Hurley's Medical Bills

I'm Emily Barrett and this is Hurley, my family and I's loving best friend. Our baby boy is a 7-year old dachshund-labrador mix, which makes his body big and heavy, but he's long and short. Because of this, he has recently developed back problems.
On February fifteenth or sixteenth, we started noticing shivering and a slow in eating and drinking. A couple days later, he wouldn't jump up on the couch or beds, and the pain was even more obvious than before. After seeing what we thought was just a typical cold or fever progress into whimpering, limping, and lack of walking for anything longer then from room to room, we took him in to his vet. He explained to us that there is a rupture in one or more of his vertebral discs. This means that his spine is not supported how it should be and is rubbing together, making him uncomfortable. They gave us three different medications for him to take over the next three to four weeks. These medications seemed to help with his pain and appetite, but before long we started to notice the symptoms come back, then go away again, then back once more.
This morning my dad woke up to find Hurley not wanting to stand up. When he finally did, his left back leg was limp and barely held himself up. When he walks, his back feet cross over themselves, and when he goes to the restroom or moves his back left leg into a strange position, he'll let it drag on the floor behind him. My parents and I took him in to the Heart of Texas Veterinary Specialty/Emergency Center, where they further examined him, and came back with the news that we needed to decide what type of screening we want to do for him, since they can only see so much of what the problem is from the outside. Our options were to do a CT scan or a MRI. The difference between the two is that the CT scan uses X-rays and the MRI uses magnetic fields that allow us to be able to see abnormalities also in organs and soft tissues, as compared to bone and only very prominent other abnormalities in the CT scan.
If the doctor thinks what's going on is really going on, our Hurley will need a surgery to correct the ruptured disc in his back, which will take place immediately after the MRI tomorrow. Until then, we are not sure if we'll need to pay for the surgery as well or some other treatment for a completely different problem. However, MRI's can be very expensive, and will cost nothing less than $1,500 (which is not including the price of the anesthetic, which will cost a few hundred dollars as well). If the surgery does take place, that will also cost two or three thousand dollars (with a success rate of 95-99% ). This brings us to a total in medical expenses of up to $5,000-$6,000 after the surgery, MRI, and recovery/his hospital stay. 
Right now, however, we first just need to get through his MRI and see what to do from there. Any help to pay his medical bills would be beyond greatly appreciated. He's such a sweet dog and deserves many more years of happy and healthy life. Any donations even if they're small would mean the world to my family and I, and Hurley would thank you too if he could. Updates will come as soon as we hear anything.