Cerebellar Abiotrophy(CA) in Scotties: Some Information and Contacts for you and your veterinarian.
CEREBELLAR ABIOTROPHY (CA) IN SCOTTIES Some Information and Contacts for you and your veterinarian.
What is Cerebellar Abiotrophy? It is a genetic neurological disease recently described in the Scottish Terrier. The term defines progressive, premature cell death in the cerebellum, an area of the brain that controls smooth, coordinated motor skills such as walking.
What are the symptoms? Slow loss of motor skills, clumsiness, unsteady gait, wide based stance, loose and wobbly rear or roll of the hips. Dogs may trip, fall or have trouble negotiating stairs. It is progressive and, although it may become severe, it often remains relatively mild. It is not fatal. Personality, positive outlook and mentality are not affected. CA can be difficult to diagnose and may be confused with other conditions and movement disorders. There is no known treatment at this time.
What is being done? In 2001, the HTF retained the services of Dr. Jerold Bell DVM, Assistant Professor of Genetics at Tufts University for the purpose of investigating the presence of CA in Scotties. Dr. Bell now assists owners and our research project. He asks that those who have a dog they suspect may have CA contact him for instructions on submitting information and a video for review by him and by renowned neurologist Dr. Alexander deLahunta. He offers complete confidentiality and there is no charge for this service. He can also recommend appropriate testing and make local referrals when/where additional diagnosis is needed. The STCA maintains a voluntary database of CA affected Scotties to help breeders in breeding away from this defect until a test can be found. Owners and/or breeders of diagnosed Scotties may elect to participate and must complete release forms supplied by STCA through Dr. Bell.
How can I help? Owners of clinically diagnosed CA Scotties are strongly encouraged to join the research sponsored by the Health Trust Fund of STCA, through the AKC Canine Health Foundation. Dr. Natasha Olby leads a research team at North Carolina State University whose goal is to find the responsible gene and develop a test to eliminate CA in Scotties. Blood samples are needed from affected dogs, their parents, siblings and offspring. The more samples, the faster the research will go!
For help and instruction on how to make a 10-15 minute videotape of your dog on lead from the side, front and back; off lead from the side, front and back and going up and down a stairway
To participate in the research: Ms. Pragna Mehta, at Dr. Olby’s lab at
For forms and instructions for you and your veterinarian to submit blood samples from clinically diagnosed Scotties and/or their parents, siblings and offspring.
To learn more about CA on the STCA Website: visit CA Central,
Click on the Scotties Health menu on the STCA Home Page at http://www.stca.biz
Wobbly and Uncoordinated Scotties
By Debbie Smith
STCA HTF CA Project – January, 2003
In June 2000, Dr. Jerold Bell, DVM, and Dr. Alexander de Lahunta, PhD., DVM, examined a videotape of Murphy, my Scottie, who suffered for years with an undiagnosed movement disorder that affected his ability to walk normally. After considering Murphy's history, both doctors agreed he had clinical symptoms of Cerebellar Abiotrophy (CA), a rare, slow-to-progress neurological disease that causes loss of coordination. Having experience with this disorder and after finding other CA affected Scotties, these doctors realized CA was a newly described disorder affecting the breed. Prior to that time, it wasn't yet established that this disease existed in Scotties so their discovery was quite astounding.
CA causes ataxia or the "inability to coordinate voluntary muscular movements." Some Scottie owners might have encountered this disorder over the years, no one can be certain. In 1995, the STCA HTF breed survey indicated the incidence of ataxia in Scotties was 1 affected out of every 200 dogs. It was therefore established Scotties had ataxia, but no cause was determined. In an effort find more CA affected Scotties, Carole Fry Owen, a well-known health advocate for the breed, published the article "Ataxia in Scotties: Wobbly Dogs" which appeared in the Bagpiper, the Scottie Scamper and on the STCA website. Many owners of "wobbly" Scotties responded to that article and have since received a clinical diagnosis of CA in their dogs. Recently, in August 2001, two veterinarians from South Africa published the first scientific study on CA in the Scottish Terrier, confirming the disease affects the breed, however, before that report was even published, Dr. Bell, Dr. de Lahunta and the STCA HTF were already at work on the problem!
