A dog biscuit, also going by names such as a dog treat, is most often described as a hard, biscuit-based, sometimes dietary supplement for dogs or other canines, marketed to be “A similar version of the snacks humans often enjoy.”

Dog biscuits tend to be hard and dry, While they do often differ in toughness depending on the specific brands advised use, they are generally distinguished by the flat bone like shape.

When prescribed by a vet the common use is often to be for the animals Oral health, the dry and hard biscuit texture helping to clean the dog's teeth. Sometimes seen as the dog equivalent of “Brushing their teeth.”

Another item of consideration is the therapeutic benefits for the dog, fulfilling their ancestral instincts of hunting - while causing no danger, chewing is a highly relaxing activity, clearly shown to lessen anxiety.

"Dog's bread", made from bran, has been mentioned since at least Roman times. It was already criticized (as in later centuries) as particularly bad bread; Juvenal refers to dog's bread as "filth" - "And bit into the filth of a dog's bread" Et farris sordes mordere Canini.

In Spain, "pan de perro" is mentioned as early as 1623 in a play by Lope de Vega. It is used here in the sense of giving someone blows; to "give dog's bread" to someone could mean anything from mistreating them to killing them. The latter meaning refers to a special bread (also called zarazas) made with ground glass, poison and needles and intended to kill dogs.

The bread meant as food for dogs was also called parruna and was made from bran. This was very likely what was referred to in associating the bread with (non-fatal) mistreatment.

In France, Charles Estienne wrote in 1598: "Take no notice of bran bread,... it is better to leave it for the hunting, or shepherd, or watch dogs." By the nineteenth century, "pain de chien" had become a way of referring to very bad bread: "It is awful, general, they give us dog's bread!"