Should You Breed Your Pet Rats? Weighing the Ups and Downs

Rats are adorable creatures, so it isn’t surprising that many owners wonder about breeding their pets. Some people want to make “more” of a loved animal, while others wonder if it could be a side-income.

However, breeding rats well, in a way that is healthy for the animals, is not as simple as putting a male and female together. Breeding rats can be hugely rewarding, but it can also be frustrating, heart-breaking, and very expensive.

Here are some things you need to think about before deciding to breed.

Why Do You Want to Breed?

Breeding creates new little lives, capable of both joy and suffering. It’s not something to be done lightly – especially with more than enough unwanted pets in the world. Therefore, it’s worth interrogating why you want to breed before deciding to do so.

Good Reasons for Breeding Pet Rats

Good reasons to breed your rats are:

• Improving the health, temperament or life-span of pet rats in your area
• Improving a specific variety (e.g. coat colour or type)
• Developing or understanding a new variety

The first of those is the reason I am planning to breed. I live in an area with quite a restricted pet rat population and I’m seeing an increasing number of genetic health problems coming through my door as rescues. It’s starting to depress me. There are a few breeders round here, but not many. So, I am considering starting my own line to work specifically on improving health and life-span, while maintaining good temperament.

The second and third reasons are common among people who show rats, or who have fallen in love with a specific variety. However, working with a completely new variety is challenging and is best left until you have substantial breeding experience. In these cases, even though the motivation for breeding is in the variety, any good breeder will still be selecting to maintain or improve health and temperament in their lines – that is one of the criteria for “improving” a variety.

Bad Reasons for Breeding Rats

To Make Money

Rat breeding, done conscientiously in a way that cares for all the rats involved, and ensures they have good food and vet care whenever needed, rarely makes any money. Let’s break it down.

Say a rat has 12 healthy bouncing babies. A breeder will probably keep at least 4 of them, depending what their aims are. So that’s 8 babies for sale. In my area, breeders sell their babies for around $30 each. So, an average litter might bring in $240.

However, as well as set up costs such as multiple cages, all those babies need lots of good, protein rich food (and you’d be amazed by how much baby rats can eat). They need bedding and litter (you’d also be amazed by how much baby rats can poo). They also need daily time for playing and spot cleaning – which has a cost even if it isn’t paid for in cash.

And then there is medical care. Any pet, breeding or not, should receive veterinary care regardless of the time of day. And that can add up. My normal vet is brilliant and very generous with his pricing, but a major surgery such as a spay is easily $250. An out of hours emergency consult at the local vet hospital is $195 before you add on treatment or diagnostics. I don’t know what an out of hours emergency spay there would cost, but my wallet is wincing thinking about it!

Most litters hopefully won’t need vet treatment, but in a breeding career, things will go wrong. And of course, a breeder owns a number of rats long-term. All of those rats will have their own medical needs, especially in old age, and it’s highly advisable for breeders to have necropsies performed on animals in at least their direct line to fully understand cause of death – that’s another cost.

Breeding rats ethically is a vocation rather than a business opportunity.

Because You Love Your Rat

It’s natural, if you own a particularly adorable pet, to want to have more of the same. Unfortunately, that isn’t how either nature or nurture work. An awesome rat can sire or birth litters with very different personalities, markings, or health issues – selecting for health in a line is a long and often frustrating job that takes generations.

Furthermore, an adorable pet is not necessarily a pet suitable to breed from. I have a super-fabulous little girl called Bingles who we adore beyond words. However, we would never breed from her because:

• She’s a rescue – we know nothing about her genetic background or the health of her family.
• We don’t know her exact age, but she’s certainly too old to breed safely.
• She’s very small-boned, and not a healthy body shape to carry and birth a large litter.

To Experience (or Let Children Experience) the Joy of Birth

Birth can be a joyous experience. It can also be a devastating tragedy. Does can die or have catastrophic hemorrhages requiring immediate surgery, litters can spontaneously abort and reabsorb, dead babies can get stuck in the birth canal causing life-threatening infections, mothers can eat their litter, or kits can die as pinkies for other reasons.

These things can happen in the healthiest, best researched and planned lines, but are even more common in litters with an unknown history. Preparing to breed also means preparing yourself to cope with the worst – and to have a motivation that justifies that risk.

Researching What Breeding Involves

I didn’t decide to breed and then research what that meant. I did the research first, because I wanted to make a decision from an informed stand-point. What kind of things do we need to know?

Rat Genetics and How to Breed to Achieve Your Aims

Genetics is a big subject, and still contains a lot of unknowns, even in a well-studied species like Rattus norvegicus. It’s fairly easy to look up basic genetics for colour and coat texture online, but you also need to understand how genetic mixing and epigenetics can affect health and temperament, and that is a lot more complicated.

On top of the basic science, it’s also necessary to learn how selective breeding works. Will you in-breed, out-cross, or line breed in any particular litter? Do you understand the strengths and disadvantages of all three tools, and how to avoid issues like in-breeding depression, or bringing a lot of hidden problems into your line via an outcross?