Symptoms and Diagnosis
Symptoms of CA include failure to control the rate, range, and force of a movement, exaggerated limb responses, such as goose-stepping or hopping and delayed and exaggerated postural responses, such as under or overshooting a food bowl when attempting to eat. Limb movements are spastic, clumsy, faltering, and jerky. Often a broad-based stance is present and swaying of the hips may be seen while walking. Symptoms are usually noticed between six months to one year of age and beyond and can be subtle at first; often an owner only suspects their Scottie is clumsy.
CA can be difficult to diagnose. The relative mildness of symptoms and its slow-progression can cause some to mistake CA for Scottie Cramp. Most dogs with Cramp appear normal and only exhibit symptoms occasionally. Signs of incoordination associated with CA are always present once symptoms develop. Some Scotties have Patella luxation (slipping-kneecaps), which can also complicate diagnosis but that is another unrelated condition affecting one or both hind legs.
History of CA Project
Dr. Bell is the Assistant Clinical Professor of Genetics at Tufts University School of Veterinary Medicine and is the national project administrator for numerous genetic disease control programs of purebred dogs. Once aware of CA in the Scottish Terrier, Dr. Bell explained the following: "As this disorder has not been "worked up" and reported in the breed, there are many owners, veterinarians, and neurologists out there that are not informed of its presence. An important first step and contribution to the breed is to document it".
Dr. Bell contacted the STCA and submitted a proposal, offering to determine the genetic parameters of CA in the breed. In May 2001, less than one year after learning of CA in Scotties, the STCA HTF formally retained his services. In the short time Dr. Bell has been working on this project, he's been able to confirm CA is hereditary in Scotties and caused by a defective autosomal recessive gene.
Autosomal recessive inheritance means both parents carry a defective gene that can be passed on to male or female offspring. If a dog inherits two copies of the defective gene, one from each parent, they will be affected. If only one copy is inherited a carrier is produced and if no defective gene is inherited, the dog remains clear. Because both parents of an affected dog are positively identified as carriers and repeat breedings would produce additional affected dogs, anyone having a Scottie diagnosed with CA should notify the breeder and owner of the sire who produced the dog.
Presently Dr. Bell is working to determine how widespread CA is the breed and his database grows with each Scottie diagnosed. He has made recommendations to the STCA HTF for collection and storage of blood samples from affected Scotties, and possibly their relatives, to insure DNA is available for future studies. Hopefully that will lead to the development of a test for carriers. Once a test is available, a breeder could determine if their dog carries the defective gene before they were bred.
Dr. Jerold Bell, DVM
What We Know So Far
In August 2002, Dr. Bell reported that 20 Scotties were diagnosed with CA. He had reports of additional dogs with symptoms that sounded like CA and was awaiting videotape or follow-up on those dogs. He's indicated the defective gene responsible for CA is very old and widespread throughout the breed. At least 6 ancestral lines trace back 7 or 8 generations and come together to produce an affected dog. The Scotties from South Africa trace back to English ancestors common to American dogs. At this time Dr. Bell says there is no particular "hotspot" of risk and pedigree analysis is still premature right now. Eventually, that will become available by Dr. Bell once more information is learned about CA in Scotties.
The STCA HTF has retained Dr. Bell for an additional year, September 2002 to August 2003. Please see The Bagpiper and the STCA website for any additional updates.
Original Doc: Wobbly and Uncoordinated Scotties.doc
Scottish Terrier Club of America Health Trust Seminar, A Personal View..
Barbara Albright This article first appeared in the Scottish Terrier Club of New England newsletter, Scottie Tails.
October 2 2004, Lulu Temple, Ambler, PA
Cerebellar Abiotrophy and the Scottish Terrier and Control of the Spread of Genetic Disease Jerold S. Bell, DVM of Tufts University
Cerebellar Abiotrophy: progressive loss of muscular coordination due to Purkinje cell death in the cerebellum part of the brain. CA is an autosomal recessive genetic disorder, that is not painful, does not affect the mind, nor is it an episodic condition. Symptoms in the Scottish Terrier can range in severity and the age of onset is as early as puppy-hood to 3-5 years of age. Attendance topped all previous years' Montgomery weekend sponsored health seminars for this controversial topic affecting Scottish Terriers. Cerebellar Ataxia was reported on the STCA's 1995 health survey as a 0.5% affected or approximately 1 in 200 dogs with a guesstimated 13% carrier rate.
