The RSPCA is appealing for information after a dog was dumped at their Potters Bar Animal Centre.
The boxer type dog - nicknamed Teddy by the charity's rescuers - was found tied to a gate on New Year's Eve.
He had several lumps and swellings, including a large one on his side which had ulcerated and needed to be removed by vets.
Teddy was not microchipped and there is no CCTV, so RSPCA officers are now appealing to the local public for help.
"This poor dog, who was clearly in need of veterinary help, was found left alone and tied to a gate near one of our centres," RSPCA inspector Nicole Pendrell-Smith.
"It's heartbreaking to think that while so many of us were getting ready to celebrate the New Year, poor Teddy was left alone. We're just relieved he was found and is now in our care.
"I'm really eager to find out what happened here - so anyone with any information, or who recognises Teddy, is urged to contact our inspectorate appeal line in confidence, on 0300 123 8018.
"Sadly, it's a tough time on the RSPCA frontline right now - which is why we're asking anyone able to do so, to join the rescue and support us this Winter, so we can reach even more animals like Teddy."
The incident comes as the charity reports a dramatic 25 per cent increase in reports of abandonment to its emergency line.
Up to October 2022, RSPCA rescuers dealt with 13,159 incidents of abandonment, up from 10,519 for the same time period the previous year.
The RSPCA fears the cost of living crisis is having a serious impact, with findings from the their Animal Kindness Index suggesting nearly one fifth of owners are worried about how they'll afford to feed their pets.
"We know times are tough right now - but there's never any excuse to abandon an animal in this way," added Nicole.
"There's loads of support out there for animal owners struggling - which is why we've launched a new cost of living hub, highlighting resources which could provide a lifeline at this time."
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here