When I took my sixteen year old dachshund to the vet today, he agreed that the most humane option for him was to help him go easily today. He had weighed just under 10 lbs in August, and today he was only 6.5 pounds. He wasn't able to digest his food, so he was wasting away.
He was nearly blind, but that had happened slowly and he had adjusted to that quite well. However, he started to become senile during the spring and summer, and then, starting in about August, he started to loose weight quickly. In July we were still saying that he would outlive us all because he was still so healthy, but he deteriorated very quickly. The vet theorized that he may have been experiencing renal failure, which was making it impossible for him to digest anything, but he said it could have been from another reason. At any rate, because he was so senile, even if we could have improved the digestive issue, he didn't even know where he was much of the time. It seemed the most humane option to let him go.
I don't think I have any pictures I could share. If I find some, I will post them later.
I like to remember funny things about him. He was - well - "slow". I have had two other dachshunds, and they were both as intelligent as your average dog, but not poor Dudley. Once he walked under the back side of a reclining chair while my son Paul was sitting in the chair with the leg part only half way up. He bumped his head on the half raised section, but couldn't walk under it because it was too low. Instead of turning around, he just kept backing up and then going forward again and hitting his head. He repeated this at least 20 times before Paul realized what was happening and lifted the foot rest the remainder of the way up so he could walk out. In 16 years of life, he never figured out that the dog in the mirror was him. At least he probably wasn't too upset when he became senile because he wouldn't have had much of a mind to loose.
He was, however, a very obedient and sweet dog. Once he realized what you wanted him to do, he never disobeyed.