The Research Continues
Life Expectancy
My immediate question was about Allie’s life expectancy. Because of her age and the early development of DCM, this proved to be more difficult to answer than I anticipated. Since DCM was thought to be rare in English Cocker Spaniels, I began searching for information that was just about Cocker Spaniels in general.
I found two studies; the MUST study from 1997 which discovered American Cocker Spaniels with DCM had reduced levels of Taurine and Carnitine (1), and a more recent one regarding English Cocker Spaniels with DCM with low plasma Taurine (2). For a disease that was considered to be so rare in this breed, there were apparently enough affected dogs to warrant a study!
In order to enter the MUST study, the dog had to be an American Cocker Spaniel (ACS) and had to have a FS (Fractional Shortening) of <20 with no evidence of severe valvular disease. (Allie’s FS, as of May 31, 2024, was 22).
In the MUST study, dogs were given either a placebo or Taurine and Carnitine supplements and examined monthly over a period of 4 months. All of the dogs represented were Taurine deficient at the beginning of the study. Most of them improved during that time and were weaned off medication.
One of the youngest dogs in the study was 5 years old when diagnosed, and lived 53 months after being supplemented with Taurine and Carnitine. Another 5 year old dog lived an additional 48 months. Both dogs lived considerably longer than the older dogs, and both were eventually euthanized for reasons other than DCM.
“Consequently, it appears that the long term prognosis for younger ACS with DCM that respond to supplementation is very good. It also appears that the primary factors that determine the long-term prognosis in most of these dogs are the age at diagnosis and the presence or absence of severe disease other than DCM.”
This sounds promising! But what about English Cocker Spaniels? Are they different?*
The purpose of the study done on English Cocker Spaniels with DCM was to evaluate their Taurine levels and assess their survival time and natural progression of the disease. This study was inconclusive, but it did show that English Cocker Spaniels with DCM commonly have low Taurine levels. It also showed that they improved with Taurine supplementation and cardiac medications, but similar results were shown on the English Cocker Spaniels that had normal Taurine levels and were only taking cardiac medication.
The conclusion was that there’s a possible association with Taurine deficiency in English Cocker Spaniels but supplementing with Taurine was not curative.
The dogs in this study were an average age of 6.75 years +/- 3 years. Survival time was calculated at the time of diagnosis of DCM. On average, they survived 1155 days (about 3 years).
“… data suggest that taurine supplementation might not be curative and taurine deficiency may not be the sole cause of DCM phenotype in this breed.”
The only optimistic view, if you can call it that, was that cocker spaniels tend to live longer than other breeds with DCM. The occult phase (asymptomatic) could last a few years, followed by the symptomatic phase which was significantly shorter.
Allie and her littermate were so young at the time of diagnosis, and were still asymptomatic. They seem to be in a unique category. They were both put on Vetmedin, Enalapril, Taurine and Carnitine immediately, and are closely monitored with Echocardiograms and bloodwork. Since they’re both being treated early on, it stands to reason that their occult phase could last several years.
Who is Conducting Research?
I contacted several well known breeders of English Cocker Spaniels. They all said they hadn’t heard of DCM in any of their lines. Yet, with two young dogs diagnosed with nearly identical symptoms, there was clearly a genetic link. They live on opposite sides of the continent, so they didn’t share any environmental or infectious issues. What was I missing?
When I saw that Laboklin and Embark had some breed specific tests, I assumed someone was probably working on a genetic test for Cocker Spaniels since they were listed as being known to have DCM. I went back to Laboklin Laboratories in the UK and asked if they knew of any research being done for DCM in English Cocker Spaniels. The answer was no. I then asked Embark the same thing. Again, the answer was no. (Embark does, however, have a large research project happening right now for all dogs of any breed that have DCM)
Why wasn’t anybody conducting research for the Cocker Spaniel?
English Cocker Spaniel Club of America
One of the breeders kindly pointed me in the direction of the English Cocker Spaniel Club of America. They are known for funding research into various health conditions for the breed. I contacted their Health and Research Department and had an insightful conversation with the Chair.
No one has reported Taurine deficiency in English Cocker Spaniels for over 20 years. That’s possibly because Taurine was added into dry dog food after it was discovered that cats were developing DCM from eating Taurine deficient kibble. DCM that is reported now in English Cocker Spaniels is generally with older dogs.
The Chair of the English Cocker Spaniel Club also informed me that breeders/owners of field/working lines of English Cocker Spaniels are not as diligent about health testing as are those who have the bench lines of the breed. The English Cocker Spaniel Club of America sent out a health survey several years ago, which was used in part to determine the occurrence of DCM in different breeds. (3) Only 19 people with field English Cocker Spaniels filled it out, possibly resulting in unrepresented numbers for the final result. Dobermans far exceeded in the reports of DCM. For that reason, research was focused on Doberman Pinschers and two genetic tests have since been developed.
There are no plans at this time for the club to finance research for DCM.
Cocker Spaniel Database
The Cocker Spaniel Database (https://cockerspanieldatabase.info/ ) is a large database of 250,000 English Cocker Spaniels, representing both bench and working lines. It is maintained by one person who does an excellent job of keeping pedigree and health reports up to date.
I was informed that many people have submitted reports of DCM in their dogs, but have not provided the documents to prove it, so they have not been included in the database.
It would be in the interest of the breeders to report DCM, but I can see why the owners of affected dogs might not report it to a central database, or even think to inform the breeders. It’s also possible breeders and owners don’t know about the database.
To date, Allie is the only Working English Cocker Spaniel listed as having DCM.
How did she and her littermate acquire this disease? I’ll delve into genetics in my next post.
* Allie is 1/8 bench English Cocker Spaniel from the dam’s lineage, coming from US, UK and Finnish lines. Her sire’s lineage is working English Cocker Spaniel from UK lines.
References
(1) Kittleson, Mark D., et al. “Results of the Multicenter Spaniel Trial (MUST): Taurine‐and Carnitine‐Responsive Dilated Cardiomyopathy in American Cocker Spaniels with Decreased Plasma Taurine Concentration.” Journal of Veterinary Internal Medicine, vol. 11, no. 4, July 1997, pp. 204–211, https://doi.org/10.1111/j.1939-1676.1997.tb00092.x.
PDF: https://onlinelibrary.wiley.com/doi/pdfdirect/10.1111/j.1939-1676.1997.tb00092.x?download=true&campaigns=[{“position”:”ereader-last-page”,”uri”:”uri:707b1a3c-73e6-4188-b21f-2b05b70307d8″},{“position”:”ereader-first-page”,”uri”:”uri:7691ea89-90f5-4086-9241-486673caed61″}]
(2) Basili, M., et al. “Low Plasma Taurine Levels in English Cocker Spaniels Diagnosed with Dilated Cardiomyopathy.” Journal of Small Animal Practice, vol. 62, no. 7, 16 Feb. 2021, pp. 570–579, https://doi.org/10.1111/jsap.13306. Accessed 23 Nov. 2021.
3) “Dcm at Univ of Guelph -.” Doberman Pinscher Club of America, 10 Jan. 2010, dpca.org/breeded/dcm-at-univ-of-guelph/. Accessed 18 Aug. 2024.