Dermoid Sinus Ridgeless and Culling

Dermoid Sinus, Ridgeless and Culling

The main health problem in our breed is Dermoid Sinus. The Demoid Sinus is a neural tube defect formed at the time the cells of the foetus enclose the spinal cord. There are five types of demoid sinus. Four types run vertically and range in depth from just into the skin to through the bone of the spine to the spinal cord. Type 5 runs horizontally either through the skin, the muscle, or the supraspinous ligament with no external opening.

What was considered to be type six is when there is a skin dimple located at the base of the tail has now been classified as a lipoma of the terminal filum with skin dimple and extra spinal connection, LTF.

Most dermoid sinuses are found at birth or soon after by running the loose skin between the finger and thumb from just behind the occiput down the spine to the point of the tail. The sinus feels like a thread of string between the fingers.

It is considered the best course of action when sinus positive puppies are found at birth or soon after to euthanize. If a sinus is not apparent at birth they are often operated on and found pet homes. Often this can backfire for the breeder if the pet owner’s pet has health problems relating to the removal – if not completely removed they can grow back.

I have seen an adult dog that was successfully operated on for a sinus at three weeks old and unless you looked for a scar you would not know. He is a very handsome dog it is to the owner’s credit that she will not allow him to be bred from. There were incidences of Dermoid Sinus dogs being bred from in South Africa after the war when they increased in popularity and there was a massive increase in sinus positive puppies.

It is not the ridge that is a mild form of spina bifida, as reported in some newspapers recently, it is the Dermoid Sinus. In a study in the 1980’s in Australia Folic Acid was proven to reduce the number of DS positive puppies and this was used by many breeders. At the World Congress it was said that some breeders that have used Folic Acid for generations are having more incidences of DS now. The Folic Acid may have repressed DS in a mild form from being evident but it was still there in the genes. Dogs that carry the genes that would have been discounted from a breeding programme have been used and the problem has returned.

Our breed is in fact one of the healthiest and ridged dogs that are not DS positive live long and active lives with few health problems.

Ridgelessness is a cosmetic fault but an extremely undesirable one in our breed - it is not a Ridgeback without a ridge. It is proven that it affects about 10% of puppies born but it is possible that the figure is higher. Ridgeless puppies are healthy puppies in every way apart from this fault.

It has been suggested recently that in order to breed out the Dermoid Sinus that breeders should consider breeding ridged to ridgeless dogs, this is not acceptable. Correct ridgebacks are extremely difficult to breed. In a typical litter of 10 and you have discounted your ridgeless puppy, and possibly a DS puppy also, you could be left with 8 of which 2 or 3 may have excess white and others will have ridge faults. For judges who only see ridgebacks in the ring with perfect crowns and ridges be aware that many pet puppies have extra crowns, one crown, no crowns, crowns too low, ridges to short, too high or low and offset crowns. For these reasons ridgebacks are rarely inbred. From a litter often the best puppies conformation-wise have to be excluded from breeding programmes because of cosmetic faults. To breed a ridged dog to a ridgeless bitch would increase the ridgeless, to breed correct ridgebacks would be almost impossible and our breed would disappear altogether.

In my opinion breeders have managed the breed and health issues very well, improving on type and conformation, as can be seen in the successes recently in the Group ring, whilst also maintaining the good health of our breed. The research linking the DS to the ridge was only published last year, there is no gene marker and it is too early to decide the best way forward. Credit should be given to those breeders who participated in the research. For all the research we must use our common-sense. In the words of one of our experienced breeders “You don’t the baby out with the bathwater”.

A few months ago when I said that I reared and homed my ridgeless puppies I was told I was very brave; I am not the only breeder that rears them though. It has been perceived that ridgelessness is more of a problem now than in the past but I think we are just more honest about it.

To find homes for them is extremely difficult as most potential puppy buyers that come to reputable breeders, have the researched the breed and been referred by either the Ridgeback Clubs or the Kennel Club aren’t often interested in having a ridgeless ridgeback. Breeders that rear them often find homes through friends and family through word of mouth.

In the public’s eye all dogs with a ridge, whether crosses or not are ridgebacks but ridgeless ridgebacks can be misidentified. Dog World 22^nd Aug had an article on ‘Larry’ who was identified as a pit-bill type and spent four years locked up in a kennel. Looking at the photo that was either a ridgeless ridgeback or a ridgeback cross and no way should it have been mistaken as being of pit bull type.

So how can we protect them from this sort of ignorance? I can appreciate that some breeders feel that it is best to put them to sleep rather than them going to a bad home but I am sure that there are loving homes that could be found. There are many people who perhaps cannot afford the price of a ridged ridgeback but would love to own one. Perhaps one good result from the BBC programme is that with increased awareness perhaps more people will come forward for them. I have never seen ridgeless puppies advertised anywhere; perhaps it is time that an individual or a club set up a list to help potential homes to be found.

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