When your pets are outside, remember that there are plenty of outdoors objects and chemicals that are harmful to your pets. Here is a list of the most common ones from the ASPCA.
*Algae (can be found in ponds or other bodies of water. Certain forms may be hazardous).
*Fences or gates. Pets can run away if fences are old and they find an opening. Pets can also get stuck in those openings and possibly get wounded or even strangled.
*Deck Lattice - Same as for fences
*De-icing salts. Some formulas may contain chemicals that are hazardous to pets if ingested. Wipe your pets paws after going for walks in areas where there might be salts. Also, look for pet-friendly brands for your home.
*Compost, particularly if moldy.
*Swimming pools and hot tubs. Never leave your pet unattended near uncovered pools, even if they can swim.