In 2001, STCA member Carole Fry Owen, a long-time journalist on Scottish Terrier health issues, took special interest to learn more about the incidence and gather initial information. She placed short ads in various Scottie publications seeking individuals that owned "wobbly Scots" asking them to contact the STCA Health Trustees and Dr. Jerold Bell. STCA member Debbie Smith further enhanced the project by putting together a video of affected Scottish Terriers, an official Health Trust Fund sponsored pamphlet, and took on the task of CA Project Chairman.
Dr. Bell's two hour presentation was executed concisely, nearly flawlessly, with deep conviction for, and knowledge about the disease. The audience learned that he is a breeder/owner of Gordon Setters, one of several known breeds to be affected by the same disorder. Part of the presentation included a video of both Gordon Setters and Scottish Terriers, affected by CA, performing a few different motions for a longer period that weren't as obvious in the STCA sponsored video. This was helpful to distinguish more characteristics of the disease. Also included were a few examples of Scottish Terriers with diagnosed "Scottie cramp" to show the differences to that particular disorder.
Dr. Bell stressed repeatedly that Cerebellar Abiotrophy is fluid motion, involves all limbs, and never episodic, while cramp is episodic, jerky in nature, thought of as painful, and typically is noted the most in rear limbs. Pedigree analysis showed that this disease crosses all lineage, dates to the early '50's in the US, pre-WWII in South Africa, and could possibly be traced back earlier in the breed. The disease is thought to be simple autosomal recessive, requiring a copy of the defective gene from each parent to cause the disease. To diagnose the disease, a Veterinary specialist in Neurology should examine the dog, a CSF sample (spinal fluid) obtained can rule out toxins & infections, and scientific conclusive confirmation requires an MRI (magnetic resonance imaging) to view actual atrophy or shrinking of the cerebellum, and following the dogs natural death, a necropsy on tissue obtained from the cerebellum will show destruction of the Purkinje cells.
The oral presentation concluded with a live demonstration of three affected Scotties accompanied by their owners: a mildly affected 12 yr. old bitch, a moderately affected 5 yr. old male and a severely affected 8 yr. old bitch. Owners described limitations, time frame & difficulty obtaining diagnosis, and all noted that early symptoms were largely puzzling and mild in form; easily confused with other disorders.
The charged atmosphere in the audience became apparent when Dr. Bell was wrapping up the Control of the Spread of Genetic Disease segment of the program. In addition to affected individual dogs, he stated that known carriers should be removed from breeding programs; with the suggestion that littermates of the carriers be substituted.
It was my perception, that there were several issues at stake:
1 Owners of affected dogs concerned that its low incidence may cause the project to halt
2. Breeders and membership looking for more evidence and numbers to support the project
3. And just maybe, those that wish a painful subject would go away.
There are a lot of canine movement/gait disorders: luxating patellas, spinal disc disease, ataxia caused by encephalitis, and peculiarly inherent to the Scottish Terrier, "cramp". Recently, I reread Dr. T Allen Kirk's article of why/how he became intrigued and subsequently researched the then only whispered "cramp" nearly a half century ago and pondered the current easy acceptance and all too casual suggestion of many disorders to be "a case of cramp". Proceeding full steam forward with both Cerebellar Abiotrophy and Scottie Cramp projects may very well serve to aid each other.
Not part of the presentation, but also noteworthy, was a recent article in Cornell's newsletter Dog Watch, about a Scottish Terrier affected with both Cerebellar Abiotrophy and von Willebrand's disease. We can all understand how CA could present itself, but unfathomable and inexcusable that vWD should appear in any Scottish Terrier.
This past decade of scientific advancement and particularly with the canine genome research completed, provides a wonderful time and opportunity to proceed on this important disease. All Scottie Fanciers can contribute in many ways. Owners of affected can contribute by providing the necessary and undisputable clinical evidence, breeders should seek and urge others to obtain accurate diagnosis of movement disorders, and all of us can educate ourselves and earmark monetary HTF contributions to support and continue this very worthwhile project.
Original Doc: STCA HTF Seminar CA.doc
Scottie Cramp or CA? Two Neurological disorders affecting the breed
By Debbie Smith 2003
Murphy, who can no longer walk, a rare, but possible result of CA in Scotties
For years, Scottie owners have been aware of a movement disorder in the breed known as Scottie Cramp. Descriptions of this disease abound, and anyone who knows anything about the breed has undoubtedly heard of it. The symptoms of Cramp are very easy to recognize … or are they?
