Reddit reviews Carlson Extra Tall Walk Through Pet Gate with Small Pet Door, Includes 4-Inch Extension Kit, 4 Pack Pressure Mount Kit and 4 Pack Wall Mount Kit

You can't let chasing and biting happen, ever. It's fun for the puppy and terrifying for the kitten. Please keep them separated all the time until the dog learns some basic commands and impulse control.
If all goes well, eventually you can graduate to gates like this that allow the cat to pass through but stop your (by then larger) puppy. You should also make sure that the cat has access to comfortable high spaces out of the dog's reach and cannot be cornered.

They make baby gates with built in cat doors if that helps at all.

http://www.amazon.com/Carlson-0941PW-Extra-Tall-Walk-Thru-White/dp/B000JJFNJK

We use a baby gate too. I found one on amazon with a cat door.

https://www.amazon.com/gp/aw/d/B000JJFNJK/ref=psdcmw_2975349011_t1_B000JJDI0G

When you have cats I really don't think crate training is optional, sorry! I really do think you have to do it. It's just the safest thing. And I think the cats would probably be a lot happier if they get to sleep where they normally would. Having as many things as possible be "normal" for them might make the transition easier. I would say put the gate in the hallway leading to the bedrooms (if you have one) and let the cats have that whole side of the apartment.

This is the gate I got. There are probably better ones but the price was right lol. One of the reviews said it held up to their 80lb GSD for a year so I was sold lol. I'm going to pull the door off the cat hole tho so I don't have to worry about it swinging shut on them.

For what it's worth I don't think you're overreacting. The puppy is big and puppies are clumsy and it sounds like they're not all getting along yet. You have to keep everyone safe :)

I have 2 cats and 2 labs and I got this baby gate that has a pet door in it so the cats have an escape route to the cattery (my office). I keep the pet door open with a bungee cord and it's great.

Yeah, I'm not sure how it would hold up with the posts, but it could work?

This is the one that I have (two actually) and they work great. To your point though, it does cost more than $20. I have to say I'm super happy with it though. I have one on our bedroom door to keep the dog in (at night) / out (during the day to give the cats a safe space) and one on the door to the room with the litter box.

Only other suggestion I would have for you is to attach it via hinges to the wall so that it can swing open/closed.

http://www.amazon.com/Carlson-0941PW-Extra-Tall-Walk-Thru-White/dp/B000JJFNJK/ref=sr_1_12?ie=UTF8&qid=1419910226&sr=8-12&keywords=walk+through+gate

There's a little door that's cat sized that you can leave open. Also, I am fairly certain this one has these cup things that you can screw into the wall so that it is much harder to knock the gate down when it is put up.

Here you go! I have that one and it works perfectly for my cat and German Shepherds.

Also they make really tall gates for dogs that your husband would NOT be able to climb over. We had one, and in the center was a little door for walking through. You could leave it set up but Open during the day, then close it at night.

Edit: this one is very similar to what we had: http://www.amazon.com/gp/aw/d/B000JJFNJK

I have one bedroom baby gated off for my cats. That's where food and litter boxes are. Dogs are frequently poop eaters and it's best to keep cat box temptation out of their way. Every other room has somewhere the cats can jump up to get out of the way of the dogs. A gate like this:

http://www.amazon.com/Carlson-0941PW-Extra-Tall-Walk-Thru-White/dp/B000JJFNJK/ref=sr_1_16?ie=UTF8&qid=1374681271&sr=8-16&keywords=walk+through+gate

can be really convenient. The cat can get out. The dog can't get in, and you don't have to take down or climb over the gate every time you go into the room.

There are baby gates made for pets, like this one. I'm sure you can find them a lot cheaper in the US, but this is the one I have and it works great.

We brought a 5 year old Akita home to our 12 year old cat last year. We live in an older home with lots of doorways, so we got this baby gate that separated our back living area with with the front. We were very cautious most of the time. Sometimes the dog would be on a leash around the house in case we would need to restrain him. The cat ate and had her litter box upstairs in a room with one of these on the door so the dog couldn't get in. We just took it very slow and never trust them alone together. My dog is crated when we're not home.

We also watch for any triggers the dog seems to have and act accordingly. He doesn't like when the cat sneaks up when he's in his crate. He always jumps up and barks at her which he literally NEVER does in any other context. He gets a bit defensive when his toys are around and the cat is there so we make sure to always pick them up when he's done. They don't really try to play together so rough play isn't an issue.

We haven't needed the baby gate or door stop since around Thanksgiving and the house is very peaceful now. :) It's possible but it definitely involves knowing your pets and reacting accordingly to keep everyone safe and happy! Luckily we've never had any incidents or close calls.

What size is the dog? You could use this: http://www.amazon.com/Carlson-0941PW-Extra-Tall-Walk-Thru-White/dp/B000JJFNJK

I have this gate with a small door within the door for the cat to get through for this exact issue and the dog eating the cat food too. It's probably the best purchase i've ever made!

Not an expert by any stretch, but have been dealing with the same problem for 7 months now. This was key for us:

https://smile.amazon.com/Carlson-Extra-Tall-Gate-Small/dp/B000JJFNJK/ref=sr_1_12?crid=1SAPZZNQR0H9X&keywords=door+gates+for+pets&qid=1563882838&s=gateway&sprefix=dooor+gate%2Caps%2C129&sr=8-12

Not sure if it was that exact model, but it looks right. The cats have two rooms during the day they can escape to through the kitty door and feel safe, and when we're not home we keep the cats in one of them with the door and gate closed.

