throat and lungs which gives an easy opening to bacteria. Phenols affect the kidneys and liver, the organs responsible for filtering blood and urine and eliminating toxins from them. Long-term exposure to phenols can cause liver damage and make the animal very sensitive to anesthetics. Exposure to phenols can also depress the immune system, thus causing lowered resistance to diseases such as respiratory infection. Pine and cedar shavings are toxic to small animals and should not ever be used.

Unfortunately, cedar and pine are the easiest to find in pet stores. Under no circumstances should they be used. Hardwood shavings are the best, such as aspen. Other acceptable litters are paper products such as Bio-Flush, CareFRESH, and Yesterday_s News. Corncob bedding is okay but when it gets damp it can start growing mold, thus requiring frequent changing. Rabbit food pellets can also be used. It is absorbent and breaks down easily, but is safer than soft woods or corncob.

INTRODUCTIONS

Q. What is the best procedure for introducing rats? Is it possible to introduce two males without them getting into a big fight?
A:
If possible, put rats in separate cages near each other so they can get used to the smell (and sight) of the others. After about a week, let them out on a neutral area (possibly your bed or a couch). If they fight, separate them and try again in a day or so.

Clean out both cages and disinfect them. Dab some vanilla extract on the bridge of the nose (between the nose and the eyes), on the back, and on the genitals of each rat. Let the rats go in and out of both cages until they are comfortable and there is no fighting. The whole procedure may take a day, days, a week or a month. Be patient. Also be prepared for the fact that some rats may never get along and will need to be housed separately.

FOOD

Q: What kind of food should I feed my rats? Is it okay to feed them table scraps?
A:
Laboratory pellets or lab blocks, as they are referred to, should be considered to be your rat’s basic diet. These blocks are nutritionally balanced for rats and mice and are used exclusively by many laboratories and breeders as the animals’ entire diet.

Lab blocks have been formulated to meet a rat’s nutritional needs and recommended brands are Teklad, Hagen, and Kaytee blocks. Rat and Mouse grain mix is available in most pet stores, but should only be fed as a treat a couple times a week. The best of the grain brands is Universal Supreme, made by Kaytee.

Add fresh foods such as fruits and vegetables to your rat’s daily diet. Rats do love table scraps, but don’t overdo. Chicken bones are fine. Rats gnaw the bones and will not choke on them like a dog will. Treats may be added sparingly.

Q: Someone told me I should not feed my rats corn or chocolate. Is this true?
A:
The Rat Health Care booklet by Debbie Ducommun reports that corn should be fed with caution due to high levels if nitrates and amines which can combine in the stomach to form nitrosamines which are carcinogenic. In theory, this is true, but you would have to feed your rat a diet almost entirely of corn for this to be a problem. You don’t want your rat to exist soley on any one type of food, but there really isn’t a problem with corn, other than too much in the diet will make your rat fat. A well balanced diet containing corn in moderation is perfectly fine.

Chocolate is also fine in moderation. It’s the Theobromine in chocolate that can be dangerous for dogs, but rats do not have a problem with it. Again, moderation is the key or you will end up with a fat rat.

Don’t freak out if your rat gets into your soda-pop, either. Although the Rat Health Care booklet reports that carbonated beverages should never be given to rats because rats can’t burp and can be fatal, this is simply not true.

WATER

Q: How much water should I give my rat each day?
A:
Rats should always have fresh water available in a demand-type water bottle. Bowls can be tipped over, leaving the rat with no water for long periods of time, depending on how often you check on your pets. They can also be contaminated with all kinds of bacteria due to contact with bedding and feces. The average rat will drink up to two ounces of water per day. Flavoring the water will sometimes make them drink more, and feeding lots of fresh fruits and vegetables containing a lot of moisture will make them drink less.

TOYS

Q: What kind of toys can I put in my rat’s cage?
A:
Wheels are a favorite of most rat owners and can be introduced at any age, but best results are achieved by acquainting the rat with one while it is very young. A rat that is a runner most often remains a runner for life and will spend a great deal of time doing so. Females are more inclined to be runners than males.

PVC pipes make excellent tunnels. Also check out bird toys such as ladders and nut rings. Ferret tents, hammocks, swings and tunnels are usually popular, but they can be expensive and often made of cloth so the rats can chew them up. Large cotton ropes made for birds can be strung across wire cages. Let your imagination run wild!

