We have a State Lab about 20 miles from where I live......and they will take an animal in for necropsy and disposal for $65. They cremate. I have taken an animal there on a trailer before. This lab takes all types of blood samples for testing, so I can get a coggins in 1/2 hr if I hand carry
it from the vet.
Any chance you have such a lab near you?
There is a crematory in our area that will pick-up, etc. Fees are $250 & up, depending upon what services you want. It's actually owned and operated by a people funeral company. So, you might ask some of those groups which ones may accept animals. The one here is about 50-60 miles from me.
Now, I have also buried on my own property before. Used to have a larger farm and heavy equipment and a burial area. With a few hundred goats, mini horses and donks, well -- it's gonna happen! Now it would require my hiring a backhoe, so limiting again. PLUS, nights, weekends, holidays....it's a real issue.