The importance of Those genetics...
And... What is genetic testing in Beagles all about?
Not only is it super important for breeders to ensure that they breed happy, good-looking puppies with sound temperaments and good conformation, but they must also consider the genetic health of their breeding stock before important breeding decisions are made!
Genetic diseases affect many canine breeds. To date, there is no cure for any canine genetic diseases. Consequently, affected canines may experience painful, distressed and often shortened lifespans. The genetic tests on offer at inqaba biotec™ are able to determine whether your canine family member is clear of a disease, is a carrier for the disease or is affected by the disease.
~Source: inqaba biotec™~
At Ekara Beagles we understand the importance of the Genetic Health of your puppy! As many symptoms of Genetic diseases only appear when the dog is older, we believe that it is better to ensure that all puppies bred by us are not affected by any diseases! All our breeding dogs are tested and we know that our pups are healthy!
How does these genetics work, though?
Genetic diseases affect many canine breeds. To date, there is no cure for any canine genetic diseases. Consequently, affected canines may experience painful, distressed and often shortened lifespans. The genetic tests on offer at inqaba biotec™ are able to determine whether your canine family member is clear of a disease, is a carrier for the disease or is affected by the disease.
~Source: inqaba biotec™~
At Ekara Beagles we understand the importance of the Genetic Health of your puppy! As many symptoms of Genetic diseases only appear when the dog is older, we believe that it is better to ensure that all puppies bred by us are not affected by any diseases! All our breeding dogs are tested and we know that our pups are healthy!
How does these genetics work, though?
Any responsible breeder will invest in getting all breeding dogs tested for the most important, known, breed-specific genetic disorders. This will help them to choose suitable breeding partners in order to limit the number of dogs affected by any genetic disorder.
A dog can be proven clear from a genetic disorder by testing, or they can be "clear by parentage". This means that both parents were clear, and thus the puppy won't be affected. |
This diagram illustrates the expected results of progeny of any combination, where the parents are either clear, carriers or affected. Hereby a short description of the terminology.
Clear - Simply put, clear means that the dog does not have the genetic disorder. For breeders, it is ideal to breed only from clear dogs, although this is not always possible. Results indicated as N/N (Negative/ Negative) Carrier - Means that the dog carries one copy of the gene, but the other copy in the gene-pair is normal. Carriers will not show any clinical symptoms of the disorder. Owning a carrier will generally not be a problem, as you will never notice that the dog carries a genetic disorder. Breeders should take care if one of their dogs are carriers of a disease, that they choose partners carefully and wisely, in order not to increase the number of affected dogs, and keep the number of carriers as low as possible. N/P (N/Positive) Affected - Dogs that are affected by a genetic disorder will show clinical symptoms. Preferably, breeders should refrain from breeding with affected dogs AT ALL, as they will only increase the number of dogs with this disorder. Indicated as P/P (Positive/Positive) |
Beagle-Specific Genetic Disorders
Hereby a short explanation of genetic disorders known to exist in Beagles. The first 5 are the most important and most commonly tested disorders.
MUSLADIN-LUEKE SYNDROME (MLS)
Years ago Beagle breeders in the USA and Canada stepped forward and said they wanted to stop producing puppies with so-called Chinese Beagle Syndrome (now more correctly named Musladin-Lueke Syndrome). They enlisted the help of scientist Dr Mark Neff to collect DNA samples and look at the genetics of the condition. Fortunately for the breed this condition was found to be a recessive disorder and a DNA test was developed from the research, which is now available commercially at The Veterinary Genetics Laboratory at UC Davis.
MLS is a genetic disorder, caused by a founder mutation (a gene mutation which has been dated to the foundation of the Beagle population over 100 years ago) and having two copies of the gene results in a beagle born with several defects characterized by short outer toes on the front and sometimes all four feet giving a ballerina gait, high set creased ears on a flat skull with extra cartilage in them, slant narrowed eyes and very thick tight skin with little scruff. Such pups are small in stature with a very stiff gait BUT not all affected puppies will show all these signs. They have a very good gregarious temperament although many have been reported to develop seizures. There are some clear dogs that have conformation defects as above so we must be careful and not assume anything unless a dog has been DNA tested.
