Did you know that a Mama rat can get pregnant again right after giving birth to her babies? If the male rat is not removed from the cage PRIOR to birth, the female will deliver another litter 3-4 weeks after her first one arrives. (this could mean 25+ babies for mama) This does not give her a chance to recoup from the first litter beginning to wean and means more babies will need to find a loving home, which is not always easy.  

I often get emails from new rat owners telling us they just adopted from a pet store or from a 'breeder' where they got two rats but think one is the wrong sex. I can pretty much guarantee that the female is pregnant if she is over 6 weeks of age. This is not an ideal breeding age (females should really be closer to 4-6 months/300 grams to give them the optimum health and successful litters) No matter how much you want to have them enjoy each other's company male and female rats cannot play together. (unless the male is neutered or female spayed) When rats breed they only need a few seconds, yes seconds!   I often encourage those with two babies different sexes to take one or the other sex back to where they got them and get one of the correct sex as a companion.

Of course sometimes we also hear that someone adopted two females (correct sex) but one or both are pregnant and deliver 1-3 weeks after joining the family. This is not something everyone is prepared to deal with after just adding new rats to the family. Most important all babies need to be sexed correctly, especially by 4-5 weeks of age. Though the males are not always able to, they sometimes can breed their mama/sisters by 5-6 weeks. If this happens the whole crazy cycle can start again!! It is not always easy to find good homes for 'the oops! litter' babies. 

What happens when people can't find homes for the babies??? This is were many rescues have stepped up to help the new rat owners and those that have gotten overwhelmed with 'oops! litters' Right now a great rescue in British Columbia has a plethora of babies. A social worker brought in two mamas and their new babies the end of November 2017. Unfortunately, the mamas had already been bred again prior to joining Small Animal Rescue Society so they have BABIES!!! LOTS OF BABIES on the way! in need of good homes. 

Because we have such amazing support in the rat community Best Friends Rodent Rescue in Washington is also helping in the efforts to get the SARS babies home.  What a great way to start the new year - with an new furbaby or two! Contact them at  sarsrats@gmail.com to see if they have a sweet baby or two to join your mischief. 

If you are not close to British Columbia, don't be discouraged there are so many rescues out there with babies and lovable olders in need of furever homes. 

A common post I often see on social media is,

“I have a small baby in this litter, could it be a dwarf?”

Most likely not. If the baby has always been small, hitting all the milestones as it’s litter mates, such as pigment showing around same day and eyes opening, you most likely have a runt on your hands. Often a dwarf rat will not slow down in growth until around weeks 3 - 4 in an average litter. (It was recently brought to my attention by someone that had a smaller litter that their difference was more obvious much earlier.)   Sometimes you won’t notice a runt until the first week passes. Sometimes there are more than one in a litter. Runts will often catch up to their litter mates by weeks 9-12.  However, if you have a little one that is skinnier than it's litter mates, lagging, not hitting their milestones, you may have FTT (Failure to Thrive also known as 'ill thrift' by veterinarians.) They are often very skinny and weak; not able to absorb all the nutrients needed to meet those milestones. Most often FTT will not survive into adulthood. Either the mother will push them out of the nest, sensing something not right, or they will pass on their own before 2 weeks. There are exceptions, my 939 gram boy, CRUS Bennet, being one of them. He was FTT, ½ the size of his siblings and too weak to be able to push them off so he could nurse. If his breeder didn't make sure he latched on and supplemented him with extra formula he most likely would have never survived past 2 weeks. He was one of my biggest boys and lived to just shy of his 2nd birthday. 
​
As with CRUS Bennet (mentioned above), I have become known as 'The Collector of Runts'. I have a soft spot for the lil guy in a litter. This is simply as a pet lover, not a breeder. Wanting to keep runts or adopt runts from others, fills up the mischief rather quickly. This limits my space so I am not able to work with all the varieties I want. Often a breeder will have what they call a 'bucket list' of rats they would like to someday work with.  My list of those that I would like to someday have would include:  Harvel, Roan, Whiteside, & Rex.  I also love a beautiful Self rat. (All one color). I am trying to get the pigment of my lines all the way down to their toes. There will sometimes be an odd recessive blaze, or variegated popping up, keeping the litters even more entertaining.  The most recent marking surprise in a litter happened at the end of last year, in the 2016 Winter All Science Litter, appearing at 4 ½ weeks. OCRA Inertia was our very first Himalayan and OCRA Tesla ended up being a beautiful Burmese! Up until she showed up, I had never even seen a Burmese. WOW! I must say, my favorite look for sure.  Currently we are working with Standard & Satin coats in Burmese, Himalayan, Siamese, Mink, Russian Blue, Agouti, Blue, Chocolate, Black and all of their dilutes. I also loved our pets that were Hairless and enjoy the Drex but do not want to work with those as a breeder. Hairless often have lactation issues that would mean doubling up on my breeding so I would need a foster mother for the babies. With my 2 Drex rats that I love as pets, I have found a lot of issues such as the eyelashes growing wrong and extra pory due to the irritation. The constant shedding from coarse broken hairs also drives me batty but they are worth it. I love them dearly. 

