On July 29-30, 2000, the 2nd International Conference on Feline Inherited Diseases was held at the University of California/Davis covering a wide variety of topics. Although the actual scientific study may have been conducted using a breed other than Persian or Exotic, some of the insights and data collected would be of interest to Persian and Exotic breeders, and so is included in this over view.
About the Author From 1976 to 1984 Susan Manley was involved in feline rescue of feral cats for the City of San Jose Parks and Recreation at Happy Hollow Park. Returning to cat rescue several years ago, Sue successfully raised and subsequently adopted a 2 day old kitten, Solomon. Fascinated by the fact that Solomon carries his tail curled in a ring over his back, Sue has pursued a greater understanding of the genetics of his tail anomaly, purebred cat registries and good breeding practices in general. You can see photos and read about Solomon and his "special" tail at http://www.angelfire.com/nh/Ringtailcats/ |
Below is an alphabetical list of some of topics included in this synopsis. The individual topics are linked to the correseponding synopsis.
- Amyloidosis (Abyssinians)
Amyloidosis (Siamese)- Blood Type Incompatibility
- Cardiomyopathy (American Short Hairs)
Cardiomyopathy (Maine Coons)- Coat Color in Cats
- Feline Genomics
- Feline Urinary Syndrome
- Gangliosidosis
- Genetic Counseling and Genetic Diversity
- Genetics and Infectious Diseases
- Genetic Registry for Cats
- Hip Dysplasia
- Inherited Diseases
- Nutritional Pecularities in the Cat
- Polycystic Kidney Disease
- Ovarian Function
- Retinal Atrophy
- Spasticity
- Spinal Muscular Dystrophy
- Veterinary Information Network
1. Amyloidosis in Abyssinian Cats/Stephen DiBartola/Ohio State University/AA protein deposits found primarily in the kidneys of Abys (and other cats), but the Oriental-type cats primarily get them in the liver, causing sudden rupture/hemoabdomen. In all cats, only the lungs, bladder and nervous system have been found free of deposits. Chronic inflammation in some part of the body is associated with this disease. Mode of inheritance still not determined.
Pedigree analysis of death due to Amyloidosis in the Siamese cat breed/Bernard VanOost/Utrecht University (NL)/Started study three years ago (too small sample). Mean age of death was 4.1 years. Possible causes: overreaction of the immune system, metabolic storage defect, coagulopathy and familial. Malik mentioned study in AU of 22 Siamese cats. What is it? Deposition of insoluble amyloid fibrils leading to organ failure, in Siamese spontanious hepatic bleeding Usually goes unnoticed w/ sudden death. Necropsy finds ruptured liver & possibly other organs.
2. Blood Type Incompatibility Problems: Are you my type?/Urs Giger/Univ of Penn/Have not found B type blood in Siamese, Burmese, Tonkinese and Russian Blues. He needs 100+ of any breed to publish data on blood types (ASH is one large breed he needs samples from). Test cards that breeders can buy were shown. - Type B blood has more anti A antibodies: Type A blood has a lower B antibody count. - The biggest item of note for me is that sometimes blood type incompatibility does not kill the kitten and can cause the tail tip of the kitten to slough off. Some of the breeds have as high as 40% type B blood. DSH on the West Coast have the highest incidence of type B at 7%.
3. Familial Hypertrophic Cardiomyopathy in the ASH Cat/Kate Meurs/Ohio State University/Believed to be caused by an autosomal dominant gene (as yet unidentified).
Familial Hypertrophic Cardiomyopathy in the Maine Coon Cat/Mark Kittelson/UCDavis/Believed to be caused by an autosomal dominant gene (as yet unidentified). NOTE: common name for this disease in general is left ventricular hypertrophic cardiomyopathy (LVHC), and it is different from the dilated form of cardiomyopathy caused by lack of taurine in the diet (Paul Pion's research).
4. Coat Color in Cats: Solid Colors and Tabby Patterns/Heather Lorimer/Youngstown State University/More on color genetics and theories of tabby pattern inheritance.
