rattekonigin
04-12-03, 10:43 AM
A lot of people post regularly asking about rat breeding and husbandry, so I figured I'd put together a little FAQ so the same questions don't keep getting asked over and over again.
Here we go:
Q: What should I look for when I buy rats for a breeder colony?
A: The rats should be active and alert, they should approach a hand put into their cage (if they are terrified of people you'll have a lot of trouble dealing with them later). Their eyes and nose should be free and clear of any discharge, and they should not be sneezing. They should have a smooth coat (unless they are rex or hairless rats). Check the cage for any diarrhea or loose stools, and don't buy those rats if you do see it. Signs of a sick rat are excessive sneezing and the aforementioned discharge, hunched up body posture with little movement, puffed up and scraggly looking coat and laboured breathing, or any breathing noises (like honking or rattling).
Q: How long is a rat's gestation period?
A: 21-28 days...could be shorter, could be longer, depends on the rat.
Q: How long until the pups can be taken away from their mother? How long until they are weaned?
A: At 3-4 weeks old
Q: How long do rats live?
A: 2-3 years, the longest lived rat was 6 years old. A rat at 2 years old is comparable to a human at 73.
Q: When will rats start breeding?
A: Males have been known to be able to breed at 4-5 weeks old (which is why they should usually be separated from the mother and sisters by this time), females have been known to breed at 5-6 weeks, but it can be substantially longer than that depending on the rat. I find the best age to breed is at 3-4 months old, at this point both the male and female are of good size and will be more fertile and be able to produce larger litters.
Q: Can I keep the male in with the females all the time?
A: Yes, in this case you will be almost guaranteed to have a litter of rats every 3 weeks since the female goes into heat within 48 hours of giving birth to a litter. The female's heat cycle, under normal circumstances, is 5 days.
Q: Can I keep more than one male together?
A: It's not a good idea unless they were litter-mates. Males will almost always fight as adults unless they were introduced at a very young age. It's even less advisable to keep more than one male in with a group of females, as this will almost surely instigate fighting and you will end up with a very injured or dead rat (or 2) on your hands.
Q: How can I tell my females are in heat?
A: When the male approaches they will arch their backs and vibrate their ears (I call it "helicopter ears" because that's what it looks like)
Q: My rat keeps killing/eating its babies, why?
A: This is uncommon among rats (neither the male, nor the females will normally kill or eat their offspring), it could be caused by increased stress, i.e. have you recently introduced a new rat to the colony? Have you moved the cage to a new area of the house? etc...It could also be just because that particular rat is neurotic, this could diminish with time or it might never go away. Another common cause is sick, dying, or dead babies.
Q: What's the minimum sized enclosure I should use for a breeding colony?
A: Depends on the size of your colony. 6 rats can live in a cage with 1.5x2.5 feet of floor space, but any more in that sized cage would be pushing it. I, personally, believe the minimum cage size for even one rat is 2x1 feet of floor space, or about the size of a 20 gal aquarium. Hamster cages are for hamsters, they are WAY too small for rats.
Q: I'm building a custom enclosure system for my rat colonies, is there anything specific I should know?
A: Yes, always make sure that there are no ledges or places where the rats could begin chewing at the enclosure, because you'd be surprised how quickly they can chew their way out...even if they've never chewed a vulnerable place before, they could get the idea in their heads one day, and then you have a bunch of loose rats on your hands. ALSO, if you are using mesh or wire make sure that it is NOT galvanized. If the rats chew the galvanized metal they can get zinc poisoning, and this can kill the rats as well as contaminate your feeders. The best thing to use is powder coated mesh.
Q: How can I sex baby rats?
A: The distance between the anus and the genital "nub" is much larger in males, just look through the litter and compare babies, eventually you'll find a male and a female and it'll be obvious. It's also easier to sex the rats the older they get. (I'll put up some representative pictures with my next litter)
Q: My rats sneeze all the time and/or have blood around their nose and/or eyes, what's up with that?
A:
#1- it's probably not blood (unless the rat has been in a fight or has been injured), it's actually rat snot. Rats excrete a compound called "porphyrin" in their nasal and eye discharge, this is the same compound that makes up heamoglobin, which makes your blood red...so that's why it looks like blood
#2 - Rats commonly have a chronic respiratory disease caused by a bacterium called "Mycoplasma pulmonis" also known as "Myco", almost all rats carry this bacterium in their lungs so odds are that your rat has it. The actual disease crops up because of stress, respiratory irritation, lowered immune response, or a number of other factors. Some rats are more susceptible to having chronic myco than others. The real problem is not usually the myco infection itself, but rather secondary infection by other agents (these set in once the lungs are sufficiently damaged and the immune system is overworked) which can lead to severe pneumonia.
It is very difficult to get rid of a myco infection, and it will always require antibiotics. BUT, you can avoid and sometimes reverse the onset of myco symptoms if you get rid of the factors leading to its onset, the most common being the type of bedding used. If you're using cedar, DON'T. Cedar is very toxic and rats are particularly sensitive to it. Pine (any softwoods, really) can also cause respiratory irritation, but to a lesser extent than cedar. The best bedding options to avoid RI problems are aspen, and paper bedding products like carefresh. You can even use shredded paper/newsprint, but this usually needs to be cleaned more frequently. If changing the bedding doesn't help reduce the RI symptoms, then you could either be dealing with a non-myco related RI (see below), or you could have a rat that will have chronic myco its entire life.
There are other, more serious causes of RI in rats, the most significant being a host of viral infections (such as Sendai or SDA), these are extremely contagious and very lethal. Often the disease progresses very quickly with the onset of the first symptoms, whereas myco tends to "stagnate" and takes longer to lead to severe respiratory distress. There isn't much you can do in the way of drugs for a viral infection.
