Over half a million pounds has been donated by members of the public following the suspected arson at one of the country's largest kennels, in the Harpurhey area of Manchester.
Colin Ballance, the liaison officer for Manchester Dogs' Home, said the scene was "horrendous" with flames up to 20 feet in the air when he arrived on Thursday night.
Mr Ballance managed to rescue two dogs from the building complex before thick black smoke stopped him.
"You could hear them screaming but the thing was, you couldn't do anything," he said.
A 15-year-old boy has been arrested on suspicion of arson following the blaze.
Detective Chief Inspector Neil Jones, from Greater Manchester Police, said the youth from the local area was detained within an hour of the fire being reported just after 7pm.
Residents reported hearing "dogs yelping" as the fire spread through the buildings.
There were reports of people risking their lives by running into the burning building to save animals.
At least 43 dogs were confirmed by police to have died, with "numerous" other animals having to be treated for injuries, the Greater Manchester force said.
Greater Manchester Fire and Rescue Service station commander Paul Duggan confirmed part of the roof of the single-storey kennels collapsed and 30 firefighters battled the flames.
Outrage and shock at the blaze resulted in several fundraising campaigns being launched which have raised hundreds of thousands of pounds for the home.