For the past two years I’ve talked with Scottie owners who believed their dog suffered from Cramp, and many of their vets agreed. These Scotties began life normally but slowly developed irregularities in movement. They became a bit clumsy, began to trip occasionally and their gait seemed to worsen when overexcited. At times the back legs slipped or slid out from under them, almost as if they suddenly encountered a patch of ice. This was especially noticeable on smooth surfaces such as wood floors, tile or linoleum.
The rear-end seemed to have a life of its own, especially while running or attempting a sharp turn, causing the dog to fall or somersault, often rolling over and over again until coming to a stop. These Scotties exhibited irregularities in the front legs too, some pranced with a fancy high-stepping gait and others developed a very cute, soldier-like march. Some had a mild, stiff-legged gait and a slightly elevated rump, which made it appear asif the dog tip-toed. Others began moving at a slower or more cautious pace, and some developed a wide-based rear-leg stance.
As time went by, many owners began to question their diagnosis. The symptoms they saw didn’t quite fit those describing Scottie Cramp. The abnormal movements were present at all times, not only occasionally or only when the dog was exercised or excited. No matter where the dog was or what he/she was doing, the subtle gait abnormalities remained.
Indoors, these dogs had more trouble on smooth flooring than carpeting, some could no longer jump on a couch and some began to refuse stairs. Those that continued to go up and down steps, tripped easily, and sometimes tumbled to the ground. These dogs bunny-hopped while running, exhibited goose-stepping movements and some refused to jump over unexpected obstacles. If they tried to jump at all, they usually tripped, or would over-flex their legs as though perceiving the jump to be higher than it actually was, causing some owners to conclude the dog had problems with vision. People unaccustomed to seeing the dog move, failed to detect the problem as easily as those living with the dog on a daily basis. The early symptoms in the first few years could be misinterpreted as clumsiness by the casual observer.
Eventually these owners found their answer and it was not one they would have expected. It turned out these dogs suffered from a newly described disorder in the Scottish Terrier known as Cerebellar Abiotrophy, better known as “CA”.
CA is a progressive degenerative disease resulting from a premature loss of brain cells in the cerebellum. It causes ataxia or the inability to coordinate movement. The condition is proven to be hereditary and caused by an autosomal recessive gene in the Scottish Terrier, confirmed by Dr. Jerold Bell, DVM, the geneticist working on this disease in thebreed. Both parents must carry the defective gene to produce affected offspring. CA is a late-onset disorder so symptoms aren’t usually noticed until about 6 months of age. Some might detect the problem sooner, or a bit later. Dogs with CA start out life seemingly normal, however, as more brain cells die off, they gradually develop a sloppy gait, lose control of their fine-tuned motor skills, and begin to exhibit inconsistencies in movement. A slight tremor, often present during initiating movements, will disappear at rest. Over time, symptoms become more apparent and some dogs may, eventually, require assistance or support.
A Scottie with this disorder can live out a full life span and the mind remains normal throughout the disease process, but in time, affected dogs must work harder than the average dog just to walk, and they will never regain what has been lost to them.
Perhaps we should take a look at some similarities seen in these two neurological diseases. Maybe it will help us understand why some Scotties affected with CA are thought to have Scottie Cramp. Below is a list of symptoms describing each disorder. Keep in mind, both are already established as widespread hereditary conditions, both are caused by a defective autosomal recessive gene, and both are permanent conditions in the Scottie.
Cerebellar Abiotrophy Scottie Cramp
Symptoms are constant and progressive Symptoms are occasional, not progressive
Changes in gait Changes in gait
Abnormal movements in forelegs Abnormal movements in forelegs
Spine or lumbar may arch Spine or lumbar may arch
Rear legs over-flex Rear legs over-flex
Dog begins to goose step Dog begins to goose step
Dog may somersault and fall Dog may somersault and fall
Dog represses movement Dog represses movement
Severity of symptoms varies widely Severity of symptoms varies widely
Dog experiences no pain Dog experiences no pain
Uncoordinated movements Uncoordinated movements
The similarities in these two diseases are remarkable, aren't they? If one happens to forget that Cramp is only present occasionally and is not a progressive disease, it would be easy to confuse the two disorders.
