Common Genetic Diseases of Ragdoll Cats
The Ragdoll cat is a breed developed in the 1960s. They are known for their docile but playful personality. The name “Ragdoll” comes from their tendency to go limp or “floppy” when picked up or relaxed. The breed was developed using other purebred cats, such as Persians, Burmese, and Birmans. As a result, the genetic diseases common to these breeds can also be a problem for the Ragdoll.
- Feline hypertrophic cardiomyopathy (HCM) – Feline HCM is caused by a thickening of the heart’s walls and ventricles, resulting in heart enlargement. Signs of this disease include anorexia (decreased appetite), lethargy, difficulty breathing, fainting, and paralysis of the legs due to blood clots. Some cats may show no symptoms. Cats with heart murmurs, arrhythmias, or gallop rhythms can also be predisposed to HCM. It is estimated that about 30% of Ragdolls carry the genetic mutation for this disease. Echocardiograms (a non-invasive ultrasound of the heart) are used to diagnose the condition, as well as a proBNP blood test. At the current time, there is no cure for HCM. Once diagnosed with HCM, the objective is to slow down the progression of the disease. Conventional treatment includes medications such as diuretics and ACE inhibitors. Natural alternative therapies include supplementing with ubiquinol (CoQ10), taurine, L-arginine, acetyl L-carnitine, omega-3 fatty acids, feeding heart glandulars, and herbs. These natural supplements are recommended for a Ragdoll of any age even without an HCM diagnosis.
- Polycycstic kidney disease (PKD) - With PKD, multiple cysts develop in both kidneys, sometimes leading to chronic kidney insufficiency or failure. Problems occur when the cysts start to grow and progressively enlarge the kidney, reducing the kidney's ability to function properly. The disease is the most common kidney disease in Ragdolls, accounting for almost 70 percent of all kidney disease cases. The disease is passed from parents who carry the PKD1 gene. Prevention includes testing prior to breeding and removing cats from breeding programs if they are a carrier of the disease. Signs of the disease include increased thirst, increased urination, decreased appetite, weight loss, vomiting, and lethargy. Routine blood work and a urinalysis can signal problems with kidney function, but follow-up testing such as abdominal ultrasound will lead to confirmation of PKD. 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, dry or canned 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-vitamins, phosphorous binders, amino acids, and herbs.
- Feline mucopolysaccharidosis (MPS) - MPS is a group of lysosomal storage disorders in cats that involve the deficiency of specific enzymes required to grow and maintain healthy connective tissue and a normal vertebral structure. Signs and symptoms of MPS can include facial deformities (characterized my small ears, a wide space between the eyes and a flattened face), skeletal abnormalities, bone degeneration, paralysis, stunted growth, dwarfism, corneal clouding, and an enlarged liver. Diagnosis includes urinalysis, a blood workup including a complete blood count (CBC) and a biochemistry profile, and a blood smear test. An enzyme test will determine levels of the lysosomal enzyme. Radiographs of the bones may also be done to evaluate the stage or type of Mucopolysaccharidosis your cat has. Currently, the only effective treatments are gene replacement therapy or enzyme replacement therapy. These therapies are executed through a bone marrow transplant and can be expensive. In lieu of these treatments, your veterinarian may recommend treating the symptoms (i.e. surgery) to give your cat a better quality of life. Cats intended for breeding should have genetic testing performed to determine if they carry the genes for this disease. Carriers should be removed from breeding programs.
- Progressive Retinal Atrophy (PRA) – This eye disease is a late-onset blindness condition characterized by the progressive degeneration of the photoreceptors (rods and cones) in the retina. Cats affected with this form of blindness have normal vision at birth. Vision loss progresses slowly with most cats becoming blind by 3 to 5 years of age. The progression of the disease can be tracked with an electroretinographic (ERG) exam starting at about seven months of age. There is currently no effective treatment available for PRA. To date, the use of antioxidant supplements or vitamins has not shown any measurable effect on this disease, although these supplements are not harmful to your pet, they may reduce stress on the lens cells and delay cataract formation.
- FIP Susceptibility - Feline Infectious Peritonitis, or FIP, is a fatal disease caused by a type of coronavirus. All cats may carry this virus in a dormant state, but if the virus undergoes a combination of specific mutations, it can act on a susceptible cat’s immune system, causing the cat to develop FIP. Ragdolls seem to be more at risk for developing FIP than other breeds. FIP causes damage to the blood vessels (vasculitis) and fluid build-up inside the abdomen or chest. Blood testing is available for detecting coronaviruses in cats, but these tests don’t differentiate well between non-harmful coronaviruses and the actual FIP disease. Symptoms and disease progression depend on whether the FIP is the wet or dry form of the condition. A standard treatment for FIP does not exist, although new therapies are being developed and await FDA approval; the prognosis for most cats is poor. Prevention includes ensuring the health of the pet’s immune system, decreasing stress, and feeding a nutritionally optimal, species-specific diet.
If you are considering adopting a Ragdoll from a breeder, ask for DNA test results. The first four conditions listed in this blog can be traced back to specific genes. A DNA test that identifies any of these genes doesn’t necessarily mean your Ragdoll will get the disease; however, breeders should remove any cat that has these markers from their breeding lines. You can lessen the chances of “turning on” any of these genes by giving your cat a species-appropriate diet, providing supplements to support the immune system, and making regular visits to your veterinarian.