Brief History of Newfoundland Forelimb Anomaly

Newfoundland Forelimb Anomaly - A brief history 

Early in 1998, NCA member Barbara Jenness with input from NCA member and breeder Peggy Helming contacted Michigan State University regarding a condition reported in the Newfoundland breed. How wide spread the condition was had been masked by differing diagnosis from veterinarians and no central clearing house for the disease. As information was gathered, it became apparent that the problem had been seen all over the country and abroad.

It was first described in 1981 in Norway by Jorunn Grondalen of The Veterinary College in an article for the Journal of Small Animal Practice, titled "A generalized chrondropathy of joint cartilage leading to deformity of the elbow joints in a litter of Newfoundland dogs".  

Armed with several x-rays of affected animals Barbara Jenness met Dr. Ulreh Mostosky and Dr. George Padgett of Michigan State University to engage their help in determining what was going on in these puppies and what could be done.

An initial report was published in Newftide in 1998. After x-raying 9 affected puppies Dr. Mostosky noted that there was an asynchronous growth of the radius and ulna coupled with a subluxation of the elbow. It was difficult to tell which came first, whether the elbow luxation caused the uneven growth or whether the growth pattern caused the elbow luxation. In this article the condition was referred to as elbow anomaly. Information regarding where to send x-rays, pedigrees and cheek swabs was included in the report.  

Dr. Ulreh Mostosky, Dr George Padgett, NCA members Barbara Jenness and Peggy Helming worked together on collecting pedigrees, and cheek swabs. Dr. Mostosky spent countless hours interpreting x-rays from around the world, and helping to x-ray animals that were sent to him. NCA members Jennifer Beals and Dr. Jennifer Zablotny helped in the housing and transportation of several animals.

After this period of data collection another report appeared in Newftide in 1999. This report included x-rays and photos of affected animals, reported the incidence of the disease, and the suspected inheritance. It also coined the name “Forelimb Anomaly”, which was felt to be a more accurate description of the problem.

Based on the collected data and suspected mode of inheritance, a test breeding of two affected animals was done. This breeding produced two live puppies both were normal. The breeding was done in a controlled environment. The male was housed at a Veterinary clinic and semen was collected for insemination. The female was housed by an NCA member and was brought to the clinic for insemination. Shortly after the breeding the male was euthanized.

After the breeding produced two normal puppies. The outcome of this breeding certainly was not expected. It proved that researchers were not dealing with a simple recessive and finding a marker would be much harder than anticipated.

After this breeding and follow up x-rays on the puppies, Barbara Jenness, central contact person turned over information to the NCA Health and Longevity committee due to the growing demands of a goat dairy and cheesemaking facility, Dr. Padgett passed away in 2004, Dr. Ulreh Mostosky retired in 2008. Dr. Mostosky continued to work on the Newfoundland Forelimb Anomaly up to and after his retirement. He continued this work funding it himself., He continued to accept and read x-rays from around the world. Working with NCA member/ breeder, Kathy Whitney, he helped facilitate a second breeding of affected to affected animals. The second litter confirmed the results of the first breeding, producing 6 puppies, all normal. These puppies were x-rayed every other week from 3 weeks until 12 weeks of age. 

In July, 2012, Dr, Mostosky suffered a major stroke. His recovery is progressing and it is reported that he continues to read x-rays.

In August, 2012, Dr. Mostosky’s facility at his home burned. The building was a total loss. Twenty years of research were destroyed. This included all his records on Newfoundland Forelimb Anomaly. This is a tragic loss. During his years of research, he collected DNA on affected and non affected animals, this data is stored at an OFA facility under the heading Newfoundland Forelimb Anomaly. So that data was preserved.

This brief history shows that the disease has been around and is not going away. Newfoundland Forelimb Anomaly has lacked a “cheerleader” over the last decade. It is time that Newfoundland owners and breeders push for more awareness and continued research.

What we know about FA...

Newfoundland Forelimb Anomaly is complex and the mode of inheritance has not yet been determined. The severity of the condition varies from mildly affected to severe. It can be unilateral or bilateral. There is no cure. Affected animals can be diagnosed as early as 4 weeks of age. Diagnosis is by an AP and lateral x-ray of the radius and ulna including the elbow and wrist joint. Treatments from massage to diet change to surgery to euthanasia have been suggested. It should be noted that while many of the treatments might help the animal, without controlled studies there is no data to back up claims of recovery. NFA is frequently misdiagnosed which adds to the confusion surrounding the problem. It has not been associated with any particular diet or rearing practice. A similar disease has been noted in Nova Scotia Duck Tolling Dogs.

The Genetics…..

Evidence regarding the inheritance of the forelimb anomaly is still absent from the peer-reviewed literature. In view of the radiological evidence above, it does appear to be a discrete, recognizable entity, though it may vary in severity. To the eye of an experienced observer it is unlikely to be mistaken for any of a variety of forelimb or elbow problems present in Newfoundlands or other breeds and should lend itself to formal genetic analysis.  

The breed predilection (to date only Newfoundlands and Duck Tolling retrievers) provides prima facie evidence of a strong genetic component, but this has yet to be verified with more refined methods. The previous data published in NewfTide suggested that the malformation might be recessive since two unaffected dogs can produce affecteds (21 instances in this study alone) and examination of litters with at least one affected suggested that the overall ratio of unaffected to affected was not significantly different from the nominally expected 3:1. Obviously, the litter resulting from breeding two affecteds virtually rules out a simple recessive, e.g. 6 puppies all unaffected. Two affecteds should not produce even 1 unaffected since there would be no source of the normal allele.

A retrospective analysis of the NewfTide data reveals that the inheritance, does, in fact, differ from expectation for a simple recessive. Although the overall ratio of unaffected to affected approximates 3:1, there is significantly more variation between litters than would be expected for a simple recessive. Litters of 7 out of 9 and 6 out of 7 alone would be extraordinarily unlikely in a sample of 21 carrier to carrier breedings. This can be contrasted to many litters from two presumptive carriers with few or no affected puppies. Across the entire data set, the simple recessive hypothesis can be rejected with a high degree of certainty (p=.001).  

This pattern may give us some direction in our search for a solution to the forelimb anomaly. The mechanism must be one which might have systematic “litter effects”. Different litters from the same parents have had very different results, e.g. 12 unaffected: 0 affected in one breeding and 4 unaffected: 3 affected in the next. Litters from apparently similar breedings in the original study range from 1 of 12 to 7 of 9. This suggests that some factor is acting at the level of the litter. A likely possibility would be a genetic factor (gene or genes) that results in the vulnerability to an environmental trigger that is present in some litters and absent in others. This could appear as an incompletely penetrant recessive (or possibly even dominant) where the penetrance varies systematically from litter to litter.

Where do we go from here…..

Recently several Newfoundland owners and breeders have formed a small group that is committed to raising awareness about Newfoundland Forelimb Anomaly through education. The group will encourage continued data and blood collection for future research and the development of guidelines for help in early diagnosis. But this group needs everyone’s help. Help make sure that data and a DNA sample has been collected and banked on all affected dogs. Breeders who have had affected litters should make sure that data is recorded .You may contact the Newfoundland Forelimb Anomaly Group through e-mail at forelimbanomaly@gmail.com or through the website at www.newfoundlandforelimbanomaly.com . If you would prefer to talk to someone please call 203-927-0458. If you are unsure of a diagnosis, we will provide you with information for submitting an x-ray.