BATHING

Q: How do you give a rat a bath?
A:
Have a towel ready before you begin. Fill both sides of your kitchen sink with lukewarm water. Dip your rat in one side of the sink in the water, but only up to the neck. Use a soap made for cats or kittens, or even dish washing liquid (like Dawn on male rats for the oily buildup on their skin) and apply several drops on the rat’s back. Begin working the soap into a good lather and scrub well with your fingertips. (It is best not to use a brush as you can apply too much pressure without realizing it.) Be careful not to get any water or soap into your rat’s eyes or ears. When you feel the rat is clean, lower him into the other side of the sink and rinse. Again, be careful not to get any water in the rat’s eyes or ears. If you don’t feel you can rinse the rat well enough this way, you can hold him under a stream of running water, but be sure the water is not too warm.

HEALTH PROBLEMS

Q: What are some of the signs I can look out for to be able to tell if my rat is sick?
A:
Excessive sneezing is probably the most common sign of illness. Lethargy, loss of appetite, dull coat, puffy appearance of coat, loud or raspy breathing and labored breathing are all signs of respiratory illness and are a very good indication that your rat needs to see a vet immediately.

Red discharge (porphryin) around the eyes and nose is sometimes a sign that your rat is ill, but can also be present simply due to stress or an irritant such as dust. The harderian gland, which lies behind the rat’s eyeball, secretes a red, porphyrin-rich secretion that lubricates the eye and eyelids. This secretion sometimes gives the appearance of blood, but contains little or no blood.

Head tilt, often called “wry neck” is usually caused by an inner ear infection. The rat should be seen by a vet to determine whether or not the eardrum is still intact and to decide upon the proper course of treatment. If the cause is an infection, it should be treated with antibiotics, but he may also prescribe an ear drop which contains both a topical antibiotic and an anti- inflammatory drug. Another possible cause can be a pituitary tumor, which is more common in older female rats, but can be seen in younger rats and even in male rats. There is no treatment for this condition that will cure it; however, anti-inflammatory drugs such as Prednisone or Dexamethasone may reduce the swelling slightly and prolong the life of the rat for a short time. A stroke is another possibility. Again, it would be more common in older rats, but it is not impossible for a younger rat to have a stroke. Anti-inflammatory drugs may help, but only time will tell if the damage is permanent. In many cases, a full recovery from a stroke can be made in a short period of time (a few days to a week).

Q: What is mycoplasma?
A:
Mycoplasma pulmonis is an organism which all of our rats in the pet population carry. Stress or other illness can make your rat break with an active infection that can lead to pneumonia if left untreated. There is no cure for mycoplasma, but it can be controlled with antibiotics until the very advanced stages of the disease. It is the main cause of rat respiratory illness.

Mild cases of mycoplasmosis can be treated with non-prescription drugs such as Tylan and Tetracycline, but in more severe cases you will need to see your vet to obtain stronger antibiotics such as Baytril, Doxycycline, Gentocin, and Chloramphenicol.

Q: I just noticed blood coming from the vagina of my one-year old rat for the first time. Do female rats have periods?
A:
No, female rats do not menstruate, so if your female rat is bleeding vaginally then something is wrong and you need to get her to a vet. Vaginal bleeding can be a symptom of a uterine tumor, genital mycoplasmosis, a urinary tract infection, a miscarriage, or the beginning of labor. If you can eliminate a miscarriage or labor from this list, and if after antibiotics have been given to rid her of any infection she is still bleeding, then the only treatment left is to have her spayed.

Spaying will eliminate the problem altogether and may extend her life. Be sure to find a competent vet to perform the surgery. It should cost in the neighborhood of $65 to $150 for the entire procedure. Also make sure that your vet gives you post surgical antibiotics to prevent possible infection. Remember, this surgery involves going into the body cavity and should not be decided upon without considering the risks. If she is a young rat, the benefits will probably outweigh the risks, but if she is very old it may be best to let her live out her life in peace. Many females have bled vaginally on and off for over a year before leaving this world.

Q: My rat got his foot stuck in the wire on the bottom of his cage and now his whole leg is swollen. What should I do?
A:
A trip to the vet for an injection of an anti-inflammatory drug such as Dexamethasone may speed the healing process, but it is imperative that you get the rat into a cage with a solid bottom. Injuries like thse are very common in wire-bottomed cages which is one reason we do not recommend them at all (not to mention ulcerative pododermatis, also known as Bumblefoot).

