Is the prayer of someone who owned a dog before converting to Islam accepted, even if they were aware of its impermissibility?

Islam is submission to God and obedience to His law. The love of God and His messengers is the foundation of faith, as stated by the Almighty: (Say, [O Muhammad], "If you should love Allah, then follow me, [so] Allah will love you"). Whoever truly loves God will prioritize His obedience over their personal desires and seek His pleasure in all things. For such a person, opposing their own self and spending their wealth in the way of God becomes easy. Keeping a dog without a valid, recognized benefit is prohibited and diminishes a Muslim's reward by a qirat every day, as mentioned in the hadith (definition): (Whoever keeps a dog, his reward will be decreased by a qirat every day, except for a dog for farming or a dog for herding livestock). The duration for which the dog has been kept is not a justification for retaining it. However, if the previous duration was before you knew of the prohibition, then there is no blame upon you.