To start, put yourself in your audience's shoes. What would they want to read about?
Scenario - My name is Lindsey. I'm a huge animal lover and a self-professed dog person. My life revolves around my dog. I want to give her all the love an attention she deserves. How do I do that?
Questions I may have:
Try to come up with other scenarios for different types of readers.
Scenario 2 - My name is Allen. I'm a "professional" dog walker but I really just got started. I'm juggling how to walk multiple dogs and find clients.
Also try using Google's Keyword Research tool to get insight on what others may be searching for.
Here's a different approach. There's a popular blog called Waiter Rant, written by a guy who worked for a long time as a server at a high-end French bistro. It eventually landed him a book deal.
He wasn't trying to do content marketing, but I think it's a great example of how to take what might seem like an uninteresting subject, and turn it into engaging, enjoyable content that builds an audience. The key is to tell stories.
Dog walkers should have a big pool of anecdotes, observations, and thoughts from their walks that are all seeds of potential stories. Pets have personality. How they interact with each other, with strangers' dogs, with people are all things dog owners can connect with.
Waiter Rant gets pretty thoughtful / introspective / philosophical at times, especially in the more recent content, and I wouldn't recommend emulating that. Posts that are entertaining or that (in a self-aware way, since it is about dogs) create drama and tension from encounters, are what I think would resonate more with your target audience.
Your goal should be to write stories people will share with their friends and family, and earn enough links that you rank better for a high-level keyword that's part of your branding "Stories from a Libertyville Dog Walker". Write stories that will make people say, "this is why I love my dogwalker," and you'll get shares from there.
Absolute gold from Brian Clark of CopyBlogger:
Choose who you want to reach, and find out everything you can about them. Their problems and desires. The topics that relate to those problems and desires. The language they use when searching Google and social media for those topics. Who else is serving the needs of these people, both with content and with products and services. This is where you always start.