If you want to read the full CKCSC-USA or AKC standards, or check out the history of the breed, here are some good resources:
If you want to see lots of very pretty pictures, check out these (or of course lots of other) sites:
On the other hand, if you want to know what a Cavalier is like, to own and to live with, then you probably want a more informal description. I've owned Papillons and can draw a contrast between that breed and Cavaliers; I've met a lot of breeds in the course of obedience training and so forth, for what that's worth. Here's my take.
I'm assuming here, btw, that you really do want a dog in the first place and understand that you're going to need to vacuum dog hair off the couch, teach the dog not to bark hysterically and jump when visitors drop by, train the dog not to pee on the carpet, tolerate the occasional troublesome moment when the dog throws up on whatever piece of furniture you most value, and so forth. I'm also assuming that you understand that when you get a dog you're going to need to provide a lot of social contact for it, like nearly all evenings and weekends if you work during the day. It is not nice to get a dog when your aim is to keep it in solitary confinement except for the ten minutes per day you let it out a tiny crate to pet it. Who was it -- Jean Donaldson? -- who said If you don't like ordinary dog behavior, don't get a dog? I would add, If you don't plan to train the dog and let it be a member of the family, just get a cat or a gerbil or a boa constrictor or a teddy bear.
Now, what are Cavalier King Charles Spaniels like?
1. Cavaliers are spaniels. There are lots more kinds of spaniels out there than most people realize and they’re all sporting dogs at heart, even the toys, which were, after all, bred down from sporting dogs. If your heart is set on a Cavalier, good choice! If you’re still considering different breeds and just like the spaniel look, here’s how Cavaliers fit into the world of spaniels:
English Toy Spaniel (King Charles) – 12-14 lbs, some oversized; pug-faced.
Cavalier King Charles – 12-18 lbs, quite a few oversized; extra-sweet.
American Cocker – 22-28 lbs; the good ones are exquisite and the bad ones are numerous.
English Cocker – 26-34 lbs; setter-type head, wonderful dogs.
Boykin Spaniel -- 25-40 lbs; rangier than a cocker and with less coat, brown, energetic.
American Water Spaniel – 25-45 lbs; kinda like a cocker with a curly coat, less outgoing.
Sussex Spaniel – 35-45 lbs; built heavy and low, beautiful unusual golden-liver color.
Welsh Springer – 35-45 lbs; less coat than English Springer, needs a fair bit of exercise.
English Springer – 40-50 lbs; divided into show and field lines; field dogs need a lot of exercise.
Field Spaniel – 35-50 lbs; looks kinda like a cocker, higher-energy and more reserved.
Irish Water Spaniel – 45-65 lbs; tall, athletic, elegant dog, curly-coated and reserved with strangers.
Clumber Spaniel – 55-85 lbs; very heavy low-built dog, lots of stamina but not so much bounce.
These are obviously thumbnail sketches only. Go looking elsewhere if you’re interested. Some really good breed books and some really bad ones are out there, and of course there’s lots of info on the Internet. I like these breed books the best, in this order:
The Perfect Match, Walkowitz
Paws to Consider, Kilcommons and Wilson
Your Purebred Puppy, Welton
In general, you can expect a Cavalier to be sweet, loving, outgoing, easy to train (with positive treat-based training methods, please), enthusiastic about food (watch that weight!), a little stubborn (in a cute way), very sensitive, distinctly submissive compared to many other breeds, and pretty low-key indoors but active and distractible outdoors.
Some Cavaliers are shy. This is not ideal. Choose only an outgoing puppy whose mother is outgoing if you want the easiest job of socializing and training the puppy, especially if your household is busy and constantly filled with people coming and going.
Lots of sources will tell you that you must keep your Cavalier on leash every second. I don't agree. Teach your puppy a really solid off-leash recall and a decent heel and stay and then take him hiking. Leashes are for in town. (Yes, yes, I know -- almost no one seems willing to do the training necessary to make off-leash runs safe. Why not be different? It's not hard. Just do it!)
I find Cavaliers very different from Papillons in some important ways. Both can bark, despite what you may hear about Cavaliers not being barky. (My girl may have learned this from the Papillons, I admit). But they do not seem as prone to be set off on a barking jag by every little thing. In situations where a Papillon would fret and quiver with excitement, such as restrained on your lap in a crowded room, a Cavalier seems much more willing to settle down and sleep. This seems typical of Cavaliers at shows, not just of my personal Cavalier.
2. Cavaliers are small but sturdy. They’re not tiny toys by any means. The standard indicates that a Cavalier should stand about 12-13 inches tall at the shoulder and weigh about 12-18 lbs, and you’re more likely to see ‘em on the high end, up to 24 lbs or so, than on the small side. Even the small ones are solid, not dainty and fine-boned like Papillons. Cavaliers, unlike the more delicate toys, usually do very well with kids. They have a lot more tolerance for rough handling. Not only are they less breakable than many toy breeds, but they're a lot more stoic. This isn’t a license to let your tots torment the poor dog, obviously, but my Papillons know they can be hurt and stay out of touching range of children and my Cavalier doesn't worry about it. The flip side of this is that Cavaliers don't tend to tell you that they have been hurt, which means that you may suddenly discover you have a serious injury or illness on your hands which the dog didn't tell you about back when it would have been easy to take care of.
