Al-hamdu lillaah. (All praise be to God Almighty, Allaah.)
To the dear noble inquirer:
You have reached the doorstep of entering into Islam and are hesitant due to concern over what you may face vis-à-vis the response of fellow Muslims regarding the dog you use to guide you to the masjid or Islamic center. Let me assure you that the matter is simple and much easier to deal with than you may think.
You are a man for whom Allaah has ordained blindness as a trial, and there is little or no practical recourse for your daily movement, coming and going, other than a trained guide dog. Whereas keeping a dog without due need is censured and objectionable according to Islamic shari’ah (due to its filth and uncleanness), in your case keeping a dog is clearly for an urgent need and not out of custom, tradition, or love for owning the dog itself. So perhaps you have a valid excuse regarding this issue, Allaah willing.
I can’t imagine that you would require to enter the mosque or Islamic center with the dog; rather, you most likely would leave him outside and enter for worship, attending a religious gathering, or to learn and ask about matters concerning your religion. As long as the case is as such, the issue is solved and the matter is settled. If you leave the dog at a distance from the entrance to the mosque, then whoever among the Muslim does not welcome you warmly would clearly be committing a mistake. You could also contact the director of the Islamic center or whoever fills such a position, in order to explain to him your situation. I would expect him to assume the responsibility for informing those who administer as well as attend the mosque. If you like, feel free to take this response as a letter to him and ask him to peruse it, and I am confident you will find only goodwill and cordiality, Allaah willing.
In closing I would like to welcome you to the religion of Islam and send you a warm salutation and an extraordinary congratulations on your desire to accept the religion. I urge you to hasten in taking the greatest step of your life since your mother gave birth to you, and would like to leave you with glad tidings regarding the disability with which you are afflicted. In fact, you will receive a great reward for your blindness if you accept Islam, as per the saying of our Prophet Muhammad (peace be upon him) [translation of the meaning]:
"Verily Allaah has said, ‘If I afflict one of My worshippers with a trial regarding his two dearest ones (i.e., his eyes) and he is patient and perseveres, I will compensate him for them Heaven.’ " (Hadeeth al-Bukhari, Fath ul-Baari #5653)
We ask Allaah to open your heart to the truth and to assist you in holding fast to it, and Allaah is the One Who Guides to the true path of righteousness.