When looking for exact keyword match domains in the areas I am an expert in, I come across a lot of subjects that have very little information on the internet, but they also have very little global and local search volume numbers. Less than 1,000. Is it worth it to even develop these? I can say most are within the "pet" niche.
It sounds like you're using the Google Keyword Tool. If so, it's also quite important to show the CPC (cost per click) column to get an idea of how lucrative a topic will be if you plan on using AdSense (you will receive some fraction of the cost as earnings).
So, don't just go by Local/Global search volume, but also look at how high the CPC (and Advertiser Competition) values are. Some of my niches are double lame: the search volume is low, and the earnings per click are low too!...
In a case like this, there is no right or wrong answer. The best suggestion that I can give you is to expirement. Write some articles with the less competitive keywords and see how much traffic you get.
Trying is the best way to achieve anything. The information and awareness about pets is surely growing, which you can even testify via google trends. And apart from this, I would suggest you to find some long tail keywords that are somewhat related to your domains.. You can focus your articles on those keywords and this will naturally do the SEO for your blog or site in case of low search volume.