6. FUS - Are Lower Urinary Tract Diseases Inherited/Tony Buffington/Ohio State University/I'd say the answer is "probably not". Since 1981 (and thanks to the reformulation of commercial pet foods - don't quote me
7.An International Program to Eliminate the Gangliosidosis from Korats by Molecular Testing/Henry Baker*/Scott-Richey Research Center (Auburn Univ)/Testing and certification program (now required by FIFe) for autosomal recessive genes gm1 and gm2 in Korats and other breeds (gm1 gangliosidosis was originally found in Siamese). 351 Korats tested to date and 20% are carriers. NOTE: Dr. Baker will be speaking at the CFA Intl Show this year. Fables of genetics: Fable 1 Inherited diseases are rare The truth is inherited disease in people is rare, its quite common in purebred cats and dogs. Human Tay-sachs 1~300 .03% Concentrated in Easter European who have emigrated to NYC 3% in that population 1 in 5 Korats are carriers of Korat Gangliosidoses (20%) Fable 2 Phenotype
8. Genetic Counseling and Genetic Diversity Considerations for Pedigreed (was Purebred
9. Genetics and Infectious Diseases/Niels Pedersen/UCDavis/summary of where we are with FIP. Feline leukemia has three forms Types A, B & C only type A is passed from cat to cat B is manufactured when A combines with Felv genetic material that is in a cats genetic material. FIP Happens in 5% of catteries and shelters 100% of all catterys and shelters tested that had 11 or more cats had corona virus UC Davis itself has a very difficult time keeping this virus out of its pathogen free colony. It can ride in on the litter dust on your shoes, clothes etc. DR Pedersen thinks it impossible to segregate cats enough in a home to keep this virus from spreading. FIP has a fecal to oral transfer - anything that a cat gets on its fur will get into its mouth. Monitoring several catteries with FIP incidenced showed a decrease of incidence to zero or almost zero after 2 years with no changes made in the cattery management. 50-75% of cats that come into contact with FIP cannot fight it off.
10. Genetic Registry for Cats/Paul Poulos/Institute for GDC in Animals, UCDavis (Genetic Disease Control)/Says they are collecting data and will provide KinReports - genetic pedigrees - to owners/breeders planning matings, but at the same time he stated that the information gathered is confidential and no names are released (so I'm not sure what good the information is if you don't know what animals to avoid). Cats have about 150 known genetic defects. Note: Dogs have 400 known genetic diseases.
11. Hip Dysplasia in Maine Coon Cats/Gail Smith*/University of Pennsylvania/Believed to be inherited polygenetically. Notes: This talk was given using hard data from Dog breeding programs. The overall consensus is that 3 breeds of dogs are free of hip displasia and all other breeds are mildly to severely affected. (The 3 breeds including the Borzoi, and I am sorry I forgot to write down the other breeds). Radiographs were shown showing how the rating of the Hips and Patella were created. The ratings were then plotted per breed on a horizontal chart. The overall consensus of the data was have your breeding animals examined and breed the best hips and patella to the best to get the best.
12. Inherited Diseases in Burmese in the UK/Tim Gruffydd-Jones/University of Bristol/"FCKs" (flat-chested kittens) are found in Burmese, Bengals and Oriental-type cats. Small group of Burmese have hypokalemia (low blood potassium). One familial group has keloidosis (abnormal scarring). Burmese may be more susceptible to FIP (very small sample however). No craniofacial malformations (head defects) in UK Burmese have been found. Sues Notes: Flat chest was divided into two groups - Flat chested ( Chest was V shaped with a noticeable corner on the ribcage where the bones connect with cartilage) -Pectus Excavatum ( chest had a dimple in the middle of it with a noticeable line down the center.) Clinical signs of flat chested were: - weight loss - failure to grow - difficulty breathing 75% of kittens with flat chest survive. At 4 months old they usually catch up to their littermates and have no visible deformity. Of all of the flat chested kittens evaluated 9% have Pectus Excavatum and 6% had splay legs ( Back legs not able to support weight usually resolves at 2-3 months). - Flat chest appears to be familial, autosomal recessive, variable expression/penetrance. Variable expression and the fact that it can resolve makes it difficult to remove animals with the trait from the breeding population. Hypokalemia in Burmese: - Not seen in DSH - Experience based on 18 cases - Clinical signs usually at 4 months of age - Low potassium seems linked - Low potassium is not from inadequate intake or from excessive loss - Possibly related to Hypokalemic Periodice Paralysis in Humans. ( Sues thoughts: Possibly also related to HYPP in American Quarter Horses, although note this is Hyperkalamic, HYPP is mapped on the equine genome) - 5 affected litters - 12/32 kittens affected - In humans is associated with/ ion channel in muscle ( defect in calcium channel) Sometimes a defect in the sodium channel.
