Polycystic Kidney Disease in Dogs
Polycystic kidney disease in dogs is a condition characterized by the presence of numerous cysts that displace large portions of the renal parenchyma, the functional tissue of the kidneys. These cysts, which can be filled with air, fluid, or semi-solid material, develop within the existing nephrons and collecting ducts of the kidneys. This disease affects both kidneys of the dog.
While polycystic kidney disease is typically not immediately life-threatening, early treatment is essential to prevent the progression of cysts and the development of secondary bacterial infections. These complications can potentially lead to sepsis, a serious condition characterized by the presence of harmful organisms in the bloodstream.
Polycystic kidney disease can affect both dogs and cats, although certain breeds, such as the Cairn Terrier and Beagle, are more prone to developing this condition than others. Early detection and intervention are crucial in managing this disease and ensuring the well-being of affected animals.
Symptoms and Types
Detecting polycystic kidney disease in its early stages can be challenging as the cysts often go unnoticed until they reach a size and number that contribute to kidney failure or an enlarged abdomen. Typically, patients do not display any symptoms when the cysts are initially forming and growing.
As the disease progresses, veterinarians may detect bosselated (lumpy) kidneys through abdominal palpation, during which the abdominal muscles may twitch involuntarily. Although most renal cysts are not painful, dogs may not exhibit any discomfort initially. However, later discomfort may arise due to secondary infections associated with the cysts.
Causes
The precise triggers for the formation of renal cysts are not fully understood. However, it is believed that a combination of genetic, environmental, and internal factors plays a role in the development of this disease.
Endogenous substances thought to be involved in cyst development include parathyroid hormone, which is secreted by the parathyroid glands of the endocrine system, and vasopressin, a peptide hormone synthesized in the hypothalamus region of the brain.
Diagnosis
When polycystic kidney disease is suspected, diagnostic procedures may be employed to confirm the condition. One such procedure involves evaluating kidney fluids through fine needle aspirates, where fluid is extracted via a needle to identify the origin of the cysts.
Additional diagnostic tests may include abdominal ultrasounds to detect cysts in various organs, urine analysis, and examination of cystic fluid. Bacterial culture of cyst fluids can determine if secondary infections are present and require treatment. Hypertension, or high blood pressure, may also be observed.
If polycystic kidney disease is ruled out as the cause of the dog’s symptoms, alternative diagnoses such as abnormal cell growth (like tumors in the kidneys), kidney failure, or other kidney cystic diseases may be considered.
Treatment
Currently, complete removal of renal cysts is not feasible, so treatment typically focuses on managing the effects of cyst formation, particularly kidney infections. Periodic aspiration, which involves removing fluid from large renal cysts using a needle, may be utilized to alleviate pain and decrease cyst size. Additionally, various medications may be prescribed to address symptoms and secondary issues like bacterial infections.
Living and Management
Regular monitoring is essential for dogs diagnosed with polycystic kidney disease, with evaluations scheduled every two to six months to watch for related conditions like kidney infections, kidney failure, and heightened pain. If bacterial infection and sepsis do not develop, the short-term outlook is generally positive, even without treatment.
The long-term prognosis for dogs with polycystic kidney disease typically hinges on the severity of the condition and whether it progresses to kidney failure.
Prevention
As the precise cause of polycystic kidney disease remains unidentified, there are no targeted preventive measures available. However, it’s worth noting that selective breeding aimed at reducing genetic diversity may inadvertently lead to a higher prevalence of other undesired inherited traits within affected breeds.