I've had guinea pigs. They are social animals and will be healthier and live longer if you have two. Buy a very good cage - I recommend a Midwest Cage like this one: https://www.chewy.com/midwest-guinea-habitat-guinea-pig/dp/131305?utm_source=google-product&utm_medium=cpc&utm_campaign=16415508701&utm_content=MidWest&utm_term=&gclid=Cj0KCQiA64GRBhCZARIsAHOLriK7g0sVI4sUmiQpbXcTEzJHgUsYtioRdiRzxyBO47UnHfDwORIfX6caAj97EALw_wcB
Guinea pigs need lots of room to run around. And, you may have issues with genders. I had 2 males and they fought like gladiators. We ended up getting 2 Midwest cages and putting them end to end. The piggies could visit but were not sharing a space. Of course, don't get a male and a female unless they are neutered or you want babies - which you don't. Best if you get two females. Less drama.
Taking good care of piggies may require more work than you realize. Daily or almost daily cage-cleaning, preparation of foods, cleaning water bottles, getting toenails clipped regularly. They need fresh fruits and vegetables. You can Google which ones. We provided 1/2 cup per piggy of cut fruits and veggies each day. And, they needs lots and lots of sweet Timothy hay and hay pellets. Hay is the most important part of their diet. They must have fresh water daily. Their toenails never stop growing, so it is imperative that either you or your vet needs to trim their nails regularly. We took our piggies to the vet every 3 months for nail trims. If their nails aren't trimmed, they will curl under and grow into the pads of their feet causing pain and infections.
Although people will tell you their cage(s) only need to be cleaned once or twice a week, don't believe it. They poop and pee A LOT. Daily or every-there-day cleaning is necessary for the health of your pet and the well-being of your household. We lined our cages with old cotton bath towels that we washed regularly. You can also buy bedding material but that gets expensive.
They are prey animals and are scared of EVERYTHING. It will take a while for them to get used to you but once they do, they are cuddly and so loveable. We adored ours. (The both passed in 2021 within one month of each other.)
As for your cat, our cats never bothered the cages. We used to have what we called "piggy time" each evening when we would let the piggies out, one at a time. While I played with and fed a guinea pig, my husband cleaned the cage. My cats would get up on the sofa where I had the guinea pig and would nuzzle him. The cats never tried to harm the guinea pigs but, of course, I NEVER LEFT THEM ALONE with a guinea pig. Instinct trumps all else and even the tamest cat has the instinct to hunt and kill.
If you aren't sure about your cat, keep the cage in a room that can be off limits to the cat. The cages are not truly cat-proof. If a cat tried hard enough, he could manage to get into the cage. But, ours never tried. In fact, they paid little attention to the guinea pigs until it was "guinea pig time".
I'm happy to answer any questions you may have, Ellie.
