Chance, a Boxer dog about three years old, was found chained to a fence at the rear of the house in the St Johnston/Carrigans area last week.
Donegal Pet Rescue say they have been overwhelmed by the response from the general public.
Welfare officer Ryan McCauley said: “I thought I would update donegaldaily.com because so many people responded to your story.
“Chance had another visit to the vets this morning and the good news is that he has put on 2kg over the last week.
“Chance is still on another course of tablets to help keep back the infection. But all in all good news so far but there is still a long way to go.”
Mr McCauley said enquiries as to how the emaciated dog had been left behind for more than a month by its owners are ongoing.
“I have also visited Carrigans Garda Station today to see how they are getting on and they are following a number of calls that have come to the station in relation to Chance.
“If anyone has any information in relation to Chance’s background please call Carrigians Garda Station on +353 74 914 0113,” he added.
Our report on the original incident is below: