Congenital myasthenic syndrome (CMS)

Congenital myasthenic syndrome (CMS) causes muscle weakness in Devon Rex and Sphynx cats. Affected cats show ventroflexion of the head and neck, head bobbing, scapulae protrusion and generalized muscle weakness and fatigability. Signs become evident at 3 to 23 weeks of age and usually progress slowly or remain static. Moderately to severely affected cats show evidence of more generalized muscle weakness, particularly following exertion, stress or excitement. Typically they have a high-stepping forelimb gait, head bobbing and progressive dorsal protrusion of the scapulae. Affected cats tire easily with exercise, with progressive shortening of the stride and superimposed tremor. Eventually they collapse in sternal recumbency, typically with the head coming to rest on, or to one side of, their front paws. Affected cats frequently adopt a characteristic 'chipmunk' position, usually with their front legs resting on a convenient object.

This illness requires a lot of care from the owner. Due to the inability to keep the head upright, feeding has to be supervised to make sure the cat can eat, but also to help prevent “inhalation” of the food (in the airways). The latter situation can be the main cause of pneumonia, often resulting in death or the need to euthanize the cat.

The genetic disease is recessive, meaning that affected cats have two copies of the mutation. Cats with one copy of the mutation (carriers) are not affected, but can pass the mutation on to their offspring.

History

Soon after the Devon Rex was established, affected cats were found in all the countries where Devon Rex were bred. Before the arrival of the dna-test, the only way to pinpoint carriers, was through test-breeding. A lot of carriers were taken out of breeding plans, but as the disease is inherited in a recessive fashion, the gene remained afloat in the Devon Rex gene pool. Sphynx cats run a similar risk of getting the disease, because Devon Rex cats were used as outcross partners from the start of that breed. The gene responsible for the Drx curls, is recessive to the gene that causes hairlessness in the Sphynx, resulting in hairless kittens when mating a Devon Rex to a Sphynx. An outcross of the Sphynx with any other breed of cat, will bring forth coated kittens.

The mutation responsible for CMS has been discovered in 2015 by Marie Abitbol, Alfort School of Veterinary Medicine in Maisons-Alfort, France. A dna test followed soon after. Consequently the Universities of Missouri, California - Davis, California - San Diego, Sydney and Milan also developed a dna test.

Unfortunately, a lot of newer breeders of both the Devon Rex and the Sphynx are not aware of the risks of passing on CMS. Since the genes is inherited in a recessive mode, the genes can still be afloat in the gene pool of both breeds. In recent years some cases of DRX myopathy have surfaced in France. Breeders that have tested their breeding animals have come across carriers of the gene.

With GCCF In the United Kingdom, the test was made compulsory for breeding with Devon Rex and Sphynx soon after its discovery. More info on the history of the dna-test can be found here:
http://www.devonrex-ownersclub.co.uk/uploads/1/0/2/5/10250122/genetic_testing_for_spasticity.pdf

The Devon Rex owners club has kindly given permission to us to use the majority of the CMS-texts used on their website. Many thanks to Jen Pinches for correcting and editing the Pawpeds texts on CMS.

Breeding Recommendations, CMS

Congenital myasthenic syndrome in Devon Rex and Sphynx

Interpretation of the test results:

A Normal, clear, or N/N (-/-) Congenital myasthenic syndrome (CMS) genetic test result means that the cat does not have the known gene variant causing the disease.
A Carrier, N/CMS (+/-) Congenital myasthenic syndrome (CMS) genetic test result means that the cat has one copy of the gene variant. The cat will not have the disease, but may pass the gene variant to their offspring.
An Affected, CMS/CMS (+/+) Congenital myasthenic syndrome (CMS) genetic test result means that the cat has two copies of the gene variant. The cat will develop Congenital myasthenic syndrome (CMS).

For breeders, the following is advised:
a) Cats with a normal result (-/-) can be used for breeding.
b) Carriers (+/-) can be used for breeding, but only when partnered to cats that are normal (-/-) for CMS.*
c) an affected (+/+) cat may NOT be used for breeding.

* Here is a 50% chance that offspring will also be carriers. All buyers of carrier kittens and kittens of unknown CMS status should be informed about the disease and the risks of using the kitten for breeding. These heterozygous carriers will never get any signs of the disorder; so one might think it is irrelevant information for a pet buyer. However, since it isn't uncommon that pet buyers later get the idea to have a litter from their cat and sometimes without contacting its breeder, it is important that also pet buyers fully understand the nature of the disease and the
cms-status of their kitten.

Testing for CMS

How do I DNA test for CMS?

You can do a simple DNA-test with a cheek swab, or send blood or a semen sample. The possible methods differ
per laboratory. Carefully read the instructions of the lab you choose, to prevent mistakes. Veterinary identity verification via
microchip is advised, but not compulsory for the Pawpeds database. Without it, the remark: "ID not verified" will be
placed next to the results.

