Maine Coon Health Testing: What Should Responsible Breeders Test For?
Updated: 5 days ago
If you ask a Maine Coon breeder whether their cats are health tested, the answer will probably be yes.
But “yes, our cats are health tested” isn't enough information.
What were they tested for? How were they tested? Can you see the results? And perhaps most importantly, what does the breeder actually do with those results when making breeding decisions?
Maine Coons, like all pedigreed cats, have certain health conditions that occur within the breed. Health testing cannot guarantee that a kitten will never develop a health problem, but it gives breeders valuable information that can help us make more informed breeding decisions and reduce preventable risks.
At Maine Coon Mayo, health testing is one part of a much bigger picture that includes pedigree research, temperament, structure, genetic diversity, family history and ongoing veterinary care.
This is what I believe prospective Maine Coon families should understand about health testing—and what I would ask another breeder if I were purchasing a kitten myself.
What Health Testing Should a Maine Coon Breeder Do?
There isn't one single test that makes a Maine Coon “health tested.”
Different conditions require different forms of screening.
In our program, our core screening includes:
Comprehensive DNA testing
DNA testing for the known Maine Coon-associated HCM mutation
OFA hip evaluation
FIV and FeLV blood testing
Blood type testing
Additional veterinary, infectious disease or reproductive testing when indicated
Each test tells us something different.
And that's an important distinction because DNA testing alone is not a complete Maine Coon health-testing program.
1. Comprehensive DNA Testing
DNA testing is one of the easiest places for breeders to start, and in my opinion, there is very little excuse not to do it.
At Maine Coon Mayo, we use Wisdom Panel to screen our breeding cats for more than 50 genetic health conditions and other genetic traits.
We typically DNA test a prospective breeding cat after they arrive and have first received negative FIV and FeLV results.
DNA testing can tell us whether a cat carries certain known disease-associated genetic variants. Depending on the condition, a result may show that a cat is clear, a carrier or genetically at risk.
But understanding how a condition is inherited is just as important as receiving the result.
A Carrier Isn't Necessarily an Affected Cat
This is something I think kitten buyers should understand.
Not every positive genetic result means a cat should automatically be removed from a breeding program.
Some diseases are autosomal recessive, meaning a cat generally needs to inherit two copies of a disease-associated variant—one from each parent—to be genetically at risk of developing the associated condition.
Pyruvate kinase deficiency, or PKDef, is one example.
One of our queens, Jitterbug, carries one copy of the PKDef variant. That doesn't mean she has PKDef.
It means I have to know the PKDef status of every male I consider pairing with her.
She is only paired with a male who is clear for that variant so that the pairing cannot produce a kitten with two copies of it.
This is one of the reasons I don't believe responsible breeding can be reduced to looking for the word “clear” beside every result.
The breeder needs to understand the genetics and use the information appropriately when planning a pairing.
2. HCM Testing in Maine Coons
Hypertrophic cardiomyopathy, commonly called HCM, is one of the most important health concerns discussed in Maine Coons.
HCM causes abnormal thickening of the heart muscle and can range considerably in severity.
A known HCM-associated genetic variant has been identified in Maine Coons, and our breeding cats are DNA tested for it.
In our program, a cat carrying even one copy of the known Maine Coon HCM-associated mutation would not be used for breeding.
However, there is an extremely important limitation to DNA testing:
A negative HCM DNA result does not mean a cat can never develop HCM.
The known mutation does not explain every case of HCM in Maine Coons.
That distinction matters.
What About Echocardiograms?
This is an area where breeding programs differ.
An echocardiogram is an ultrasound examination of the heart and can identify structural changes consistent with HCM at the time the examination is performed. TICA currently recommends DNA screening along with periodic echocardiograms evaluated by a board-certified veterinary cardiologist for Maine Coons.
Some Maine Coon breeders strongly believe in routine echocardiographic screening and consider it an essential part of their breeding programs. Others are more skeptical about its ability to predict future disease because a normal echocardiogram tells you what the heart looks like at that point in the cat's life; it cannot guarantee that HCM will never develop later.
At Maine Coon Mayo, we currently perform DNA screening for the known Maine Coon HCM-associated mutation but do not routinely perform echocardiograms on our breeding cats. Several of our imported breeding cats come from parents with clear echocardiograms.
We also provide a 4-year genetic health guarantee that includes HCM.
I think breeders should be transparent about which screening methods they use rather than suggesting that any single test can guarantee that HCM will never occur.
If you're interviewing breeders, this is a very reasonable subject to ask about.
3. SMA and Other Genetic Conditions
Spinal muscular atrophy (SMA) is another inherited condition associated with Maine Coons and is included in our genetic screening.
Our breeding cats have tested negative for the known SMA-associated variant.
Comprehensive DNA panels can screen for numerous additional genetic conditions, depending on the laboratory used.
