Would the statements about that being a bad idea apply to running telephone wire between a house and a barn that is also about 150 feet away?

We needed a phone line in the barn to install a foal alert system that detects the mare starting to give birth, and calls several phone numbers to alert you to get to the barn _now_. The barn had a phone line but apparently mice kept chewing through the phone lines, and in any case the line was dead at the network interface.

I know the right answer would be to have the phone company fix things up to the network interface, and then string new internal wire from there, but it was a time sensitive situation: one of the mares was already two weeks overdue and another was due "any day now"

So I strung a long piece of phone cable up the side of the house, across a tree, and over to the barn, and hooked up both ends, and plugged the wire into the foal alert system.

It is now less time sensitive, those two mares have had their foals, and the system worked great. But a third mare is due in about a month. So what should I do now?

1) Take the wire down _NOW_ and have the phone company come out to fix the wire up to the network interface, and hope they can get it done before foaling time?

2) Leave the wire up until the phone company can fix the wire up to the network interface, just in case, then switch over to that new wire?

3) Leave the wire up, disconnect the equipment until closer to the time for foal number three, use the system, then disconnect and remove the wire?

Whats the level of risk here?

Unless that wire is certified for wet and UV, it's likely to be toast in short order anyway. When you have the opportunity, run one properly (or have it done).