Dear all,
Thank you, everyone, for the feedback on the anomalous dog femur I posted last week on behalf of Stefan Hartmann. As the feedback was very diverse, I would like to share it with you. I learned a lot myself and - once again - was amazed of the different paths one scientific inquiry can take. As Laszlo wrote me in his reply: "Something looks relatively simple, even straightforward. Then you scratch the surface and immense depths start opening up.". I couldn't agree more, Laszlo.
Possible reasons for the anomalous dog femur fell into three categories.
I hope it is okay for everyone who replied, if I summarize these here for the others to see as well.
1) The femur is from an achondroplastic dog, as the Dachshunds or other short legged breeds (caused by genetic mutation which can occur in many breeds and species). This would also include the suggested chondrodysplasia (fibroblast growth factor fgf4, in other words a "dwarf").
2) Well-healed (but dislocated) diaphyseal fracture (simple oblique / spiral / greenstick fracture), possibly from the time the individual was still a puppy (the curvature-deformity and radiography are consistent with an old healed and remodeled callus), possibly related to de-mineralizing disorder (thinned appearance in the bone cortex), and possibly with the occurrence time of 3-5 months before death (the medullar cavity is not yet rebuilt). The radiograph shows the initial cortical surface of the two bone fragments (diagonal fracture lines), now incorporated in a thick and remodelled callus (especially seen on the 3rd radiograph), with a strong angulation between the two sections of bone. The puppy was lucky as the fracture did stabilize during the healing, although causing the deformation and possibly some limping - but probably without any pain :)
3) rickets (a rather extreme case) / osteomalacia / some other metabolic bone disease - caused by lack of phosphor or vitamin D / chronic renal insufficiency.
Similar finds:
* Dachshund type of dogs have been found from e.g. 17th c. Sweden;
* Some disease related bent bones from middle Egypt
* Healed greenstick fracture causing bent bones in Riga (Latvia)
* Healed fracture with similar bent appearance (on one of the femurs while the other is OK) from Roman time.
Thank you again!
Best wishes,
Eve Rannamäe
University of York, UK / University of Tartu, Estonia
