You're in your car, heading somewhere or other, a long list of things to accomplish and already running late. Suddenly, you see him—a dog, there, by the side of the road. With a sinking feeling, you realize he's alone. Your car is coming alongside him now. You have only seconds in which to act. But what should you do?

This is a wrenching scenario for all who care about animals. Once you've seen the dog (or cat), it's too late to avert your eyes and drive on, even if you wanted to. After all, what if your own dog or cat were standing there? So, before you pull over, good Samaritan that you are, here are some guidelines for assisting animals safely and effectively.

• Be ready to rescue. If you know in your heart that you're a rescuer, why not equip yourself to do the best possible job? Here are some things to have in your car at all times: Phone; phone numbers of local animal control, a shelter, and a 24-hour emergency veterinary clinic; cat carrier or cardboard box; collars and strong leashes for dogs; heavy blanket; water bowls and water; strong-smelling foods, such as canned tuna or dried liver; and an animal first-aid kit.

• Think about your safety first. You cannot help an animal if you become injured yourself in the process. Look in your rear-view mirror before braking, signal your intentions, pull your car completely off the road, turn off the ignition, set the parking brake, and put on your hazard lights. If you have emergency flares, prepare to use them.

• Consider the safety of the animal. A strange, frightened, and possibly sick or injured animal may behave unpredictably. A sudden move on your part, even the opening of your car door, may spook him, causing him to bolt—possibly right onto the highway. If the animal looks or acts threatening, or if for any reason you feel uneasy about the situation, remain in your car.

• If possible, restrain the animal. Create a barrier or use a carrier, leash, piece of cloth, or length of rope to keep the animal from leaving the area. Signal approaching vehicles to slow down if you cannot confine the animal, or divert traffic around him if he appears to be injured and is still on the roadway.

• Use caution when approaching the animal. Should you succeed in getting close enough to capture him, you stand a good chance of being scratched or bitten. Even a small animal can inflict a painful wound, and if you are bitten by a cat or dog whose vaccination status is unknown, you will be advised to undergo preventive treatment for rabies.

• When approaching the animal, speak calmly to reassure him. Make sure he can see you at all times as you approach, and perhaps entice him to come to you by offering a strong-smelling food such as canned tuna or dried liver.

• Try to lure an animal into your car with food, close the door, and wait for help. But do this only if you are certain someone will come to get the animal very soon. In most cases it is not a good idea to attempt to drive somewhere with a strange dog unrestrained in your car; he may become frantic or aggressive once you're in the car with him. Cats may do the same, as well as lodge themselves under the car seat, from which extracting them can be dangerous.

• If you're not able to safely restrain the animal, call the local police or animal control agency. Do so whether or not the animal is injured, and whether or not he appears to be a stray or to be owned (meaning he is wearing an identification tag or flea collar or has recently been groomed). If you have a phone in your car, call the local animal care and control agency (in rural areas, call the police or sheriff) and report the situation. Leave your phone or beeper number with the dispatcher and try to get an estimate of how long it may take someone to respond. If possible, stay on the scene to keep an eye on the dog or cat until help arrives. Make sure you report to authorities precisely where the animal is. For example, say "one mile north of Livingston on Highway 101" or "between markers 65 and 66 on the New York State Thruway."

• If you are able to transport the animal, take him to the nearest animal shelter. Or, if you plan to keep the animal in the event no owner is found, notify animal control that you have the animal or that you have taken him to a veterinary hospital for treatment. You usually can place a free "found" ad in your local newspaper. Keep a copy of the ID to prove your good intentions should any question arise later. To check on any relevant laws in your state, county, or town, contact your local animal control agency, humane society, or SPCA. Many times, the dog or cat you find along the highway will turn out to be unowned, unwanted, and unclaimed. Even so, the person finding the stray dog or cat does not automatically become the owner or keeper—as in "finders keepers"—until he has satisfied certain state and/or local requirements. In almost every state, the animal is not "owned" by the finder until the holding period for strays (as specified by state or local laws) has expired and the finder has made an attempt to reunite the animal with his original owner and/or has taken steps—obtaining vaccinations, license, collar and identification tag—to prove he is now the owner.

• Don't assume you are dealing with an irresponsible owner. Good Samaritans who have never lost a cherished companion animal may conclude that the owner of the found dog or cat callously abandoned him or, at the very least, neglected to keep him safely confined at home. But accidents can happen to anyone. The frantic owner may be looking everywhere for their beloved pet.

• Understand the limitations of animal care and control agencies. Once you have taken the initiative, time, and trouble to rescue a dog or cat along the highway, you may be surprised to find that the rest of the pet care community may not necessarily rush forward to do what you see as its part. For, instance, you may take a badly injured stray dog to animal control, only to learn that the agency is unable to provide expensive surgery to treat the dog's injuries and, to relieve him from his suffering, euthanizes him instead. A cat with relatively minor injuries may be kept for only the mandated stray holding period and then euthanized. Virtually all animal control facilities have severe budgetary or space limitations and must make painful decisions on how best to allocate their inadequate resources.

• Before you take an injured animal to a private veterinary hospital for treatment, be willing to assume financial responsibility for the animal before treatment begins. Good care is not cheap, and many veterinarians have many Samaritans in their waiting rooms every year. Anyone who is committed to trying to save injured stray animals should discuss these issues in advance with the veterinarian. Fortunately, some states have laws that allow the veterinarian to collect from a fund for treating unowned injured animals who have been presented to them by animal control or a good Samaritan.

If you're uncertain about whether or not to assist or keep an animal you see alongside the highway, here's a final word of advice: First, think of what you would want the finder of your animal to do if he happened to find him injured and his collar missing. You'd want him to take your pet to a veterinarian, and you'd want him to try to find you. At the same time, be reasonable about how much you can afford to do for that animal if no owner shows up. Are you willing to add him to your household? And will you be willing to return him to his original home if the owner turns up after you've started to form an attachment? Thinking these issues through in advance may stand you in good stead the next time you see that wrenching sight at the side of a road.