What is the ruling about selling dogs?
Are there different rules depending on the type of dog or the purpose for which the dog is intended?
Narrated Abu Mas`ud:
The Prophet prohibited taking the price of a dog, the earnings of a soothsayer and the money earned by prostitution.
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ أَبِي بَكْرِ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِي مَسْعُودٍ ـ رضى الله عنه ـ قَالَ نَهَى النَّبِيُّ صلى الله عليه وسلم عَنْ ثَمَنِ الْكَلْبِ، وَحُلْوَانِ الْكَاهِنِ، وَمَهْرِ الْبَغِيِّ.
From the above Hadith, as well as many other Authentic Ahadeeth, it is haram to sell a dog, whatever kind it is (even those dogs which are halal to have, like a hunting or farm dog). So in short conclusion, no there is no different rulings depending on the type of dog.
For more information, see this(Arabic).
It is permitted by the Hanafis to buy and sell dogs for a lawful purpose, e.g., hunting. Otherwise it is not. All other schools of thought however prohibit such buying and selling. All however allow a price to be given for relinquishing control of a dog - which differs from a sale in that the one relinquishing control does not carry the usual responsibilities associated with a sale such as quality, fitness for purpose, delivery etc.
Jabir Ibn Abduallah said the Messenger of Allah (saw) prohibited receiving payment for selling dogs except for those kept for hunting (Nisa'i)
There's more details here: https://www.islamiqate.com/3985/is-it-permitted-to-buy-and-sell-dogs-in-islam