This condition was always assumed by breeders here (UK) not to be present in the UK BUT it is actually present worldwide and two UK breeders stepped forward in August 2010 and publicized it here so that the Beagle people were aware of it. Since the news broke there have been several people who feel they may have seen it over the years in the UK and reports of Beagles in packs having it, so it is likely as in other countries, we have had it unrecognized for some time. Now that testing is underway it has been confirmed that there are carriers present in the UK Beagle population and also people abroad have begun testing to see what their status is. (Carriers have been found among the tested South African Beagle population).
Dr Neff along with others has published a scientific paper describing the distribution as being seen in many countries and unique to Beagles. It is likely to have originated as a single mutation at the point the Beagle was being developed and population spread around the world so probably (at) the end of the nineteenth century. It is first described in the literature in the 1970's as being an incidence of 2-3% in the Beagle population in Britain and Australia. The November 2010 edition of Hounds talks about MLS and how the Masters of Beagles should be looking at the condition and avoiding breeding cases.
There are two human diseases which are similar called "Stiff skin syndrome"and Geleophysic dysplasia both of which are rare inherited disorders. MLS sufferers have thick inelastic skin and thick fibrous muscles with little flexion even under anesthesia. This leads to the stiff gait and also the hard inflexible abdominal wall. The facial features are produced as the bone is very dense and the ears and skin thickened pulling back the skin and hence the slanted eyes.
The only way to know which Beagles are carriers, is to test using the VGL DNA test. The gene causing the mutation is a recessive one so both parents need to be carriers to produce affected puppies. A recessive gene is one that is hidden (as opposed to a dominant gene which produces visible characteristics). We can use the test to mate clear dogs to carriers and not lose important features of the carriers.
~Originally written by Samantha Goldberg. Adapted from www.thebeagleassociation.co.za~
MLS can be tested locally, by laboratories such as inqaba biotec™. Due to the nature of this disorder all breeding dogs MUST be tested, and when present in any bloodline, breeders should really be careful with mating their dogs. This disorder is not seen often in local and international bloodlines as testing has made it quite easy to eliminate affected dogs.
MLS is a genetic disorder, caused by a founder mutation (a gene mutation which has been dated to the foundation of the Beagle population over 100 years ago) and having two copies of the gene results in a beagle born with several defects characterized by short outer toes on the front and sometimes all four feet giving a ballerina gait, high set creased ears on a flat skull with extra cartilage in them, slant narrowed eyes and very thick tight skin with little scruff. Such pups are small in stature with a very stiff gait BUT not all affected puppies will show all these signs. They have a very good gregarious temperament although many have been reported to develop seizures. There are some clear dogs that have conformation defects as above so we must be careful and not assume anything unless a dog has been DNA tested.
This condition was always assumed by breeders here (UK) not to be present in the UK BUT it is actually present worldwide and two UK breeders stepped forward in August 2010 and publicized it here so that the Beagle people were aware of it. Since the news broke there have been several people who feel they may have seen it over the years in the UK and reports of Beagles in packs having it, so it is likely as in other countries, we have had it unrecognized for some time. Now that testing is underway it has been confirmed that there are carriers present in the UK Beagle population and also people abroad have begun testing to see what their status is. (Carriers have been found among the tested South African Beagle population).
Dr Neff along with others has published a scientific paper describing the distribution as being seen in many countries and unique to Beagles. It is likely to have originated as a single mutation at the point the Beagle was being developed and population spread around the world so probably (at) the end of the nineteenth century. It is first described in the literature in the 1970's as being an incidence of 2-3% in the Beagle population in Britain and Australia. The November 2010 edition of Hounds talks about MLS and how the Masters of Beagles should be looking at the condition and avoiding breeding cases.
There are two human diseases which are similar called "Stiff skin syndrome"and Geleophysic dysplasia both of which are rare inherited disorders. MLS sufferers have thick inelastic skin and thick fibrous muscles with little flexion even under anesthesia. This leads to the stiff gait and also the hard inflexible abdominal wall. The facial features are produced as the bone is very dense and the ears and skin thickened pulling back the skin and hence the slanted eyes.
The only way to know which Beagles are carriers, is to test using the VGL DNA test. The gene causing the mutation is a recessive one so both parents need to be carriers to produce affected puppies. A recessive gene is one that is hidden (as opposed to a dominant gene which produces visible characteristics). We can use the test to mate clear dogs to carriers and not lose important features of the carriers.