The important thing isn't simply being told that a breeder “DNA tests.”
Ask to see what the panel actually tested for and what the results were.
4. Hip Dysplasia Testing
Hip testing is one of the areas I feel particularly strongly about.
Maine Coons are predisposed to hip dysplasia, and unlike the diseases we can identify through a simple genetic variant, hip dysplasia is a much more complicated trait.
At Maine Coon Mayo, prospective breeding cats generally have hip radiographs taken between approximately 8 and 12 months of age and submitted to the Orthopedic Foundation for Animals (OFA) for evaluation.
OFA classifies hip conformation using grades. Excellent, Good and Fair are considered within normal limits, while increasing degrees of dysplasia are classified as Mild, Moderate or Severe.
Why Can't We Just DNA Test for Hip Dysplasia?
Because hip dysplasia isn't controlled by one simple gene.
It is generally considered polygenic and multifactorial.
In simple terms, that means multiple genes can influence the development of the hips, while non-genetic factors may also affect how the condition ultimately presents.
That makes breeding decisions much more complicated than:
Clear + clear = clear.
I've seen that complexity within my own breeding program.
I've had parents with Good hip results produce an offspring that later received a Fair result. I've also had a pairing involving Fair and Good hip results produce an offspring with Good hips.
That doesn't make hip screening useless.
Quite the opposite.
It demonstrates why breeders need information from multiple generations and why continuing to evaluate the offspring we produce is so valuable.
A hip result gives us another piece of information to use when considering the individual cat, its relatives and a potential pairing.
Is a Fair OFA Result a Failed Hip Test?
No.
This is an important misconception.
OFA considers Excellent, Good and Fair hip classifications to be within normal limits.
I personally prefer to have at least one parent in a pairing with Good hips, particularly when considering a cat with a less ideal result elsewhere in the pedigree.
Hip dysplasia is exactly why I don't think buyers should accept “DNA tested” as synonymous with fully health tested.
You cannot currently determine a Maine Coon's hip quality from a standard DNA panel.
You have to evaluate the hips.
5. FIV and FeLV Testing
Not everything we test for is hereditary.
Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) are infectious diseases.
At Maine Coon Mayo, FIV and FeLV blood testing is one of the first things we do when a new prospective breeding cat arrives.
I want to know that result before moving forward with the rest of our breeding evaluation.
A cat testing positive would not enter our breeding program.
For a breeder maintaining multiple cats, introducing new breeding animals from other catteries, sometimes from other countries, infectious disease screening is an important part of protecting the entire population.
6. Blood Type Testing
Blood type may not be something the average pet owner thinks about, but it can be important information for a breeder.
We determine blood type through our DNA testing.
All of our current breeding cats are type A.
Knowing the blood types of breeding cats can be important because incompatible maternal and kitten blood types can create a potentially serious condition in newborn kittens called neonatal isoerythrolysis.
It's another example of health information that may not matter much to the eventual pet owner but can matter considerably when planning a breeding.
7. Sometimes Responsible Testing Means Investigating a Problem
Health screening doesn't stop once a cat has passed its initial tests.
Sometimes something happens that needs an explanation.
That's when additional diagnostics become important.
After one of Jitterbug's early litters, for example, we lost two kittens. I didn't simply assume it was bad luck and move on.
We performed additional reproductive testing, including an abortion/reproductive panel, to investigate whether an infectious or reproductive cause could be identified.
Nothing abnormal was found.
Her subsequent litter contained six kittens.
We also use additional testing such as fecal PCR panels, bloodwork or reproductive screening when circumstances indicate that it's warranted.
I don't routinely perform every diagnostic test available on every healthy cat. Instead, our veterinarian and I use additional diagnostics when the history, symptoms or reproductive circumstances give us a reason to investigate further.
I think this is another part of responsible breeding that doesn't always make it onto a website.
Testing isn't only about collecting certificates. It's about being willing to investigate when something doesn't go according to plan.
8. Passing Health Tests Doesn't Automatically Make a Cat Breeding Quality
This may be one of the most important points in this entire article.
A cat can have beautiful health-testing results and still not be a cat I would choose for my breeding program.
Health testing is the starting point.
When I evaluate a prospective breeding cat, I'm also looking at:
Temperament
Structure and conformation
Pedigree
Family health history
Genetic diversity
Parents and grandparents
Longevity within the line
Size and substance
Overall balance
How the cat fits into the direction of our breeding program
Temperament Matters
I pay close attention to how a cat behaves.
How do they react in a new situation?
Are they curious?
Are they friendly?
Are they the cat that comes forward to meet you?
How do they interact with people and other cats?
Temperament has always been extremely important in our breeding program because we're ultimately producing companions that will spend their lives as members of people's families.
