Gail
Sorry, no luck with Horace at all. I fared much better with Henry with the extra information you gave.
1861 census [RG9/139/68/76]
Islington, Finsbury
Henry Dodman, head, mar, 25 (b c1836), Stable man, born Sibel, Essex
Elizabeth S Dodman, wife, mar, 20 (b c1841),, born Thetford, Norfolk
Henry Dodman, son, 4
Ann Dodman, daughter, 1
1851 census [HO107/1784/430/8]
Sibel Hedingham, Essex, Swan Street
Susannah Dodman, wife, mar, 48 (b c1809), unreadable profession followed by pauper in brackets
Henry, son, 15, errand boy
Thomas, son, 12
Maria (I think - the handwriting is difficult), daughter, 7
I can find no trace of Dodman senior in Sibel, or in Essex for that matter. There are several candidates of about the right age in Norfolk - it does seem to be a more common name in Norfolk than anywhere else.
The best bet for finding the fathers name is from the birth certificates of the children:
Maria, Dec 1843, Halstead, v 12 p 115
Thomas, Sep 1838, Halstead, v 12 p 104
I don't have access to the 1841 census. Perhaps someone else could check that for you.
Regards
Derrick