Dogs can be strong companions, but they also have needs that many people forget to address.
The author’s claim is that many people forget to address the needs of their dogs. The author continues to talk about some of those needs, like regular washing and grooming to avoid becoming matted and sick. The author is not simply talking about washing and grooming, but other needs the dogs might have as well. These could include things like walking, a proper diet, or brushing their teeth.