Little ones don't always get big...

[kibakiba]

He's probably fully grown by now.

[d_virginiana]

That's sad, but it's amazing that you kept her alive for that long.

I've never heard about it in reptiles, but there are certain genetic problems with senescence markers in other species that can cause accelerated ageing and severely stunted growth, but the proportions are normal unlike in dwarfism. This just reminded me of that...

[ConcinusMan]

I've had badly inbred T. radixes do the same thing. Flat refuse to grow, die at around 2 years old. This is just probably one of those unfortunate side effects of severe inbreeding depresson.

[Thamnophis]

I've had badly inbred T. radixes do the same thing. Flat refuse to grow, die at around 2 years old. This is just probably one of those unfortunate side effects of severe inbreeding depresson.

That is what I think too. This was the only one of a litter of 40 young. There were a few that died in the first months. Most of them did well. And still do as far as I know. I keep in touch with some of the people who buy my young. Have not got many complains yet...
Inbreeding coul be an obvious reason...

[Invisible Snake]

I've had badly inbred T. radixes do the same thing. Flat refuse to grow, die at around 2 years old. This is just probably one of those unfortunate side effects of severe inbreeding depresson.

Hey could you please elaborate on what is "severe inbreeding depression". Thanks.

[BUSHSNAKE]

genetic diversity produces the strongest offspring....inbreeding is the opposite of that

[Invisible Snake]

Inbreeding is when members of the same family mate and produce offspring, does this also apply to cousins?

[Thamnophis]

In cousins the chance of inbreeding is smaller than with brothers and sisters, fathers and daughters, mothers and sons.
In case of T. s. tetrataenia you have to assume that all specimen that are kept in Europe are at least cousins.

[ConcinusMan]

Hey could you please elaborate on what is "severe inbreeding depression". Thanks.

inbreeding depression - Google Scholar

"Deleterious mutations probably play a major role in causing inbreeding depression"

When you inbreed to select for something like amelanism for several generations you not only select for the mutated gene you want, but also for other detrimental things such as dwarfism or protein sythesis or growth deficiencies. In the case of the SF garters, the inbreeding depression ("bad genes" and inferior snakes) is a result of just not having any unrelated snakes to breed to one another.