Maine Coons Disease

Understanding Polycystic Kidney Disease (PKD) in Cats

Polycystic Kidney Disease (PKD) is a hereditary condition that affects cats, particularly the Persian breed. It is characterized by the formation of multiple fluid-filled cysts in the kidneys. These cysts are present from birth and tend to grow larger over time, potentially leading to kidney failure. As an inherited disorder, PKD is caused by a single autosomal dominant gene, meaning that only one copy of the mutation is needed to produce affected offspring. Therefore, if one parent carries the gene, there’s a chance of producing kittens with PKD.

PKD1 is the most common form of PKD in cats and is primarily found in Persians due to the breed’s genetic history. The clinical presentation of PKD1 is similar to that of chronic kidney disease (renal failure), making it challenging to diagnose without specific testing. Unfortunately, this has allowed PKD1 to go unnoticed for many years and has led to its widespread presence in the Persian breed. It’s also a concern for other breeds that have used Persians in their foundation or breeding programs.

Prevalence of PKD

Studies estimate that over 37% of Persian cats have PKD. Given that Persians account for nearly 80% of the cat fancy, PKD has become a significant concern within the breed. However, many responsible breeders have been successful in reducing the frequency of PKD through careful breeding practices and the use of ultrasound screening methods.

PKD Treatment

Currently, there is no specific cure for PKD, as it leads to similar clinical signs as chronic kidney disease. Treatments mainly focus on managing the symptoms associated with kidney failure. Special diets, fluid therapy, and medications to reduce nausea and vomiting are commonly used to alleviate the effects of kidney disease. Additionally, medication may be administered to block the absorption of phosphorus, as elevated phosphorus levels can further damage the kidneys.

Polycystic Kidney Disease (PKD) in Cats

Resources and Screening

For breeders and cat owners concerned about PKD, there are resources available to help understand and address this condition. One such resource is the Veterinary Genetics Laboratory at UC Davis, which offers genetic testing for PKD1 in cats.

Moreover, responsible breeders are encouraged to conduct regular ultrasound screenings of their breeding cats to detect the presence of kidney cysts and help reduce the occurrence of PKD in future generations.

For more comprehensive information and guidance on PKD in cats, pet owners can refer to the resources provided by reputable veterinary hospitals and organizations:

Polycystic Kidney Disease (PKD) is a serious health concern for certain cat breeds, particularly Persians. As an inherited condition, PKD1 has become prevalent within the Persian breed due to its genetic history. To address this issue, responsible breeders and cat owners should be aware of the condition, consider genetic testing, and conduct regular screenings for kidney cysts in breeding cats. Through careful breeding practices and the use of available resources, we can work towards reducing the incidence of PKD in affected breeds and ensure the well-being of our feline companions.


Progressive Retinal Atrophy (PRA) in Cats

Progressive Retinal Atrophy (PRA) is a group of degenerative diseases that affect the photoreceptor cells in a cat’s retina, the tissue lining the inner surface of the eye responsible for transmitting images to the brain. With PRA, these cells gradually deteriorate over time, eventually leading to blindness in the affected cat.

Inheritance of PRA

PRA is inherited as an autosomal recessive condition. This means that for a cat to lose its vision due to PRA, it must inherit two copies of the mutation, one from each parent. Cats with only one copy of the mutation are carriers and have normal vision. To produce affected offspring, both the dam and sire must be carriers.

Symptoms of PRA

  • Dilated pupils
  • Inability to see clearly in bright light
  • Partial or complete loss of vision, often starting with the peripheral vision
  • Abnormal reactions of the pupils to light
  • Abnormal retinal structure, which may be observed during an eye examination with an ophthalmoscope
  • Cats affected by PRA may also show signs of obesity and liver issues.

Progressive Retinal Atrophy (PRA) in Cats


Retina and Retinal Degeneration

The retina is a crucial part of the eye responsible for converting light into nerve signals, which the brain interprets as vision. In retinal degeneration, the cells of the retina start to decline in function, leading to impaired vision or blindness. Progressive Retinal Atrophy is one of the causes of retinal degeneration in cats.

PRA Genetic Testing

A specific mutation in the CEP290 gene has been identified as a cause of PRA in cats. Genetic testing can determine the cat’s status regarding this mutation:

  • N/N: Normal, cat does not have the PRA-causing mutation.
  • N/rdAc: Carrier, the cat has one copy of the mutation. Breedings between carriers may produce 25% of affected kittens.
  • rdAc/rdAc: Affected, the cat has two copies of the mutation and is at risk of developing PRA.

