Hi, I,m new on here, one of my ewes had a lump like this 2 weeks ago - as she is a pet, I called vet out. She had antibiotic injections for 5 days, abcess burst on third day and has now healed. One of my wethers had CLA about 3 years ago - again as he is a pet I was able to poultice and bandage it to stop infecting the others. After about 4 months it burst and released a huge hard tennis ball sized lump and he has been fine since.