In a nutshell, how would you describe the 4 types of dwarfs as outlined by John Eberth?

I'm not sure anything about dwarfism in the Miniature Horse can fit into a "nutshell"!
To me John's discription of Type 1 is a bit confusing, as he writes:The carriers
of type 1 and sometimes
4 show subtle features of a type 1 dwarf, i.e. extremely domed forehead, large prominant eyes, very exoctic head over all. That being said however, it is NOT 100% true. In the carriers of type 1 and 4, height is extememely variable, bone structure and thickness extremely variable, length of neck extremely variable." John says," type 1 is the type of dwarf we see most often."

So if I am understanding this right, perhaps my Tessa would be a type 1 dwarf, as she is taller than most dwarves, her neck is longer than a lot of dwarves, but she does not have an extremely domed forehead Tessa's, dwarf characteristics are not nearly as severe as Little Bit's was. Here is a picture of Tessa at age 10 years old.

She was 12 in this picture and is about 28 inches tall.
She was 2 years old in this pic

A close up of her head, her bite is not off very much at all

Perhaps Inky and Smidgen are also type 1 dwarves, as they remind me a lot of Tessa, except that they are MUCH shorter.
Smidgen at age 3 and 23 inches tall
Inky at age 4 and 24 inches tall

John writes:
The type 2 dwarf is the type that looks like it has a normal body, neck and a large plain or straight head, the dwarf just looks like it had it's legs cut in half, in reality, the upper leg bones are severely shortened(forearms & gaskins), hips miss-shaped, and a large head.

The Type 2 dwarf is what we have referred to, for many years, as an "Achondroplasia" type dwarf.

My Toy is this type of dwarf.
Toy was 12 hours old.
Toy at about a year old

Toy at 3 years old and
about 26 inches tall
Toy's bite at 2 years of age

Now at age 3 years, she does have a slight underbite.

Other things I have seen in the type 2 dwarf, is that they all have VERY cow-hocked back legs, tiny ears (in comparrison to their head), and their bites are not off by much and sometimes right on and many times they have contracted tendons in their front legs, and many times it is just their right front leg, like you see with my Toy. I also believe that their bodies are MUCH longer than a horse with correct conformation.

John writes this about the type 3 dwarf:
It is the most severe type that is viable, they are extremely small usually, have severe spine (roach back) and leg deformities, usually severely shortened neck and severely deformed head with and off bite. This type is possibly a combination of types, i.e. inheritance of two recessive dwarf genes due to the fact that the bodies are so severely deformed and variable it has been difficult to find a consistant deformed type.

This Type 3 dwarf is what we have referred to for years, as a "Brachycephalic" type dwarf.

I believe that my Little Bit was a Type 3 dwarf, and so is my Strawberry Delight.
Little Bit at 2 weeks of age

Little Bit at 8 months old

Little Bit at 2 years of age, he was 20 inches tall at age 3 when he passed away. I have seen many dwarves of this type that also, could not put their tounges all the way back into their mouth. They almost always have tendon laxity in at least one leg and it's usually in all 4 legs at birth. These horses must have their legs braced or wear corrective glue on shoes, like my *Little Bit's *Magic Shoes*, in order for them to stand up on their hooves correctly. The bracing should only be temporary until some corrective shoes can be applied to their hooves, as the bracing will keep the horse from stretching those tendons even more, but it also keeps the horse's legs from getting strong enough to hold up their weight. The shoes allow this to happen. Many times this type of dwarf has respiratory problems, heart problems and digestive problems, as well. This type of dwarf almost always has a very bad bite, either an over bite or under bite, but most always an under bite
I believe the life expentency of this type of dwarf is MUCH shorter than the 1 or 2 types.

Strawberry's head as a 5 year old

Strawberry at age 5 and 25-26 inches tall

John writes this about Type 4 dwarf:

Growth--extrememly small stature
Craniofacial--Cranium large for gestation age, low nasal bridge, micromelia
Limbs--severe lmicromelia
Bones poorly ossified for gestation stage, ribs extremely short and thin
Lethal recessive
Mutation is in gene for diastrophic dysplasia which codes for a sulfate transporter DTDST

Type 4 dwarf does not go to term

This is a picture that I took from John's power point presentation and scanned into my computer, sorry the quality is not that good.

My equine dentist, Carl Mitz, was telling me that John Eberth was thinking that this type of dwarf was new on the scene, but Carl said that he has seen this type of dwarf MANY years ago, so it is not something new, in his opinion.

As far as "minimal dwarves" go, I agree with John, there is no such thing as a "minimal" dwarf....a particular horse may have a lesser degree of dwarfism than some, but that does not make it any less of a dwarf. So some folks like to refere to these dwarves with a lesser degree of dwarfism, as "minimally expressed" dwarves, in other words their dwarfism is not esxpressed as much as other dwarves.

I think there can be a very fine line between a minimally expressed dwarf and a "normal" Miniature Horse that just has bad or incorrect conformation, but in any case, neither one of these horses should ever be used for breeding. Many of the conformation faults that you see in a horse, such as an off bite, crooked legs, cow-hocked back legs, longer body, etc are all hereditary and we DO NOT want to pass these faults on to the next generation!

Here is a picture of my Dusty at a baby
This is Dusty at age 8 and 28 inches tall with his winter coat on

Dusty at age 9

I have had folks ask why do you call him a minimally expressed dwarf instead of a Miniature Horse with a lot of conformation faults? Well, one reason is that the vets up at TAMU, who did surgery on his front legs as a baby, told his owner they thought that he was a dwarf, and secondly, this little guy just has TOO MANY faults added up, to be just a little horse with bad conformation, IMO.

To read more of Janell Jensen's article please got to page 7.