Shiva Purana
दर्शनं च श्वनीचानां वर्जयेज्जपकर्मणि ॥ आचमेत्संभवे तेषां स्मरेद्वा मां त्वया सह ॥ ५० ॥
One should avoid seeing lowly dogs while chanting the mantra. Whenever possible, one should perform ablutions for them or remember Me with you.
english translation
darzanaM ca zvanIcAnAM varjayejjapakarmaNi ॥ AcametsaMbhave teSAM smaredvA mAM tvayA saha ॥ 50 ॥
hk transliteration by Sanscript