I Have a 13 Year Old Male Neutered Yellow Lab Mix with No Significant Health Issues Before

I have a 13 year old male neutered yellow lab mix with no significant health issues before about one month ago. All vaccines are up to date and he gets yearly wellness exams. One 08/16/2014, he had an episode of full body trembling (like chills) and seemed to be uncomfortable and "spaced out" for about 15 minutes. After that he returned to normal. The next day on 08/17/2014, he had another trembling episode that lasted longer, maybe 30 minutes. During this episode he got into a fight with one of my other dogs and got a puncture wound on his rear left leg. After the episode and fight he seemed weak. I took him to his usual vet that evening and they ran blood tests and did some x-rays. The only abnormal finding on the x-rays was some pretty significant arthritis in his spine between 3 vertebrae around his hip area. Blood work at that time was all normal except for slightly low RBC, HCT and EOS, and slightly elevated ALKP. The vet thought his trembling episodes were probably related to pain associated with the spinal arthritis. He required four staples for the bite wound. We went home with Metacam and Tramadol for one weekend also antibiotics for a week. We were asked to return in two weeks for staple removal.

Over the next two weeks, he was lethargic and not interested in eating very much. He had no more trembling episodes that we are aware of. I took him back in for staple removal and he had a fever of 103.5. I mentioned he hadn't been eating much so the vet nurse said I should bring him back if his fever did not subside and if his eating didn't improve. In the next 3 days his fever was down at first but then went back up and he began to refuse food altogether. He was still drinking and using the bathroom as usual, but was very lethargic and depressed.

On 09/06/2014, I took him back to the vet. His fever then was up to 104.5. RBC, HCT, and HGB were all much lower than at the previous visit. WBC, NEU, MONO, and PDW were all high and GLU was also slightly elevated. This vet said he was able to palpate a mass in the abdomen that seemed somewhat moveable but hard. He could not tell me it's size or what organ it might be associated with. He recommended 48 hour hospitalization for IV fluids and antibiotics, additional xrays and ultrasound. He said that almost any mass would require surgery. I explained that I did not want to put my dog through any major surgery at his age and that I did not feel he would do well mentally in a hospital away from family. He tends to be a somewhat anxious dog and has never been away from us for more than an hour or two since he was born. The vet said since I did not want surgery, there would probably be little use in the xrays and ultrasound. Since my dog was not eating at all for two days, the vet gave him a 3 mg injection of Buprenex SR for pain and an injection of Convenia (a two week antibiotic) and a subcutaneous fluid injection. I took my dog home with instructions on how to syringe feed him Hills A/D. He suggested I return in two days or sooner if my dog worsened.

During the next two days, my dog was still very lethargic and depressed and had continued weakness in his back legs. I made sure he got fluids every two hours and had a half can of A/D every four hours with probiotics added. He still refused to eat on his own at all. I monitored his fever which returned to normal of 102.5.

When I returned to the vet on 09/08/2014, we did more bloodwork to check his anemia. RBC/HCT/HGB were all lower than at the visit two days prior. WBC count was higher. NEU/LYM/MONO and PCT were all still elevated. This vet was unable to palpate the mass but admitted she was probably not as good at that as the other vet because he has been practicing since before they utilized xrays or ultrasound much. She did just a basic ultrasound to check for fluid in the abdomen. She said there definitely is fluid present. She suspects that to be blood since he has no injury and no blood showing in his urine or feces and he continues to become more anemic. She said he best guess is that he has a tumor of some sort that was/is bleeding and it is most likely on his spleen. She said surgery would be the only option and even if that worked it would only give him a little bit more time because that kind of tumor typically is aggressive and returns quickly. She said my options are surgery, euthanasia, or palliative care. She also said she believed that my dog is uncomfortable and there is no way of knowing how long he has. She said eventually he will bleed to death. I came home last night with Metacam for pain and more A/D to continue syringe feeding. Based on what the vet said, I felt fairly sure I would just bring him home to say his goodbyes to the rest of the pack and the family and I would take him in tonight for euthanasia. But we woke up this morning and he is much more alert, drinking well, urinating and defecating normally, and he seems a little stronger and less depressed. He still tires quickly when walks. He has even accepted a small amount of food this morning without me forcing it. So my questions are:

Based on the information given here do you agree with my vet’s educated guess that my dog probably has a bleeding tumor and nothing short of surgery is likely to help? Is there any other problem that might cause the anemia to progress this quickly? I do not want my dog to suffer but I also don’t want to euthanize prematurely. I worry he might hemorrhage and have a very painful death if I do not euthanize, but I want to feel a little more confident that we are not possibly overlooking a more benign cause of his problems that could be treated mostly non-invasively. The exact blood results for each visit follow. What are your thoughts?