Laboratories that test for CMS-dna (last updated: December 2024)

Labs with combination tests that include the test for CMS-dna

MyCatDNA (Europe) or Optimal Selection (USA/CA)
VHL genetics Combibreed (Devon Rex)

How do I get the results public on PawPeds?

CMS can be found in the DNA of Devon Rex and Sphynx, however we currently only have an active Health Programme for Devon Rex.

First make sure the pedigree of the tested cat already has been uploaded in the database.
For Devon Rex: https://www.pawpeds.com/cms/index.php/en/databases/maintainers/drxdbmaintainers
In order to have your cat's result registered in the health program, you have to send in a copy of the result to the registrar by email. You can find the contact info in the contact-link in the menu.
You can also click here:

Help!

If you have any questions, please don't hesitate to contact the contact persons for the health programme!

Hip Radiographs - Information to the Veterinarian

We also have information specific to cat owners.

PawPeds is an organisation working for better and healthier animal breeding. In January 2000 the Swedish Maine Coon Cat Club started a public register of hip radiographs. This register is since June 2010 administered by PawPeds. The recommendation is that all Maine Coons should be tested for HD before being used in a breeding programme, in order to reduce the frequency of HD in the breed.

As hip dysplasia is not only found in the Maine Coon breed, it might be of interest to know for other breeds that they also have the possibility to join this health programme. All radiographs that is sent in according to the rules of the health programme will be handled and registered independent of breed.

All results in the register are public 60 days after the cat owner has received the result. The results are published per breed on the Health Data Download page and for some breeds the results are also presented in the pedigree database.

PawPeds collaborate with the veterinarian and radiograph expert Elisabeth Ball who evaluates all the hip radiographs on behalf of the health programme. We believe that it is very important that these radiographs are evaluated by one person only, in order to obtain the most consistent assessment possible.

Below you will find information on how the cat should be radiographed, some recommendations, and how to submit the HD form and radiographs to PawPeds.

Note: Cat owners with breeds other than the Maine Coon are also welcome!

Checklist

Please note that the cat must have an identification such as a microchip or a tattoo
- The ID number written on the HD form must be verified with a chip reader or by checking the tattoo
- The ID number and pedigree name must be checked against the cat's pedigree or similar identification paper
The ID number and the date of the examination must be exposed into the radiographs, not added digitally
- If there is room for it, it would help if the cat's pedigree name and registration number is visible on the radiograph too
It is also very important that PawPeds' HD form is used
- One part of the HD form is filled in by the cat owner in advance and the second part by the veterinarian
The cat owner must have signed the HD form before the radiographs are made
- With the signature the owner gives us permission to register and publish the results into the public registry
- We need sufficient submissions to evaluate the correct frequency of HD in the breeds to see the effect of testing on later generations
- If the owner refused to sign the HD form i advance, the HD form of PawPeds should not be used and the radiographs should not be submitted to PawPeds
The images must be digital and saved in DICOM format
- The images should not be compressed

Recommendations on making a good X-ray

A mild sedative (injection) is recommended before the radiograph to facilitate the positioning of the cat. The cat should however not be heavily sedated.

The same routines should be used as radiographing a dog’s hips. The pelvis and the knee joints should be seen on the radiographs. The legs should lie parallel and the knee joint should lie in a straight line with the thighbone. The legs should not be rotated inwards or outwards.

In order for us to make the best assessment possible, the pelvis needs to be as straight as possible. Picture 1 is an example of a rotated pelvis and picture 2 is an example of how we want them to lie. The ID-number should be put on the radiograph, and a marker showing which side is which. This should be burned into the image and not added digitally afterwards. (Lead marking) The spine should lie straight. The pelvis and the knee joints should be seen on the radiographs. The legs should lie parallel and the knee joint should lie in a straight line with the thighbone. The legs should not be to rotated inwards or outwards.
In picture 1, there are no markings at all. It is crooked in the back, which means that the hip is crooked as well. The ilium wings should be straight (look the same on both sides), if one side is too wide, the hip is rotated. The obturator foramen should be equal is size and having symmetrical shape.

Submit the HD Form and Radiographs

Check and fill in information about the examination on the HD form and sign it
The HD form and the DICOM file/files with the radiographs are uploaded to PawPeds in the HealthWeb: https://health.pawpeds.com/
- The HD form must be scanned to jpg, png, or pdf
- The radiographs must be in DICOM format (.dcm) and the images must not be compressed

The first time an upload is made a personal account must be created. This can be anyone at the clinic with that responsibility, it doesn't need to be the veterinarian. Read more about the HealthWeb to get the overall process described.

