INTRODUCTION

Hamsters are one of the fastest and "easiest" mammals to breed, giving birth to very large litters which may lead many to believe that it is a quick way to make money or that it can be a great experience for their offspring but, in reality, we should never take the breeding of any pet, whatever its size, lightly. Hamsters should only be bred under the careful supervision of an experienced person who knows how to handle a responsibility of this calibre seriously.

Hamsters (Syrian and dwarf) have several characteristics in common when it comes to breeding and the care involved, but one thing they all have in common that we must bear in mind is that we must never use sick, malnourished or excessively small animals for breeding.

Although these cute animals are able to reproduce when they are only 28 days old, we have to take into account that an early pregnancy can be fatal for the mother as she will not be properly developed, so the most correct age to start breeding (in both sexes) is 3 months. If the female is receptive, copulation will take place and the associated games, which have a total duration of between 20 and 30 minutes; if the female is not receptive (in "heat") and we join her with the male, it is most likely that the encounter will end in a fight. These fights can escalate to a very high level and end with a bruised or even bitten castrated male by the female, so we must keep a constant vigilance during the process to be able to intervene if necessary or separate them once several matings have taken place within the allotted time.

If the female is receptive (the "heat" lasts between one and two days), she will acquire a submissive posture called "lordosis", in which she will lie on the floor with her tail raised to await mating.

Hamsters mount several times in a row, so the probability of pregnancy is much higher than in other species. We must bear in mind that, although the oestrus lasts between 1 and 2 days, the female's "receptive" period as such is much shorter, so we must not delay in this regard and keep a calendar for each specimen.

MATING IN THE SYRIAN HAMSTER

In order to breed our "Syrian" hamsters the first thing we have to take into account is the correct selection of the breeders (morphology, colour, health...) but, one of the most important things is the age (as we have mentioned before); in the case of "Syrian" hamsters the female has to be between 4 and 5 months old (when she will have reached full sexual maturity) while the male will have to be a little older than her.

We have to take the female to the male's cage, in this way her territorial instinct will be diminished and it will not be so easy for her to attack the male (which would happen the other way round), we will remove all the food to prevent them from being distracted and we will monitor her reaction, if she is not in heat she will attack and we will have to try again in one or two days. If all goes well, she will start the mating ritual and, in eight or ten days, she will show signs of pregnancy.

MATING IN DWARF HAMSTERS

In the case of "dwarf" hamsters, the minimum breeding age for females is between 3 and 4 months, while we will opt for males of the same age or a little older. Because they have a more sociable nature than the "Syrian" hamster towards their fellow hamsters, it does not matter at all in which cage they are placed, although specialists recommend using a "mating cage", which is only used for this purpose. If this method is used, it is advisable to leave the male in the cage a couple of hours beforehand to familiarise himself with the cage, without food that could distract either of them.

The courtship and mating time is quite similar to that of the "Syrian" hamster but with the difference that, if the female is docile and comfortable with the male, we can leave them together until the 19th day of pregnancy (the day before giving birth), after which they must be separated.

GESTATION AND PARTURITION

The gestation period of hamsters depends on their species; in the case of "Syrian" hamsters it lasts 16 days, while in the case of "dwarf" hamsters it is 20 days. Some of the symptoms that give rise to the confirmation of a pregnancy are the physical changes, as in the photo on the left, where we can see how the female's body has taken the shape of a "pear"; her character is more reserved, sensitive and nervous: they eat more, keep more food, make a nest?

Our duty is to provide them with all the necessary care, including an abundant, varied and quality diet (rich in proteins) and that they have access to abundant water and a large amount of material to make their nest, otherwise it will be poor and the babies could die of cold or be scattered as they do not have a suitable place.

ATTENTION

It is recommended that the person in charge of the mother is the person with whom she trusts the most and that strange smells or noises are avoided, in this way stress levels will be low. 

The birth usually takes place in the late afternoon or during the night, making it quite difficult for us to witness.  The pups are born at intervals, giving the mother time to break the amniotic sac, cut the umbilical cord and clean and dry the pup well before the next one is born. The whole process never takes more than thirty to forty minutes.

Before placing all the material so that our hamster can make its nest, it is compulsory that we carry out a thorough cleaning of the cage three days before the expected date of birth, afterwards we will not be able to do it so we have to make sure that everything is very clean and ready for the arrival of the babies. If we do it after this date, our scent will be impregnated in the hamster's habitat and, even if she is used to us, she could be altered.

As we have already mentioned, the male must be separated from the female, as he could become pregnant again once she has given birth, which should not happen until at least six weeks after giving birth. For their own good, female hamsters should not breed more than twice in their lifetime.

Once the birth is over we can observe that the young are bald, blind and deaf, they are totally defenceless and should not be touched at all until they are 10 days old, if any of them die the mother will take care of them and, if not, we will remove the corpse using sterile gloves to avoid leaving our smell in the nest, which would cause the mother to become aggressive and could kill or abandon the whole litter.

The hatchlings are totally dependent on their mother for all their physiological needs and communicate with her by means of squeaks and ultrasounds that the mother differentiates perfectly; for the moment, they are deaf and will not develop ears until they are eight days old. Eyes will begin to open around day eleven or twelve, by which time they are fully developed and will begin to explore the cage and taste solid food, which they will ingest almost completely at 14 days, supplementing it with mother's milk.

Baby hamsters should remain with their mother until they are 20 days old, it is possible to separate them from the age of 12 if there is a problem (cannibalism) but otherwise they should not be weaned until then because it is during these days of growth that they learn how to do things and how not to hold hands with their mother and siblings. At the age of 20 days they should be separated from their mother and the males should be separated from the females to avoid unwanted and premature pregnancies.

CONCLUSION

Breeding any type of pet is a very serious task that cannot be taken lightly, from the moment you want to be a breeder or you want to have a litter with your pet you have to study a lot, inform yourself very well, consider the pros and cons, take into account the difficulties that may arise and the way in which you will later give those pups for sale or adoption (as well as having enough space to be able to keep them well until then). 

If you want to breed with your pets, get very well informed in the official breeding clubs (RSCE, ASNAC, AECCE...) and don't get carried away by your children's illusion or your own: they are lives that are going to depend on you, that come into the world because you want them to.