"Every affected Scottish Terrier may not show all of the above symptoms," says Dr. Bell, but it is important to bear in mind that symptoms seen in CA are constant and never go away; they slowly get worse as the years go by. CA is a progressive disease, but it can sometimes take years to notice a change in a mildly affected dog. Even experienced breeders could mistake what they are seeing for Scottie Cramp.
Scottie Cramp, on the other hand, gets no worse and is not a progressive disease. Dogs with Cramp only exhibit symptoms occasionally or while under stress. Once the stressful situation is resolved, the dog is perfectly normal again and will exhibit no unusual movement whatsoever. They live a relatively normal life with only brief periods of temporary incoordination. If the stress precipitating a cramping episode is avoided, the dog may never show symptoms again.
his services, the first scientific report on CA in a Scottish Terrier was published by two South African doctors. They confirmed this disease affected the Scottie in another country, and added great weight to Dr. Bell’s earlier conclusion that CA is a World-Wide problem in the breed. In the past two years, several articles concerning CA have been published in The Bagpiper, The Scottie Scamper (Canadian Scottish Terrier Club), and in Great Scots Magazine. A health pamphlet about CA is now available from the STCA HTF and presently, two articles about CA can be found under “health” on the official STCA website: http://clubs.akc.org/stca/health.htm
If you’ve noticed any unusual movement in your Scottie, take a closer look! Have your dog go up and down steps at a fast pace, have him/her chase a ball, or jump over a small hurdle while off lead. Watch those legs; a CA affected Scotties’ rear legs are all over the place when moving at a fast pace, they will bunny-hop, trip, possibly bang their chin, and exhibit clumsy and uncoordinated movements, at all times, once symptoms develop.
What could confusion about this disease mean for the breed? If CA continues being misdiagnosed and if affected dogs or obligate carriers who produce the disease are bred, the defective gene responsible for CA will spread even further throughout the population, thereby perpetuating this degenerative disorder in the Scottie. It is imperative Scottie owners learn to identify CA. Dr. Jerold Bell, DVM, has recently stated, "We are at the stage where the defective gene is so widespread, that no breeding program is immune."
That is a frightening thought to be sure, but there are ways to control disease caused by recessive genes. He and the STCA HTF are hard at work on that, but they need your help. Anyone who suspects their dog might have CA, contact Dr. Bell and send him a videotape of your dog so he can confirm or rule it out in your dog. Please include a copy of registration and a pedigree, if available. Dr. Bell offers complete confidentiality. Any Scottie owner, World-Wide, who suspects their Scottie has CA, can contact him.
Please note: Dr. Bell first needs to correspond with an owner before a video is made of a dog, that way he can give exact instructions on what movements should be included on any videotape sent to him.
Dr. Jerold Bell, DVM
Veterinary Genetic Counseling
PO Box 3399
Enfield, CT 06083
To view a videotape or DVD of six clinically diagnosed Scotties with CA, please contact me. There is no charge. A small donation to the STCA HTF CA Project is always appreciated, but not required.
CA Research Project Chairman
6556 Pinar Rd.
Harborcreek, PA 16421
Original Doc: scottie cramp or CA.doc
Cerebellar Abiotrophy- It ain't cramp!
By Monica Madore and Linda St James
Gryndlscot Scottish Terriers, Reg.
Dunnville, ON N1A 2W8
There is a newly described disease in our breed that is about to become a major problem unless steps are taken to deal with it in a responsible manner. This disease is Cerebellar Abiotrophy, also known as ataxia or "wobbly Scottie" syndrome. Most of you probably have not yet seen it, but in the next few generations of your breeding programs it just might jump out, as it did to us out of the blue in our last litter.
Cerebellar abiotrophy (CA) is a recessively inherited genetic condition. According to the current pedigree analyses being done by geneticists in the United States, the gene has been in the Scottie breed for many generations and traces back to some of the early English imports brought in to establish and improve the breed on this continent. It is estimated that the gene is present in 13% of Scotties, a relatively high frequency, and one that seems to be on the increase in current generations. It is a brain disease in which key brain cells responsible for motor movement and gait are progressively destroyed by some type of as yet unknown metabolic malfunction. In our breed, symptoms usually occur at around 6-9 months of age (although there are some new cases now being reported in which dogs have remained symptom-free until as old as age 5, then developed full blown CA). The disease is progressive- brain cells continue to be damaged throughout the dog's life and symptoms can subsequently be worse as the dog ages.