In training, a Cavalier acts like a big dog -- a Cavalier can be physically placed in a sit or down using the same techniques you might use with a big dog, where none of the other toy dogs with which I've ever worked can be (I suspect Pugs and Havanese might be similar, but I don't know because I've never trained either breed). A Cavalier sits, lies down, and moves like, say, a Golden Retriever, where Papillons move with far more delicacy, grace, and precision. Think of a Labrador next to a Belgian Sheepdog or Standard Poodle and you'll get the idea. I once saw several dogs at an obedience match jumping a barrier on a damp floor -- every retriever who jumped skidded into the wall, but the Belgian jumped like a cat, neatly, and landed gracefully and without slipping. I mean no offense to Cavalier fanciers -- remember I'm a Cavalier fancier myself -- but a Cavalier looks like a water buffalo next to a Papillon. I think my girl looks really graceful only when running through the woods, where she never seems to put a foot wrong.
3. Cavaliers are sweet-tempered. This is the single biggest reason people are drawn to Cavaliers, and the best reason to want one. Words cannot describe the lovely Cavalier temperament. An ideal Cavalier should get along with everybody and go freely and happily up to strangers, including (in fact, especially) children, without a trace of timidity. (They may come up with submissive body language, though.) Their tails should be constantly waving. They should be fine with strange dogs, provided the other dog isn’t vicious or whatever. Toss six Cavaliers that have never met into the same X-pen and they should all get along immediately. Mine was shy of bigger dogs at first, which is not necessarily typical or desirable, but she's mostly over that now. Cavaliers should not push very hard for dominance with other dogs or with people -- their attitude should be, Sure, you can be the boss if you care that much, no problem. Papillons are a whole lot more dominant with other pets, although similar to Cavaliers in temperament when it comes to interacting with people. I can think of a lot of toy breeds that tend to be a lot more dominant than Cavaliers.
4. Cavaliers need a fair amount of grooming. Say, a bath every month and brief brushing once a day to every week or so. You may have to brush the ears almost every day, and a conditioner may be helpful to prevent tangles. This is quite a bit more grooming than a Papillon is going to need. I seldom brush my Papillons more often than once every couple of weeks and they very seldom have even a small mat (They needed a lot more grooming attention during the transition from puppy to adult coats, so be warned!) All three pick up leaves and trash in their coats, but the extremely soft, cottony coat of the Cavalier picks up a lot more.
I find my Blenheim Cavalier gets distinctly dingy and develops an obvious "doggy odor" after only a few weeks, whereas the Papillons can usually go a month between baths. A clean coat is a lot less likely to mat, so every other week is a perfectly reasonable bathing schedule for a Cavalier. You won't dry out the coat or harm the skin if you use the right kind of shampoo and rinse thoroughly.
Cavaliers shed moderately, which means more than you might expect if you’ve never had a pet before, but a lot less than a Malamute or Dalmatian. Many wear snoods to keep their ears out of their food. The correct shape of bowl can help, too. Spaniel bowls are meant specifically to keep ears out of the dish, which is helpful, as otherwise the ears will get wet every time the dog drinks. Obviously the pricked ears of a Papillon don't ever get in the food or water bowls. Also, by the way, the tails of Cavaliers are a lot easier to catch in the door, so watch out. Papillon tails, carried up over the back, are not subject to this risk.
Cavaliers vary a great deal in how thick, how curly, and how long their coats are. Spaniels in general are sometimes considered to be more likely to set off doggy allergies than a lot of other breeds. The only way to know for sure whether this will be a problem for you, if you're concerned about it, is to spend several hours surrounded by Cavaliers and see what happens.
All dogs, but especially toy dogs (toys tend to lose teeth early) benefit from having their teeth brushed, preferably daily or at least every other day. This is particularly true of any dog at risk of a heart problem, which you can assume is true of all Cavaliers. It is much easier to brush the teeth of a Papillon than the teeth of a Cavalier, because the narrow pointy muzzle of a Papillon offers much easier access to the teeth. Feeding six or more T/D Science Diet biscuits per day may help keep the teeth clean. My dogs love T/D, for some unknown reason, since the ingredients are nothing special.
5. Cavaliers are easy to housetrain. Oh, sure, I've encountered people who complained that their Cavalier was a real problem this way. But many toy dog breeds are infamously hard to housebreak, whereas Cavaliers generally seem to be regarded as pretty easy. This doesn’t mean that an eight-week-old Cav puppy comes housetrained, for heaven’s sake, but by twelve weeks they ought to have the general idea and by sixteen weeks they will probably understand the concept and be trying to be housebroken. Incorrect housetraining methods or bladder infections can create a problem in any breed, so for goodness’ sake do it right and make sure repeated errors aren't your fault or the fault of an infection. If you're tempted to buy from a pet store, keep in mind that, aside from all the other reasons not to do that, pet store puppies frequently have the cleanliness instinct trained out of them. If you're looking for your first puppy and you're not so sure about housetraining, look for The Culture Clash, by Jean Donaldson, or for one of Ian Dunbar's basic puppy-raising books.
