October 2007
The University of Pennsylvania (UPenn) team studying Juvenile Dilated Cardiomyopathy in Portuguese Water Dogs has tried the genetic marker test they developed for JDCM in PWDs on affected TMT DNA they had on file. The test did not work, confirming that the genes responsible for the disease are not the same in both breeds and supporting the UPEI team’s hypothesis that cardio as seen in Toy Manchesters is unique.
UPenn has indicated they are interested in working on identifying a marker for cardio in our breed, however they require DNA samples from 10 affected dogs plus parents and as many siblings as possible in order to begin that process.
We believed we had DNA stored for 4 TMTs but at this point it appears that in 2 of the autopsies conducted by outside pathologists, DNA was never collected. This means we are a lot further away than we had hoped, given that we now need 8 more autopsies with DNA properly collected. In the meantime, UPenn has offered to store DNA and blood samples from currently identified dogs for as long as is necessary to gather the base of 10 required. Amanda is currently working with UPenn to finalize release forms and blood collection protocols. She will then contact involved breeders/owners of the two puppies currently on file so that blood collection from relatives in those cases can be carried out.
While we have previously put more emphasis on receiving complete autopsy information, now that the study has progressed further we must emphasize how important it is for DNA samples to be properly harvested and stored during the necropsy. In order to do this it is imperative that UPEI’s study protocols be followed by the pathologist and/or that the study team be contacted as soon as possible following a fatal episode.
On another note, our team at UPEI (Dr. Cote and Dr. Martinson), are now starting work on a clinical paper on the disease for formal publication at a future date. This paper will not only look closely at the physical aspects of the disease, but will also examine pedigree data and touch of possible modes of inheritance.
April 2007
As of the end of March, the Heart Study team at the University of Prince Edward Island, led by Dr Cote, has provided the following update for us.
1. Based on 9 autopsies, 5 from last year, the team is fairly certain the cause of the sudden deaths is
not Juvenile Dilated Cardiomyopathy as seen in young Portuguese Water Dogs. Dilated cardiomyopathy is a disease of the heart muscle, where the heart muscle grows weak and flabby and is less and less able to pump blood through the heart. There are usually symptoms of the heart muscle's growing inability to properly pump blood
What the research team has determined so far is that what they are seeing in Toy Manchesters is more like an arrhythmia. The heart is not able to pump blood properly because the electrical impulses of the heart are short-circuited. Death happens suddenly because the heart cannot pump blood. Dr. Cote is considering possible links to a disease being studied at Cornell on German Shepherd Dogs
http://www.news.cornell.edu/releases/March96/sids.hrs.html.
2. There is speculation regarding Manchester Terrier's known sensitivity to anesthetic. It is possible that some cases of young dogs dying while being spayed or neutered may be due to the underlying cause of juvenile arrhythmia. Because the dogs die under anesthetic and because there is a known "problem" with anesthetic in the breed, many puppies that die under these circumstances are not autopsied. Several of the dogs in the study died under anesthetic. Only once an autopsy was performed were the underlying heart problems identified.
3. Another interesting link is the incidence of undescended testicles and a possible link to the juvenile arrhythmia. There seems to be a correlation between the two, albeit somewhat weak, as not all young TMTs with undescended testicles have died suddenly and TMTs with normal testicles have died. The cardiac team would like to locate a young puppy with undescended testicles for close study. The puppy would have to have retained both testicles at 10-12 weeks. If agreeable, the team would like to have such a puppy flown to PEI, fostered and tested at intervals. If anyone has a puppy that fits these criteria and would be willing to let the puppy go to PEI for testing, please contact
Amanda Kelly.
Dr. Cote and Dr. Martinson have agreed to write a two-page study update for the August 2007 issue of the Ratter's Review and AMTC newsletters
January 2007
Phase One of the Heart Study, investigating sudden death in young Toy Manchester Terriers, is continuing with steady progress. As announced by Amanda Kelly at the AGM, the University of Prince Edward Island (UPEI ) research team has started the process of mapping the gene. It is still too early to say how the condition is passed on, but this is considerable progress. Essentially, all of the pedigree information on the autopsied puppies is being plotted so the research team can look at how producers and affected puppies are related, or not related, whatever is the case.
We are still unable to determine if the condition we are seeing in Toy Manchesters is the same condition identified in Portuguese Water Dogs, Juvenile Dilated Cardiomyopathy (JDCM). There are similarities but there are also differences and more work between the Heart Study team at UPEI and the JDCM researchers at the University of Pennsylvania (UPenn) is needed. The researchers at UPenn have DNA from 2 TMT puppies autopsied by UPEI and have requested blood samples from those puppies’ parents and siblings. Grandparents may also be tested.
To date the UPEI study team is analyzing 5 autopsies, including the two done by UPEI. Please do not assume we do not need more autopsies as this is not the case. It is critical that all young Toy Manchesters who die suddenly be autopsied. The more information/data that the UPEI researchers are able to gather and analyze, the quicker and more reliable will be their conclusions.
We hope to soon add a necropsy guide to the heart study page on the CMTC website, for those who want to have their puppy autopsied locally or by another vet. This will ensure consistency in the information collected and also that the necessary information and tissue samples are collected.
We will keep you informed of any updates, although research and investigation can appear to be a slow process. Please do not hesitate to contact any member of the CMTC Health Committee if you have questions or concerns.
October 2006
The University of Pennsylvania recently contacted us to indicate that they have identified the genetic markers for Juvenile Dilated Cardiomyopathy (JDCM) in the Portuguese Water Dog. This is the culmination of a 12-year study for UPenn, so it is great news for the PWDCA. At this point, it isn't clear if TMTs suffer from the same disease because, while there are a lot of similarities, there are also a lot of differences. With that in mind, UPenn has asked us to gather and submit blood samples for some specific dogs. Right now, we have DNA on file for two affected puppies. The University has asked us to collect blood samples from those puppies' parents and siblings (and possibly grandparents). They will extract DNA from the samples and analyze it using the information they have gleaned from their study of the PWD.
In the meantime, the Manchester Heart Study at the University of PEI is progressing. The UPEI research team has drafted a list of possible tests for affected puppies who manage to survive the initial attack. We have only heard of one pup who survived long enough to make it to a vet but in case there are others we will publish this list of tests on the Heart Study page on the CMTC website. Final revisions are being made to a necropsy guide for those who want to have their puppy autopsied locally or by another vet. This will ensure consistency in the information collected. Both these documents will be available on the Heart Study web page.
All 3 puppies autopsied this summer were confirmed as cardiomyopathy, bringing the total to 4 since the study began a few months ago. DNA was collected for two puppies. We have one dog currently en route for an autopsy.