~Originally written by Samantha Goldberg. Adapted from www.thebeagleassociation.co.za~
MLS can be tested locally, by laboratories such as inqaba biotec™. Due to the nature of this disorder all breeding dogs MUST be tested, and when present in any bloodline, breeders should really be careful with mating their dogs. This disorder is not seen often in local and international bloodlines as testing has made it quite easy to eliminate affected dogs.
NEONATAL CEREBELLAR CORTICAL DEGENERATION (NCCD)
Cerebellar abiotrophy (NCCD) is a neurodegenerative disease described in several canine breeds including the Beagle.
NCCD is a disease characterized with a number of clinical signs causing the dysfunction of the cerebellum, such as dis-symmetrical ataxia, wide-based stance, loss of balance and body tremor. In Beagles, the neurological signs are first noticed at around three weeks of age. The affected puppies exhibit abnormal wide-based stance, loss of balance, dis-symmetrical gait with inability to regulate rate and the range of movement. The majority of puppies affected with NCCD are euthanized shortly after diagnosing the first signs of this disease.
The main histopathological lesions of the cerebellum characterizing the NCDD-disease in Beagles are extensive degeneration leading to the loss of Purkinje cells and secondary lesions in the granular layer.
The NCCD in Beagles is caused by the mutation c.5855_5862del SPTBN2 (Forman et al., 2012).
The clinical signs of cerebellar abiotrophy are also known in other canine breeds - Rhodesian Ridgeback, Samoyed and Irish Setter. In these breeds, the casual mutation has not been found yet. The described mutation in GRM1 gene is associated with neonatal cerebellar ataxia (BNAt) in Coton de Tulear dogs.
Mutation that causes NCCD in Beagles is inherited as an autosomal recessive trait. That means the disease affects dogs with P/P (positive / positive) genotype only. The dogs with P/N (positive /negative) genotype are clinically without any symptom. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers). Because of high risk of producing affected offspring, mating of two N/P animals (carriers) can not be recommended.
~ Forman et al.: Genome-wide mRNA sequencing of a single canine cerebellar cortical degeneration case leads to the identification of a disease associated SPTBN2 mutation. BMC Genetics 2012, via www.genomia.cz ~
NCCD can be tested locally, by laboratories such as inqaba biotec™. Due to the nature of this disorder all breeding dogs MUST be tested, and when present in any bloodline, breeders should really be careful with mating their dogs. This disorder is not seen often in local and international bloodlines as testing has made it quite easy to eliminate affected dogs.
NCCD is a disease characterized with a number of clinical signs causing the dysfunction of the cerebellum, such as dis-symmetrical ataxia, wide-based stance, loss of balance and body tremor. In Beagles, the neurological signs are first noticed at around three weeks of age. The affected puppies exhibit abnormal wide-based stance, loss of balance, dis-symmetrical gait with inability to regulate rate and the range of movement. The majority of puppies affected with NCCD are euthanized shortly after diagnosing the first signs of this disease.
The main histopathological lesions of the cerebellum characterizing the NCDD-disease in Beagles are extensive degeneration leading to the loss of Purkinje cells and secondary lesions in the granular layer.
The NCCD in Beagles is caused by the mutation c.5855_5862del SPTBN2 (Forman et al., 2012).
The clinical signs of cerebellar abiotrophy are also known in other canine breeds - Rhodesian Ridgeback, Samoyed and Irish Setter. In these breeds, the casual mutation has not been found yet. The described mutation in GRM1 gene is associated with neonatal cerebellar ataxia (BNAt) in Coton de Tulear dogs.
Mutation that causes NCCD in Beagles is inherited as an autosomal recessive trait. That means the disease affects dogs with P/P (positive / positive) genotype only. The dogs with P/N (positive /negative) genotype are clinically without any symptom. They are genetically considered carriers of the disease (heterozygotes). In offspring of two heterozygous animals following genotype distribution can be expected: 25 % N/N (healthy non-carriers), 25 % P/P (affected), and 50 % N/P (healthy carriers). Because of high risk of producing affected offspring, mating of two N/P animals (carriers) can not be recommended.
