Fifth Lumbar Vertebra in Arabian and Barb horses

By Yassine Jamali

Posted on July 14th, 2017 in General

So much has been said about the five lumbar vertebra of the Arabian horse. Many authors still mention it up till now. But History and science reject this assumption.
This feature was described by Auguste Rochau, then by his pupil André Sanson. Both of them were French veterinarians in the second half of the nineteenth centuryThis is a summarized translation of what Sanson said on the topic :
— The aryan horse, with a straight frontal bone and rectilinear nose bones and six lumbar vertebra is from Asia.
— The mongolic horse, with a convex profile and nose bones and five lumbar vertebra is from Africa.
 Here under is the translated text of Sanson ( extract from Denis Bogros’s book)
[Both brachycephalic, one has a flat frontal bone, rectilinear nose bones and six lumbar vertebra in the spinal column, with seven cervical , eighteen dorsal and five sacral. The other has a convex or rounded frontal bone, slightly curved nose bones, and only five lumbar vertebra, and seven cervical vertebra, eighteen dorsal, and five sacral;  and this one’s lumbar vertebra are not only different from the others by their inferior number, but they differ also by their transverse apophyses’s shape and by their disposition in the series.

The two oriental types seem to have different geographic origins, as they are obviously from different stocks.

The oriental type with six lumbar vertebraes would belong, in the hypothesis, to the Asian continent; while the five lumbar vertebraes type belongs to the African continent, as other types from the same genus yet admitted by naturalists as distinct species, and known for having only five sacral vertebraes, like donkeys and zebraes in general. Two american teachers  William E. Jones et Ralph Bogart, in their book Genetics of the Horse,1971, showed this board, from a 1962 study by R. M. Stetcher :
Thoracic vertebraes  Lumbar vertebraes 
Observed animals Nb 17    18    18 ‘/2 19 5    5 ‘/2  6    7
Common horse 55 4 50 1 0 6 1 48 0
Shetland Pony 7 0 7 0 0 0 0 7 0
Arabian horse 7 4 3 0 0 1 0 6 0
Przewalski 32 0 23 0 9 16 0 16 0
Donkey 11 1 10 0 0 9 0 2 0
Mule 6  2 4 0 0 1 0 5 0
Hemionus  9 0 8 0 1 9 0 0 0
Zebra 49 7 41 0 1  5 0 44 0

Grévy Zebra
14 0 14 0 0 1 0 12 1

End of the extract ]

This board shows clearly that most of the Arabian horses have a normal number of lumbar vertebraes, i.e six, as every breed of horse.
The number of thoracic vertebraes is equal to the number of ribs. In his book published in 1834, Karl Wilhelm Ammon reported an Arabian adage, where the Arabs were praising horses with an additional rib, which means an additional thoracic vertebra. That seems logical because it gives more volume to lungs. Only 9 Przewalski horses out of 32, had 19 ribs instead of 18 like normal horses. Sanson’s allegation still needs to be confirmed for the African horse, the Barb. That should be easy to prove with modern tools as echography and radiography.

4 Responses to “Fifth Lumbar Vertebra in Arabian and Barb horses”

  1. Yassine: I’m wondering if there was any indication in the Rochau- Sanson data about how many of the arabs with 6 lumbars had a fused bone. In other words 6 lumbars rather than 5 distinct lumbars, which would effectively create 5 functional lumbars.
    best
    Bruce Peek

  2. I would wonder if that was not the 5 1/2 entry, Bruce. It is difficult to get a good lumbar count. At one point, when we had a chance, and an X-ray machine happened to be on the farm when we had a new foal, we could take an image for the record. Unfortunately, those two events rarely coincided. At the time we were most active, x-ray machines were normally not strong enough to read through horse muscle. Even at autopsy, it was hard to get a count. It was hard physical work to get to the area, and we decided the only safe way to trust the count was to be present at the autopsy.

  3. Bruce, I guess the fused bone is the 5 1/2 lumbars type. Rochau and Sanson worked mostly on french and algerian horses. I don’t know if they had pure arabians or only Barb-Arabian crosses . Stetcher talks of seven arabians.
    Jeanne would it be possible to count vertebraes with an echograph ? I am trying to have this done by the anatomy department in my school, with arabians, (both show and race lines) Barb horses and cart
    horses.

  4. I can’t answer that question! No expertise there at all.

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