I think that covers the basics...hopefully I haven't left anything out.
Here we go:
Q: What should I look for when I buy rats for a breeder colony?
A: The rats should be active and alert, they should approach a hand put into their cage (if they are terrified of people you'll have a lot of trouble dealing with them later). Their eyes and nose should be free and clear of any discharge, and they should not be sneezing. They should have a smooth coat (unless they are rex or hairless rats). Check the cage for any diarrhea or loose stools, and don't buy those rats if you do see it. Signs of a sick rat are excessive sneezing and the aforementioned discharge, hunched up body posture with little movement, puffed up and scraggly looking coat and laboured breathing, or any breathing noises (like honking or rattling).
Q: How long is a rat's gestation period?
A: 21-28 days...could be shorter, could be longer, depends on the rat.
Q: How long until the pups can be taken away from their mother? How long until they are weaned?
A: At 3-4 weeks old
Q: How long do rats live?
A: 2-3 years, the longest lived rat was 6 years old. A rat at 2 years old is comparable to a human at 73.
Q: When will rats start breeding?
A: Males have been known to be able to breed at 4-5 weeks old (which is why they should usually be separated from the mother and sisters by this time), females have been known to breed at 5-6 weeks, but it can be substantially longer than that depending on the rat. I find the best age to breed is at 3-4 months old, at this point both the male and female are of good size and will be more fertile and be able to produce larger litters.
Q: Can I keep the male in with the females all the time?
A: Yes, in this case you will be almost guaranteed to have a litter of rats every 3 weeks since the female goes into heat within 48 hours of giving birth to a litter. The female's heat cycle, under normal circumstances, is 5 days.
Q: Can I keep more than one male together?
A: It's not a good idea unless they were litter-mates. Males will almost always fight as adults unless they were introduced at a very young age. It's even less advisable to keep more than one male in with a group of females, as this will almost surely instigate fighting and you will end up with a very injured or dead rat (or 2) on your hands.
Q: How can I tell my females are in heat?
A: When the male approaches they will arch their backs and vibrate their ears (I call it "helicopter ears" because that's what it looks like)
Q: My rat keeps killing/eating its babies, why?
A: This is uncommon among rats (neither the male, nor the females will normally kill or eat their offspring), it could be caused by increased stress, i.e. have you recently introduced a new rat to the colony? Have you moved the cage to a new area of the house? etc...It could also be just because that particular rat is neurotic, this could diminish with time or it might never go away. Another common cause is sick, dying, or dead babies.
Q: What's the minimum sized enclosure I should use for a breeding colony?
A: Depends on the size of your colony. 6 rats can live in a cage with 1.5x2.5 feet of floor space, but any more in that sized cage would be pushing it. I, personally, believe the minimum cage size for even one rat is 2x1 feet of floor space, or about the size of a 20 gal aquarium. Hamster cages are for hamsters, they are WAY too small for rats.
Q: I'm building a custom enclosure system for my rat colonies, is there anything specific I should know?
A: Yes, always make sure that there are no ledges or places where the rats could begin chewing at the enclosure, because you'd be surprised how quickly they can chew their way out...even if they've never chewed a vulnerable place before, they could get the idea in their heads one day, and then you have a bunch of loose rats on your hands. ALSO, if you are using mesh or wire make sure that it is NOT galvanized. If the rats chew the galvanized metal they can get zinc poisoning, and this can kill the rats as well as contaminate your feeders. The best thing to use is powder coated mesh.
Q: How can I sex baby rats?
A: The distance between the anus and the genital "nub" is much larger in males, just look through the litter and compare babies, eventually you'll find a male and a female and it'll be obvious. It's also easier to sex the rats the older they get. (I'll put up some representative pictures with my next litter)
Q: My rats sneeze all the time and/or have blood around their nose and/or eyes, what's up with that?
A:
#1- it's probably not blood (unless the rat has been in a fight or has been injured), it's actually rat snot. Rats excrete a compound called "porphyrin" in their nasal and eye discharge, this is the same compound that makes up heamoglobin, which makes your blood red...so that's why it looks like blood
#2 - Rats commonly have a chronic respiratory disease caused by a bacterium called "Mycoplasma pulmonis" also known as "Myco", almost all rats carry this bacterium in their lungs so odds are that your rat has it. The actual disease crops up because of stress, respiratory irritation, lowered immune response, or a number of other factors. Some rats are more susceptible to having chronic myco than others. The real problem is not usually the myco infection itself, but rather secondary infection by other agents (these set in once the lungs are sufficiently damaged and the immune system is overworked) which can lead to severe pneumonia.
It is very difficult to get rid of a myco infection, and it will always require antibiotics. BUT, you can avoid and sometimes reverse the onset of myco symptoms if you get rid of the factors leading to its onset, the most common being the type of bedding used. If you're using cedar, DON'T. Cedar is very toxic and rats are particularly sensitive to it. Pine (any softwoods, really) can also cause respiratory irritation, but to a lesser extent than cedar. The best bedding options to avoid RI problems are aspen, and paper bedding products like carefresh. You can even use shredded paper/newsprint, but this usually needs to be cleaned more frequently. If changing the bedding doesn't help reduce the RI symptoms, then you could either be dealing with a non-myco related RI (see below), or you could have a rat that will have chronic myco its entire life.
There are other, more serious causes of RI in rats, the most significant being a host of viral infections (such as Sendai or SDA), these are extremely contagious and very lethal. Often the disease progresses very quickly with the onset of the first symptoms, whereas myco tends to "stagnate" and takes longer to lead to severe respiratory distress. There isn't much you can do in the way of drugs for a viral infection.
I think that covers the basics...hopefully I haven't left anything out.