Can I sue my friend for negligent pet care?

I have a small dog weighing about 10 pounds. I needed to go to a conference over the two day weekend and because my dog is very needy I asked my friend who my dog is familiar with if he would take care of him for me. My friend agreed and I gave him specific instructions on how to care for my dog. I told him that since he was such a small dog and not used to being outdoors, he was only to be outside on warm sunny days and let back into the house when it because chilly, rained, or of course began to get dark. He agreed to my requests. When I went to drop off the dog, he was not home, but I let him know that we were on the way and that I would leave the dog in the back yard. I got in contact with him right after securing the gate to the back yard, asking him to let me know when he arrived home so that I would know that my dog was 1. still there and 2. safe. I hadn't heard back from my friend and it was about 6o'clock in the evening so I gave him a call. I asked if he had gotten home to let my dog into the house. He said that he had and he added that he (my dog) was doing fine. I called when I was an hour away from my friends home, to let him know that I would be there shortly. When I arrived I asked where my dog was and he said that he was outside. The night before and into the current day it had rained and gotten cold. I let my dog in from the back yard. While he was greeting me he began coughing and chocking uncontrollably. When I asked what was wrong with him, my friend stated "I don't know he's been doing that ever since I let him inside". I immediately asked my friend if the dog had been outside while it rained or through the night. He responded with I don't know I wasn't here, he probably did get rained on. My friend began to laugh, although I seemed to have missed the joke. When I took my dog home, he continued to cough and chock at one point the chocking had gotten so bad he threw up. I went to sleep and was woken up to the sounds of my dog heaving and gasping for air. I got in touch with my friend and asked what really happened. He stated that his roommate put the dog into the garage, where there is a hole large enough for him to escape out of, which both the roommate and friend claim happened. I asked how long he was missing and the roommate told me only for a few minutes while the friend stated that the dog was gone from the time he was let out of the garage well into the next morning. When I got the dog to the veterinarian I was told that he had kennel cough and that if I hadn't have brought him in there was a very good chance that he would develop phenomena and die. The doctor recommended cough suppressants so that my dog would not be irritated and antibiotics to cure him. When I inquired why the dog was sick in the first place, the doctor asked if he was left outside while it was cold for a long period of time. The doctor added that the dog could have also gotten sick from contact with an infected dog. When I contacted my friend he said that he would help, and since telling him that I had a veterinary bill I haven't heard from him. Can I sue him for the cost of the Vet bill, and win?