​So back to the dwarf question mentioned above. Did you notice dwarf was not mentioned on my bucket list? Never in my wildest dreams, had I thought I would work with dwarf. This is a tough variety to work with. The babies are often the same size as standards so a dwarf mama could have difficulty birthing. For the female dwarf that do deliver, their litters are much smaller than the standard litters in number. Often 3-6 verses 8-15 with a full-size rat. Talking with other breeders, the best option would be to breed dwarf carriers or a dwarf male to a carrier female. Even then, you are not guaranteed dwarf when working with carriers.  Why all this talk about dwarf?  Well.... because of our Burmese, OCRA Tesla, in the 2016 litter, we wanted to pull more Burmese out to work with. To do that we bred her back to her father OCRA Galileo. Imagine my surprise when our 2017 Summer All Science Litter v2.0 hit 3.5 weeks and 3 boys (OCRA Tesla’s Coil, OCRA Electron and OCRA Luman) slowed down. I mean WAY DOWN in their growth compared to their siblings. First thought was FTT and I hit a bit of a panic. I began supplementing them with extra goodies hoping to get them back up to their siblings’ weight. All they ended up doing was getting round. As they hit 5.5 weeks old their weigh difference was ½ their siblings, 70-79 grams verses their siblings at 140-160 grams. They continued to grow and be VERY active.  Now at 5 months they weigh 132-180 grams and their siblings are over 560 grams! The two that are heavier are VERY round still but in every way, look like dwarf – looking at their little bellies they are about 25-35 grams overweight.  They all live with standard size males with no issues. Well, except for the Napoleon Syndrome they seem to be expressing (in fact one was renamed Napoleon by his adopter). It is amazing when you have a litter of 12 thinking you are just working with your standard line and you get a surprise. We have no idea where they came from, since I can track my lines back to 2010 with one other breeder, 2012 & 2013 with another. I may never know where the recessive dwarf came from but will have a lot of fun testing it out with another proven dwarf to see how this new line will develop. Here is a link to the album on fb so you can follow our dwarf adventure with OCRA Tesla and her next litter!
 

More info on Dwarf:

Study of growth hormone in spontaneous dwarf rat 
 
Great pictures for comparison

More information on dwarf rats

​Why all this information? Is it simply to talk about this amazing discovery in our mischief? No, it is to explain growth of babies and their hidden potential. A few breeders do not like their litters to be more than 6-8 in number, sometimes even smaller. Their theory is that it will be easier on the mama and their babies will be nice and FAT.  To achieve this there are a few things they will do. If they have another nursing mom they may place a few with her. Otherwise, they may hard cull (kill) certain babies depending on size, eye colors or wait until a bit older for pigment to show before they hard cull those colors that they do not want to work with. Often the breeders that do this are multipurpose breeders as well, called Feeder Breeders. They breed to feed animals for other owners and their own pets. Though I can't imagine doing this personally, I accept that other animals need to eat. Unfortunately, some breeders that do not have to feed other animals, will still hard cull down their littler size simply because they think it is the only way to get fat healthy baby rats.  I have chosen not to do this, after years of tracking their weights, I feel confident that our females have done a fabulous job with their litters no matter what size. Mama's should always keep their weight without struggles and bouncing back to post pregnancy weight by weaning is an important goal I have for all of the mama's.  Over the years, there have been a few times I have had to increase fat offered in hopes to help with dryer skin in the babies. Another time, we did need to give mama a bit extra from the beginning – she had 18 babies! Over the years a baby has passed in the first few days and only a few times have we lost one after the first week. It is a very difficult choice to have babies euthanized. One had an umbilical hernia that did not get better and another that had a skull injury. Both of those became FTT due to their injuries. We also lost on baby to megacolon (in a line I immediately took out of my program). After several years of breeding and tracking weights weekly, I have shown that the babies of larger litters (up to 18) have all gained and are around the same size as those of litters that are as small as 2. In fact, some of my smallest babies were from a litter of 2. Their genetics were simply for a more petite rat. Thankfully we allow our litters to develop naturally, if we didn’t, we may never had known about our Burmese or the Dwarf Boys. 
 
