Franck Wang 
Allowing your cat the option to use a cat flap and come and go as they please will make them happier, and more relaxed. Having to ‘meow’ to be let in or out, is not only frustrating for the cat but also its owner.
I have previously written a blog about the subject of a draughtproof cat flap – you can read it here. As a cat flap fitter, I feel it is equally important for me to give my opinion about the size of the microchip cat flap opening as it is a matter that causes concern among cat owners.
The most common cat flap that I install is the Sureflap microchip cat flap and DualScan cat flap. (These are both a flap size of 142mm in the width x 120mm in height.)
A microchip cat flap is the best method of preventing other cats from entering your home as the microchip reader on the cat flap will only respond to the microchips that have been pre-programmed to it. The flap opening itself is purposefully made small to prevent other cats from squeezing through the gap at the same time as yours.
I am often told by clients `that’s a small opening for my cat to get through` or `my cat will never get through that gap’. And I vividly remember once while installing a cat flap on the South Coast; a lady was particularly worried about her cat fitting through the microchip cat flap. The kitty suddenly appeared in the garden, squeezed through a much smaller gap in the fence, and waltzed straight through the cat flap stopping to look at us both before entering the living room. We were in fits of laughter! It just goes to show that cats are more sleek and agile than we think.
As a cat flap fitter in glass, we install the cat flaps and we don’t manufacturer them. I don’t claim to know the personality of your cat but I hope to reassure customers that they should not worry about whether the cat will fit through the cat flap. You should never judge a cat by the human eye, but rather by the weight of the cat. Underneath all that fur and fluff is a slender body, designed by centuries of evolution to fit through tight gaps. All good cat owners should know the approximate weight of their cat, and this can also be found on your vet files. Take a look at this hilarious video to see the gaps cats can get through!
The average weight of a domestic cat is 4.5 to 5.5kg. The microchip cat flap is suitable for cats up to 6.5kg. As mentioned previously, the cat flap opening is meant to be small so that it prevents other cats from entering at the same time as yours. An added benefit of this smaller flap opening is that it could help to keep your cat lean. Not only does the exercise of going in and out maintain the ideal weight of the cat but for you as the owner, it will encourage you not to overfeed the cat for fear of it not being able to squeeze through the cat flap.
Given that the microchip cat flap is for cats up to 6.5kg, it makes it unusable for large cats, such as Maine Coon, Savannah, Ragdoll, Chausie, Ragamuffin, Siberian Cat, British Shorthair, Highlander, Turkish Van, and British Longhair. Therefore, the larger size Pet Doors (which have a flap size of 178mm in the width x 170mm in the height) are your solution. These use the same technology as the microchip cat flap but with the added benefit of timer/curfew controls. These larger Pet Doors are designed for pets of up to 14kg to enter and exit the home.
I don’t know your cat, so please be sure to select the most appropriate cat flap for your cat’s size, weight, and needs – I also recommend that cat owners use the flap sizes to cut a hole in a cardboard box to see if the cat/dog will fit through it OK.
I hope you the above reassuring and useful.
Cat out of Glass are specialists in pet doors, dog doors, and cat flap fitting. Serving the South of England and beyond, we’re expert’s installers for glass and double glazing.
