RSPCA officials are appealing for information after an elderly dog was dumped outside an animal charity in Huyton.
The male beagle has an 8cm diameter tumour near his rear end which had burst and was oozing.
There was no note with the dog and he is not microchipped.
He was found tied up outside by Dogs Trust centre staff on November 1 at around 10am. He was wearing a brown leather collar and some of his fur is greying.
RSPCA inspector Louise Showering said: “Despite his obvious discomfort he is a lovely natured dog and very affectionate.
“He was giving us big licks when we arrived to help him.
“We would really like to speak to anyone who recognises this dog as he is very distinctive and to try to find out how he ended up here.”
Anyone with information can ring the RSPCA appeal line on 0300 123 8018.