Quite often in groups I see someone posting a picture of their small rat asking if it could be a dwarf or not. So far every time I have seen someone ask, it has not been! But I wanted to make a quick guide to point out the differences.
You can also check out my page on dwarfs HERE.
First of all it is important to point out that dwarfs are not just small rats. Dwarf is a recessive gene that the rat has to have to be a dwarf. Being recessive it also has to come from both parents.
Dwarf being a newer variety they are not a whole lot of them out there just willy nilly every where. You are really only going to find them from breeders. There is always some small chance that someone had to turn them into a rescue or someone had an accidental litter. Though remember that it has to have dwarf from both parents so even in most accidental litters it is unlikely.
Most of the time when you have a small rat it is just that, a small rat. Some rats are naturally petite. Other times the rat may have been a runt or taken from mom too early or have serious health issues that just stunted it's development making it much smaller.
I actually have a runt named Yuna. At 2 days old she was accidentally kicked out of her nest & went without her mom's warmth/food all night long. I found her cold and not in good shape. Luckily little Yuna was a fighter! But she was stunted and far far behind development of her siblings. They all got pigment and then markings and then fur far ahead of her. But she hung on! I had to help feed her and rotate her feeding so she got alone time with mom. Yuna did make it though! While she seems to have no ill effects and is doing quite well, fully grown she is still so small. Maybe the size of a 6 week old or so female.
Another thing to watch out for are scammers....
There are some unsavory "breeders" who are more than willing to sell small rats or even sickly rats as dwarfs. I actually know someone who was scammed :( There could also just be very irresponsible newbie wannabe breeders who just haven't a clue and think their small rats are dwarfs..sigh.
So how can you figure out if your rat is a dwarf or not?
Weight and size is the most obvious sign. Dwarfs are VERY small. You are looking at a fully grown dwarf to be around 100-120 g. My 6 month old fully grown boy is 99 g, my 4 month old is 94 g. Around 8 weeks old they weighed around 50 g.
They reach the size of a 3-4 WEEK old standard rats. Literally baby sized!
This is an excellent picture of my dwarf boy Castiel at 4 MONTHS old sitting in my hand next to a 6 WEEK old standard boy Banner.
The 6 week old looks HUGE next to him! You can even see how Castiel just sits on my finger tips!
There are a few other signs....
Dwarfs seem to keep baby tails their whole life. They are very thin and short. (white butt dwarf tail vs standard tail)
Dwarfs often have smaller feet. (pics coming soon)
Dwarfs often have much larger eyes. And a head that appears a bit large in proportion to their body.