I flat out wouldn't go in the garden with a dog. If know there is there is one I knock the door, I do the gate rattling thing and procede slowly with my pole held as a baseball bat whilst scoping the area if I have any suspicion at all of a dog.
If there's a dog out and no one home, I'll leave it.
I remember once a long time ago, I picked up a new customer. She said I have a dog and I can't bring it in as it lives in the garden, we don't let it in the house. I said ok. Don't know why, just wanted the job. I thought I'll just see. So goes to do job expecting no one in, well woman answers front door on phone so couldnt really talk. I said window cleaner , she gave me thumbs up and off u went to side gate. Opened it slowly, great big horrible thing looking at me with teeth gritted... no chance...put pole back in van and drove off.
Never to return, quite possibly the most unprofessional flounce I've ever done no idea what the custys thought never heard anything.