What is the ruling on money received by a veterinarian in exchange for approving the slaughter of female camels, which are forbidden to be slaughtered? Is this money considered a bribe? And is the veterinarian absolved of responsibility if he seeks forgiveness from the slaughterhouse owners?

Earning money through deception and violating work regulations is forbidden (haram). A bribe paid for a forbidden (haram) purpose is not to be returned to the payer after its objective has been fulfilled, because he paid it voluntarily and received its forbidden عوض (counter-value/benefit). This money received is not permissible to consume; rather, it is illicit (khabith). The way to dispose of it and complete one's repentance is by donating it to a public utility or a charitable project.