Screening for Polycystic Kidney Disease before breeding

Clinical Need

Polycystic Kidney Disease (PKD) is the most common inherited renal disease in cats. In PKD, portions of the renal cortex and medulla are replaced by cysts. Cyst size and cyst number vary between patients. These cysts compress the functioning of the kidney as they enlarge. Sometimes one can find cysts in liver and pancreas as well. Clinical signs of CKD are similar to the clinical signs of chronic kidney failure: nausea and vomiting, polyuria/polydipsia, anorexia/bad appetite, weight loss and muscle wasting, lethargy, etc. Since PKD is an inheritable, irreversible and progressive disease, there is no long time cure. (8) The cysts cannot be removed, and their growing can’t be slowed down. Supportive care can help PKD patients, but the genetic background of the disease makes is evident that breeding programs should focus on prevention by elimination of affected animals from the breeding program.

The Persian Cat and British Shorthair have a high risk of developing PKD, but the disease is seen as well in other breeds. PKD is caused by an autosomal dominant mutation of the PKD1 gene. (8) Homozygous animals die before birth. In heterozygous animals, the cysts are very small but present at birth. They gradually become bigger, clinical signs often start around an age of 7 years. (9) It is also possible that cats develop cystic kidney disease without a mutation of the PKD1 gene. These cats do not have AD-PKD (8).

In order to definitely diagnose PKD, both ultrasonography and genetic tests are used. Radiography can be used as well, but it is not useful in the early stages of the disease (8).

Ultrasound is a sensitive tool for PKD detection. With ultrasound, renal cysts with a diameter > 2 mm can be determined. So also in the early stages of the disease, ultrasound is a valuable tool. The diagnostic sensitivity of ultrasound in the detection of PKD is reported to be 91% in cats aged > 9 months. Next to that, ultrasonography gives the veterinarian an insight in the severity of the disease. Because ultrasound is noninvasive and repeatable, it is useful for monitoring the progression of the illness. It is advisable to screen kittens of infected lines around an age of 10 months (8).

Clinical Solution

Esaote integrates the latest imaging technologies such as Tissue Enhancement Imaging (TEI) and XView algorithm processing to provide you with exceptional high resolution and artefact free images.

• Tissue Enhancement Imaging (TEI) increase the signal – to – noise ratio of your image, increases spatial and contrast resolution and decreases artifacts.
• XView is also called ‘speckle reduce software’. It is an algorithm that leads to less noise and more signal, resulting in an optimization of image quality, without any drop in frame rate.
• XFlow and advanced PowerDoppler technologies enable a precise detection of micro vascularization. These technologies make assessment of vascular patterns with a very low flow possible. For example in kidneys.

The combination of these modern imaging techniques leads to high definition ultrasound imaging, enabling the veterinarian to detect, for example early signs of PKD development in cats.

Bibliography

• 1. Linquist, Eric, et al. The Curbside Guide: Diagnosis & Treatment of Common Sonographically Detected Disease, Canine & Feline. United States of America : SonoPath LCC, 2015.
• 2. International Cat Care. Hypertrophic cardiomyopathy (HCM) and Testing. icatcare.org . [Online] icatcare.org/advice/cat-health/hypertrophic-cardiomyopathy-hcm-and-testing.
• 3. Faculty of Veterinary Medicine, Utrecht University. Syllabus Circulation . Utrecht : sn, 2010-2011.
• 4. Mc Gavin, M. Donald en Zachary, James F. Pathologic Basis of Veterinary Disease, 4th edition. St. Louis, Missouri : Mosby Elsevier, 2007.
• 5. UFAW. Genetic Welfare Problems of Companion Animals. [Online] [Citaat van: 8 12 2016.] www.ufaw.org.uk/dogs/cavalier-king-charles-spaniel-mitral-valve-disease.
• 6. Beardow, Andrew, et al. INTERNATIONAL SYMPOSIUM ON CHRONIC CARDIAC VALVE DISEASE (CVD) IN THE CAVALIER KING CHARLES SPANIEL. sl : Cavalier King Charles Spaniel Club, USA, 1998.
• 7. Cavalier Health, [Online] [Citaat van: 12 8 2016.] cavalierhealth.org/mvdprotocol.htm.
• 8. Scherk, Margie Feline Polycystic Kidney Disease. Vancouver, British Columbia : sn, September 2-14, Clinician's Brief, Consultant on Call.
• 9. International Cat Care, Polycystic Kidney Disease. Icatcare.org. [Online] icatcare.org/advice/polycystic-kidney-disease.