Here are two questions for you:

What are the early symptoms of laminitis?

How would you differentiate these from an abscess?

Here are some points that may help you identify if your horse or pony could be suffering from early laminitis:

Obvious acute sign: Rocking back and forth, reluctant to put weight on front feet

Insidious signs: heat and increased digital pulse in both front or all four feet (but can be also weak pulse)

flat sole (can be genetic so know what your horse’s foot is normally like)

horse walking on ‘hot coals’, unwilling/unable to walk

laminitic rings (sign of previous laminitic events)

depression of coronary band (indicates rotation of pedal bone in progress).

Body condition (fat horse)

If a mare… has she just given birth and did she birth the whole of the placenta?

Look at the whole symptom picture, plus an abscess usually is limited to one foot, lame on one foot only.
Here are some very informative videos available from World Horse Welfare