13. Nutritional Pecularities in the Cat/Quentin Rogers/UCDavis/12 deficiencies in diet are caused by man (let them eat mice
14. Noninvasive Monitoring of Ovarian Function in the Domestic Cat/Brenda Griffin/Scott-Richey Research Center (Auburn Univ)/Fecal samples are checked daily for estradiol levels to determine when queens are in season. Visual signs coding system also used daily. Progesterone levels measured with twice weekly blood draws (NOTE: 85% of queens ovulate spontaneously!!). Young and low (pecking) order queens have silent heats. Notes: Dr Griffen had the most amazing food dyes that were fed through the cats to identify which feces in a multicat environment they were collecting to test. - Cats used in the test were DSH & DLH. - Collected feces was tested for Estradiol. ( Same process that large animal parks and zoos use) - One queen in her study had far less frequent heats ( once every year) then the other queens. When tested to see if a problem existed it was found that there was no problem and that was her normal cycle. Its possible by modern spaying and neutering practices we have accidentally been selecting for more frequent and earlier cyclers to have kittens and passing their predilections on.
15. Polycystic Kidney Disease (PKD) in Persians/David Biller/Kansas State University/Bilateral cysts caused by an autosomal dominant gene linked to PKD1 on human chromosome 16. 40-50% of Persians and their close relatives estimated to have the gene. Polycystic Kidney Disease in Humans has been found to be both recessive and dominant. Usual onset is 3-10 years with a mean of 6 years. Cysts in the Kidneys are " Proximal" with a sodium content like Plasma "Distal" with a sodium content like Urine. German research shows 5% of the PKD positive cats also have cysts in the liver. Ultrasound equipment necessary to definitively diagnose. 7 MHZ or higher. With correct Ultrasound and an experienced person running the machine (this was stressed) a diagnoses can be make in animals as young as 4 weeks. PKD homozygous mice died in Utero. 5K Persians have been tested. Of those 5K 33% have PKD w/ multiple cysts in both kidneys. The advice is to screen future breeding animals before breeding.
16. Abyssinian Retinal Atrophy/Matthew Binns*/Animal Health Trust (UK)/Two types - autosomal dominant and autosomal recessive. AHT does DNA testing and is currently researching PRA in Abys, PKD in Persian, amyloidosis in Oriental-type cats, chronic renal failure (all cats), cardiomyopathy, and hepatic shunts.
17. Spasticity in the Devon Rex/Richard Malik/University of Sydney/Believed to be a form of muscular dystrophy. The photos and movies were heart-wrenching to say the least. Death occurs from choking on food. Clinical Signs: Head sinks to chest in the litter box. Litter box takes a great deal of time. High stepping gait. Head bobbing, Difficulty chewing and swallowing, Abnormal head position with chin resting on chest, Painful for cat to bite, Scapula of shoulders prominent above back with a dip behind the shoulders, Megaosophagus in all cases ( enlarged esophagus that traps food) Believed to be some kind of muscular dystrophy. Dorsal cervical and proximal forelimbs most affected.
18. Spinal Muscular Dystrophy in Maine Coon Cats/John Fyfe*/Michigan State University/Study of a familial group (~15 cats) in Michigan. This disease is similar to Norwegian Glycogen Storage Disease. With Norwegian Glycogen Storage Disease a large percentage of Kittens are stillborn. - It appears that the nerves supplying the muscles are dying equaling a loss in motor neurons.
19. VIN/Paul Pion/Veterinary Information Network/www.vin.com, also has Pet Care Forum for lay people