Cats, dogs and other companion animals can be poisoned by most of the same substances that can harm humans, as well as materials that don't affect humans. And, because of their relatively small bodies, household pets can be harmed by very small amounts of a toxic substance.

A recent caller to UNH Cooperative Extension Family, Home and Garden Education Center Info Line wanted to know if cocoa shell mulch was toxic to dogs. She'd recently mulched her flower garden with cocoa shells, and found her two dogs eagerly gobbling it up.

Because she knew chocolate could poison dogs, she was concerned, and had been keeping the animals cooped up indoors, since they made a beeline for the mulch whenever they were let out.

We called the national Animal Poison Control Center in search of more information, not only about cocoa mulch, but about preventing pet poisoning in general, and talked with Dr. Michael Knight, the Center's medical director.

Knight said all parts of the cocoa plant contain a compound called theobromine, a central nervous system and cardiovascular stimulant. "There are no hard numbers on just how much of the substance might be in a given batch of cocoa shell mulch, but the caller's dog was exhibiting symptoms consistent with theobromine poisoning - restlessness, panting, pacing, anxious behavior."

Knight talked about steps pet owners can take to prevent their animals from being poisoned in their own homes and back yards, also referring people to the Center's website.

Here is some information gleaned from the website and from Dr. Knight's comments.

"We need to look at our homes through the eyes of our pets, seeking out 'toys' and 'entertainments' that may be harmful for them," he said.

Be prepared. You should keep telephone numbers for your veterinarian, a local emergency veterinary service, and the ASPCA National Animal Poison Control Center (1-888-4 ANI-HELP) in a convenient location. If you suspect your pet has ingested something poisonous, seek medical attention immediately.

• Don't use garden or lawn care chemicals in the presence of your pet.
• For your own and your animal's safety, read and follow label directions carefully.
• Keep pets off a lawn or away from other plants treated with an insecticide or a weed killer at least until the plants are completely dry.
• Keep your pets out of an area where snail or slug bait has been applied. Always store such products in areas inaccessible to your companion animals. Contact the manufacturer for information concerning product usage around your pets.

Dr. Knight noted the Center receives many calls from dog owners whose dogs have been poisoned by systemic insecticides in granular form, incorporated into the soil at the base of perennial plants along with organic fertilizing materials such as bone meal, fish meal, blood meal, feather meal or manure. All of these organic materials are very attractive to dogs, who see them as a food source.

If you're a dog-owner who hires a professional landscaping service to care for your shrubs and other plants, be sure to get the names of all insecticides and fertilizers the landscaper has used around your plants. Knight says a common cause of dog poisonings is an insecticide called Disulfoton, a product restricted for sale and use by licensed pesticide applicators only.

When you treat a house to kill fleas or other insects, read the product label and follow all directions carefully. This is particularly important if a flea control product is to be applied directly to the pet. Before buying a flea product, consult your veterinarian, especially when treating sick, debilitated or pregnant pets.

The insecticide permethrin, a common ingredient in flea controls for dogs, can be fatal to cats. Read flea control product labels carefully; never apply a product formulated for one species of animal to another.

If you put out ant, roach, mouse or rat baits, make sure they're in a spot inaccessible to your pet. Keep track of the baits and remove and dispose of them properly when they are no longer needed. Record on a calendar the date the bait was put out and the name of the bait used. You'll need this if your dog eats an entire bait container, or if there was no label on the container and you need to tell the Center veterinarian what your pet ingested.

For animal emergencies, call The Animal Poison Control Center, a service of the American Society for the Prevention of Cruelty to Animals, at 1-888-426-4435. Headquartered in Urbana, Illinois, the Center opened its phone lines in 1978. Today, the phones are staffed 24 hours a day, every day, by veterinary toxicologists.

Because the center receives no government or private funding, there's a $45 charge per case, though, at no extra charge, the Center will do as many follow-up calls as necessary in critical cases, and at the owner's request will contact their veterinarian directly. The Center also provides, by fax, specific treatment protocols and current literature citations when needed.

This time of year is its peak season, and Center Medical Director Dr. Knight says they're averaging about 275 calls each day, including "quite a few from New Hampshire. The Center also has a well-designed, easy-to-navigate website (http://www.napcc.aspca.org/), which includes tips on preparing an emergency first aid kit for animals, and a page of tips for veterinarians.

Indoor Hazards:

Our homes can contain a wide variety of potentially harmful compounds. For instance, here are some common food products that can be toxic, even lethal, to pets: avocados (toxic to birds, mice, rabbits, horses, cattle, and dairy goats), alcoholic beverages, chocolate (baker's, semi-sweet, milk, dark), coffee (grounds, beans, chocolate-covered espresso beans), hops (used in home beer brewing), macadamia nuts, moldy foods, onions, onion powder, salt, tea (caffeine) and yeast dough.

Pet owners' medications are the most common cause of animal poisonings, according to Dr. Knight. Cats, in particular, are susceptible because they have a body chemistry quite different from ours in several important ways.

Don't give any of your medications to a pet. That includes over-the-counter medications such as aspirin, ibuprofen, cough or cold medicines and decongestants. Don't give your dog's medicine to your cat or ferret.

Be careful where you take your own medications. Make sure a pill doesn't drop within reach of a playful paw or quick, slurping tongue. Don't put your medications out on a table or counter to take.

Store medications for all family members and pets in high cabinets, out of reach. With their curiosity and strong teeth, dogs can crack open a pill bottle and swallow the entire contents in a very short time. Even if it's a medicine prescribed for your pet, too large a dose could cause problems.

Medications that come in tubes may also pose a large risk. Most pets have sharp teeth and can chew into a tube within seconds. Creams and ointments that may be quite safe when applied to the skin can cause serious problems when eaten.

Pain killers, cold medicines, anti-cancer drugs, anti-depressants, vitamins and diet pills are all examples of human medications that can be lethal to animals, even in small doses.

House & Garden Plants:

Ingesting parts of ornamental plants, such as azalea, oleander, castor bean, lilies or yews can be fatal to your family pet. Lilies of all types are especially toxic to cats.

In the vegetable garden, rhubarb leaves, potato leaves, stems and sprouts, and tomato foliage are poisonous to animals.

Chewing on some plants may result in severe irritation to the mouth and throat. Others, while not quite so deadly, may cause a severe intestinal upset.

Know the names of all the plants in your home and landscape, and keep any potentially toxic plants out of areas accessible to your animal companions.

Household Chemicals
Most cleaning materials can cause stomach upset and vomiting if a pet eats them. Dishwasher detergent can produce burns in the mouth.

When using household chemicals, take special care to make sure your pets can't get into them. This may mean keeping your pet out of the room where you are using such materials.

Common household items that can be lethal to an animal are mothballs, potpourri oils, coffee grounds, homemade play dough, fabric softener sheets, dishwashing detergent, batteries, cigarettes, and alcoholic beverages.

Automobile Care Supplies
Like indoor cleaners, car-cleaning compounds can cause stomach upset and vomiting. Some car-cleaning agents are stronger than those used indoors.

Car-cleaning products should be kept away from your pet, who will be safer if he or she is not allowed to "help" you clean your automobile.

Antifreeze and windshield washer fluid can be harmful to your pet. Your pet shouldn't be allowed to drink water from a car radiator. As little as one teaspoon of antifreeze can be deadly to a cat; less than one tablespoon can be deadly to a 10-pound dog. Safer antifreeze products are now available and should be used.

Peg Boyles, Extension Program Associate, Agricultural Resources and Margaret Hagen, Extension Educator, Agricultural Resources UNH Cooperative Extension