~ Forman et al.: Genome-wide mRNA sequencing of a single canine cerebellar cortical degeneration case leads to the identification of a disease associated SPTBN2 mutation. BMC Genetics 2012, via www.genomia.cz ~
NCCD can be tested locally, by laboratories such as inqaba biotec™. Due to the nature of this disorder all breeding dogs MUST be tested, and when present in any bloodline, breeders should really be careful with mating their dogs. This disorder is not seen often in local and international bloodlines as testing has made it quite easy to eliminate affected dogs.
IMERSLUND-GRASBECK SYNDROME (IGS)
Imerslund-Gräsbeck syndrome (IGS) is a disorder found in Beagles and Border Collies where dietary cobalamin (vitamin B12) is unable to be absorbed through the gut. Both breeds have independent mutations in the cubulin (CUBN) gene. The disease has an autosomal recessive mode of inheritance with both sexes being equally affected. Owners of IGS affected dogs often note a lack of appetite, failure to gain weight, lethargy and malaise that intensifies after eating. Clinically, anemia and excess urine protein is observed. Without chronic treatment, permanent brain and nervous system damage can occur. Dogs with one normal and one mutated IGS gene, carriers, are unaffected but breeding two carriers together would be predicted to produce 25% affected offspring and 50% carriers.
~ Via Veterinary Genetics Laboratory (VGL) ~
... Dogs are born with a cobalamin reserve in the liver, however if it cannot be replaced with food, it is very soon exhausted during the postnatal growth (Fyfe et al., 1991). Therefore, the clinical signs of cobalamin malabsorption appear early in 6 to 12 week of dog´s age and include failure to thrive and chronic loss of appetite. The affected dogs can suffer from neutropia, non-regenerative anemia, anisocytosis and poikilocytosis, megaloblastic changes in bone marrow, reduction of Cbl level, methylmalonic aciduria and homocysteinemia. The function of kidneys in the affected dogs is normal, but proteins with low molecular weight are eliminated in the urine (Fyfe et al., 1991).
In healthy dogs, the cobalamin (Cbl) taken up with food is bound to the internal factor, glycoprotein, produced by gastric mucosa and pancreatic duct epithelium. The intrinsic factor (IF) in complex with cobalamin (Cbl) is absorbed via enterocyte receptors in distal jejunum and ileum. The symptoms of intestinal cobalamin malabsroption are caused by the absence of the receptors for IF-Cbl complex on the brush border of the intestinal cells (Fyfe et al., 1991).
~ Via www.genomia.cz ~
IGS can be tested locally, by laboratories such as inqaba biotec™. As this disease is quite rare, many breeders don't test for it. However, I still feel it's quite important to test for as many disorders as possible!
~ Via Veterinary Genetics Laboratory (VGL) ~
... Dogs are born with a cobalamin reserve in the liver, however if it cannot be replaced with food, it is very soon exhausted during the postnatal growth (Fyfe et al., 1991). Therefore, the clinical signs of cobalamin malabsorption appear early in 6 to 12 week of dog´s age and include failure to thrive and chronic loss of appetite. The affected dogs can suffer from neutropia, non-regenerative anemia, anisocytosis and poikilocytosis, megaloblastic changes in bone marrow, reduction of Cbl level, methylmalonic aciduria and homocysteinemia. The function of kidneys in the affected dogs is normal, but proteins with low molecular weight are eliminated in the urine (Fyfe et al., 1991).
In healthy dogs, the cobalamin (Cbl) taken up with food is bound to the internal factor, glycoprotein, produced by gastric mucosa and pancreatic duct epithelium. The intrinsic factor (IF) in complex with cobalamin (Cbl) is absorbed via enterocyte receptors in distal jejunum and ileum. The symptoms of intestinal cobalamin malabsroption are caused by the absence of the receptors for IF-Cbl complex on the brush border of the intestinal cells (Fyfe et al., 1991).
~ Via www.genomia.cz ~
IGS can be tested locally, by laboratories such as inqaba biotec™. As this disease is quite rare, many breeders don't test for it. However, I still feel it's quite important to test for as many disorders as possible!
