Many of the mummies have disintegrated or been destroyed by grave robbers and industrialists, who likely used the mummies for fertilizer. Archaeologists have found enough evidence to suggest that the Anubis cult was a large part of the ancient Egyptian economy.
In 1897, French archaeologist Jacques de Morgan published a paper on the necropolis at Memphis, and metioned the canine catacombs. de Morgan drew a map showing two dog catacombs, but drifting sand and an earthquake in 1992 have made the smaller of the two inaccessible.
The catacombs were likely built in the fourth century B.C. and were made out of common stone for that time period. The catacomb, which measures 568 feet (173 meters) down the center passageway, with a maximum width of 459 feet (140 m) from the branch corridors. In addition to dog mummies, they found the mummies of jackals, foxes, falcons, cats and mongoose, although about 92 percent of the remains belonged to dogs.
Those that were found were wrapped in bandages and mummified, including with a resin applied.
The huge number of dog mummies suggests the existence of ancient Egyptian 'puppy mills'. The catacombs are believed to date from between 750 to 30 B.C.
Speculation suggests that the young pups were separated from their mothers and died from dehydration or starvation as there was no evidence of broken necks as seen in many animal offerings. The important thing was to provide a representation of the god with a fitting burial. It was a religious act that was done for the best motive.