On a morning in February, animal shelter staff were getting changed for their shift when a Russian drone slammed into the centre of their compound in the frontline Ukrainian city of Zaporizhzhia.

The steel door at the entrance probably saved their lives. More than a dozen animals sheltering at "Give a Paw, Friend" were not so lucky.

"It was terrifying, to put it mildly," says the group's head Iryna Didur.

Residents rushed to help clean up the rubble and catch the animals that had escaped in terror. The local energy company - itself the target of relentless Russian attacks - installed a new steel door.

"We've got very good people here in Zaporizhzhia. A lot of them have been visiting us to help, and we cleared almost all the rubble in three days," Didur tells the BBC.

Hers is one of numerous groups catering to animals in need of food, veterinary care and shelter - or helping to evacuate the pets to safer areas.

Others also neuter stray cats and dogs to stop their populations from growing.

Countless pets were abandoned in Ukraine when their owners fled areas near the front line as they came under Russian bombardment.

Other pets are struggling to survive because their owners have been killed.

It was the sight of abandoned and homeless dogs that moved Lala Tarapakina to get involved in the pet evacuations.

"That was the first time I witnessed the catastrophe affecting animals," said the head of the 12 Guardians charity, "they were walking along a road, and they obviously used to be family pets. It was awful."

Her organisation has since rescued more than 40,000 animals, often from extremely dangerous areas, she tells the BBC.

"Many people were forced to flee under shelling, losing friends, relatives and limbs along the way. They left lots of animals behind, and we evacuated them under artillery shelling," she says.

Evacuated animals are either placed in shelters or with adoptive families - or they are reunited with their owners.

These evacuations also help save the lives of pet owners who are either unwilling or unable to travel with pets.

Alla was the last resident to leave her village in Donetsk region because of the cats and dogs she was looking after. "I love them all! How could I abandon them? I probably wouldn't survive, my heart would just break," she told Ukrainian TV.

And it is not just pet owners who find it difficult to leave. A special police unit helped one farmer under bombardment in the northern region of Sumy to leave with his 11 goats.

Many Ukrainians have stayed near the front line because travel with animals is more complicated and expensive, and finding rented accommodation that allows pets in safer parts of Ukraine is not easy.

Travelling with animals abroad is even more difficult because they need paperwork, for instance showing that they have been inoculated against rabies.

Helping animals in wartime is also extremely risky, says Nate Mook, whose Hachiko Foundation provides veterinary treatment and pet food and has 150 feeding stations for homeless animals along the front line.

"We've had to arm our teams with drone detectors now. We're driving along highways with [anti-drone] netting," he explains.

"We've had to relocate in certain areas because it became too dangerous, and unfortunately, some of the areas where we began our work in 2022 are now no-go zones."

There are so many stray animals on the front lines that Ukrainian soldiers joke that cats and dogs have become standard issue.

For more than two years, the driver of a drone unit outside Kupyansk has been accompanied by a maltipoo dog, and the 831st Myrhorod tactical aviation brigade has a ginger cat that comes out whenever there is an air raid.

"He just sits near an air defence artillery gun, silent and motionless, as if he's also on duty," the brigade says.

But why do people choose to help animals at a time of immense human suffering, risking their lives in the process?

"Saving one animal is the same as saving several people because it gives them hope," says Lala Tarapakina. "By rescuing one dog, you make an average of about 10 people happy. That's good maths, isn't it?"

Before getting involved in animal rescue, Nate Mook ran World Central Kitchen, which feeds people affected by crises across the globe.

"Dogs and cats have no choice about what's happening around them, and there's this sense that they are really powerless. They are equally traumatised and shell-shocked, and the same thing that humans go through, the animals also go through," he says.

It is not a case of helping one or the other, and animals do not start wars, he adds.