Poisons and other toxins

Antifreeze is highly poisonous. Unfortunately, dogs actually like the taste of the stuff. Don't leave even a little on the driveway and never leave an open container where pets can reach it.

Aspirin, in appropriate doses is ok for dogs (not cats), but do not give Advil, Tylenol, or any other pain killer without specific instructions from a veterinarian.

Rattlesnake bites are rarely fatal to large dogs, but little dogs get a lot more venom in proportion to their size, and may die.

Mushrooms can cause severe illness or death. Try to keep them cleared away from places your dog can reach.

Chewing on the toads in Placerville causes alarming symptoms of salivation and disorientation, but seldom anything worse. Toad-chewing in Florida and some other places can be much more serious. 

Oleander and other poisonous plants make puppies pretty sick, but the quantities eaten are usually not life-threatening. Some flower bulbs are highly poisonous and dogs will occasionally be fatally poisoned by eating them.   Most dogs won't do this, but it has happened.

Chocolate can certainly be poisonous for dogs, not because it's highly toxic, but because dogs sometimes eat very large amounts in proportion to their size.  If a big dog eats one or two candies, it won't do anything worse than add calories.  When a beagle-sized dog eats half a box of chocolates, we have a problem. When  a Chihuahua eats most of a box, we have an extremely serious and probably fatal problem. 

Large amounts of Xylitol, a sugar substitute often found in dietetic candies and baked goods, can also be fatal to dogs.  

If your dog drinks antifreeze or eats rat poison, immediate treatment is needed. You can induce vomiting by giving 1 teaspoonful of ipecac syrup per 10 lbs, or get him to a vet right away. Another good choice is hydrogen peroxide:  give 1 teaspoonful per 20 lbs.,  if vomiting doesn't occur within ten minutes, this may be repeated once.  Dogs usually look sad and drool just before they start vomiting.  It is also possible to induce vomiting by pouring lots of very salty water down a dog's throat, but attempts are usually unsuccessful and merely waste time. Do not try to induce vomiting if petroleum distillates, caustics, or acids have been ingested, if a pet is having seizures, and/or is not fully conscious.