Overview
A number of test are available for the Cavalier King Charles Spaniel. Two or more of these tests purchased as part of this bundle will be discounted.
- Chondrodysplasia (CDPA) associated with the FGF4 -18 retrogene insertion
- Chondrodystrophy (CDDY) with risk of IVDD associated with the FGF4-12 retrogene insertion.
- Curly Coat Dry Eye Syndrome associated with the FAM83H gene
- Degenerative Myelopathy associated with the SOD1 gene
- Episodic Falling associated with the BCAN gene
- Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency associated with the
Chondrodysplasia (CDPA)
Chondrodysplasia (CDPA) is shortened long bones, resulting in dogs with short legs.
A partial copy of the FGF4 gene has been inserted (FGF4-18, a retrogene insertion) on chromosome 18 and is associated with CDPA. Evidence that suggests that any dog with one or two copies of FGF4-18 will have short legs. Unlike CDDY, CDPA is not associated with any disease.
Chondrodystrophy (CDDY) with risk of IVDD
Chondrodystrophy (CDDY) in dogs is defined by dysplastic (abnormal), shorted long bones (short legs) and premature degeneration and calcification of intervertebral discs. Chondrodystrophic breeds are prone to a type of disc degeneration called chondroid metaplasia, where the discs become hardened and less able to flex with movement and therefore more prone to bulging or rupture i.e. Intervertebral Disk Disease (IVDD). The calcified inner disc material also puts pressure on the spinal cord, causing pain and damage to the nerves running through the spinal cord. Dogs may suffer from severe pain, inability to urinate or defecate, paralysis and even death. Many affected dogs are treated by surgically removing the prolapsed disc.
A partial copy of the FGF4 gene has been inserted (FGF4-12, a retrogene insertion) on chromosome 12 and is associated with CDDY. Evidence that suggests that any dog with one or two copies of FGF4-12 will be affected with CDDY, will have short legs and will be predisposed to IVDD. However, not all dogs with FGF4-12 will go on to develop IVDD.
Curly Coat Dry Eye Syndrome
Congenital keratoconjunctivitis sicca and ichthyosiform dermatosis (CKCSID) is more commonly referred to as ‘‘curly coat dry eye syndrome’’. The disease is congenital; puppies are born with an abnormally rough/curly coat and are usually smaller than littermates. Affected dogs have reduced production of aqueous tears (keratoconjuncitivits sicca commonly called “dry eye”), a tacky mucoid discharge around their eyes and ulceration of the cornea in severe cases. They also have persistent scaling of the skin (ichthyosiform dermatosis) causing them to scratch.
The disease is progressive and beings to affect footpads and teeth. It is difficult to manage, and many owners choose to euthanise affected dog’s due poor quality of life.
Degenerative Myelopathy
Important: Degenerative Myelopathy is a rare disease that presents most commonly in German Shepherd Dogs and Boxers, sporadically in Pembroke Welsh Corgis, Cardigan Welsh Corgis, Bernese Mountain Dogs, Rhodesian Ridgebacks, Borzoi and Chesapeake Bay Retrievers. It is rarely diagnosed in other breeds or mixed-breed dogs. DM is considered genetically complex and will have more than one contributing genetic variant. The variant targeted by this test is widespread and found in more than 120 breeds. However, association of the variant with the disease has only been shown in very few breeds and should never be used to inform breeding decisions, except where close relatives have been clinically diagnosed.
Canine degenerative myelopathy (previously also known as chronic degenerative radiculomyelopathy) is a progressive disease of the spinal cord in older dogs. Most dogs are at least 8 years old before clinical become apparent. DM usually starts with a muscle weakness, loss of muscle and loss of coordination (ataxia) in the hind limbs. Progression is generally quote slow, but dogs will eventually be crippled within approximately 3 years of the onset of disease.
Episodic Falling
Episodic Falling (EF) is a paroxysmal exertion-induced dyskinesia. It is usually exercise, excitement or stress-induced and episodes begin between three to seven months of age. EF is a disorder of the muscles that causes increased muscle tone and muscle spasticity (especially those of the limbs) resulting in limbs that appear “locked” in an extended position and dogs are unable to relax their muscles. This muscle spasticity results in a characteristic “praying” position and/or collapse. Episodes can last from a few seconds to a few minutes, and dogs appear fully conscious throughout.
Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency
Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a fatty-acid oxidation disorder. A genetic form of the disease has been reported in Cavalier King Charles Spaniels. MCAD usually mediates the oxidation of medium-chain fatty acids, which provides energy to the body during periods of stress or fasting. A deficiency of MCAD results in the accumulation of medium-chain fatty acids and the inability to produce sufficient energy during periods of stress. Affected dogs present with clinical signs that include prolonged lethargy, being less responsive and proprioceptive ataxia (wobbliness and abnormal stance and gait). Episodes can last for 20 minutes to multiple hours. While the disease can result in coma and even death, it can also me managed successfully with medication and dietary and lifestyle changes, especially if diagnosed early.
The genetic variant identified is common in the breed, with an allele frequency of approximately 23.5%. Approximately 7% of dogs tested were affected (homozygous) and 32% were carriers of the variant. The disease in affected dogs does not appear to be as clinically severe as it is in humans, which suggests additional compensatory mechanisms in the dog.