If the leg is just swollen and there is no breakage of the skin, the anti- inflammatory drug and rest may be all that are required for a quick recovery, but if an open wound is present, you may need to have it cleaned out and have an antibiotic prescribed by your vet as well.

Q: My rat got into a fight and now has an abscess. How do I treat it?
A:
An abscess will frequently break open and drain on its own. In this case, clean the wound with hydrogen peroxide. You can also apply a topical antibiotic ointment such as Neosporin. If it does not break open and drain on its own and becomes hard and continues to grow, wait for a scab to appear on the surface and gently squeeze it, popping the scab allowing the old pus to be forced out. Clean the wound as described above. In all cases of abscesses, if it appears to be making your rat ill, you will need to get your rat to the vet to have it lanced. In all cases of abscesses, you may need to put your rat on oral antibiotics to fight the infection from within.

Q: My rat sways back and forth while standing still. I something wrong with him?
A:
Rats have poor eyesight and this movement is often used to detect motion. It is more common with pink-eyed rats.

Q: I think my rat is in pain. How can I tell?
A:
If your rat cries when it moves or when you touch it or pick it up or winces then it probably is in pain. Rats are very stoic, so if your rat is truly showing signs of pain then the pain must be severe. If this pain is associated with a known injury, you can ask your vet about possible pain medication. If you do not know of any injury, you will need to take it to the vet for an X-ray to determine if there is a hidden injury or tumor somewhere causing it pain.

It has been determined that household drugs such as ibuprofen, aspirin, and acetaminophen have no real effect on rat pain due to their high metabolic rate and, therefore, should not be used. Heavy duty opioid analgesics such as Butorphanol and Morphine administered frequently are considered necessry in cases of severe pain. Less severe pain should not be treated with medication at all as the pain ensures that the rat will stay calm and speed the healing process.

Q: My rat is in pain an no longer has a quality life. Should I have him euthanized?
A:
If your rat is in pain, is no longer eating, drinking, and active, it is time to let go. Unless you have an inhalant anethesia available to you at home (such as Halothane, Isoflurane, or even Chloroform), you will need to take your rat to the vet to be euthanized. Inhalant anethesia overdose, or inhalant anesthesia followed by lethal injection are the only humane methods of euthanasia. Lethal injection in rats is either in the peritoneal cavity (belly) or directly in the heart, both of which are extremely painful if the rat is awake, and, therefore, inhumane. Please INSIST on the gas prior to any lethal injection.

SCABS, AKA SPOTS

Q: My rat is scratching and has scabs on his face and shoulders. Does he have mites?
A:
It is possible that he has mites, but most often scabs are caused by too much protein in the diet, which causes hot spots that the rats scratch. Try eliminating high-protein items such as sunflower seeds, peanuts and dog food. If the scabs persist, the problem may be mites. The horse-wormer paste products "Zimecterin," "Rotectin 1," "Equalvan," or "Equimectrin" (1.87% Ivermectin) can be used to get rid of mites (or lice, which appear as little red bugs on the skin with tiny eggs on the hair shaft). The dose is a small amount of the paste orally on the end of a toothpick (the size of a uncooked grain of white rice). Repeat dose once a week for three weeks.

Bedding may be dusted lightly with cat flea powder containing carbaryl. Allow the rats to sleep in treated bedding for 1 to 2 weeks to eliminate any hatching eggs.

SPAY AND NEUTER

Q: Is it better to have a rat fixed, as far as health and longevity?
A:
There are both benefits and risks involved with spaying a female rat and neutering a male rat. The obvious benefit for both sexes is that they no longer have reproductive organs that can sometimes cause health problems later in life.

With female rats, removing the reproductive organs will lessen their chances for developing mammary and pituitary tumors, and definitely makes it impossible for her to get cancer of the uterus or genital mycoplasmosis. The risks, on the other hand, are great, as this is a major surgical procedure which should be done while the rat is quite young (for the most benefit), and the vet must go into the body cavity to perform the operation. General anesthesia must be used and can be considered a risk in itself, as any animal could die while under its effects (including humans).

Neutering male rats is most often done to allow the male to live with female rats or to stop aggressive behavior, since testicular cancer is not common in rats. While this procedure is not as invasive as spaying a female rat, it should still be considered dangerous, as general anesthesia is required and post operative infection resulting in abscesses is quite common. After any surgical procedure, you should always be sure your vet sends your rat home with a course of antibiotics.