PYRUVATE KINASE DEFICIENCY (PK DEFiciency / PKLR)
Pyruvate kinase deficiency (beagle type) is an inherited metabolic disease affecting beagles. Affected dogs have insufficient activity of the pyruvate kinase Enzyme which breaks down glycogen for energy. Deficiency of this enzyme results primarily in easily damaged red blood cells (hemolysis). Affected dogs typically present between 4 months and 2 year of age with pale gums from decreased numbers of red blood cells (Anemia) and lethargy or exercise intolerance. Clinical findings during a veterinary exam include severe anemia, hardening of the bones, and an enlarged spleen and liver. While dogs can live for several years with this disease, they typically die from severe anemia or liver failure by 9 years of age.
~ Via Paw Print Genetics ~
Pyruvate kinase is a key regulatory enzyme in anaerobic glycolysis. The deficiency of this enzyme causes insufficient production of ATP, which results in erythrocyte lysis or their premature destruction in the spleen. The increased destruction of erythrocytes expresses itself clinically as anemia. The life-span of erythrocytes in dogs is approximately one month; in case of PK deficiency is the life-span of erythrocytes only several days. The PK deficiency is accompanied by general weakness, increased heart rate, very pale mucous membranes (gums), liver function disorder, hepatomegaly, splenomegaly, exercise intolerance and loss of weight.
The first clinical signs usually occur approximately at 4 months of age of the affected dog. The heterozygous dogs (carriers of the mutation) are usually asymptomatic, although they have half the normal level of pyruvate kinase activity. Affected physically inactive dogs show later onset of clinical signs.
The hematologic analysis usually discovers severe anaemia and high concentration of ferritin level in the serum. Some dogs develop other symptoms such as severe secondary hemochromatosis, progressive myelofibrosis and osteosclerosis of bone marrow.
As the clinical sign can be easily confused with other metabolic disorders, the testing of the responsible mutations in dog breeds is a suitable solution for determination of a correct diagnosis caused by the pyruvate kinase deficiency.
~ Via www.genomia.cz ~
PK Def can be tested locally, by laboratories such as inqaba biotec™. As this disease is quite rare, many breeders don't test for it. However, I still feel it's quite important to test for as many disorders as possible!
~ Via Paw Print Genetics ~
Pyruvate kinase is a key regulatory enzyme in anaerobic glycolysis. The deficiency of this enzyme causes insufficient production of ATP, which results in erythrocyte lysis or their premature destruction in the spleen. The increased destruction of erythrocytes expresses itself clinically as anemia. The life-span of erythrocytes in dogs is approximately one month; in case of PK deficiency is the life-span of erythrocytes only several days. The PK deficiency is accompanied by general weakness, increased heart rate, very pale mucous membranes (gums), liver function disorder, hepatomegaly, splenomegaly, exercise intolerance and loss of weight.
The first clinical signs usually occur approximately at 4 months of age of the affected dog. The heterozygous dogs (carriers of the mutation) are usually asymptomatic, although they have half the normal level of pyruvate kinase activity. Affected physically inactive dogs show later onset of clinical signs.
The hematologic analysis usually discovers severe anaemia and high concentration of ferritin level in the serum. Some dogs develop other symptoms such as severe secondary hemochromatosis, progressive myelofibrosis and osteosclerosis of bone marrow.
As the clinical sign can be easily confused with other metabolic disorders, the testing of the responsible mutations in dog breeds is a suitable solution for determination of a correct diagnosis caused by the pyruvate kinase deficiency.
~ Via www.genomia.cz ~
PK Def can be tested locally, by laboratories such as inqaba biotec™. As this disease is quite rare, many breeders don't test for it. However, I still feel it's quite important to test for as many disorders as possible!
FACTOR 7 DEFICIENCY (FVII)
Factor VII deficiency in beagles is known to cause a mild bleeding disorder. This disorder has been known to occur in beagles for decades, a few years ago a test was developed by Dr. Giger at PennGen - University of Pennsylvania to identify carriers of this genetic trait. There are only rare reports of severe bleeding requiring blood transfusions from Factor 7 deficient beagles as many of the affected dogs may remain totally asymptomatic. Factor VII deficiency is most often diagnosed coincidentally when coagulation screening tests are performed; the PT is prolonged, while APTT and other test results are normal. Some beagles may actually be genetically affected but have normal PT and PTT. This autosomal recessive disorder maybe unknowingly passed on through generations via asymptomatic carriers but also thru affected dogs as they may not show obvious signs. Affected dogs "may" exhibit an increased bleeding tendency following trauma or surgery.