Structure and Breed Type Matter Too
There is no perfect Maine Coon.
Every breeder has traits they are trying to preserve or improve, and if you follow a breeding program long enough, you'll often begin to recognize that breeder's particular “look.”
At Maine Coon Mayo, I enjoy a somewhat wilder European expression while still wanting a balanced cat.
I evaluate features such as the profile, muzzle, chin, ears, body structure, bone and overall proportions.
I don't want exaggerated features simply for the sake of making a cat look extreme.
Our goal is a recognizable Maine Coon with the type we love while maintaining balance, health and temperament.
9. Look Beyond the Individual Cat
When I'm considering purchasing a breeding kitten, I don't only look at that kitten.
I want to know about the family.
Are the parents healthy?
Are the grandparents still alive?
How old are they?
What health problems have appeared within the line?
What health testing has been performed?
I've declined breeding kittens because of health concerns within their family history, including hip dysplasia and entropion.
A beautiful kitten doesn't erase a pedigree or family history that makes me uncomfortable.
That is also why having a relationship with other breeders matters. Health information isn't always something that fits neatly onto a certificate.
Sometimes one of the most important questions you can ask is simply:
“What health issues have you seen in this line?”
10. What Is COI?
Another number buyers may encounter on a pedigree is the coefficient of inbreeding, usually shortened to COI.
Put simply, COI estimates the probability that two copies of a gene in an individual were inherited from a shared ancestor.
A higher COI generally indicates greater genetic relatedness within the pedigree. A lower COI indicates less.
But, like most things in breeding, COI shouldn't be viewed as a single magic number that determines whether a cat or pairing is good or bad.
Breeders have to consider genetic diversity alongside health, temperament, breed type, pedigree and the characteristics they're trying to preserve.
Our pairings generally produce kittens with COIs around 15–17%, depending on the pairing and pedigree calculation used.
I consider COI when planning breedings, but I don't use it in isolation.
11. Health Testing Is Risk Reduction, Not a Guarantee of Perfection
This is something I think responsible breeders need to be willing to say.
Health-tested parents can still produce a kitten that develops a health problem.
We're working with biology, not machinery.
Health testing allows us to identify known risks, avoid certain high-risk pairings, monitor conditions that occur within the breed and make increasingly informed decisions over generations.
But no breeder can truthfully promise that every kitten they produce will remain perfectly healthy for life.
What I want to see is a breeder doing everything reasonably available to stack the odds in the kittens' favour.
And when something does go wrong, I want to know that the breeder pays attention, investigates it, keeps records and uses that information when making future breeding decisions.
That's what health testing is really about.
12. Ask to See the Results
If there is one thing I want prospective Maine Coon families to take away from this article, it's this:
Don't accept “yes, our cats are health tested” as an answer.
Ask:
What do you test for?
And then:
Can I see the results?
A responsible breeder should be comfortable discussing their testing protocol and explaining what the results mean.
At Maine Coon Mayo, we believe this information should be as accessible as possible. Health-testing results for our breeding cats are being added to their individual profiles on our website so prospective families can view them directly.
You shouldn't need a genetics degree to purchase a Maine Coon.
But you should be able to see enough information to know that the person making decisions about your future kitten understands the health concerns within the breed and is actively doing something about them.
Final Thoughts
There is more to responsible Maine Coon breeding than producing beautiful kittens.
Health testing costs money. It takes time. Sometimes it gives you an answer you didn't want and means altering a cat you had hoped would become part of your breeding program.
But that's exactly why we do it.
The purpose isn't to collect certificates or put a “health tested” badge on a website.
The purpose is to make better breeding decisions.
DNA results help us understand inherited variants. Hip evaluations help us monitor orthopedic health. FIV and FeLV screening help protect our cats from infectious disease. Blood typing helps us plan safer breedings. Family history gives us information no individual laboratory test can provide.
And all of those pieces have to be interpreted alongside the actual cat standing in front of us.
For me, responsible breeding means continually gathering information—and then being willing to let that information influence the decisions I make.
If you're currently looking for a Maine Coon kitten, you may also want to read our guide, How to Find a Reputable Maine Coon Breeder in Canada, for more information about breeder registration, contracts, scams, reviews, kitten raising and other things to investigate before choosing a breeder.
About Maine Coon Mayo
Maine Coon Mayo is a small, home-based Maine Coon cattery located near Nelson, British Columbia, Canada. Our breeding program focuses on health, temperament and breed type, supported by genetic screening, OFA hip evaluation, infectious-disease testing, pedigree research and a 4-year genetic health guarantee.
Health-testing results for our breeding cats can be viewed on—or are currently being added to—their individual profiles on our website.
Interested in learning more?
Explore our Health Testing, meet our Breeding Cats, read about our 4-Year Health Guarantee, or learn how our Priority List works.
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