Below are a few interesting things I have found online about overweight babies and basic litter size. (Warning some of the scientific studies can get graphic in their descriptions of their testing and how they cull)  Often in scientific studies they will want to have same numbers of offspring and equal sex ratio to help them get to the outcomes for their studies. As a pet breeder I do not see the necessity to do this. Though I love a squishy fat baby, I do not want to simply focus on having equal sized litters to have the fat babies but rather overall healthy babies thinking of the long term health of the rat.  
  

• Long-term effect of early postnatal overnutrition on insulin resistance and serum fatty acid profiles in male rats

 

• How different litters size handle stressors 

 

• Developmental programming in skeletal muscle in response to overnourishment in the immediate postnatal life in rats

 

• This one shows many benefits for smaller litters but also a few for larger 

 

• Increase of Long-Term ‘Diabesity’ Risk, in Neonatally Overnourished ‘Small-For-Gestational-Age’ (SGA) Rats

 

• This one says though weight smaller in larger litters the brain development was greater in the larger litters than small

 

• Early redox imbalance is associated with liver dysfunction at weaning in overfed rats 

 

• Overnutrition in Prenatal and Neonatal Life: A Problem? 

 

• The more babies the more milk the female will make 

 

• The Prenatal diet will effect the babies until about 4 months

 

• Again huddling and the ability to do so if smaller vs obese baby

 

• Another about how much milk made by Dam less did not mean more milk 

 

• Interesting tidbit about litter size as rodents matured 

 

• Nutrition smaller litter had larger fat cells

If you are interested in more information about the average weights of our babies at different ages feel free to contact us.  

I had no idea July 22nd was Rat Rescuers' Day!! 

I received this a link to an article, This Animal Rights Activist Reminds Us That Rats Need Rescuing Too Basically it is a write up about someone that has worked and adopted lab rats. From reading the article, I do feel compelled to mention that I would not pay to rescue a feeder from a feeder breeder/pet store and consider them a rescue. In the life of that one rat you are rescuing them from a fate that is rather sad (I also understand that all creatures need to eat) but you are also lining the pockets of the store/feeder breeder to just supply more feeders that will have that same fate.


The one thing that upsets me, as a rat mama, is seeing all these posts on facebook with tiny 2-4 week old babies that people pull from the bins. These babies need to stay with their mamas to get the proper nutrition and mental development that happens within  the  first 5 weeks. Do not buy babies younger than 5 weeks, it will hurt them in the long run.   Here at our rattery, I do not like for our babies to leave until 6-8 weeks. We had a family emergency and needed to let a few go at 5.5 weeks but I felt so terrible not sticking to my own guidelines. Knowing they were all healthy and VERY close to our 6 week mark made me feel a bit better but still wanting them to have as much time as possible with the rest of our mischief to learn how to behave from the adults.  All the time babies can get, learning how to be proper ratties from more mature rats the better. Being at least 125 grams at 6 weeks will give their overall system a bit more protection from the stress a new home can cause them.  Right now I have 2 girls snuggled up in my neck wrap waiting for their adopter to show up, they are 194 grams at 6 weeks! They will have a GREAT start in their furever home!

Now back to Rat Rescuers' Day! If you are local to Oregon, Washington and British Columbia there are some great places to adopt/rescue ratties.

Oregon

•  The Oregon Humane Society 

Washington

• Best Friend Rodent Rescue

British Columbia

• Pitter Patter Rescue Society 
• Small Animal Rescue Society of BC

If you are interested in adopting Lab rats please keep in mind many do have serious issues due to their treatment and the testing they had to undergo. Also, unlike rats you can get from a rescue/or breeder these rats also do not have the same immunities. Think of a child starting preschool or kindergarten. Their poor systems are hit hard by the multiple viruses they are exposed to. Quarantine is not an option it is a MUST! You do not want them to join your mischief only to become ill from a nasty virus.  

So many people have asked me what a rat should weigh at a given age, or how much a mama should gain during pregnancy. This varies a lot due to genetics but also to environment. You have probably noticed that we often post the weights of our ratties. This is such a great resource for us. If we have an older rat that suddenly drops weight (illness in rats move so quickly) we can usually find a problem 'before' it gets chronic. It shows us that a mama maintains her weight while feeding sometimes over a dozen babies, and if a baby is failing to thrive. Over the last couple years we have randomly tracked over 36 different babies up to 12 weeks of age (and beyond) Some were 'foster', some were emergency rescues but most were born here or added here at 6 weeks. One thing we noticed, is that even with a huge litter, on average the rats catch up with their weight at 6-8 weeks with those of a smaller litter. If you would like to see the different weights of 'healthy' babies with litter size, feel free to contact us for this information.

