Have a Goal in Mind
When you decide to start breeding rats, set a goal as to what you are trying to achieve from breeding. Whether it is a certain color, coat, marking, or just the best possible personality, having a goal will help you plan your breedings accordingly. If you know what you want to breed for before you begin breeding, you can seek out the best rats for your goals from the best breeders, and research the thing you are breeding for so you know as much as possible before you even begin. Keep in mind that you may change your goal if you find you don’t like what you had originally planned, or if you can’t find suitable rats for your breeding stock, so don’t obtain a large number of rats right off the bat. The best idea for new breeders is to find at least one unrelated male and female and breed just the one litter at first, to see if it really is something you’d like to get into. If the first litter goes well, you can then get more rats to breed into your lines.
Set Up Your Policies
Once you have decided that you definitely want to become a breeder, you need to decide what your policies will be. Are you going to sell rats for breeding? How much are you going to charge? What will people need to do to buy a rat from you? When you decide, make sure you stick with your policies.
Keep Detailed Records
Breeders are responsible for maintaining the health and personalities of the rats of the future and improving on them even moreso by pairing the right rats. It is therefore extremely important to keep detailed records of any and all rats you breed from so that you know what health or behaviour problems to expect and about how long the rats from each line are living. When you receive a new rat from a breeder, ask for as much information about the rats in its pedigree as possible including date of birth, date and cause of death, and any health or behaviour information that may be important whether good or bad. Keep a record of this information for yourself, don't rely on the rat's breeder to do so for you. When you breed a rat, make sure all the people who are adopting your rats' babies know that they must contact you if their rat ever has a health or behaviour problem, and also when their rat dies so you know how long it lived and what it died from. Most people will forget to do this, even if it is in your contract, so it is a good idea to keep in touch with everyone who adopts a rat from you asking how their rats are doing about every 6 months or so.
Dealing with Illness
Even the most reputable breeder will eventually have either an illness or a genetic disorder crop up in their rattery. Most of the time it can’t be helped. It is a learning experience, and most breeders will become better from it. The real test of character is what you do about it. With a genetic disorder, megacolon for example, the only way to avoid it is to stay away from breeding lines that have had megacolon appear in litters, but even two completely unrelated rats from megacolon-free lines can produce it. So what should an ethical breeder do? In the case of megacolon, the only thing that can be done is to humanely euthanize the afflicted ones when they start to suffer, and adopt out the healthy ones to pet homes only. If there are other breeders breeding rats from similar lines, inform them so they know the risk of breeding similar rats. Also, never breed the parents again, at least not to each other.
There is also the case of a widespread illness, that is, one that is contagious and spreads through all or part of your rattery. An ethical breeder would treat the affected rats according to their veterinarian’s recommendations, run tests on the deceased rats to try to find the exact disease, and quarantine very carefully for at least 4-6 months after all signs of illness disappear. Steps must be taken to ensure that this disease is not passed on to any other rats. Wash your hands with antibacterial soap after handling any of your rats, both the sick ones and the healthy ones.
Culling
Culling refers to the process of removing unwanted babies from the litter by killing them. Some breeders do this so they don’t have to go through the trouble of finding homes for the less desirable colors or types in the litter. It is extremely irresponsible and inhumane to do this. An ethical breeder would treat all babies equally, and never remove healthy babies from a litter.
Inbreeding & Linebreeding
Some breeders, rather than search for new rats to add to their lines, will breed two closely related rats together. This can be risky, because when rats are inbred, they have a much higher chance of being born with a genetic defect or disorder, and could potentially be less healthy overall than non-inbred rats. Though rats are genetically simple, comparatively speaking, and one or two generations of inbreeding usually don't cause any harm, It is always best to breed rats that are not related, to greatly increase the chance that they will be as healthy as possible.
Inbreeding is sometimes necessary when trying to breed for a new color or marking that has shown up by genetic fluke. Breeders are always looking for the next new rat variety, and when a very unique rat is born they will often breed its children back to it and see if the unique feature it has can be duplicated. Though most breeders frown on inbreeding, the fact is that almost every color of rat was created by inbreeding and it may be necessary to preserve the unique feature. If the first generation of inbred rats show any problems, however, the line should be discontinued.
Some breeders use inbreeding as a form of 'quality control', where they will breed brother to sister or offspring to parent to see if any genetic disorders occur. If they do, they will have an idea of what kind of genetic disorders the parents are passing on. If the babies are healthy, they will know that there are likely no genetic disorders that will occur in the line. Except in a large scale rattery, this is not recommended, as it is unnecessary to have so many extra rats born just to see if any of them will have a genetic fault, not to mention the suffering of a rat who ends up born with a problem.
Linebreeding refers to breeding rats that are related, but not closely, such as breeding a rat to its great aunt, or to its mother’s cousin. Most breeders use linebreeding to preserve certain traits in a line, like temperament, size, marking, or color. This is much less risky than inbreeding, but if possible it is still better to breed completely unrelated rats.
Adopting Out Rats
Some breeders breed for the fun of it, and don't really care where their babies end up. These breeders will sell to anyone who will buy, or may even sell them to a pet store where they know or don't care that they may be sold for snake food. This is much frowned upon; an ethical breeder should want to breed for the improvement of the species as pets and would love all of their babies and never want them to be eaten by a reptile or adopting out to a stranger they don't know anything about. Ethical breeders should have a way to screen potential owners so they know their babies are going to a good home. Having an adoption application can help, as it will show you how a potential adopter plans to care for the baby.
