It's always hard to figure out if you should push this or not and what to do. If you catch them outside maybe try to stike up a conversation and discuss dogs. This really works if you have yours with you. This way you might be able to figure out if this is abuse or just someone who needs to be educated as well as be able to slip in a few suggestions using your experience with your own dogs without coming out and saying they have no idea what there doing. We had a situation with our next door neighbor, who unfortunately was also our landlords son so we had to be extremely careful what we said or asked. Like you there were no definate signs of abuse. 1 dog was fairly skinny but not emaciated, and I couldn't see where the dogs had any food, water or shelter, but I also couldn't see the entire back yard. So we talked to him in casual conversation, asked about his dogs, etc. This way we found out they could slip under the house for shelter and where their food and water bowls were w/o offending anyone. Long story short, we ended up with 2 of his dogs after he disappeared for about a month.