I found my Cavalier very easy to housetrain. By four months, she was peeing not only as soon as she was let outside, but also right before she came in -- just as though she was thinking, Okay, better do it now 'cause I can't go indoors. Clever girl! She responded to praise alone so well that I barely bothered to give her treats for correct elimination behavior, although normally I strongly recommend treats for housetraining. She had a total of four accidents, none on carpet (I supervise puppies very closely!). Two were definitely my fault, when circumstances beyond my control prevented me from supervising her or letting her out when she clearly might need to go. I stopped crating her when she was five and a half months old -- I only waited that long to be sure that she wouldn't chew up the couch cover when left alone. One of my Papillons was easy and one was very difficult, but neither became trustworthy as fast as Xan. Frankly, although I trust them, I trusted Xan more by the time she was six months old than I trust the boys right now, at nine and ten years.
6. Cavaliers are moderate in energy-level. Cavaliers love hiking and playing with toys and chasing stuff; Cavaliers are great for agility and fine for obedience, if you lean that way; but they’re happy to spend a lot of time snuggling with you on the couch, too. This is a far cry from, say, a Labrador or Border Collie or almost any terrier. Or even a Springer, for that matter. My Cavalier was less active indoors at a year old than my eight-year-old Papillon. Cavaliers should do great in the city. They are also, according to Kilcommons and Wilson, likely to be able to handle a nine-to-five lifestyle, as long as you don’t work all day and then desert the dog all evening, too.
My dogs get a minimum of half a mile of off-leash exercise every day that it's not raining or ultra cold, plus if they want to dash around in the yard in the middle of an summer day, I'm willing to sit in the shade and watch them. If they only got to stroll around the block twice a day on lead, then they'd without question need a whole lot more fetch games inside. I have met hyper Cavaliers and (so far) they have all belonged to elderly couples who provided very little vigorous exercise. I occasionally get calls from people (not Cavalier owners!) who crate their dog all day while they're at work, all evening to keep it from pestering them, and all night while they sleep. Then they want training advice to keep the dog from barking in its isolated misery or behaving like a lunatic when it's let (at last!) out of its crate! No dog deserves to be treated like that. If you're not willing or able to give your dog any exercise or attention, please don't get one.
7. Cavaliers frequently love to eat. This is not universal -- my Cavalier was not a chow hound by any stretch of the imagination until she (suddenly, at age two) decided that food was a great idea. Now she is at the top of her ideal weight range and I have to watch her intake. If you're willing to give a Cavalier too much food, it will most likely be happy to eat it, which is not the case with either of my Papillons. You may think that everything will work out if you let your Cavalier get flabby and then plump and then obese, but in fact, it will not. Almost every common health problem in this breed is seriously exacerbated by obesity. A bit too thin is better than overweight. If you want your dog to live a miserably short unhealthy life, feel free to ignore this warning.
8. Cavaliers are expensive. Some breeds are, due to simple supply-and-demand economics. This is one of them. Don’t – do not – try to cut corners by buying a Cavalier from a newspaper add or a pet store or the guy outside of town with Cavaliers lined up in rabbit hutches in his barn.
Oh, okay, I can’t stop you if you’re determined to ignore this piece of advice, but keep in mind that improperly bred Cavaliers are VERY likely to suffer from heart problems and other health problems (and temperament problems). Would you rather spend a good chunk o’ change up front for the puppy, or support your vet’s kids through college? For more on Cavalier health, click here. Besides, if you buy a puppy from a pet store, you’re supporting the puppy mill it came from. Surely you don’t want to contribute to that problem, do you? Also, if you want your pet to match the picture you have in your head of a proper Cavalier, I can tell you, a puppy mill animal probably won't.
Right now a normal price for a quality pet puppy from a reputable breeder is likely to be around $1500. (A show puppy will most likely run somewhere in the $2000-2500 range, depending on this and that.) What you buy for that sum is the best, most temperamentally stable, most physically sound puppy that breeder can produce, plus support later if necessary. This is not a guarantee, but you probably have no idea of how much effort, time, and money that breeder pours into her dogs. Have a chat with her about it. Read a copy of her buyer’s contract and note how it protects you as well as her [and the dog]. If you want a Cavalier, don’t let the price scare you off. Everything worth having is worth saving up for.
Watch out for commercial puppy producers trying to cash in on Cavalier big bucks. Don't assume that a huge $2500 price tag necessarily comes with a guarantee of quality. I do know of puppy producers who charge this much while running a commercial breeding operation with no regard for quality or health. Do read the breeder's contract. (There had better be a contract.) Do chat with the breeder about health and genetics. Do let bad vibes turn you off. Be an informed buyer.