The true frequency of this genetic deficiency in beagles is unknown, but recent stats from various labs that offer the genetic test for Factor 7 had indicated that well over 50% of beagles are either affected or carriers. Affected beagles have been noted in the United States, Canada, Europe and Australia. Factor 7 deficiency has been identified in show and field bloodlines. Input from breeders in America that have tested their beagles have supported the fact that this seems to be a widespread occurrence. Of the breeders that offered information to me, only a small number of "clear" beagles have been identified. The majority of beagles tested have been shown to be carriers and many of them have actually tested to be affected. Limited case reports are at end of this page.
It is apparent from the information I have received that this problem probably exists across most show lines in America. One breeder/veterinarian characterized this as a condition without symptoms.
Dr. Marjory Brooks,Section Director-Comparative Coagulation Section-Animal Health Diagnostic Center Cornell University stated-
"Based on the clinical histories of Factor VII deficient beagles in general, however, they do not appear to have any increased risk of problems when whelping than other beagles. We have also worked with clinicians managing Factor VII deficient beagles that safely underwent routine spay and more complex pyometra (uterine infection) spay procedures without transfusion. So, having frozen plasma available in case of complication would be a good precaution and you should discuss the situation with your veterinarian ahead of time (and I’m happy to share my experience with them."
Factor 7 deficiency is a simple autosomal recessive trait. This means that carriers bred to carriers can produce "clears", "carriers", or "affected" offspring. Knowing the status of breeding partners can help to decrease the frequency of affected beagles. Having a carrier does not mean having to remove that beagle from your breeding program. Breeding a "clear" to a carrier can produce "clears" or "carriers". Just as with all other health tests, knowing the Factor 7 status of your Beagle can help you make better breeding decisions. The genetic test to identify the Factor 7 status of your beagle is available at many labs. This test is a simple cheek swab.
Unfortunately, as we see with other health problems in our breed, many breeders do not test and do not want to admit that they have any problems. Breeders that step up to the plate and do health testing and openly admit to having problems and that are working hard to breed away from them; are often ostracized by other breeders. This problem may be insignificant, as compared to other problems in our breed-that is a personal choice. If you as a breeder, choose to do this health screening for your knowledge then you are doing the best you can to breed better.
A wise seasoned, breeder once told me: "If you breed long enough and often enough; you will have to deal with problems. The measure of a good breeder is not if you deal with problems but how you deal with those problems". Factor 7 deficiency is just one of many health issues that must be considered and ranked according to importance in our own personal breeding programs.
~ Copied from www.aladarbeagles.com ~
Fvii can be tested locally, by laboratories such as inqaba biotec™. Across the world, Fvii is found quite often. Due to the fact that symptoms of this disorder is not drastic, and very ofteninvisible, breeders should try to eliminate affected dogs from their breeding programs, but this shouldn't be the only factor taken into consideration.
The true frequency of this genetic deficiency in beagles is unknown, but recent stats from various labs that offer the genetic test for Factor 7 had indicated that well over 50% of beagles are either affected or carriers. Affected beagles have been noted in the United States, Canada, Europe and Australia. Factor 7 deficiency has been identified in show and field bloodlines. Input from breeders in America that have tested their beagles have supported the fact that this seems to be a widespread occurrence. Of the breeders that offered information to me, only a small number of "clear" beagles have been identified. The majority of beagles tested have been shown to be carriers and many of them have actually tested to be affected. Limited case reports are at end of this page.
It is apparent from the information I have received that this problem probably exists across most show lines in America. One breeder/veterinarian characterized this as a condition without symptoms.
Dr. Marjory Brooks,Section Director-Comparative Coagulation Section-Animal Health Diagnostic Center Cornell University stated-
"Based on the clinical histories of Factor VII deficient beagles in general, however, they do not appear to have any increased risk of problems when whelping than other beagles. We have also worked with clinicians managing Factor VII deficient beagles that safely underwent routine spay and more complex pyometra (uterine infection) spay procedures without transfusion. So, having frozen plasma available in case of complication would be a good precaution and you should discuss the situation with your veterinarian ahead of time (and I’m happy to share my experience with them."
