The 40-acre zoo has been closed since March 23 and is currently losing around £100,000 a week.
Now it is hoping to follow in the footsteps of Chester Zoo, which managed to raise £2 million in just 72 hours following an appeal.
The Castle Hill attraction is said to be reaching crisis point, as there is no reopening date in sight.
Derek Grove, the director of Dudley Zoo and Castle, said it's an “incredibly frustrating situation for the entire zoological industry”.
Earlier in the lockdown the zoo revealed it was losing £50,000 a week but these loses have doubled as the attraction is busier in the summer months.
Money is also set aside to help the attraction through the winter, Mr Groves said.
A Just Giving page, set up by the attraction, has so far raised more than £20,000 – but more money is still needed to secure the future of the zoo and it is now looking to widen the appeal.
Meanwhile, Wild Zoological Park, based at Halfpenny Green, near Wolverhampton, says it is “scraping through by the skin of our teeth with fundraising”.
Its fundraising page has so far raised £13,000.
They are among a host of wildlife parks across the country who have issued rally calls to their supporters to help them survive. Chester Zoo, one of the UK’s largest, said it has been left “at risk of extinction”.
Mr Grove said: “It is an incredibly frustrating situation for the entire zoological industry.
"We are losing around £100,000 a week and are now having to dip into our redevelopment reserves.
“We have got all the correct social distancing procedures in place so we are ready to reopen once we get the green light.”
In a bid to highlight the plight of zoos and wildlife parks, the British and Irish Association of Zoos and Aquariums has secured a UK parliamentary debate for Thursday.
Its senior manager Dr Cerian Tatchley said: “It is vital as many people as possible show their support for zoos at this time of crisis.
"We know millions would normally be enjoying a visit to our members, but as the Government has forced our zoos to close their incomes have dropped to zero.”
Dudley North MP Marco Longhi said he was hoping to speak during the debate.
He said: “I am lobbying at the highest levels in Government to have Dudley Zoo reopened safely with social distancing measures in place.
“I cannot justify how it is fine for people to queue for ages and then to walk around a large shop not be able to visit and walk around our zoo – which is a safer outdoor activity.”