Both humans and their furry friends need to stay vigilant to avoid heat stroke this time of year. Just like us, dogs need to keep hydrated and out of direct sun during the hottest parts of the day.

As a pet owner, you play a large part in ensuring your pet's health. Keeping their water dish full, avoiding mid-day walks under a scorching sun and by wetting their coat with a towel or spray bottle to keep them cool.

One thing to exercise caution with is refreshing summer human foods. Watermelon, grapes and pineapples may be the perfect treat for us, but not all fruit is safe for pets to consume.

Can dogs eat grapes? 

Dogs should not eat grapes or raisins. Even a single grape can put your pet's health at risk, according to the American Kennel Club. Grapes are highly toxic to dogs and can cause sudden kidney failure that can be lethal to dogs of all breeds, ages and sizes.

Experts are still puzzled as to why they're toxic, though VCA Animal Hospitals speculates it may be due to the presence of a mycotoxin, salicylate or tartaric acid.

Many human foods are perfectly safe for dogs, but owners should be cautious, veterinarian Diana Watkins previously told USA TODAY. Some foods, like cheese, unflavored rice cakes or turkey can make a nice occasional treat, but most human food doesn't offer any health benefits for dogs. Regulated dog food has everything your pup needs for a balanced, nutritional diet.

Check out the full list:Human foods that are safe (and toxic) for dogs

What to do if your dog eats a grape 

Contact your vet or the ASPCA’s 24-hour Animal Poison Control Center at 888-426-4435 if you suspect your dog ate a grape. According to VCA, the toxic dose of grapes is unknown, so there's no way to predict how dogs of any breed or size will react. It's better to be safe than sorry.

Look out for these signs and symptoms of toxic ingestion listed by the AKC:

• Appetite loss 
• Lethargy 
• Vomiting
• Diarrhea
• Increased thirst
• Change in urine: increased, lessened or unable to urinate
• Abdominal pain 
• Dehydration: Panting, pale gums, dry nose and mouth
• Kidney failure 

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