Hello and welcome.

It's great that Fernando is healing well!

First, I completely understand dealing with a reactive dog and how much work it takes to get close to 'normal'.  I adopted my newest pup a little over 1.5 years ago.  Callie is a little Pug x Pom who had been abandoned and lived on the street for a few months before she was 1 year old.  Although small her reactivity was MIGHTY!  She reacted to everything that moved... she chased airplanes through my backyard and once lost her mind when she saw a chain-link gate sliding closed! At first we couldn't get within 25 yards of another dog without her triggering and if she triggered I couldn't get her attention with a handful of chicken.  It was year of hard work before we could reliably walk by another dog and it only works if she is 'with me' (my heel command).

My current Tripawd is also a Pug mix who lost her back leg to a car accident when she was 7 months old, Elly is almost 10 years old now.  When I adopted her at 10 months old she had severe fear and anxiety issues, she was fear reactive around other dogs.  To answer your question- yes, Tripawds can do a heel but it is a harder gait for them especially front amps I think.  Even though Elly is small her most comfortable gait is generally faster than I walk so when we are by ourselves I let her go at her own pace.  I did train 'with me' for her which I use whenever we are passing dogs or are in crowded situations like at the vet or in stores. One advantage with Elly being a fearful/anxious dog is that she tended to go behind me to hide, and her inclination was to stay close to me even when she is off leash.  On the other hand Callie is pretty fearless and would charge after things if I let her.  BTW- Elly's reactivity would show after we walked by a dog.  I would relax after we were past but that is when she would decide to lunge and bark at the dog walking away from her.  So I learned to keep her 'with me' until we were well past the dog and she did fine with that.

You are on the right track with rehab.  Fernando will be better able to do a short 'heel' when he is fully recovered from the surgery and stronger.  Core strength, balance and leg strength will help.  We do balance and strength building exercises, train on obedience and tricks, and play food games and puzzles all of which help build strength and balance.  Long walks are not great for Tripawds- our rehab vet suggested 2 or 3 walks a day of 10 to 15 minutes.  That isn't really practical when you are walking two dogs so I have a stroller for Elly, she walks sometimes and rides sometimes. At her age now I give her a day or two a week off from walking but we always do something like exercises or food puzzles to keep her moving and her mind engaged.

A thought on having Fernando 'heel'... it might be useful to have a harness on him with a top handle so you can help take a little weight off and maybe have a bit of control over his pulling.  Elly wears a harness exclusively.  I don't use collars with my small dogs for leash walking (once they have leash manners) and with Elly I have found that having the leash attached to her harness helps keep it way from her feet.

I hope the swelling resolves on it's own. Seromas  are not uncommon with this surgery and the body reabsorbs the fluid. My first Tripawd Maggie didn't have a seroma from her amp but about 6 months before her amp she had a tumor removed from her side and a large seroma developed.  I had doubts but it did finally disappear without intervention.

Karen and the Spirit Pug Girls and Boy