BREEDING

Q: How can you tell when a female rat is in season?
A:
It happens every four to five days, mostly in the evening hours, for twelve hours at a time. You will quite often see the other female(s) in the cage trying to mount the female in season. If you look at her vaginal opening, it will be open, moist, and kind of purplish in color. If you touch her hind quarters, she will stretch out, putting her nose and rear end in the air, arch her back downwards, and vibrate her ears.

Q: What are the recommended breeding ages (upper and lower) for female rats?
A:
Female rats can get pregnant as early as five to six weeks of age, but they really should not be bred until they are three and a half to four months of age. If they are not bred at that time, they should be bred (if you plan to breed them at all) before they are eight months old. If they have a litter between these ages, you can breed them up until about one year, but it is not recommended breeding beyond that.

If they have not been bred by eight months of age, their chances of conceiving go down as well. Being overweight will also reduce their chances of getting pregnant.

Q: How long is the gestation period for rats?
A:
21 to 23 days. She will not begin to show her pregnancy until the third week, and will not be interested in nest building until the day before or the day she gives birth.

Q: Does my pregnant or nursing rat need any special care?
A:
Pregnancy and nursing require a lot of nutrients. A good quality dry kitten food, such as Iams and Nutro, will give her the extra protein and fat her body needs at this time. Be sure she also has plenty of her normal diet and water available at all times.

Q: What is the average size litter?
A:
The average size litter is 12, but numbers from 1 to 22 are possible. Although the female only has 12 nipples, she can care for many more babies as long as she is getting the proper nutrition. Most females with very large litters will separate the babies into two piles and will alternate feeding each group, therefore, there is no reason to ever consider culling. Finding homes for the highest possible number of babies should be something you consider before you decide to breed.

Q: Can I keep the male in with the female when she has her babies?
A:
The female will go into season within 36 hours of giving birth and can become pregnant again right away. It is not healthy for her to be pregnant and nursing a litter at the same time. It is recommended that the female be given a rest period of at least two months between pregnancies and litter rearing to restore her body to full strength.

Q: Can I keep two females together while one or both has babies?
A:
This is not recommended. Although some females will share the responsibilities of raising their families without any problems, there are other females who will steal all of the babies and try to nurse them herself. These females most often will not let the other mother get near her babies. This may not be a problem with small litters, but is with large litters since the female will not be able to produce enough milk to feed all of the babies and many may die. It has also been reported that a female has gone berserk and killed all of the babies of another female. Why take the chance? It is very easy to set up two tanks for the mothers to raise their babies separately. It is much less stressful for them this way.

Q: When should the babies be weaned?
A:
The babies should be left with the mother for a minimum of four weeks. Large litters may be left for five weeks. They should not be left beyond this time.

SEPARATING BABIES

Q: At what age do male and female baby rats need to be separated in order to prevent early breeding?
A:
The general rule is to separate the babies from mom by the time they are five weeks old to avoid a male offspring possibly impregnating his mother, and separate the males from the females by six weeks of age.

IMPOTENCE

Q: Do male rats become impotent or infertile with age?
A:
Some males who have been used for breeding while they are somewhat young will breed almost until the day they die, and some have been known to continue to breed but lose their ability to impregnate the female (become infertile). If a male has not been used for breeding while young, he will sometimes not be interested in breeding at all.

HAIRLESS RATS

Q: Is it true that you have to keep Hairless rats warmer than rats that have fur?
A:
It is recommended to house Hairless rats with furred rats. Their skin is a little thicker, but they probably get colder not having any fur to keep them warm. If you choose to keep a Hairless rat alone, or with other Hairless rats, give them a box of some sort to sleep in, small enough to hold their body heat. It also might be helpful to give them an old T-shirt or something equivalent to help them stay warm. Be sure to launder any fabric frequently.

TEETH GRINDING

Q: When my rat is sitting with me, sometimes her head shivers slightly and she makes funny noises with her teeth as if chewing on something, but she's not eating. Is this "teeth grinding"? Is it similar to cat purring?
A:
Yes, this is teeth grinding and they always seem to do this while they are very content. They also grind their teeth to keep them at the proper length (as food really has nothing to do with keeping them short) and this could simply be what they are doing.

OTHER SOURCES OF INFORMATION

Q: Are there any other ways to get good information?
A:
Please check to see if your questions are answered at Quick Answers from Rat-Help and Rat-Info. These "answers" are from a compilation of the most frequently asked questions provided by that service, and also provide a list of Rathelp's mosts often recommended links.