with all the acronyms we use today the letters all seem to run together what do they mean? what are they testing for?
PRCD/PRA: Progressive retinal atrophy (PRA) is a collection of inherited diseases affecting the retina that cause blindness. Each breed exhibits a specific age of onset and pattern of inheritance, and the actual mechanism by which the retina loses function can vary. The result of almost all types of PRA is similar - generally an initial night blindness, with a slow deterioration of vision until the dog is completely blind. The age at which the dog becomes fully blind also varies, depending on the genetic disruption present and the breed.
Affected eyes are not painful, unless complicated by a secondary problem, such as cataract or uveitis (inflammation due to a leaking cataract).
Progressive retinal atrophy (PRA) has been classified in several different ways. The simplest of these is by age of onset. Early onset PRA occurs when the affected dog is night blind from birth, and generally is completely blind between 1 - 5 years of age. Late onset PRA is where the dog is night blind at some time over 1 year of age, and full blindness will occur at a somewhat later stage in life.
Primary lens luxation (PLL) is thought to be heritable in most breeds in which it is seen, although clinical signs are generally not seen until the dog is an adult.
Secondary lens luxation is not heritable, and occurs secondary to another disease process within the eye.
In the terrier breeds (such as the Jack Russell terrier) PLL is associated with an inherited degeneration of the zonules, or the thin ligaments that suspend the lens in place behind the iris (the coloured part of the eye) and in front of the vitreous (a clear, gel-like substance).
The genetic mutation has been characterised in a number of breeds, and a genetic test is available.
Lens luxation refers to the lens being in an abnormal position inside the eye.
Clinical signs in the fox terrier are usually not seen until the dog is in middle age, and include a sudden onset of pain (squinting, tearing etc), redness, and cloudiness of the cornea.
The lens may partially or fully luxate into the front chamber of the eye, causing acute glaucoma (increased pressure within the eye).
Sometimes the lens may fall backwards into the posterior (back) chamber of the eye, which may displace the vitreous forwards.
This may then also lead to a blockage of drainage of fluid from the eye and a secondary glaucoma.
Glaucoma (increased fluid pressure within the eye) is a common consequence of lens luxation, and can rapidly lead to blindness.
Lens luxation is a veterinary emergency, and if you notice the signs of PLL in your dog’s eye you should see your vet immediately.
Diagnosis is by examination of the inside of the eye by a veterinarian, and possibly an ultrasound of the eye.
Treatment of PLL is aimed at reducing the fluid pressure within the eye and preserving vision in acute cases, then removing the lens surgically.
Blind eyes may be removed to treat pain.
Genetic testing is available for the screening of breeding animals, so that two carriers (or any affected animals) are not bred.
Although the disease is treated as a recessive one, carrier animals will also occasionally develop lens luxation.
Dogs suffer from many of the same hereditary progressive neurodegenerative diseases that occur in humans.
Among these are a group of disorders designated the neuronal ceroid lipofuscinoses (NCLs).
In people these diseases are characterized by apparently normal development followed by progressive declines in cognitive and motor functions, loss of vision, seizures, and in most cases premature death [1].
These clinical signs are accompanied by progressive degeneration of the central nervous system and usually the retina as well.
Myotonia congenita also known as myotonia hereditaria (Australian cattle dog type) is an inherited muscle disorder affecting dogs. The muscle cells of an affected dog are over-excitable, which causes muscles to remain contracted rather than relaxing after voluntary activity.
Multidrug Resistance 1, also called MDR1, is an inherited condition affecting several breeds of dogs, especially herding dogs such as the Australian shepherd.
The Mutation in the ABCB1 gene associated with MDR1 causes dysfunction of P-glycoprotein, which is responsible for removing certain drugs and toxins from the body.
Clinical signs are most commonly associated with distribution of the drug in the central nervous system.
MDR1 is inherited in an autosomal incomplete dominant manner in dogs meaning that dogs only need to inherit one copy of the mutated gene to be at an increased risk of developing adverse reactions to certain medications.
