Heatstroke
Symptoms of heatstroke in dogs can range from a sudden collapse during exercise or prolonged weakness and heavy panting to more subtle signs (unusual lethargic behavior, or even diarrhea or vomiting). If you believe your dog is showing signs of heatstroke, seek immediate treatment. In the meantime, you can cool the animal down with cool or room-temperature water. Do NOT use cold water, ice, or ice packs, as it can actually cause the animal’s blood vessels to constrict, making it harder for them to naturally lower their body temperature. The application of cold water can cause shock and decrease blood flow to vital organs such as the heart, intestines, and kidneys.
Water Hazards
Don’t assume all dogs (or cats) are great swimmers. Strong ocean currents and waves can overwhelm your pet, and you may be put into the dangerous position of having to rescue them yourself. Keep an eye on saltwater consumption as well, since even playful romping in shallow water can increase salt consumption, leading to vomiting and dehydration. Jellyfish, crabs, and other sea creatures may cause additional problems for your dog. If you have a backyard pool, be sure to teach your pet how to get in and out safely. Inground pools should be properly fenced, particularly if you have senior pets with decreased vision. Properly fitted life vests are also a must whenever boating, kayaking, or paddleboarding with your pet.
Standing Water
Summer rain showers create puddles that can harbor bacteria, runoff toxins, and parasites that are harmful to pets. Stagnant bodies of water, including ponds, are another potential source of bacteria such as Leptospira, which can cause severe illness in animals—and sometimes even death. Leptospirosis is transmissible between animals and humans. Do not allow your dog to drink from stagnant puddles or ponds, especially if they are covered with algae. I don't recommend allowing your dogs to drink from public water bowls that are shared by unfamiliar pets.
Hot Cars
Never leave your dog alone in a hot, enclosed space like a car for any amount of time. Dogs don’t sweat like people do; panting is their only defense. If you see a dog left in a car on a hot day, dial the emergency number or local police to have someone get the dog out of the car quickly.
Insect Stings
Bee and wasp stings can be difficult to plan for, but try to be aware of any nest colonies on your property. Facial swelling from stings can cause breathing problems for your pet, and should always be treated as an emergency. While you can see the swelling on the face, you cannot see if there is internal swelling in the airway. If your pet is experiencing an unusual reaction to a sting, contact your veterinarian immediately.
High Temperatures and Humidity
Asphalt, cement, and sand can reach incredibly high temperatures on hot sunny days. Walk your dogs on the grass whenever possible. Walking early in the morning or later in the evening will be much more comfortable for you and your pets. You may also want to shorten your route on very hot days. This is particularly important for brachycephalic (short-nosed) breeds such as bulldogs, boxers, Boston terriers, and pugs, which have an increased risk of developing respiratory problems. High humidity will cause respiratory stress in brachycephalic dogs and any dog with cardiac disease or laryngeal paralysis. Obesity predisposes pets to overheating.
Summer Foods
From picnics to barbeques, summer presents plenty of opportunities for your dog or cat to eat things that aren’t good for them. Corn cobs, peach pits, used barbeque skewers, and other discarded items present problems with intestinal obstruction or perforation. It’s also a good idea to cut up large, empty chip bags to reduce the risk of potential suffocation.
Wounds & Injuries
People and animals tend to spend more time outside during the summer. This means that outdoor cats have a greater chance of getting into scuffs with other animals, while dogs are more likely to experience injuries during outdoor play. Fight-injuries and chances of getting hit by a car increase during the summer months as well. Any wounds that remain open have the potential of becoming infected or infested with maggots. Keep wounds clean; have them checked by your veterinarian if they are more than a superficial scrape. A pet appropriate first aid kit is especially helpful.
Dehydration
Your pet should always have access to fresh water to encourage hydration. Even dogs who spend most of the day inside should have constant access to water. Be sure to clean the water bowl daily, as dangerous bacteria can grow there; replace with clean, fresh water. It's not a good idea to put ice cubes in the bowl, as good digestion is promoted with food and drink served at room temperature.