kathy pastes this ;
J Comp Pathol. 1984 Apr;94(2):215-31. Related Articles, Links
Neuropathological lesions in experimental lead toxicosis of dogs.
Hamir AN, Sullivan ND, Handson PD.
Light microscopical examinations were carried out on the central and peripheral nervous systems of 9 dogs maintained on a high-fat-low-calcium diet and dosed orally with a mixture of lead chloride, lead bromide and lead sulphate. Microscopic lesions were present in 7 (78 per cent) of the lead-treated dogs. Cerebrocortical lesions comprising spongiosis, vascular hypertrophy and gliosis predominated. These lesions were bilateral, had a predilection for gyri and were located mainly in the parietal and frontal cortex. There were bilaterally symmetrical spongiform changes in the brain stem. The cerebellum had spongiform changes in the roof nuclei and in the lingula there was spongiosis of the Purkinje cell layer and vacuolation of Purkinje cells. Axonal degeneration was evident in a sciatic nerve of one dog. In a second experiment, designed to study the early ultrastructural changes in the brains of dogs with lead intoxication, 2 groups of dogs, one on a commercial balanced diet and the other fed a high-fat-low-calcium diet, were given similar amounts of lead. Cytoplasmic accumulation of lipid was found in the cerebrovascular pericytes of all dogs treated with lead but vascular changes were otherwise not obvious. Quantitative evaluation of numbers of blood vessels by light microscopy revealed an apparent increase in all dogs receiving lead. This increase in vascularity was greatest in the dogs fed the high-fat-low-calcium diet.
PMID: 6736309 [PubMed - indexed for MEDLINE]
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BUT KATHY IGNORES THE OBVIOUS WITH THE CANINE, SHE IGNORES THE TSE i.e. MAD COW AGENT;
GAH WELLS (very important statement here...TSS)
HOUND STUDY
AS implied in the Inset 25 we must not _ASSUME_ that
transmission of BSE to other species will invariably
present pathology typical of a scrapie-like disease.
snip...
http://www.bseinquiry.gov.uk/files/yb/1991/01/04004001.pdf
76 pages on hound study;
http://www.bseinquiry.gov.uk/files/sc/seac16/tab04.pdf
> I thought that in Britain dogs had contracted BSE, but perhaps not.
not so fast here;
The spongiform changes were not pathognomonic (ie.
conclusive proof) for prion disease, as they were atypical,
being largely present in white matter rather than grey matter in
the brain and spinal cord. However, Tony Scott, then head of
electron microscopy work on TSEs, had no doubt that these
SAFs were genuine and that these hounds therefore must have
had a scrapie-like disease. I reviewed all the sections
myself (original notes appended) and although the pathology
was not typical, I could not exclude the possibility that this was
a scrapie-like disorder, as white matter vacuolation is seen
in TSEs and Wallerian degeneration was also present in the
white matter of the hounds, another feature of scrapie.
38.I reviewed the literature on hound neuropathology, and
discovered that micrographs and descriptive neuropathology from
papers on 'hound ataxia' mirrored those in material from
Robert Higgins' hound survey. Dr Tony Palmer (Cambridge) had
done much of this work, and I obtained original sections
from hound ataxia cases from him. This enabled me provisionally to
conclude that Robert Higgins had in all probability detected
hound ataxia, but also that hound ataxia itself was possibly a
TSE. Gerald Wells confirmed in 'blind' examination of single
restricted microscopic fields that there was no distinction
between the white matter vacuolation present in BSE and
scrapie cases, and that occurring in hound ataxia and the hound
survey cases.
39.Hound ataxia had reportedly been occurring since the 1930's,
and a known risk factor for its development was the feeding
to hounds of downer cows, and particularly bovine offal.
Circumstantial evidence suggests that bovine offal may also be
causal in FSE, and TME in mink. Despite the inconclusive
nature of the neuropathology, it was clearly evident that this
putative canine spongiform encephalopathy merited further
investigation.
40.The inconclusive results in hounds were never confirmed,
nor was the link with hound ataxia pursued. I telephoned Robert
Higgins six years after he first sent the slides to CVL.
I was informed that despite his submitting a yearly report to the
CVO including the suggestion that the hound work be continued,
no further work had been done since 1991. This was
surprising, to say the very least.