Though adverse reactions to certain drugs are most commonly seen in dogs having two copies of the mutated gene, Carriers are not typically expected to have any features of the disease but are at risk of passing on the disease to offspring if bred with another carrier of the same condition." data-original-title="" title="" style="box-sizing: border-box; text-decoration-line: none; color: #1d5eae; font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif; font-size: 16px;">Carrier dogs can also experience drug sensitivities and dosages need to be adjusted accordingly.
Thus, dogs that have one or two copies of the mutation are considered at-risk for adverse drug reactions.
If an at-risk dog is treated with one of several common drugs (see below*), they are at risk of developing neurologic symptoms that could range from tremors, excess salivation, anorexia, and blindness to coma and even death.
Because of the defective ability to metabolize specific drugs, these drugs can be lethal even at low doses.
The MDR1 mutation does not cause adverse effects in dogs unless the dog is exposed to these drugs.
Therefore, veterinarians should be notified when a dog is at risk for multidrug resistance 1 prior to administration of any medications.*Drugs known to cause neurological signs related to the MDR1 mutation:Acepromazine, butorphanol, doxorubicin, emodepside, erythromycin, ivermectin, loperamide, milbemycin, moxidectin, rifampin, selamectin, vinblastine and vincristine
Cystinuria was one of the first identified inborn defects of metabolism.
It is an inherited defect of renal transport that included malabsorption of cystine and the dibasic amino acids ornithine, lysine and arginine, collectively known as COLA.
In dogs it has been reported for the first time in 1823 and today it is known to affect more than 70 dog breeds.
In the normally functioning kidney, amino acids and some other substances are filtered out of the blood, and then reclaimed from the urine.
Malabsorption of COLA amino acids in the proximal renal tubules causes their high concentrations in the urine of the affected individual.
Main problems are caused by low solubility of cystine in urine of acidic and neutral pH.
High concentrations of cystine in urine and its low solubility leads to cystine crystals and bladder stones formation, known as uroliths.
Uroliths in the urinary tract can result in stranguria, hematuria, urinary obstruction and renal failure with possible fatal outcome.
Symptoms of disease include straining to urinate, frequent urination or inability to urinate.
In Labrador retrievers both males and females are affected, but obstruction of urine flow is more common in males due to differences in anatomy and females tend to develop stones later than males.
Dogs with cystinuria often have recurrent inflammation of the urinary tract and if not treated, urinary stones can cause urinary tract infections, kidney failure and even death.
Congenital Sensorineural Deafness in Dogs: A Note on Australian Stumpy-tail Cattle Dogs (ASCD)
Congenital sensorineural deafness, an inherited condition, affects numerous dog breeds, including the Australian Stumpy-tail Cattle Dog (ASCD).
This form of deafness is typically noticeable in young pups and can impact either one ear (unilateral) or both ears (bilateral).
The exact genetic locations responsible for this condition remain unidentified across all breeds.
In cases of congenital cochleosaccular deafness, degeneration of the strial cells has been linked to a lack of melanocytes—pigment-producing cells that play a crucial role in maintaining the stria vascularis.
This structure helps sustain the inner ear environment necessary for hair cell health.
The absence of melanocytes may explain why breeds with diluted pigmentation—such as merle Border Collies—or those with piebald or predominantly white coats (e.g., Bull Terriers, Dalmatians) often experience hearing loss.
While a 2004 study on Australian Cattle Dogs found no correlation between pigmentation and deafness in a sample of 293 animals, no breed-specific research has yet been published on the ASCD regarding this pigmentation-deafness link.
Important Use DisclaimerThis test and its results are intended strictly for data gathering and statistical research purposes.
It is strongly recommended that key breeding decisions should not be based on these results alone.
Always assess the animal’s phenotype to ensure it reflects the genotype.
For any breeds not explicitly listed or published in association with this risk, it should be clearly communicated that no published genetic association currently exists.