Machete-wielding thieves snatched seven puppies and slashed their mum in the face when she tried to stop them.
There are fears the newborns may not survive without their mother.
They were taken after two men armed with machetes followed a man into a flat in Harpurhey, north Manchester, at roughly 9.30am on Saturday.
The two began attacking their victim leaving him on the floor with defensive wounds to his forearms and hands, before searching the property, looking for any valuables to steal.
After snatching cash, keys and a phone, they came across a litter of five-week-old Staffordshire cross puppies and their mother, Zena.
They shoved the puppies in carrier bags and when Zena tried to defend her pups, she was hit on the head with a machete by one of the men, causing a deep laceration.
The offenders then fled the scene.
Detective Constable Nick Kershaw, of Greater Manchester Police, said: "We are urgently appealing for information which will help us locate the puppies which were stolen this morning.
"The dogs are only five-weeks-old and without their mother, they likely won't survive very long so it is important that anybody with information that can assist, please contact police as a matter of urgency.
"This was an incredibly callous robbery, where the offenders showed absolutely no regard for the safety of anyone, human or animal, who was present at the time. They only had one thing on their mind, which was to take whatever they could.
"Please help us return these puppies and reunite them with their very sad mother, Zena, who has been left devastated."
Both suspects are described as black, skinny build, believed to be in their 20s and were wearing dark clothing with the hoods up.
One of the men is believed to be around 6ft 3in to 6ft 4in and was wearing a grey and black camouflage face covering.
His accomplice was slightly shorter and wearing a plain black face covering.