41.The hound work could have provided valuable evidence
that a scrapie-like agent may have been present in cattle offal long
before the BSE epidemic was recognised. The MAFF hound
survey remains unpublished.
Histopathological support to various other published
MAFF experiments
42.These included neuropathological examination of material
from experiments studying the attempted transmission of BSE to
chickens and pigs (CVL 1991) and to mice (RVC 1994).
http://www.bseinquiry.gov.uk/witness/htm/stat067.htm
It was thought likely that at least some, and probably all, of the cases
in zoo animals were caused by the BSE agent. Strong support for this
hypothesis came from the findings of Bruce and others (1994)
( Bruce, M.E., Chree, A., McConnell, I., Foster, J., Pearson, G. &
Fraser, H. (1994) Transmission of bovine spongiform encephalopathy and
scrapie to mice: strain variation and species barrier. Philosophical
Transactions of the Royal Society B 343, 405-411: J/PTRSL/343/405
), who demonstrated that the pattern of variation in incubation period
and lesion profile in six strains of mice inoculated with brain
homogenates from an affected kudu and the nyala, was similar to that
seen when this panel of mouse strains was inoculated with brain from
cattle with BSE. The affected zoo bovids were all from herds that were
exposed to feeds that were likely to have contained contaminated
ruminant-derived protein and the zoo felids had been exposed, if only
occasionally in some cases, to tissues from cattle unfit for human
consumption.
snip...
http://www.bseinquiry.gov.uk/files/ws/s324.pdf
2005
DEFRA
Department for Environment,
Food & Rural Affairs
Area 307, London, SW1P 4PQ
Telephone: 0207 904 6000
Direct line: 0207 904 6287
E-mail: h.mcdonagh.defra.gsi.gov.uk
GTN:
FAX:
Mr T S Singeltary
P.O. Box 42
Bacliff
Texas
USA 77518
21 November 2001
Dear Mr Singeltary TSE IN HOUNDS
Thank you for e-mail regarding the hounds survey. I am sorry for the long delay in responding.
As you note, the hound survey remains unpublished. However the Spongiform Encephalopathy Advisory Committee (SEAC), the UK Government's independent Advisory Committee on all aspects related to BSE-like disease, gave the hound study detailed consideration at their meeting in January 1994. As a summary of this meeting published in the BSE inquiry noted, the Committee were clearly concerned about the work that had been carried out, concluding that there had clearly been problems with it, particularly the control on the histology, and that it was more or less inconclusive. However was agreed that there should be a re-evaluation of the pathological material in the study.
Later, at their meeting in June 95, The Committee re-evaluated the hound study to see if any useful results could be gained from it. The Chairman concluded that there were varying opinions within the Committee on further work. It did not suggest any further transmission studies and thought that the lack of clinical data was a major weakness.
Overall, it is clear that SEAC had major concerns about the survey as conducted. As a result it is likely that the authors felt that it would not stand up to r~eer review and hence it was never published. As noted above, and in the detailed minutes of the SEAC meeting in June 95, SEAC considered whether additional work should be performed to examine dogs for evidence of TSE infection. Although the Committee had mixed views about the merits of conducting further work, the Chairman noted that when the Southwood Committee made their recommendation to complete an assessment of possible spongiform disease in dogs, no TSEs had been identified in other species and hence dogs were perceived as a high risk population and worthy of study. However subsequent to the original recommendation, made in 1990, a number of other species had been identified with TSE ( e.g. cats) so a study in hounds was less
critical. For more details see-
http://www.bseinquiry, gov.uk/files/yb/1995/06/21005001 .pdf
As this study remains unpublished, my understanding is that the ownership of the data essentially remains with the original researchers. Thus unfortunately, I am unable to help with your request to supply information on the hound survey directly. My only suggestion is that you contact one of the researchers originally involved in the project, such as Gerald Wells. He can be contacted at the following address.
Dr Gerald Wells, Veterinary Laboratories Agency, New Haw, Addlestone, Surrey, KT 15 3NB, UK
You may also wish to be aware that since November 1994 all suspected cases of spongiform encephalopathy in animals and poultry were made notifiable. Hence since that date there has been a requirement for vets to report any suspect SE in dogs for further investigation. To date there has never been positive identification of a TSE in a dog.
I hope this is helpful
Yours sincerely 4
HUGH MCDONAGH
BSE CORRESPONDENCE SECTION
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TSS