Factor 7 deficiency is a simple autosomal recessive trait. This means that carriers bred to carriers can produce "clears", "carriers", or "affected" offspring. Knowing the status of breeding partners can help to decrease the frequency of affected beagles. Having a carrier does not mean having to remove that beagle from your breeding program. Breeding a "clear" to a carrier can produce "clears" or "carriers". Just as with all other health tests, knowing the Factor 7 status of your Beagle can help you make better breeding decisions. The genetic test to identify the Factor 7 status of your beagle is available at many labs. This test is a simple cheek swab.
Unfortunately, as we see with other health problems in our breed, many breeders do not test and do not want to admit that they have any problems. Breeders that step up to the plate and do health testing and openly admit to having problems and that are working hard to breed away from them; are often ostracized by other breeders. This problem may be insignificant, as compared to other problems in our breed-that is a personal choice. If you as a breeder, choose to do this health screening for your knowledge then you are doing the best you can to breed better.
A wise seasoned, breeder once told me: "If you breed long enough and often enough; you will have to deal with problems. The measure of a good breeder is not if you deal with problems but how you deal with those problems". Factor 7 deficiency is just one of many health issues that must be considered and ranked according to importance in our own personal breeding programs.
~ Copied from www.aladarbeagles.com ~
Fvii can be tested locally, by laboratories such as inqaba biotec™. Across the world, Fvii is found quite often. Due to the fact that symptoms of this disorder is not drastic, and very ofteninvisible, breeders should try to eliminate affected dogs from their breeding programs, but this shouldn't be the only factor taken into consideration.
PRIMARY OPEN ANGLE GLAUCOMA (POAG)
Similar to conditions seen in humans, Primary Open Angle Glaucoma (POAG) in the Beagle dog is an inherited disease that is characterized initially by increased intraocular pressure (IOP) and subsequently by serious ocular pathology that can include lens subluxation, cataracts and optic disk atrophy.
POAG in Beagles is inherited as an autosomal recessive trait, which means that individuals with two copies of the ADAMTS10 mutation, inherited from both parents, are at the highest risk of developing POAG. Carriers of only one copy of the mutation are not expected to develop the disease but will pass the mutation to their offspring. It is recommended not to breed two dogs together that carry one or two copies of the mutation in order to avoid producing offspring that are affected with POAG
~ Via OptiGen ~
The clinical symptoms in Beagles occur between 9 and 18 months of age (Kato et al., 2009). They are very different and depend on the duration and rate of disease development and the age of the dog. The main symptoms are:
~ Via www.genomia.cz ~
POAG testing recently came available in South Africa, introduced to the county by inqaba biotec™. Due to the nature of this disorder all breeding dogs MUST be tested, and when present in any bloodline, breeders should really be careful with mating their dogs.
POAG in Beagles is inherited as an autosomal recessive trait, which means that individuals with two copies of the ADAMTS10 mutation, inherited from both parents, are at the highest risk of developing POAG. Carriers of only one copy of the mutation are not expected to develop the disease but will pass the mutation to their offspring. It is recommended not to breed two dogs together that carry one or two copies of the mutation in order to avoid producing offspring that are affected with POAG
~ Via OptiGen ~
The clinical symptoms in Beagles occur between 9 and 18 months of age (Kato et al., 2009). They are very different and depend on the duration and rate of disease development and the age of the dog. The main symptoms are:
- Painful eyes
- Blepharospasm - lid spasm, squinting
- Behavioural changes - apathy, loss of appetite, looking for dark places, depression, aggressive behaviour, eye rubbing
- Mydriasis - dilatation of pupil
- Cornea oedema that causes greyish-blue up to cloudy colour of the cornea
- A red (bloodshot) eye - typical for glaucoma
- Elevated pressure of aqueous fluid
- Visual changes, orientation problems
- Exophtalmos - protrusion of eyeball from the socket
- Lens luxation - dislocation of the lens from the normal position
- Shallow anterior chamber - narrowing of chamber angle
~ Via www.genomia.cz ~
POAG testing recently came available in South Africa, introduced to the county by inqaba biotec™. Due to the nature of this disorder all breeding dogs MUST be tested, and when present in any bloodline, breeders should really be careful with mating their dogs.
