Sorry for your loss. Saying goodbye is tough but remember, he is waiting for you at the rainbow bridge.
I will tell you, giving Pouter the gift of peace was the greatest gift of love you could have given. I will share with you a letter that was shared with me when I said goodbye to my beloved Maddie. This may make you cry at this point but it also may help you with your grief:
THE LAST WILL AND TESTAMENT OF AN EXTREMELY DISTINGUISHED DOG
I, Chelsea, because of the burden of my illness and realizing the end of my life is near, do hereby bury my Last Will and Testament in the mind of my Master. She will not know it is there until after I am dead. Then, remembering me in her loneliness, she will suddenly know of this testament, and I ask her to inscribe it as a memorial to me.
I have little in the way of material things to leave. Dogs are wiser than men. They do not set great store upon things. They do not waste their days hoarding property. They do not ruin their sleep worrying about how to keep the objects they have not. There is nothing of value I have to bequeath except my love and my faith. These I leave to all those who have loved me, to my Master, Vicky, who I know will mourn me the most, to my companion, Will, but if I should list all those who have loved me, it would force my Master to write a book. Perhaps it is vain of me to boast when I am so near death, which returns all beasts and vanities to dust, but I have always been an extremely exceptional dog.
I ask my Master to remember me always but not to grieve for me too long. In my life I have tried to be a comfort to her in time of sorrow and a reason for added joy in her happiness. It is painful for me to think that even in death I should cause her pain. Let her remember that, while no dog ever had a happier life, I have now grown ill and pained. I should not want my pride to sink to a bewildered humiliation. It is time for me to say "good-bye". It will sorrow me to leave her but not sorrow me to die. Dogs do not fear death as men do. We accept it as part of life, not as something alien and terrible which destroys life. What will come to me after death? I will be in a place where one is always young; where I will someday be joined by companions I have known in life; where I will romp in lovely fields with those that have gone before me; where every hour is mealtime; where in long evenings there are fireplaces with logs forever burning, and one curls oneself up and remembers the old brave days on earth and the love of one's Master.
This is much to expect but peace, at least, is certain, and a long rest for these weakened limbs. And eternal sleep is perhaps, after all, the best.
One last request I earnestly make. I ask her, for love of me to have another. It would be a poor tribute to my memory never to have another Lab. What I would like to feel is that, having once had me, she cannot live without one! I have never had a narrow spirit. I have always held that most dogs are good. Some dogs are better than others--like me--and so I suggest a Black Lab as my successor. She can hardly be as well bred or as mannered or as distinguished and beautiful as I, but my Master must not ask the impossible. She will do her best, I am sure, and even her inevitable defects will help keep my memory green. To her I bequeath my collar and leash. I leave her my place in the car which I loved so much and wish for her long rides with open windows.
One last word of farewell, dear Master. Whenever you think of me, say to yourself with regret but also with happiness in your heart at the remembrance of my happy life with you, "She is the one who loved us and whom we loved." No matter how deep my sleep, I shall hear you, and not all the power of death can keep my spirit from wagging a grateful tail.