Complications from Dog Walking in Summer (non-boarding)?

She could just get carsick. It sounds like you are doing everything you can to keep her cool, or to cool her down after a walk. I always keep water and a dog bowl in my trunk to cool the dog down after a walk. It is good that you are keeping a conversation going with your client about this. I feel you'll learn more about the dog as you keep in touch with the client. If you notice improvements after future walks, you should definitely let the client know, so they won't have to worry about anything.

Karen and Mary already provided good answers. Adding to that, there could be something else the owners changed such as food or medicine that you weren't aware of. I'd always tell pet owners in case they need to determine if administration of anything additional is needed.

I don't think you need to consider shortening the length of the visit, like Karen said, just spend the time together a bit differently. I'd also think about if it is possible to eliminate getting in the car to walk and walk closer to home.

I also bring water & bowl, walk on a cool path, carry dogs over hot surfaces(you can test real quick with your hand), change paths as needed, and avoid car travel. Never had to change a service charge based on weather.

First, you should have told the owners immediately and then, after staying with the dog awhile to ensure the vomiting didn't continue, reassured them that the dog appeared alright and that you would check back on it later. You never know if something else might have caused the dog to vomit other than heat. I just had a dog staying with me who vomited on two successive days. I thought the fruits and vegetables I had given him might have caused it, although he never had a problem with them before, and stopped. I emailed the owner and she now told me that he had had a sensitive stomach for a few days. Your client may know the cause.

As for walking in hot temps, you are doing the right thing, bringing water and staying in the shade. The pavement can be brutal on dogs' paws, so a nice grassy area/park might be better.

I'm sensing that you are concerned about the loss of revenue from a shortened walk. Talk to you client about their dog's ability to tolerate the heat. Do some walking, but spend the rest of the time in a shady area, playing with their dog. Everyone should put the dog's well-being first and the owners should appreciate your concern and the precautions/care you've provided.