Superficially, the symptoms of CA resemble very closely what we have always described as "Scottie Cramp". A CA-affected dog will display the odd gait and movement patterns commonly ascribed to "cramp", including a goose-stepping motion of the front limbs, "bunny hopping" rear movement, arched back, falling over. Like cramp, the condition does not appear to be painful.
A severely affected CA dog has severe "cramp" symptoms at almost all times. Unlike "cramp", which is episodic and appears to be triggered by a specific stress stimulus, CA in a severely affected dog appears to be "cramp gone wild". It is always "turned on" no matter what the dog is currently experiencing and the dog always shows gait problems, especially on smooth surfaces, at a run and when doing a sharp turn. These dogs have particular problems doing stairs, up or down, as you will see in the video of the severely affected dog from our litter we have provided for viewing. This video shows the same dog that Janet Hale has sent you a video of- but taken six weeks after her video was shot.
Unfortunately, a real problem seems to be arising in our breed, because not all CA dogs are severely affected. There appear to be milder versions of the disease, which probably reflect disease in which fewer numbers of brain cells in the cerebellum are destroyed. It is these mildly affected dogs who are now cause for concern, because they can easily be misdiagnosed as "cramp" dogs. The similarities between the symptoms of the two diseases are remarkable, and in the case of a mildly affected dog, almost indistinguishable if the term "episodic" is used as a determining factor to discriminate between "cramp" and CA.
Our litter contains not only the severely affected dog on the video but also one mildly affected puppy. This dog became suspect after his brother was diagnosed, as he too had difficulty climbing stairs (could do so but only very clumsily) and would frequently have his back end slip out from under him on tile floors when running. At all other times he showed what would have been considered perfectly normal gait, as long as he was moving at a good clip in a straight line. This boy was entered in his first dog show at 7 months, and showed extremely bad rear movement when moving in the ring. His back legs could barely stay on the mat and he bunny hopped profusely and goose stepped when his rear was really wobbly. Outside on the grass, his gait looked completely normal. Inside on the concrete, especially when moving slowly and turning, his rear swayed and slipped badly and the goose step reappeared. Outside, on the asphalt, where his nails could get a better grip, he gaited normally on a straight down and back and a wide circle. And as he tired after his first show, the gait problems got worse and worse.
If nothing was known about CA, this dog would be diagnosed as a cramp dog, as his gait problems could easily be thought to fit an "episodic" pattern (i.e. not seen every time the dog moved.) And the stress and exhaustion of the dog show could easily be explained as the "triggers" that induced cramp episodes. And herein lies our present problem. We need a new definition of what is truly meant by "episodic"- mildly affected CA dogs can have periods where they are able to compensate for their brain damage and walk in what we would consider a perfectly normal fashion. They are always afflicted by their disease, but unless you are really looking, the gait problems might not be all that evident. So they too have a form of "episodic" disease- but it is NOT CRAMP!
In the past, cramp episodes were reported to occur maybe a few times in the lifetime of the dog, and could often be eliminated entirely if stress triggers were also eliminated. CA is different- obvious episodes will occur at a much greater frequency, especially if the dog is tired- perhaps daily, perhaps several times a day. If you are seeing what you think is "cramp" in a 6+ month old puppy, especially one that does not handle long walks well, is clumsy on stairs, slips on linoleum and just in general seems "clumsier" than a six month old should, you should immediately suspect CA.
CA is probably "ramped" in our breed right now. So far we have been "lucky", producing carriers and not affected dogs. But as we carry out more and more line breedings, those carriers are going to be brought together and we will see an explosion of this disease. Until we get a definitive genetic test, and especially since "cramp" and mild CA are so hard to distinguish, it is essential that we stop having a cavalier attitude towards Scottie Cramp and at all costs avoid ever breeding affected dogs. They may be mildly CA affected, not cramp dogs, and there is no way of telling how severely affected any of their progeny might be. Watch the video- it is absolutely heartbreaking to see such a happy, beautiful Scottie stumble, crash, and wobble as he tries to do something as simple as play ball or follow his owner upstairs.
For more information on CA, please visit the following links: