It is not wise to perform immediate surgery on an acutely inflamed abscess that has not "ripened." Puppies under 3 months of age are said to be high anaesthetic risk.

In this 5-month-old Maltese, I gave the puppy an antibiotic and anti-inflammatory injection. After 2 weeks, the abscess had reduced by 50%, now becoming 1cm x 1.5cm. The owners remembered to return for surgical excision of this encapsulated abscess, which I thought was an embedded microchip with infection in the subcutaneous area.

ANAESTHESIA
I used isoflurane gas by mask and intubate. This is the safest method although there is a bit of struggling during the initial stages. The puppy woke up within 1 minute at the termination of the gas, making some noises. No ill effects. What the owner wanted was a live puppy and this was the outcome. 

SURGERY
There are 2 approaches.
1). Excise the whole abscess including the skin. That would leave a big gap. I had done such a procedure before and needed to pull skin from surrounding areas. This resulted in a much bigger stitched area.

2). In this case, the skin was not inflamed and I used scissors to undermine the skin above the encapsulated abscess and took the abscess out intact. However, there were micro-abscesses in the subcutaneous fat. These were excised, resulting in some bleeding. Check carefully for any more abscesses. A neck bandage stopped all bleeding. The puppy went home within 1 hour. No problems.

MICROCHIP. Surprisingly, no microchip was present in the encapsulated abscess. This showed that a vet should not make instant diagnosis. I had told the owner that this could be a microchip abscess with a microchip inside. After removing the abscess, the scanner still revealed the microchip number somewhere in the neck region.