Guinea Pig Basics:
Sorry if this is a bit long. There's lots of information in here.
Cages (We recommend C&C cages): Most rescues, including ours, require a cage that is 7.5 square feet or larger. Most cages sold in pet stores are too small. They aren't much more than a glorified bathroom. You'll enjoy your guinea pigs more and they'll enjoy life more if they can have a bigger cage. You also won't have to clean the cage as often if it's bigger! www.GuineaPigCages.com is a great website. They show you how to make a big C & C cages for cheap. I can make one in about a half hour and I am horrible at this type thing normally. You can make a cage that is over 2' wide to 4' to 6' long for under $40. If you need help locating the materials or need advice on how to cat-proof it, just email us at CavyHouse@gmail.com or sue@cavyhouse.org. We have all the supplies you need to make one of these cages at our rescue.
Another possibility if the Midwest Guinea Habitat. It can be ordered on line for $35-$50 (prices vary as do shipping costs.) It is 2' x 4' and expandable. It can also be ordered with a lid. They are not quite as sturdy as C&C cages but some people prefer the ease of a kit. Cavy House generally has one of these cages available to adopters for $40-50 (depends on what price we were able to find it). When last checked, these cages could be purchased online from 3 places: All Pet Furniture Amazon.Com This Little Piggy Marketplace
Diet: Guinea pigs need a diet that is consists of unlimited hay along with pellets and fresh vegetables. .
Hay (timothy or grass hay): Guinea pigs need to have hay available 24 hours a day. They also need guinea pig pellets, which is covered below. They need hay to wear down their teeth, which grow their whole lives. I read somewhere (but haven't validated this) that they they refill their stomachs 17 times a day! They do need food to be moving through their systems constantly. Adult guinea pigs need to have timothy or grass hay available 24/7. Pregnant and nursing guinea pigs and guinea pigs under the age of 12 months should have alfalfa hay offered in addition to grass or timothy hay because it has more calcium. The extra calcium in alfalfa can contribute to bladder stones so it's recommended to avoid extra calcium in adults. They do need hay available constantly - not just at mealtime.
Guinea pig pellets (Oxbow Cavy Cuisine, Oxbow Cavy Performance, Kleen Mama's Hayloft): Plain guinea pig pellets without all the extra gourmet goodies are the best for your guinea pigs. You can follow the recommended amounts on the packages - I sometimes free-feed the pellets but some guinea pigs eat too many pellets and not enough hay and get too fat. Avoid the feeds that have seeds, nuts, dried fruit, sugar, corn syrup or dyed pieces. Guinea pigs can choke on seeds in husks. Most guinea pig feeds have vitamin C in them, which guinea pigs need. Rabbit pellets do not have vitamin C and so are not a good substitute. Most of the vitamin C in guinea pig food will degrade 3 months after the milling date so it's best to not buy more food that you can use within 3 months of the milling date (not the date you open the package). The milling date should be on the label. Oxbow makes a high-quality pellet with a more stabilized form of Vitamin C which lasts longer than three months. Their Cavy Cuisine pellet is good for adult guinea pigs (timothy hay based) and their Cavy Performance pellet is good for pregnant, nursing and guinea pigs under the age of 12 months. You can order pellets and hay of a very high quality online at Kleen Mama's Hayloft .
Vegetables: Guinea pigs need about a cup or two of dark green leafy vegetables daily. Favorites are romaine, green leaf and red leaf lettuce (iceburg is worthless), cilantro, Italian Parsley, dandelion greens and others. Red bell peppers have a lot of vitamin C, which is good. Don't let your piggies talk you into unlimited veggies! We had one guinea pig come into our shelter in very poor health (almost died) because she had convinced her previous owners she needed veggies all the time.
Vitamin C: Guinea pigs can't make their own so they need to get it from their diet. They can get scurvy without it. They need around 10-30 mg daily. A good guinea pig food should have it in it. You can also supplement with a chewable vitamin C (cut into pieces because they don't need the whole tablet). Some people put vitamin C in the water. Most recommend against this because it may alter the amount of water your guinea pig drinks. Vitamin C in the water also degrades within 24 hours so needs to be replenished. Don't get multi-vitamins for your piggy. Vitamin C is the only one they need. You can print out charts that have the vitamin C content of various fruits and vegetable from this website:
http://www.guinealynx.info/charts.html
Fruit: Fruit should be fed very sparingly as too much can lead to diabetes. A slice of orange (good vitamin c) a few times a week is fine.
Water: Like all animals, guinea pigs need access to water at all times. I always buy the 32 oz water bottles instead of the smaller size. Aside from the extra dollar it costs to buy, there are no downsides and if you happen to be delayed getting home because of some emergency, at least your piggy will have water. My guinea pigs never liked the "Critter Canteen" brand. I don't know why but they wouldn't drink out of those. I've had the most luck with the Oasis brand of water bottles.
Temperature Range: Guinea pigs do best between 65-75 degrees. They are very prone to heat stroke and shouldn't be kept in direct sunlight. Guinea pigs will die from high heat. On hot days, place frozen water bottles in their cages - they often lay right next to them to cool off. They really need to be sheltered from bad weather too and do best indoors. They are a very social animal and do great if they can share your home with you.
Bedding (Carefresh, kiln-dried pine, aspen, fleece & towels): There are a lot of bedding products available. Carefresh is a good product but a bit pricey (especially if you have 12-30 guinea pigs at a time like I do!) I use Kiln-dried pine shavings. You have to use kiln-dried because of the volatile oils in non-kiln-dried shavings. Don't use cedar shavings. If you have room to store a large bale of shavings from a feed store (not a pet food store), you can save a ton of money. I buy the horse-size bale. It costs about $8 for the size that would cover an entire horse stall. For $6-7 at a pet store, you can get a very small package that might last one cage change. Many people are switching to towels and fleece, with the towels being the bottom layer and fleece the upper layer. It does require frequent cleaning of poops though and extra laundry.
Scale: We highly recommend purchasing a scale for your piggies. You can get a postal scale or baby scale that weight up to 5 pounds. You'll need something that measure to the ounce or gram. Being prey animals, guinea pigs are very good at hiding illnesses. They will often have a weight loss before showing any symptoms that should alert you that you should seek veterinary care. You can buy a scale on-line here:
Guinea Pig Scale - just scroll down a ways until you find the scales.
Nail Trimmers: You'll want to purchase either cat claw clippers (scissor type) or have human finger nail clippers on hand. Guinea pigs need to have their nails trimmed every 4-6 weeks.
I'll add more information as I get more time.
For lots of great Information: see http://www.guinealynx.com/healthycavy.html and Cavy Spirit
This is a great website for detailed information about guinea pig care. A lot of what I've listed here is information I read on the www.guinealynx.com website. There is a whole lot more information on this website than I can list here. I recommend taking a look.