High-Risk Breeds

The CEP290 mutation linked to PRA has been found in several breeds, including Abyssinian, Somali, Ocicat, American Curl, American Wirehair, Bengal, Balinese/Javanese, Colorpoint Shorthair, Cornish Rex, Munchkin, Oriental Shorthair, Peterbald, Siamese, Singapura, and Tonkinese. Particularly, Siamese and related breeds have a high frequency of the CEP290 mutation, posing a significant health risk within this breed group.

Resources and Genetic Testing

Genetic testing for PRA in cats is available through the Veterinary Genetics Laboratory at UC Davis. It helps breeders make informed decisions and avoid producing kittens affected by PRA.

By being aware of PRA and utilizing genetic testing, responsible breeders and cat owners can work together to reduce the occurrence of this inherited condition and ensure the well-being of their feline companions.

Understanding Hypertrophic Cardiomyopathy (HCM) in Cats

Hypertrophic Cardiomyopathy (HCM) is a condition that affects the muscular walls of a cat’s heart, causing them to thicken and reduce the heart’s efficiency. HCM is prevalent in certain cat breeds, including Maine Coon, Ragdoll, British Shorthair, Sphynx, Chartreux, and Persian cats. Although the exact cause of HCM is not fully understood, genetic factors play a significant role, as mutations of several cardiac genes have been identified in cats with this disease.

Hypertrophic Cardiomyopathy (HCM) in Cats

Inheritance of HCM

HCM is inherited as an autosomal dominant condition, which means that a cat needs to inherit only one copy of the mutation from either parent to develop the disease. If a cat inherits two copies of the mutation (one from each parent), it is at a higher risk of developing more severe cardiac disease.

Symptoms of HCM

  • Many cats with HCM may not display obvious signs of illness.
  • Some cats may show signs of congestive heart failure, including labored or rapid breathing, open-mouthed breathing, and lethargy.
  • Other symptoms may include loss of appetite, weak pulse, difficulty breathing, abnormal heart sounds, and an inability to tolerate exercise or exertion.

Hypertrophic Cardiomyopathy (HCM) in Cats


Prevalence of HCM

Approximately 30% of Maine Coon cats have a genetic mutation associated with HCM.

Genetic Testing for HCM in Maine Coon Cats

The A31P breed-specific mutation is associated with inherited HCM in Maine Coon cats. Cats with two copies of this mutation (homozygotes) are at a higher risk of developing severe cardiac disease, often leading to sudden death by the age of 4 or younger. Cats with one copy of the mutation (heterozygotes) have a longer life expectancy but may still develop HCM.


Treatment of HCM

  • Medications may be used to slow the heart rate, correct abnormal heartbeats, improve blood flow and cardiac function, and decrease blood clot formation.
  • Medication can be given to alleviate fluid build-up in cases of congestive heart failure.
  • Special diets may be prescribed to minimize sodium intake and optimize adequate nutrition for cats with congestive heart failure.


For more information on Hypertrophic Cardiomyopathy (HCM) in cats, you can refer to the following resources:

Early diagnosis, genetic testing, and appropriate management can help improve the quality of life for cats with HCM and support responsible breeding practices to reduce the prevalence of this inherited heart condition in susceptible cat breeds.

Spinal Muscular Atrophy (SMA) in Cats

Spinal Muscular Atrophy (SMA) is an inherited neurodegenerative disorder that has been identified in Maine Coon cats and shares similarities with human spinal muscular atrophy. SMA affects the spinal cord’s motor neurons, leading to muscle weakness and instability.

Inheritance of SMA

SMA is inherited as an autosomal recessive condition, meaning that two copies of the mutation are required for a cat to be affected by the disease. If a cat inherits one copy of the mutation from one parent and one normal copy from the other parent (carrier), it will not display any symptoms but can pass the mutation to its offspring. If two carriers are bred together, there is a 25% chance of producing an affected kitten, a 50% chance of a carrier kitten, and a 25% chance of a normal kitten.

Symptoms of SMA

  • Fine muscle tremors and fasciculations (involuntary muscle twitching)
  • Progressive muscular weakness and instability
  • Abnormal posture

Genetic Testing for SMA

SMA in Maine Coon cats is caused by a large deletion of chromosome 1. Genetic testing can identify cats that carry one or two copies of this mutation.

  • N/N: The cat does not have any copies of the SMA mutation.
  • N/S: Cat has one copy of the SMA mutation and is a carrier. It will not be affected by SMA but can pass the mutation to its offspring if bred with another carrier.
  • S/S: Cat has two copies of the SMA mutation and is affected by SMA.

Treatment of SMA

Unfortunately, there is currently no specific treatment for SMA in cats. Management of affected cats mainly focuses on pain management and providing supportive care to maintain their quality of life.


For more information on Spinal Muscular Atrophy (SMA) in cats, you can refer to the following resources: