Medium, because they are small-medium sized dogs.
Small/Medium
medium
From the size of the dog they should be in a medium crate maximum.
A crate should be big enough for them to stand up, lie down, and turn around fairly easily.
They are small dogs. Here is a link to a picture: http://www.kennels.co.uk/Terrier/West%20Highland%20White%20Terrier.html
The crate should be big enough for them to stand up in and move around a little in, but not so big that they can go to the bathroom and move away from it. The right size will encourage them to hold it until you let them out.
That would depend on the size of the crate, and the size of the apples.
If you were my client, first question I would ask you is in regards to the size of your crate in proportion to the size of your puppy. Unless a dog is sick or has been left in a crate for an extended period of time (more than 6 hours) most puppies will not potty where they sleep. If your puppy is in a crate that is too large for him, he will have the freedom to use the other side of the crate than he sleeps to relive himself. During puppy crate training, the crate should only be big enough for the puppy to stand up, turn around and lay back down. Some larger crates come with a divider so the crate can grow with your puppy. Also, the puppy should be in and out of his crate during the day, teaching the puppy that the crate is a safe place. For example, when you can't have your eyes on the puppy 100% of the time (doing chores, taking shower) the puppy should be in his proper size crate and should be rewarded when he enters the crate with either affection, or small treat. This will teach him that the crate is a good place to be.
I purchased a medium size crate for my Maltese puppy. It fits him right, and when he gets bigger, it will still work for him.
Yes you can and you often have to if you are using a crate to house train a young puppy. Some crates come with a divider panel that you can place where ever you need it in the crate depending on the size of your dog. If yours does not have a panel you could use a piece of plywood cut to fit inside. Sometimes if the space is much bigger than the dog they will still eliminate in the crate. Dividing it and making the space smaller usually corrects this.
The weight of a milk crate varies from between four to ten pounds, depending on the size of the crate and the material it was made from.
Make sure your dog has plenty of room to turn around and lie down. The size of the crate depends also on how much time the dog will be in it. A general guide to size is to get at least a 24" crate for a 25 lb. dog, 36" for a dog up to 70 lbs., and 48" or bigger for a dog of 100lbs or more. The best size of crate to get for your pet is one that is large enough for them to adjust themselves and stand up in. However, it should not be so large that they are able to hurt themselves by thrashing around.
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