A great money making tip from my local area is to do haircuts on dogs or/and care for them then the owner is away on holiday/vacation. It is a untapped marked here where I live.

If you give 5 dogs a day a haircut. In a week you does that on 25 dogs. Taking a fee like 60 dollars per dog, (yes, it is that expensive in my country).

The math:
5 dogs a day x 5 days in the week = 25 dogs a week.
25 dogs a week x 60 dollar a dog =  1500 dollars a week in income.

You’ll need one cage per dog, 5 cages if you handle maximum 5 dogs a day.

The best thing is to loan a dog or bring your own dog to a dog haircutter to observe that he/she does. Ask a bit on their business and how many dogs they do per day. See how they are equipped with cages and tools.

I know of a female that does haircutting of dogs from her own home. It’s not to difficult. It just need some planning and daily routines set up before you start.

If you start a vacation home for dogs, you need to do a bigger investment.And you need a bigger space like a big backyard not to close to your neighbors.

Just check your competitors prices and how many dogs/cages they have and do some basic math. I guess you will be surprised.

But, before you start: gather info and plan ahead.

About advertising:
Put up flyers in your mall, at your local vet, bus/train stations etc. Places there people travels and passes a lot.