They've slowly (again, 7 months now) gotten used to each other. The dog chases less now, but still goes every once in a while. The things that have worked the most for us have been giving lots of treats as long as the dog can see the cat and isn't chasing. Like, constant treats at first. Someone on here suggested you should start (for a long time until she really gets it) with the dog sitting at the gate and seeing the cat on the other side, but not reacting. We did that a bit, but probably not for long enough. And only once the dog can do that with no problem, start to do it in the common space.

Both our cats and our dog love tuna, so we can actually get them seated next to each other and eating canned tuna (hand feeding them little pieces) calmly, which I think helped them get comfortable too.

It's still a work in progress. For some reason, the dog still gets the urge to chase every once in a while, which is tough because I'm not always close enough to stop her right away and I feel bad having the leash on her constantly. But there's definitely been improvement. One of the cats trusts the dog not to try to kill him at this point and will let her sniff at him and handle him a bit, the other is a bit more skittish but also getting better. Hopefully we keep seeing some improvement.

Also, our dog is between one and two years old, so I don't know if the issues are totally different when it's an older dog like that.

We have three cats and a dog. Both this dog and our previous dog LOVED cat poop. Two key items 100% solved our problems:

1. Doorway gate with cat door: https://www.amazon.com/Carlson-Extra-Tall-Gate-Small/dp/B000JJFNJK/
   
2. Litter cabinet: https://www.amazon.com/Merry-Products-Washroom-Bench-White/dp/B004E8M7PK/
   
   As a bonus, the doorway gate provides a room where the dog is never allowed. This is pretty key to most peaceful cat/dog coexistence situations. The cats need to know they have a space they can retreat to that is safe and all their own.

My chihuahua turned out to be able to CLIMB my first baby gate! So, I went with this one:
https://www.amazon.com/Carlson-0941PW-Extra-Tall-Walk-Thru-White/dp/B000JJFNJK/ref=sr_1_3?s=pet-supplies&ie=UTF8&qid=1466111174&sr=1-3&keywords=tall+dog+gate

It's 41" tall, and has only vertical bars (so no footholds). My cat can't get over it. The only problem is that there is a single 3-inch gap between bars, and my boy was able to wriggle through it - he must be able to dislocate his hips! I was able to McGyver up a solution, bringing the gap down to 2 inches, and he can no longer escape.

I use a gate to keep the dog out of the litter box room like this one.

We put a big tall gate up in our bedroom doorway and put the litter box in the master bath behind the gate. So the cats had a dog-free suite where they could relax and feel safe knowing Jack could not get in there. Also because he ate cat poops. But mostly to give them their own dog-free space. We got the tall gate with a little cat hole in the bottom so our elderly cat wouldn't have to jump the gate. This is the one we got and it's worked well for the past three+ years: https://www.amazon.com/Carlson-0941PW-Extra-Tall-Walk-Thru-White/dp/B000JJFNJK

The less you know about a dog's history with cats, the more precautions you should take in my opinion. You can always let your precautions go as time goes on, but you can't undo the dog terrifying or even injuring the cat. I had originally written out what I did with my new dog (a week and a half in now), but I don't feel comfortable laying out my path for someone who has a terrier. Here are some tips:

• Put your cat's food, water, and litter all in the room they're enclosed into so they're not too scared to eat/eliminate. Make sure your cat gets attention in there, so for instance my cat was in my bedroom which meant we had quality time in bed at night/in the morning.
  
  
• Rather than locking your cat in, you can get a dog gate with a cat door in it (I have this one ). A dog could easily wedge into the cat door or pull down a tension gate so it's definitely only a supervision thing, but it will let your cat explore at his/her own pace.
  
  
• Crate train your dog ASAP. You don't want the dog loose while you're out of the house or sleeping. It will also help to have the dog contained and let the cat wander through the room to see the dog's reaction.
  
  
• Especially if you use the gate, the dog must be leashed at ALL TIMES when not in her crate.
  
  
• Whenever the dog sees the cat, ask her to look away. This is going to be your gauge for how possible this situation is. It can range from: her looking directly at you and forgetting the cat was even there to looking at you but checking back in on the cat when he moves all the way to cannot be distracted even with treats.
  
  
• If things progress to them checking each other out closely (dog still on leash), let the cat correct the dog. This is important for 2 reasons: you want to make sure that the dog's response to a hiss and swat is to back off (not defend or bite) and you also want the dog to learn that the cat is the boss.
  
  I am lucky in that my dog is already off leash and unrestricted when I'm home, she deferentially walks around my cat and won't walk through a doorway if my cat is sitting in/near it. She is all tail wags and friendly but so far has not crowded the cat. She is still going to be crated for a long time when I sleep/am gone, especially because once she settles into the house in a few weeks she may become more confident and start harassing him.
  
  Introducing an adult dog to a cat is a full-time job that will probably last at least 6 months if everything goes well. You have your work cut out for you trying this with an adult terrier who already likes to chase raccoons (though, my dog fixates hard on squirrels outside but that behavior doesn't translate to my cat).

I have a similar situation with a 17 mo old and 2 cats. One cat purrs and licks him while he throws himself on top of her with all of his weight and "snuggles her". The other cat is normal...meaning she doesn't like getting manhandled by a crazy toddler. Over time, my son seems to have gotten the message via warning hisses and one swat to the face that resulted in a little scratch, that he needs to be gentle and keep his distance from that kitty. Is your cat demonstrating any warning behavior that your daughter may pick up on? Also, sounds like it may not help in your situtation, but we use a gate with a cat door https://www.amazon.com/Carlson-41-Inch-Extra-Included-Extension/dp/B000JJFNJK.