I'm a retired realtor and also have knowledge of horses. I have several MAJOR concerns with what you wrote. Please read the following issues:
1. I know to care for horses is very expensive. If you own a horse, is it possible to use your horse as a business strategy to make money? In your situation, if you don't have enough cash saved and you are struggling financially, how can you spend money on vet care, feeding and other expenses on a horse? If your horse earned some money, would this help reduce your expenses?
2. Lease To Own or Rent To Own does not work the way you think. The person buying the property on your behalf and allowing you to live there will charge you additional rent and ask for a down payment. You will need to sign a contract and the contract states the person who bought the house will keep all of your money if you cannot qualify to buy it at a later time. You need to know that the person who buys the home will want to make a profit. The only way to make a profit is have you pay extra money which you do not get back. You will lose thousands of dollars doing this.
3. You need to sacrifice something and make a decision. Can you afford to keep your horse? It's not about buying this house. You need to analyze your financial situation. What is keeping you from saving more money and earning more income?