Following are a number of back-translations as well as a sample translation for translators of Proverbs 25:19:

• Kupsabiny: “When a matter becomes difficult and one relies on an untrustworthy person, it is like when a person tries to chew with a loose tooth or limp on a paralyzed leg.” (Source: Kupsabiny Back Translation)
• Newari: “The friend who is not available [to help] in time of trouble,
  is like an infected [Lit.: bitten by an insect] or aching tooth,
  and like a lame foot.” (Source: Newari Back Translation)
• Hiligaynon: “Trusting a man who can- not -be-trusted in times of difficulty has no value like a bad/[lit. ruin] tooth or a broken/fractured foot.” (Source: Hiligaynon Back Translation)
• Kankanaey: “If your (sing.) friend is not trustworthy in the time of hardship, you (sing.) are as if a-lame-person to walk or one whose teeth hurt to chew.” (Source: Kankanaey Back Translation)
• English: “Depending on unreliable people when you have troubles
  is as bad as trying to eat when you have a bad/hurting tooth or trying to walk when your foot is crippled.” (Source: Translation for Translators)