Here are our average weights for babies up to 12 weeks 
male/female
Week one 
 19/19 grams
Week two
32/35 grams
Week three
51/59 grams
Week four
81/93  grams
Week five (numbers off because of male rescue)
110/123 grams
Week six  
151/156 grams
Week seven
209/183 grams
Week eight
271/202 grams
Week nine
292/229 grams
Week ten
320/243 grams
Week eleven
354/266 grams
Week twelve
381/283​ grams

​We rescued 2 boys at week 5, they came to our mischief weighing only 50 & 54 grams.  They were obviously failure to thrive due to their rescue home being hit by SDA (A very infectious virus among rodents) when they were only about a week old. We offered to help these boys with our 'magic potion' since they had not gained in almost 2 weeks. By week 6 they gained over 70 grams (in 1 week) and by week 7 they were holding their own with the rest of our mischief's weights. Once quarantine was over for these boys they actually became some of our largest boys.​

OCRA's Magic Potion for Weight Gain

We came up with this mixture after we had ZERO success with the Oxbow Critical Care our vet prescribed for an ill rattie. Critical Care is for herbivores, we might have had more luck with the Carnivore Care. The best thing about our mixture is it isn't something new for the rats. We offer them eggs every once in a while (They love to peel hard boiled) We are always offering them a mix of veggies and a few fruits. When they are not sick we also train them to take sugar water or diluted Torani syrup from a syringe. Such a great thing to teach them for if they do get ill they will already know the habit.  It is very hard to get them to take a new food because they are SO smart. In the wild they actually will send their weakest to test the new food to make sure they don't die if that isn't an option they will only take a tiny portion to make sure it is safe. If you grind up rat block, that they have already been eating, you should have much success in getting them to eat new foods with that mixed in.  

Here is what we do with our rat block

Take rat block (18% protein) put into a blender to make it into a fine flour type powder. It usually takes just a few seconds. Grind about 1/2 cup - 1 cup for several meals.  Melt tablespoon of coconut oil into skillet. Add yummy veggies and fruits (use shredded carrot, peas, avocado, shredded apple or even banana mashed up) Then add eggs to the skillet. (about 3-4 scrambled raw eggs) Once all in the skillet, sprinkle the powdered rat blocks into the skillet. Stir well, letting it all cook together on med/low with lid. If needed you can add a little water. When it is finished it is almost like a souffle. Offer this mixture to the rat needing a bit more  sustenance, keeping leftovers for a few days in fridge.  If they are really struggling,  we also add baby soy formula to the mix right before we feed them it becomes a soupy oatmeal texture.  In our opinion, soy formula is so much better for them than 'Ensure'  (full of unneeded sugars and dyes) or even puppy or kitten formula which many like to offer to those needing extra goodies. This Magic Potion has NEVER let us down for struggling weanlings, ill or elderly rats.

Rat Milk Composition
14.8% fat (by day 20 it drops to only 4.2%) 11.3% protein

Information from The Rat Fan Club on raising orphans 
Soy Formula 
25% Fat 12% Protein 
Formula for puppies
40% Fat 33% Protein 

We were going to wait until Aurora gained a bit more but by her actions and the current weight gain we are looking forward to hearing lil pips(queaks) in another week. On average we have tracked a weight gain of 43 grams by this point in pregnancy. That is with litters ranging from 4-18 babies - surprisingly the the largest gain was one with 11 in the litter. Aurora is pretty much gaining the same as the one that had 9 babies.  (36 grams so far) Should be interesting to see what happens this next week. 

We have moved Aurora to the bottom section of our TCN,  locking the ladder for most of the day. As I type this she cuddled up in a nest full of a whole receipt paper roll. She does enjoy visiting with most of the mischief, however, our new girl Niki seems to really irritate her. Now looking back, timing of adding her was a poor choice on our part. Aurora had the protective mama hormones just starting to surge and knows most likely this new girl won't be watching out for her 'babies' like the rest of the girls in the mischief (her mama, sisters, nieces and Celtic Rose who we added when Aurora was just 5 weeks). Of course that is only our observations as we wish they could talk and tell us what they really want/need.  

Her and Apollo have still had a few visits during the evenings but she has not gone back into heat. The only problem they have had together is when he wants to eat what she is eating.  You can almost hear her say, "Seriously, I am the one with the cravings and you dare want my noodle!?!"  I cannot wait to see the temperaments of their babies. She has always been the quiet sweet snuggle girl and Apollo is our huge cuddly oaf, reminding us of Ludo (Labyrinth 1986). 

