This is a partial list of common household toxins:  

ASPCA | Animal Poison Control Center

We are your best resource for any animal poison-related emergency, 24 hours a day, 365 days a year. If you think that your pet may have ingested a potentially poisonous substance, call (888) 426-4435. A $65 consultation fee may be applied to your credit card.

Chocolate and chocolate mulch is as toxic as chocolate itself.  Bakers chocolate is the most toxic. 

All human nonsteroidal antiinflammatories.  ie: Acetaminophen

Amphetamines

Antidepressants

Antifreeze even in small amounts.

Cleaning products

Herbicides 

Rodenticides

Snail Bait (Metaldehyde)

Silica gel

Grapes

Caffein 

Garlic and onions

Macadamia Nuts

All mushrooms from the yard are considered toxic 

Dog food recall  (Melamine/cyanuric acid)   (Purhase food and treats from reputable sources)

Peach Pits  (Also a intestinal hazard)

Raw Meat as a source of E coli and Salmonella

Tooth paste and sugarless gum (Xylitol)

Raw salmon, smoked raw salmon  and trout (Salmon Poisoning)  Not really a poisoning.

Moldy food

Potato green skin

Bread dough