Are keeping assistance dogs permissible in Islam? I have speech dysfluency and assistance dogs can be kept for emotional support. They can provide reassurance in public situations. I know that its not permissible to keep them just for the reason of it so do the rulings apply in this circumstance?
It is not permissible for a Muslim to keep a dog, unless he needs this dog for hunting, guarding livestock or guarding crops.
As Quran says :
وَ تَحۡسَبُهُمۡ اَيۡقَاظًا وَّهُمۡ رُقُوۡدٌ ۖ وَنُـقَلِّبُهُمۡ ذَاتَ الۡيَمِيۡنِ وَ ذَاتَ الشِّمَالِ ۖ وَكَلۡبُهُمۡ بَاسِطٌ ذِرَاعَيۡهِ بِالۡوَصِيۡدِ ؕ لَوِ اطَّلَعۡتَ عَلَيۡهِمۡ لَوَلَّيۡتَ مِنۡهُمۡ فِرَارًا وَّلَمُلِئۡتَ مِنۡهُمۡ رُعۡبًا (18:18)
On seeing them you would fancy them to be awake though they were asleep; and We caused them to turn their sides to their right and to their left, and their dog sat stretching out its forelegs on the threshold of the Cave. Had you looked upon them you would have certainly fled away from them, their sight filling you with terror.
But this is not to say that we should treat the dogs unfairly (I won't comment on the whole killing the dog issue, because i'm not even sure if it is true or not) because stories are told how a prostitute gained a place in heaven because she gave the thirsty dog a drink. The story gain a place in Islam teachings because the animal was a dog (God knows that it will be an issue) and it shows that all animals should be treated equally with kindness only then will God look kindly to us as well.
As they may be used as guards, so the Quran says :
يَسۡـَٔـــلُوۡنَكَ مَاذَاۤ اُحِلَّ لَهُمۡؕ قُلۡ اُحِلَّ لَـكُمُ الطَّيِّبٰتُ ۙ وَمَا عَلَّمۡتُمۡ مِّنَ الۡجَـوَارِحِ مُكَلِّبِيۡنَ تُعَلِّمُوۡنَهُنَّ مِمَّا عَلَّمَكُمُ اللّٰهُ فَكُلُوۡا مِمَّاۤ اَمۡسَكۡنَ عَلَيۡكُمۡ وَاذۡكُرُوا اسۡمَ اللّٰهِ عَلَيۡهِ وَاتَّقُوا اللّٰهَ ؕ اِنَّ اللّٰهَ سَرِيۡعُ الۡحِسَابِ (5:4)
They ask you what has been made lawful to them. Say: 'All clean things have been made lawful to you, and such hunting animals as you teach, training them to hunt, teaching them the knowledge Allah has given you - you may eat what they catch for you19 - but invoke the name of Allah on it.20 Have fear of Allah (in violating His Law). Allah is swift in His reckoning.'.
Hope this helps.
I am not sure how it affects those with speech dysfluency, but you might need to consult your local scholar or Muslim community on the matter for more context. Because as for dogs, it is quite difficult to clean oneself from its Najasah.