Other Cavalier Health Problems
Eye Disease
Ear Disease / Deafness
Dry Eye / Curly Coat
Episodic Falling Syndrome
Chronic Pancreatitis
Eye Disease (multifocal retinal dysplasia, MRD)
This is a hereditary disease involving the defective development of the retina (innermost layer of the eye; it includes the light sensitive rods and cones which transmit impulses to the optic nerve). Defective retinal development results in linear folding of the sensory retina and the formation of rosettes composed of retinal cells. These abnormalities can result in severe visual impairment, although many dogs will have no obvious visual defect. It is essential that breeding dogs are screened under the BVA/KC eye scheme.
DNA research into MRD is being undertaken by Claudia Hartley at the Animal Health Trust, who believes that the gene marker for MRD in Cavaliers will be the same as in Golden Retrievers.
There is no reliable data available on the level of incidence of MRD in Cavaliers.
Ear Disease / Deafness
Cavaliers can suffer from congenital deafness which is present at birth and is due to a lack of formation or early degeneration of receptors in the inner ear. Cavaliers can also develop progressive hearing loss, which usually begins during puppyhood and progresses to profound deafness between the ages of three and five years. This is believed to be due to degeneration of the hearing nerve. There is no reliable data on the level of incidence of either of these ear diseases.
A common ear disorder in Cavaliers is caused by a build up of mucoid material in the tympanic bullae. This is a viscous plug which fills the middle ear rather like 'glue ear' in children. Some vets refer to this as middle ear disease or primary secretory otitis media (PSOM). This condition is very common in Cavaliers and is thought to be linked to poor drainage (due to skull conformation) through the eustachian tube. In many cases this does not cause pain or discomfort for the dog but some experts believe that middle ear disease can cause outward signs of pain similar to Syringomyelia.
More research is needed in this area and as far as I am aware, there are no attempts by breed clubs to tackle the problem of deafness and ear disease. However, BAER (brainstem auditory evoked response) testing is available and should be used by breeders to test their breeding dogs for hearing deficiencies prior to being bred. BAER testing should be conducted at the minimum age of two and a half years (as MVD and MRI screening), and at the low decibel intensity threshold of 30 dB, to ensure that hereditary deafness is not passed on to offspring.
Dry Eye / Curly Coat (Ichthyosis Keratoconjunctivitis Cicca)
Dry eye in conjunction with curly coat syndrome is unique to the Cavalier breed. Puppies may be identified at birth by the curly abnormality of the coat and extreme dryness of the skin. Such puppies need daily skin care, medicinal bathing and daily eye treatment to prevent ulceration and infection. Such dogs will have a lifetime of extreme discomfort and permanent eye damage and for this reason are usually euthanased shortly after birth.
There is an absence of reliable data on the frequency of the condition as many cases are not reported and no breeding protocol in place to prevent its spread. However, research is taking place at the Animal Health Trust under Claudia Hartley which involves collection of DNA and skin tissue. The aim is to identify the gene(s) responsible for the condition which may then lead to a DNA test. It is hoped also that dry eye / curly coat will be part of the EBV program.
Dry eye can also exist on its own and is an immune mediated destruction of the tear glands. Initial symptoms include chronic redness of the eye and a viscous discharge. Early and regular treatment is needed to prevent damage to the cornea. Treatment is aimed at increasing tear production, applying artificial tears, and reducing bacterial infection and inflammation. Needless to say, dogs with dry eye should not be bred from.
Episodic Falling Syndrome (paroxysmal hypertonicity disorder), EF
Episodic falling is a syndrome of muscle stiffness or collapse that occurs in the Cavalier. In severe cases, the front legs curl up over the head, hind legs become rigid and jaws are clenched. The dog's quality of life can become significantly affected as episodes can last for hours and happen several times a day. Chronic pain is also believed to be associated with EF.
There is no reliable data on the frequency of this disease but a dramatic increase has been reported in the last few years. There is no breeding protocol in place for this disease, although it can be assumed that both parents of an affected puppy will be carriers of EF.
Research is underway at the University of Glasgow under Dr Jacques Penderis, now working collaboratively with Dr Cathryn Mellersh at the Animal Health Trust genetics centre. This team hopes to find the gene(s) responsible for episodic falling syndrome, and it is hoped that EF will be part of the EBV program.
An excellent website on Episodic Falling in Cavaliers can be found here.
Chronic Pancreatitis (CP)
Cavaliers appear to have an increased risk of developing chronic pancreatitis (CP), which is a progressive inflammatory disease of the pancreas. This can result in recurrent vomiting and diarrhoea (although there are of course, many other causes of this apart from pancreatitis).
In some dogs, eventually, when 90% of the pancreas has been destroyed by the inflammation, the dog will develop a deficiency of pancreatic enzymes ('exocrine pancreatic insufficiency' EPI) and/or a deficiency of insulin which is also produced by the pancreas. The latter results in diabetes mellitus, and it is likely that end stage chronic pancreatitis is the commonest cause of diabetes mellitus in the breed, although this has not yet been proved.
Dogs which suffer from CP may show no obvious signs of recurrent mild to severe gastrointestinal upsets and/or abdominal pain. However, once they develop EPI, they start to lose weight in spite of good appetite, and also produce voluminous faeces. A dog can live without a pancreas, so the disease is often not fatal, but enzyme supplements in the food and insulin treatment will be necessary in the end stage. Sometimes, an acute bout of pancreatitis can, however, be fatal.
Vets will recognize an acute bout of pancreatitis and provide appropriate treatment - but researchers are only just beginning to realise that this is could be just the 'tip of the ice-berg' and that Cavaliers often have serious, underlying chronic disease in their pancreas already.
Pathology studies suggest it is very common in the breed - although under-recognised. Penny Watson at Cambridge University Vet School is investigating the disease, but the mode of inheritance is not yet known. If you are concerned that your dog may have chronic pancreatitis, Dr Watson would be very happy to give your vet advice and help as necessary. Studies into this disease are at a very early stage and calls will be put out for help and information as the study develops.
Currently neither the Cavalier clubs, nor the Kennel Club have identified CP as a breed health problem.
Information on other Cavalier health issues and more details can be found at CavalierHealth.org.