PROGRESSIVE RETINAL ATROPHY (PRA)
Progressive Retinal Atrophy or PRA is a condition of the retina of the eye. PRA encompasses many disease which all progress over time and eventually lead to blindness. The retina works in the eye much as the film in a camera works. It changes the light it receives into images which are then sent down the optic nerve to be interpreted by the brain. When a dog has PRA the retina either stops developing prematurely or the light receptors degenerate early in life. With this condition both eyes are equally affected. The different forms of PRA vary in the age at which they first develop and in the rate at which they progress. Cases can be early onset with rapid progression to late onset with slow progression or any combination of the sorts. Every case is different and definite age of onset or how quickly progression will occur can never be known for sure.
PRA is a hereditary disorder which means it is passed from parents to offspring and animals that have this condition should not be used for breeding.
PRA over time will lead to blindness. The first sign of this disease is typically night blindness. Owners may observe their dog being hesitant to walk down dark hallways or staircases, or be less likely to go outside at night. As PRA progresses daytime vision will also be lost. In addition to these symptoms, pupil dilation, or enlargement is seen due to the eye attempting to let in more light along with an increase in the amount of light reflected back off the eye. In some cases cataracts may appear but are not the cause of the blindness. There is no pain associated with PRA and dogs seem to adjust very well to their blindness. In some cases owners may not even realize the dog is having problems seeing until they are taken out of their home environment.
PRA is diagnosed by an eye examination by a veterinarian. There are certain changes which can be seen in the eye characteristic of PRA. In addition to an eye examination an electrocardiography may be done to obtain a diagnosis. An electrocardiography measures the electrical responses in the retina to determine if it is functioning properly.
Blindness is the eventual result of PRA. Because the blindness does not occur quickly dogs have time to adjust to not being able to see well. Dogs that are blind can still live normal healthy lives. There are certain things that you as owner can do to help your pet adjust. One of these is keeping your furniture in the same place. Your dog will become accustomed to the layout of your house. If you move furniture it may cause them to run into chairs or tables because they are not used to them being in that place. Another thing you can do is to keep floors and walkways clear of clutter. This will prevent your dog tripping over objects. When introducing your dog to a new area always leash walk them around first so they can get a feel for the area and learn the boundaries. All of these will help your dog adjust to their vision loss.
~ Via www.thebeagleassociation.co.za ~
Testing not yet available in South Africa. If at all possible, breeders should try to get testing done abroad and take the results into consideration when choosing breeding partners.
PRA is a hereditary disorder which means it is passed from parents to offspring and animals that have this condition should not be used for breeding.
PRA over time will lead to blindness. The first sign of this disease is typically night blindness. Owners may observe their dog being hesitant to walk down dark hallways or staircases, or be less likely to go outside at night. As PRA progresses daytime vision will also be lost. In addition to these symptoms, pupil dilation, or enlargement is seen due to the eye attempting to let in more light along with an increase in the amount of light reflected back off the eye. In some cases cataracts may appear but are not the cause of the blindness. There is no pain associated with PRA and dogs seem to adjust very well to their blindness. In some cases owners may not even realize the dog is having problems seeing until they are taken out of their home environment.
PRA is diagnosed by an eye examination by a veterinarian. There are certain changes which can be seen in the eye characteristic of PRA. In addition to an eye examination an electrocardiography may be done to obtain a diagnosis. An electrocardiography measures the electrical responses in the retina to determine if it is functioning properly.
Blindness is the eventual result of PRA. Because the blindness does not occur quickly dogs have time to adjust to not being able to see well. Dogs that are blind can still live normal healthy lives. There are certain things that you as owner can do to help your pet adjust. One of these is keeping your furniture in the same place. Your dog will become accustomed to the layout of your house. If you move furniture it may cause them to run into chairs or tables because they are not used to them being in that place. Another thing you can do is to keep floors and walkways clear of clutter. This will prevent your dog tripping over objects. When introducing your dog to a new area always leash walk them around first so they can get a feel for the area and learn the boundaries. All of these will help your dog adjust to their vision loss.
~ Via www.thebeagleassociation.co.za ~
Testing not yet available in South Africa. If at all possible, breeders should try to get testing done abroad and take the results into consideration when choosing breeding partners.
Discussions of the following disorders will soon follow.