Information

The Evaluation Grades

The evaluation grades on the scale used are the same ones as for hip radiographing dogs, but due to the fact that the anatomical picture is different for cats the usual "Norberg’s angle" is not used. This means that we do not use the ABCD evaluation scale. Instead we use "normal", "1", "2" and "3" where each hip will be scored separately:

Normal (grade 0) - no signs of hip dysplasia and/or degenerative joint disease and the acetabulum covering at least 50% of the femoral head
Grade 1 (mild hip dysplasia) - mild signs of hip dysplasia and/or the acetabulum covering less than 50% of the femoral head but no signs of deforming degenerative joint disease
Grade 2 (moderate hip dysplasia) - moderate signs of hip dysplasia and/or signs of deforming degenerative joint disease
Grade 3 (severe hip dysplasia) - severe signs of hip dysplasia and/or deforming degenerative joint disease

Payment

The cat owner pays directly to PawPeds for the assessment of the radiographs, made by PawPeds' evaluator. There is no action expected from the veterinarian.

Access to the Assessment

When PawPeds' evaluator has made the assessment the result will be visible for you in the HealthWeb. Also until that time you can view the status of the HD cases that you have submitted to the evaluator.

Help!

If you have any questions, please don't hesitate to contact the contact persons for the health programme! You can also email This email address is being protected from spambots. You need JavaScript enabled to view it..

Information about the HealthWeb system

In the beginning of 2023 we launched a new web based system called HealthWeb where the veterinary clinic can upload the images of the hips directly in the system.

To initiate a HD case in the new system the owner must first create the HD form via the system. The HD form is then printed and signed. Se more detailed information on the page How to test.

The HealthWeb is available on this page: https://health.pawpeds.com/

Both owners and veterinarian needs to have an account for the HealthWeb. For the owners it is the same account that is used for NetPedigree (the online database system for pedigrees). The veterinarian must create a new account the first time they want to use the system.

More information and details are found when visiting the HealthWeb via the link above.

How do I create my case

What does the status mean

Criteria for Fancy Certificat

The Overall Process

The cat owner registers a new HD case in the system and prints a pre-filled form and signs it before the visit to the clinic
At the clinic the veterinarian fills in information about the examination, signs the form, and performs the x-ray
The form is scanned by the clinic
The clinic first uploads the form which has a QR code that is used to connect the form to the right HD case in the HealthWeb
Then the DICOM files (that contains the x-ray images) are uploaded by the clinic to the HD case
When everything is uploaded and filled in, the HD case is submitted by the clinic
When payment has been received from the cat owner and is noted in the system, the HD case becomes available for our evaluator
Our evaluator looks at the images and register the assessment
The result of the assessment is registered in our health register
The result is sent to the cat owner by email

How do I create my case?

1. Register an account if you do not have one yet, if you already have an account login.
2. When logged on click on CatOwner if you are at the start page, there you will see up in the top row "New FHD Examination", click on that to enter your cat.

3. When the cat is added, click on Download form to download the already filled in form to your computer, print it out, sign it and take it with you to the veterinarian.

What does the status mean?

Here is a list of the statuses that you might see, the one in bold is the one you most likely will come in contact with or see.

Started - This is the first status when you created the case.

Form uploaded - Your veterinarian uploaded your picture.

Image uploading ongoing - Uploading of pictures are ongoing or is partially done.

Returned to vet for completion - Elisabeth sent the case back to the veterinarian for completions. 
(Both veterinarian and owner shall get an email including Elisabeths message)

Sent in for evaluation - The veterinarian marked that the upload of the x-ray is done 
The files will go to Elisabeth when payment is received.

Returned case sent again for evaluation - A case sent back for completion is now back for Elisabeth to check again.

Evaluation ongoing - Elisabeth is doing the reading, will only show if she cannot finish the assessment right away for some reason.

Evaluation done - Elisabeth is done with the evaluation, but still not printed the document she is signing.

Ready for registration - The evaluation has arrived at the registrator to be registered.

Registration ongoing - The registrator is managing the registration 
(Will only be shown if something needs to checked before the registration can be finished).

Result registered - The result is registrated and results sent out by mail.

Criteria to get a fancy certificate?

We now send out official certificates with the result to the owner by email.
It’s a PDF document that shows the official result and the details of the cat. You can validate the authenticity of the certificate and its content, by scanning the QR-code on the right bottom.
It will take you to the verification page, where you should see the same information about the cat, as written on the certificate.

Not all evaluated X-rays will receive an official certificate.
It will only be sent when all these criteria are met:
- The cat’s identity is verified by the veterinarian and the ID (chip) is visible on the image (X-ray).
- The owner has signed the HD form in advance.
- The images are sent in by the veterinarian through their account on Healthweb (https://health.pawpeds.com/).
Images that are sent in by the owner will not receive an official certificate.
- The cat is at least 10 months old when the X-ray was taken. (Younger cats will get a preliminary result.)
- And of course the evaluation fee is paid. If not all of these criteria are met, you will receive the result in a different looking document with a remark added.