Keeping a dog for a valid purpose — guarding, farming, or hunting — is permitted, while keeping one purely as an indoor pet is discouraged in the Sunnah. Their saliva requires a specific washing, and this is an area where practical scholarly guidance helps.
Evidence — the daleel
Sahih al-Bukhari 2322 ṢaḥīḥSahih Muslim 279 Ṣaḥīḥ
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.