Where Will You Get Your Breeding Rats From?

I mentioned above that breeding from rats with an unknown history is a bad idea. Sometimes it may be necessary – e.g. if you live in a country without a variety of responsibly bred lines already available, or if you are working on a new variety. But as a novice breeder it is always better to work with rats of known lineage. It’s less likely to result in a first litter with health or temperament problems, and it makes understanding the genetics and breeding approach simpler.

The best place to find rats for breeding is from a breeder whose lines, approach and ethics you are comfortable with. Building a relationship of that type allows you not only to work with known rats, but also benefit from advice and support.

Note: if you are intending to breed from rats you buy, it is really important to let the breeder know about this upfront, so they can decide whether to home to you. It is a matter of courtesy, and a matter of safety. A rat can be absolutely suitable for sale to a pet home, but (like my girl Bingles) not be suitable for breeding. By talking to the breeder upfront, they can make sure the rats you adopt are suitable for what you want to do.

Some breeders will say no; they don’t want their rats used for breeding outside of their lines, or they aren’t happy with your plans or set-up. If that happens, respect it – if you do breed, one day you will be in that breeder’s shoes and will want your decisions respected too.

How to Prepare for Breeding, Pregnancy and Birth

One reason I’m comfortable with breeding is that I’m very experienced with rats. I’ve not only got 20 years of experience on husbandry and health, but I’ve had a litter born and reared in my house under difficult circumstances (a rescue girl who came with 13 embryonic hitchhikers and health issues), and I’ve also handraised babies.

I know which cages to use for which stage, how to feed for pregnancy, lactation and kitten growth, what bedding to give an expectant mother, what the signs are for problems in pregnancy, and how to safely handle tiny babies. And I have my vet on speed dial.

Most of these aspects are fairly easy to pick up, but they do need to be learnt before rats are mated. A good way to do this is to be mentored by a more experienced breeder.

How the New Babies Will Be Homed

Rats can have quite big litters. A doe has 12 nipples and average litter sizes seem to range between about 8 and 14 depending on the line. But up to 20 babies in a litter has been known. Keeping all your rats as a breeder isn’t practical, so you will need to home a majority of them on elsewhere.

There are two things to think about here – how you will home them, and who you will home them to. The second influences the first. Personally, I won’t be homing babies from my first litters to anyone I don’t already know well as a rat owner. This is partly because I want the security of knowing my babies will be cared for, and partly because I need my pet homes to be committed partners in collecting the health and life-span data necessary to breed for health long term. It’s all being done via personal networking – I won’t be advertising babies for sale.

If you are more comfortable with babies going to unknown homes, how will you find and choose those people? Where will you advertise? What sort of application system will you use to screen potential homes? How many people in your area keep pet rats?

And of course – if you can’t find suitable homes for all your rats, are you in a position to keep them, and give them the well-cared for life they deserve?

My husband and I know that our maximum number of permanent residents (i.e. parents, keepers from breeding, and any odd rescues, because there are always odd rescues) is 25 – and that will place limitations on my breeding programme and litter spacing. But working within a parameter is much better than breeding too many rats and letting that affect their welfare.

Do You Have a Lot of Patience?

Ethical rat breeding is not a hobby for the impatient. First up, we have to source our breeding rats. It’s best not to breed from boys until they are a year or so in age, as that allows time to ensure they don’t have any hormonal aggression or early health issues. A new breeder can circumvent that wait by borrowing a stud for their first mating from their mentor, but if you can’t or (like me) don’t want to do that, then that’s nearly a year to wait from adopting your first breeding rats.

My potential breeding boys were born at the start of April 2020, so the earliest date I’m considering for my first mating is March 2021. In the interim, I’m going to get to know them really well, so when the time comes, I can make the best breeding decision I can.

Girls should be at least 5 months old. I’m aiming for 6-7 months for my first does, so one of the things I’m doing while the boys mature is make breeding plans and sourcing the most appropriate girls.

However, it’s not just waiting for rats to come of age that requires patience. Breeding ethically means not breeding from rats with poor health or temperament. That in turn means that one of the lovely rats we hope to breed from can wash out suddenly at any stage. If there isn’t a suitable back-up, then it’s a case of starting again from scratch or from elsewhere in the line.

And this isn’t just an issue for the first litter. A beautifully tempered doe might suddenly show hormonal aggression post-birth, which for me would remove not only her, but all her daughters from my breeding plans.

A superficially ideal pairing might produce a litter that is very unhealthy or has birth defects, and which means washing out a whole section, or even all of your line. If you are breeding for variety, a litter you hoped would throw up a certain colour based on the genetics of the parents, might not do so – or the only suitably coloured kitten might wash out due to poor health, temperament or build.

The rewards in breeding come from both the rats and working through the frustrations of the process – but it means we have to have the temperament ourselves to weather those lows.

Are you thinking about breeding your rats? Tell us about it in the comments.