Residents have taken to the dangerous waters to rescue trapped neighbours while others have cried for help from the rooftops of their flooded homes.
Yaryna Vintoniuk, a representative from Animal Rescue Kharkiv, told The National of teams battling to save animals from freezing to death.
Teams have been trawling through toxic water on motor boats since 6am on Wednesday to reach trapped animals traumatised by what Ms Vintoniuk described as “a terrible act of hatred and inhumanity.”
“Now our main task is to save those who can still be saved. Since the animals are hypothermic and cannot save themselves, we must act quickly, and in these conditions, it is quite difficult.”
“We can only guess how many deaths this calamity has caused.”
Cats and dogs were left clinging to trees as floodwaters rose.
Locals have been filmed pulling terrified dogs out of submerged buildings.
Video footage shared with The National showed dogs cowering on collapsed roofs and submerged in filthy water as they waited to be rescued.
In another video, a woman evacuated by rescue teams begged to return home to save her cat.
Rescue teams and vets from across Ukraine have travelled to the region to join locals in saving animals, including deer and livestock.
The Kharkiv shelter, which has been rescuing animals for 10 years, saw their work increase “tenfold” after the Russian invasion. Their staff have since rescued more than 10,000 animals, often evacuating them from the front lines.
“We will do it as long as necessary,” said Ms Vintoniuk.
At least three people were killed in the Nova Kakhovka region, where Moscow-backed officials have imposed a state of emergency.
More than 4,000 people have been evacuated from riverside areas controlled by both Russia and Ukraine.
14,000 homes have been flooded, according to Russia's TASS state news agency.
All animals at the Nova Kakhovka Zoo were killed in the flooding, local officials confirmed.
Ukraine, which has blamed Moscow for the disaster, had previously warned of a Russian attack on the dam, controlled by Moscow, to trigger severe flooding in the area. Experts say the incident may complicate a Ukrainian counteroffensive and play to Russia's advantage as its war gains stall.
Several Ukrainian officials have blasted the tragedy as “ecocide” and experts have said the disaster will “wipe out entire communities.”
With water levels starting to recede, the full extent of the damage is not yet known.
Anton Gerashchenko, an adviser to Ukraine's interior minister, said 70 endangered animal species are at further risk from the flooding, and thousands of fish will die.
Ukrainian President Volodymyr Zelenskyy said hundreds of thousands of people have been left without clean drinking water, and animal rights groups claimed volunteers have been turned away from many areas of Kherson due to biohazards in the water.
“The water is polluted with chemicals, oil, fertiliser, pesticides and all kinds of toxic things,” said Animal Rescue Ukraine.
Kateryna, a member of the rescue group UAnimals said the situation on the ground is “chaotic.”
“It's difficult to determine exactly where evacuations can be conducted as not all areas are accessible,” she said in a video posted to Twitter as the team travelled by boat through flooded streets, searching for animals to rescue. “Perhaps we will find animals in need of help.”