We paired OCRA Aurora with OCRA CRUS Apollo this last week. We only leave them together overnight. This is the first time I have not seen them actually mate. It is a bit frustrating to not have instant confirmation but with weight observations and tracking Aurora's heat cycle I can pretty much confirm that have mated.

In Heat?
To know when a female rat is coming into or already in heat is pretty easy if you know what you are looking for.  For basic anatomy here is a link to see what I am talking about Sexing Rats. The female's vaginal opening is directly below her urethra. Many people mistake females for males because they think the urethra is a penis. Here is a picture of our Ariel, being hairless you can see her nipples (only female rats have nipples - 12 in all) you can also see her urethra. The vaginal opening is directly below that. I wish I had a better shot of it but with the link above and Ariel's picture it should help you know more about rats then you ever wanted.  When a female rat is in heat the vagina is open. Sometimes it becomes discolored, a blue or purple hue. Which often shows up in our darker rats.  When a female is not in heat, the hole is tightly closed.  With tracking our rats they seem to go into heat every 5-6 days. Usually a female in heat will also behave a bit different. If you scratch her back she may arch it. She may also be more jumpy, darting and sometimes spinning around. To tell the male she is interested, she will even stiffen her legs and lift her tail.  With our new girl, Pumpernickel, we will even be able to see her ears vibrate when she is in heat. The dumbo mutation prevents female dumbo ears from doing this. 

Courtship
It is possible for a female to get pregnant from a single mounting. However, during courtship, they will mount many times before the male can complete the act. Usually the female is in heat for about 10-12 hours at night but this is not always the case. Our EmmaOreo went into heat around 10 am. I have read, it is very important not to let your male rats 'play' with your female even if she is not in heat, the male might stimulate her to come into heat. What I find amazing, is how a female in heat is also VERY determined to procreate. Rats will usually synchronize their heat cycles. This helps them in the communal living to take care of each others offspring like many other animals in the wild.   A friend's new females actually chewed through their cage and chewed out the male (YES, it pays to watch CSI - the fragments were on the outside of the male's cage)  Both females became pregnant. My friend knew right away for one because she saw a mucus plug. It is a waxy plug in the vulva of the female. It is formed by the secretions from the males and can be visible for up to a day after mating. This prevents other males from breeding her. Like dogs, superfecundation, is one way to keep the genetics diverse within a colony.

How We Pair
​There are a couple different methods for breeding rats. We usually use our single level cage.  On the day the female goes into heat, we place them both together into the cage. Often it is immediate but we will leave them in the cage together overnight. In the morning, we put them back with their cagemates, usually without any problems. Occasionally the male is still a little amped up, so we often provide some yummy extra food as a distraction as he settles back into the boys dormitory. The second method, usually used by larger scale breeders, is a bit longer and less involved with the 'humans'.  They will place the male with one or two females for about 10 days. This method, insures that the female has had at least two heat cycles. However, it does sometimes make it difficult when reintroducing the rats back  with their cagemates. For this reason they usually keep the females in the cage or tub until after the babies are weaned. The male will need to be bathed and slowly reintroduced to his old cagemates to prevent any posturing or aggressive attacks. 

Tracking Weight
Now many of you know, I am a bit OCD when it comes to weighing our rats. This habit has come in handy for me to see that a rat has lost weight quickly over a weeks time. Might not look visible at first but if a healthy buck drops 15 grams in one week that is usually a sign that something is off. We weigh our juveniles and adult rats once a week. We weigh dams daily, starting from day of pairing. This has been a valuable resource helping us and others in knowing if there are complications, predicting how many babies, and overall just plain fun!  Once the babies are born depending on the size of the litter we will usually weigh the largest and the smallest the first few days. If we have runts we have even weighed them before and after us feeding them to insure they 'swallowed' formula. As for determining weight gain for a female. We notice right away a weight gain of 8-12 grams then slowly 2-10 grams a day during first few weeks. The last week there are usually huge daily gains. We have tracked up to a 24 grams gained in just 1 day with our litter of 18 (Spring 2015 'X-Men' Litter)! 

Is She Expecting?
As for Lil Miss Aurora, her weight has fluctuated so far. Last week before pairing her weight was 324g. The next morning it was 214g. The following days it went back up to 324g, yesterday it was 326 and today it is 330. I am tracking her heat cycle to see if she comes back in. We do hope she took last week. If not, this week we will continue with her evening 'playdates' with Apollo.

Very excited about our Marvel Line Pairing of OCRA Beast ♡ CRUS Celtic Rose. If all works we should hear the lil pip (squeaks) making their debut the weekend of 9/11/15.