The tourist attraction, which is one of the most popular zoos in England, is said to cost more than £25,000 per day to run - and is struggling to 'survive' as it remains shut to the public.
'The future is bleak'
"As we are in the unknown of how long we will be closed, it is very painful to say but the future is very bleak," a spokesperson for the zoo told Essex Live.
"It is heartbreaking to say but the realistic answer is that yes, there is every possibility that the zoo may be forced to permanently close if we cannot reach the finances that we will need if we are to be closed until September or even later.
"The management and staff here are part of the effort to first survive until we can re-open, then stabilize, the next stage will be to then prosper and continue the very ambitious plan to keep Colchester Zoo at the very top, where we always strive towards."
Colchester zoo has not commented what will happen to the animals living in captivity if it does permanently shut.
'Don't go to any zoos'
Many people have compared self-isolating to animals being kept in captivity, including Formula One champion Lewis Hamilton.
"If you are home on lockdown, perhaps you can feel a little of what the animals in captivity go through every day, their entires lives stopped from them," the star said on Instagram.
"In the future, please don't go to any zoos or circuses because this is what our money goes to supporting #NoMoreZoos #Freedom."