[SIZE=12pt]The little girl in my avatar was 16" tall and 16 pounds when she had surgery to repair her broken leg and dislocated hip at 3 1/2 days old. She was a little sweetie - of course, she is all of maybe 29" now.[/SIZE]
Here's a picture of her 48 hours post op.
Now tomorrow with the blessing of her surgeons she goes to be bred - talk about a nervous mom, that's me.
Our smallest so far (and hopefully we never have one smaller in the future) was Mira who was born last April. She came out at about 293 days (can't remember for sure off the top of my head). Below is a pic of her in the hospital at about 4 days of age. For reference, her dam pictured next to her is a 29" mare. Unfortunately we didn't weigh or measure her when she was born, we were too consumed with keeping her alive!
But at day 4 or 5 she was 11lbs and approx 14.5" tall.
Her cannon bone to coronary band measurement was 5.25". At Nationals last year she was the smallest horse to be measured. The measuring stick went as low as 24" and the steward estimated she was about 22" tall. She took a top ten in the Weanling Mare class (10th in a class of 23). Needless to say we were very proud!
Today, at one year of age she is about 25" tall (maybe on a tall day!) and she's not big enough to even spit at! OH! But we LOVE her!
BTW, this is the filly that I am CONVINCED would not even be alive if it weren't for Charlotte and all her guidance during the difficult pregnancy!
We have had quite a few that were in the 14"-16" range at birth and generally have matured between 25.5" and 28". I looking through my files I didn't find many of the foal pictures, but here are a few.
Little America's Starlet by Rolex, around 16" at birth and now, as a two year old, 26" and doesn't look like she is going to get any bigger.
Little America's W T Samara was around 15" (I don't measure all the foals) and is 25.75" as a four year old.