Samples were taken from three coprolites from Area 2CA to determine their potential for detailed analysis; all were identified as from dogs. These coprolites were of small dried aerated lumps, pale brown in colour, and they appeared to be mineralized. This work was undertaken during 1990 and has not been expanded as part of this assessment.
The coprolites samples were examines at x60 magnification under the microscope, to ascertain contents such as bone fragments. A number of methods were applied to the examination for parasitic helminth (worm) ova, but only one was successful. The successful method involved crushing specimens with a pestle and mortar. Then 0.2g of each specimen was placed in a test tube and 10 cubic cm of 0.5m Hydrochloric acid and three drops of a surfactant (soap) added. These were left for 24 hours but with occasional mixing. At 24 hours, the specimens were mixed, poured through a 360 micrometre sieve and centrifuged at 2000 rpm for 2 minutes. The supernatant was discarded, the volume of the deposit was made up to 0.5 cubic cm. Fifty micro-litres of mixed deposits were examined under the microscope at x100 and x400 magnification. The deposits were also examined after 48 hours and 5 days.
One sample was examined. This was a small piece of coprolite about 1 cubic cm. No bone was seen on initial examination. Helminth ova were seen on examination at 48 hours; these measured 57-60 x 30-33 micrometers and have been identified as Capillaria hepatica due to their size, polar plugs and eggshell features. The ova counts were low and averaged only 100 ova per gram. Much crushed bone was present under high power magnification and this, along with the ova, positively identifies the coprolite to that of dog.
Capillaria hepatica are primarily a parasite of wild rodents, including the hare as a host. These parasites occur occasionally in dog, cat and man. The life cycle is such that the eggs are laid in the liver of a host, where there is no natural access to the exterior. These eggs are released by ingestion from a predator, in this case a dog, but they do not develop at this stage. They are passed out in faecal droppings. They can now obtain the oxygen they need to develop and hence infect a new host. Therefore the dog in this case was not directly infected with Capillaria hepatica although the faeces contained parasitic ova. This is known as a spurious (false) infection.
Further to this, a larva was discovered by a colleague, Dave Brady, whilst checking out this sample. This larva must be presumed to be a contaminant, probably that of a free-living nematode from the soil around the coprolite.
Two samples from this coprolite were examined, one taken from the broken centre (a) and the other was a loose piece (b). Many bone fragments were found in sample (a) and one bone fragment was discovered in sample (b).
Helminth ova eggshells were discovered in both samples and these have been identified as that of Dicrocaelium denditriticum (Lancet fluke or small liver fluke). The operculum and embryonic matter were missing from the majority of the ova. Ova size varied from 30-39 x 21-26 micrometres and the ova counts were also variable but averaged 875 ova per gram for sample (a) and 375 ova per gram for sample (b).
The identification of the ova was kindly confirmed by S/Leader Neville Holden of the Institute of Pathology and Tropical Medicine at RAF Halton, who, on further examination, saw some structures resembling Toxocara ova, but these were inconclusive.
On further examination, one differing ovum was seen and photographed. This ovum was approximately the same size as Dicrocaelium denditriticum and remains unidentified. It resembles Eurytrema species ova in size and morphology, but Eurytrema are parasites of ruminants found in Asia, Brazil and Venezuela today. This ovum came from the centre of the coprolite and is unlikely to be a soil contaminant of this material, but on reviewing the evidence the ovum must remain as an unidentified nematode ovum.
This coprolite is that of a dog, on the evidence of mineralization and bone present. Dicrocaelium denditriticum is a parasite of herbivores and not of the dog, although Geoffrey Lapage in his book Veterinary Parasitology of 1968 infers that this parasite can infect dog. It is almost certain, though, that the finding of Dicrocaelium denditriticum ova in a dog coprolite is due to a spurious infection, probably caused by the dog eating offal, such as infected liver or intestines from either sheep, deer or cattle. The dog could also have picked up the ova by eating grass, but this is less likely, although some vegetable fibres were seen under x400 magnification.
The life cycle of Dicrocaelium denditriticum is complex and requires an intermediate host, which are snails. The snails implicated are Hellicella and Zebrina, with Hellicella itala being the most likely candidate. Hellicella itala are found on sand dunes and calcareous grassland throughout Britain, although they have now become extinct in many inland areas. Formica species of ants are also required to complete the life cycle of this parasite.
Dicrocaelium denditriticum helminths are extinct in Britain today except for the Hebrides off the west coast of Scotland, although the ova has been discovered on several archaeological sites in southern England, including pits at Winchester and Owlesbury, Hampshire.
Two samples were taken from this coprolite, one from the largest lump and the other consisting of small loose pieces. Bone fragments were abundant in both samples, with cancellous or spongy bone present. No Helminth ova were detected. This coprolite is identified as that of dog.
It is impossible to estimate the original ova counts as many will have decomposed with time and conditions, but it would have been much greater than discovered in this investigation.
The presence of dog coprolites in many of the Grubenhäuser is some indication of the nature of the development of the fills of these structures after abandonment. A small number of possible human coprolites deserve attention, as these may give important evidence on the health of the population in addition to dietary information which can be considered in relationship to the extensive agricultural evidence provided both by the faunal and floral assemblages. Examination of additional coprolites offers the opportunity for the recovery of additional environmental data with possible potential for the recovery of pollen, which does not generally survive on this site. (see also 6.5.2 Anglo-Saxon settlement evolution and decline and 7.1.4.2 Reconstruct the environment and economy of the settlement).
© Internet Archaeology
URL: http://intarch.ac.uk/journal/issue5/westhes/4-6.htm
Last updated: Tue Dec 15 1998