Five Genetic Diseases of Maine Coon Cats

The Maine Coon cat is a fun loving, giant breed. They love to talk, chatter and even sing! They make great companions and are extremely loving. The breed dates back thousands of years – the Maine Coon is a descendant of the Norwegian Forest Cat, along with a “mysterious and supposedly extinct breed.”  They were bred to be fierce hunters; the Vikings brought them aboard their ships to keep the rodent population under control. Because of their size, they are often found in the Guinness Book of World Records. The five most common genetic disorders of Maine Coon cats are:

  1. Spinal Muscular Atrophy (SMA): Spinal Muscular Atrophy affects the neurons in the cat’s spine, resulting in an awkward gait and odd posture. The affliction is not fatal and relatively not painful in Maine Coons. SMA is due to a recessive gene; if a Maine Coon kitten receives this gene from both parents, it will start showing signs of the disease within 3 to 4 months after birth. Kittens who receive the gene from one parent will not acquire SMA. Signs and symptoms include:
  • Loss of muscle mass in hindquarters (cat may sway as it walks)
  • Posture will appear abnormal
  • Cat will struggle to jump
  • Progressive muscular instability and weakness
  • Fine muscular tremors and fasciculations (muscle contractions)

There is, unfortunately, no way to slow or stop the progression of SMA. However, your cat can still live a long and healthy life with proper care. Cats with SMA should be kept indoors, as they cannot get out of harm’s way as quickly as a cat with no spinal abnormalities. Owners also need to take care to keep all of their cat’s food, water and other necessities on the same level. If your cat has a favorite perch, you can add a small set of stairs or a few stools to minimize jumping.

2. Hypertrophic Cardiomyopathy (HCM): This disease is one of the most common forms of heart disease in cats and is often found in the Maine Coon. It typically strikes in middle to older aged cats. Hypertrophic Cardiomyopathy is characterized by a thickening of the heart walls; when the heart walls thicken, the heart cannot pump blood efficiently. This condition eventually results in heart failure and possible sudden death. The gene thought to cause this condition has been isolated; however, a recent study suggests that 1/3 of cats that undergo genetic testing will contract the disease. Breeders play a huge role in eliminating this disease by conducting genetic testing for all breeding cats. Cats with HCM may not show any signs of being sick. Diagnosis is confirmed with cardiac ultrasound and is recommended on an annual basis once the cat reaches middle age (about age 6). 

Signs that your cat may have HCM include:

  •  Lethargy
  • Open-mouthed breathing
  • Rapid breathing
  • Labored breathing
  • Coughing
  • Excessive vomiting

Cats suffering from HCM are likely to have the following conditions:

  • Blood clots in the heart
  • Thromboembolism (blood clots forming in veins deep within the body)
  • Acute hind limb pain or paralysis
  • Rapid heartbeat
  • Arrhythmias (heart beats irregularly, too slowly, or too rapidly)
  • Weak pulse 

There is no cure for HCM. Conventional management of HCM includes medication to: slow the heart rate, correct abnormal heart beats, improve blood flow and cardiac function, decrease blood clot formation, and alleviate fluid build-up with congestive heart failure. Medication for pain control may be indicated. A diet aimed at minimizing sodium intake and optimizing nutrition is highly recommended. Natural alternative therapies include supplementing with ubiquinol (CoQ10)taurine, L-arginine, acetyl L-carnitine, omega-3 fatty acids, feeding heart glandulars, and herbs.


3. Hip Dysplasia: A Maine Coon has roughly a 20% chance of developing Hip Dysplasia. Hip Dysplasia is a condition affecting the hip joint where the socket portion does not fully cover the ball portion of the upper thighbone, resulting in the dislocation of the hip bone. The earlier treatment begins, the better the outcome. Early signs of hip dysplasia, which are more subtle and less easy to spot include joint laxity or looseness and hip joint pain. Other symptoms of hip dysplasia include:

  • Reluctance to jump, run or climb
  • Difficulty getting up from a lying or sitting position
  • Intermittent or persistent hind-limb lameness; more noticeable after exercise
  • Grating sounds when the cat moves
  • Reduced thigh muscle mass and increased shoulder mass as the cat increases the amount of weight placed on its shoulders to avoid pain. 
  • Swaying gait

Hip dysplasia is diagnosed with a thorough examination and radiographs. Treatment considerations are based on the severity of the radiographs as well as the symptoms your cat exhibits. Treatments vary, from pain relief medications to surgery for joint replacement. New therapies include Stem cell treatment, platelet rich plasma, physical therapy, acupuncture, and cold laser therapy. Keep your Maine Coon at a lean weight – if he is overweight, weight reduction plays a large role in managing pain.

4. Stomatitis is one of the most common health issues Maine Coons are prone to develop. This disease is characterized by painful mouth ulcers and inflammation of the cat’s gums and mouth. Pain may cause the cat to stop eating. Contact your veterinarian and ask for an assessment if any of the following signs and symptoms occur:

  • Loss of appetite
  • Unexplained weight loss
  • Bad breath
  • Pawing at face or mouth
  • Dropping food
  • Messy coat of fur
  • Yelping when they eat food

There is no specific test for feline stomatitis. Diagnosis of stomatitis is based on a physical examination, dental X-rays, and routine and specialized bloodwork to rule out other potential causes (feline leukemia virus, feline immunodeficiency, liver and/or kidney disease, oral infection). Chronic cases may require teeth extraction. When treating stomatitis, the goal is to reduce inflammation.  Stomatitis does not respond well to medication treatments. However, there are several natural anti-inflammatory remedies to treat stomatitis. Cold laser therapy has been beneficial for many cats. Raw feeding will also promote good dental health.  Supplements to add to your cat’s regimen include my dental drops, plant-derived sterols, proteolytic enzymes, Ubiquinol, probiotics, and a product from Standard Process called Biodent. For more information, check out this post:  How To Manage Stomatitis In Cats - Two Crazy Cat Ladies

5. Polycystic Kidney Disease (PKD): PKD is a hereditary condition whereby cats are born with cysts growing on their kidneys. The cysts, or pockets of fluid, are present at birth; they are initially very small but grow larger over time and at varying rates. They eventually disrupt kidney function, resulting in kidney failure. Most cysts grow slowly and are not usually evident until a Maine Coon reaches seven years old. Cats only need one parent to be infected with the defective gene to inherit PKD. DNA testing is needed to confirm or rule out the presence of the gene that causes PKD.  Routine blood work and a urinalysis can signal problems with kidney function, but follow-up testing such as abdominal ultrasound will confirm a PKD diagnosis.

 The symptoms of PKD include:

  • Weight loss
  • Increased thirst
  • Lethargy
  • Loss of appetite
  • Vomiting
  • Frequent urination

Conventional treatments include antibiotics, anti-inflammatory medications, pain medications, appetite stimulants, fluid therapy, and dietary modification. A diet that supports kidney function is essential for this disease. I do not recommend low-protein or dry prescription diets for animals with kidney disease. Cats with renal disease do best by eating high-quality human-grade canned, raw, or gently cooked food or a fresh, balanced homemade diet. Other natural therapies include B-vitaminsphosphorous bindersamino acids, and herbs.

A few words about Polydactyl genetics in Maine Coon cats…

Polydactyl is a condition in animals where more than the common number of fingers and/or toes are present. Even though it is a dominant trait for the Maine Coon to be born with extra toes on one or more of their paws, breeders have managed to eliminate the majority of polydactyl paws. Polydactylism only affects the physique of the paw. With the right care and maintenance, these cats enjoy a long, happy, and healthy life. 

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