When you live with guinea pigs, you quickly become accustomed to their vocalizations. With a vocabulary of squeaks, wheeks, squeals, grunts, chattering, rumbling, and more, it's not hard to gauge a pig's mood or that of an entire colony. A rapid-fire barrage of wheeks at the sound of the fridge door tells you they're hoping for an extra, unscheduled snack. Rumbling and chattering start up when someone won't share (or just leave) a warm cozy cup. A squeal might be in response to one's ear being thoroughly sniffed by a roommate. No doubt about it, guinea pigs will clearly tell you everything.

Except when they're sick.

Guinea pigs, being both communal animals and animals of prey, will hide illness out of the instinctive fear that they'll be abandoned by their colony and targeted by predators. And they hide it so well that my own vet calls guinea pigs "black boxes." This means that once the signs of a problem are visible to us, it has advanced to a stage where immediate, if not urgent, veterinarian help is necessary. (Guinea pigs, like all species of animals, have a list of critical, need-to-go-to-a-vet-ASAP symptoms. Guinea Lynx's Emergency Medical Guide is a good list that belongs on the Favorites/Bookmarks menu of every guinea pig owner.)

At the rescue for which I work, we’ve been asked many, many, many questions by owners about their guinea pigs’ health. Questions about loud and frequent teeth grinding, crying out during urination, blood in the urine, partial loss of appetite, total loss of appetite, hair loss, crying out while being handled (or even at the prospect of being handled), and so forth. All these situations require immediate medical help. For example:

• What sounds like the grinding of teeth may be congestion in the nasal cavity (also known as an upper respiratory infection). If not treated quickly, the condition can advance to pneumonia (often fatal). Or, the pig may be grinding its teeth as a result of a rear molar problem. Either way, immediate medical care is needed.

• A guinea pig crying as it is peeing may be an indication of a bladder infection or, worse, bladder stones. Guinea pigs also can become blocked if there is a small stone in the bladder and it becomes dislodged; this is extremely painful for the guinea pig and dangerous. In both cases, immediate medical care is necessary.

• Not eating at all, or only eating very small amounts, is a sign of a several potentially serious problems. Waiting to see if the pig will start to eat again in a couple of days (or more) is not an option. Immediate veterinarian care is required.

Because guinea pigs can be so vulnerable, the wait-and-see approach is not in their best interest. Rescue workers, while happy to offer advice based upon their experiences, are not medical professionals. Additionally, their attempts to help are handicapped by the fact that they're talking with you by email or phone, and can't see, hear, and touch your guinea pig (and, no, sending photos or video files or connecting via webcam aren't good substitutes). To increase your pig's chances of recovery, an appointment with a veterinarian has to be made at the onset of a problem. (If you need to find a vet who treats guinea pigs, there are vet finder lists on Guinea Lynx and Seagull’s Guinea Pig Compendium, and many listings are accompanied by owner recommendations.)

When a guinea pig is having problems or is in full-blown distress, that's not the time to post questions in forums on Guinea Lynx or Yahoo! Groups, write panicked updates on Facebook, or call every rescue on Petfinder until you find one who answers the phone. We frequently monitor online forums to help field guinea-pig-related questions and, on any given day, a good third of the questions are from owners whose pigs are clearly in a state of distress (e.g., heaving sides, crying out while urinating, extreme listlessness, blood in urine, diarrhea, even seizures). Their comments included phrases like "I probably should go to a vet but..." or questions like "Should I go to the vet?" Some revealed that they'd been asking the same questions in a Yahoo! Group and/or some other unidentified forum(s) for a couple of days before they showed up in one we were watching.

In every case, there were respondents who advised, directed, ordered, begged, pleaded, and cyber-YELLED at the owners to get their guinea pigs to a vet immediately. In the cases of the folks who'd been asking around in forums for days (and still hadn't gone to a vet), there were respondents criticizing them for "wasting crucial hours" by firing up the computer, logging into forums, posting questions, and then waiting for answers. As one member put it, "If you're concerned enough to be asking whether you need go to a vet, then you absolutely should go to one."

There's nothing wrong with going online to ask for help in reliable forums (such as the one on Guinea Lynx) when the symptoms you're seeing are (much) less severe, or when a vet has already diagnosed and started treating your guinea pig. Forums are a great place for information on everything from sparking the appetite of a sick guinea pig to advance advice on identifying the nuances in behavior that can help you tell if a guinea pig is being finicky or if he's not eating as much as usual because a larger problem is starting to brew.

But when the symptoms you're seeing are on the emergency list, get thee to a vet. In these circumstances, every hour counts.