Introduction: I am focusing on the primary health problem suffered by this cat: inherited progressive retinal atrophy which is very serious. The first section was written by ChatGPT, an AI computer. It is well written and accurate in my view. There follows references to 3 studies.
Progressive retinal atrophy (PRA) is a group of inherited eye disorders that primarily affect the retina, leading to progressive vision loss in animals, including cats. Abyssinian cats are among the breeds known to be predisposed to PRA.
Here are some key points about progressive retinal atrophy in Abyssinian cats:
Causes: Progressive retinal atrophy in Abyssinian cats is primarily caused by genetic mutations. It is an inherited condition, meaning it is passed down from parent cats to their offspring. The specific genes involved in Abyssinian cat PRA are not yet fully identified, but ongoing research aims to uncover the exact genetic basis. Comment: my research indicates there is more than one gene involved; one recessive and the other dominant (see study 3 below). Langfordvets.co.uk say “A mutation (rdAc) in the CEP290 gene produces a defective protein that is associated with progressive retinal atrophy (PRA) in Abyssinian and related cats”.
Progression: Progressive retinal atrophy refers to the gradual degeneration of the retinal cells responsible for vision. The disease typically starts with the rods, which are responsible for vision in low-light conditions, followed by the cones, responsible for daylight and color vision. As the condition progresses, cats experience a decline in their visual acuity, night vision, and ability to perceive colors. Ultimately, complete blindness can occur.
Symptoms: The initial symptoms of PRA in Abyssinian cats may be subtle and difficult to notice. Over time, you may observe signs such as decreased visual acuity, difficulty navigating in dim light, increased clumsiness, reluctance to jump or play, dilated pupils, and changes in the cat’s behavior. In the later stages, cats may exhibit signs of vision loss, including bumping into objects, hesitancy or fearfulness in unfamiliar environments, and changes in their eating or litter box habits.
Diagnosis: If you suspect your Abyssinian cat has progressive retinal atrophy, it is crucial to consult a veterinarian or a veterinary ophthalmologist. They will perform a thorough ophthalmic examination, which may include a visual assessment, fundoscopy (to examine the back of the eye), electroretinography (ERG) to evaluate retinal function, and genetic testing to confirm the diagnosis and identify the specific mutation responsible for the condition.
Treatment: Unfortunately, there is currently no cure for progressive retinal atrophy in cats. Since it is a genetic condition, the primary focus is on managing the symptoms and providing supportive care. Maintaining a consistent and safe environment for the cat is important, including avoiding rearranging furniture and keeping potential hazards out of their way. Regular visits to the veterinarian or veterinary ophthalmologist are essential to monitor the progression of the disease and ensure the cat’s overall well-being.
Genetic Testing and Breeding: Genetic testing is available for Abyssinian cats to identify carriers of the PRA mutation. Responsible breeders can utilize these tests to make informed breeding decisions, reducing the risk of passing on the disease to future generations. By selectively breeding cats without the mutation, the prevalence of PRA can be decreased over time.
It’s important to remember that this information is not a substitute for professional veterinary advice. If you suspect your Abyssinian cat may have progressive retinal atrophy or any other health concern, please consult with a veterinarian or veterinary specialist who can provide accurate diagnosis and guidance for your cat’s specific situation.
In a Dutch study which took place between 1981 and 2001, 248 Abyssinian and 127 Somali (longhaired Abyssinian) cats in The Netherlands were examined for hereditary eye disease. Eleven Abyssinian cats had the disease and three Abyssinian cats had subtle signs of the disease. In almost all the cases there was a familial relationship i.e. it was inherited.
One cat had advanced retinal degeneration at only seven months of age, the other cats were aged between 2 and 12 years of age at the time they were diagnosed.
In another study dated 1983 (which tells us how well established this diseases in this breed) and which was conducted in Sweden, the scientists found that 45% of Abyssinian cats aged two years or older were affected. The youngest cat affected was 16 months old and at the age of 3-4 bilateral (in both eyes) retinal atrophy was usually present in the affected cats. They concluded that the disease was caused by an autosomal (non-sex-linked) recessive gene.
In a further study dated 1985, Abyssinian cats in England were studied in reference to this disease and compared with a similar study in Sweden (which may be the one I refer to above). They concluded that there are two distinct conditions one occurring at an early age in kittens with an autosomal dominant mode of inheritance and the other in young adults but this time due to an autosomal recessive gene.
Study 1: Djajadiningrat-Laanen SC, Vaessen MM, Stades FC, Boevé MH, van de Sandt RR. [Progressive retinal atrophy in Abyssinian and Somali cats in the Netherlands (1981-2001)] Tijdschrift Voor Diergeneeskunde. 2002 Sep;127(17):508-514. PMID: 12244853.
Study 2: Kristina Narfstrōm, Hereditary progressive retinal atrophy in the Abyssinian cat, Journal of Heredity, Volume 74, Issue 4, July 1983, Pages 273–276, https://doi.org/10.1093/oxfordjournals.jhered.a109782.
Study 3: K. C. Barnett , R. Curtis, Autosomal dominant progressive retinal atrophy in Abyssinian cats, Journal of Heredity, Volume 76, Issue 3, May 1985, Pages 168–170, https://doi.org/10.1093/oxfordjournals.jhered.a110058.