Ureterotomy for removal of two ureteroliths in a parrot

Urine Output Monitoring and Acute Kidney Injury in Non-mammalian Exotic Animal Critical Care

Acute kidney injury (AKI) is a sudden, severe decrease in kidney function which can occur in any species. There are various causes of AKI, some of which are seen in domestic species and some that are unique to birds, reptiles, and amphibians. These species present unique challenges with AKI management, such as differences in anatomy and physiology, intravenous and urinary catheterization, repeated blood sampling, and their tendency to present in advanced states of illness. This article will discuss AKI, diagnosis, treatment, and prognosis for non-mammalian exotic species.

Diagnostic Imaging of the Avian Urinary Tract

Due to the special anatomy and physiology of the avian urinary system, the value of diagnostic imaging techniques differs from the use in mammals. The diagnostic imaging methods regularly used in practice to evaluate the avian kidneys are often limited to traditional radiography and ultrasonography, whereas other imaging modalities (urography, scintigraphy, computed tomography, MRI) are rarely used. Furthermore endoscopy may be performed and taking a renal biopsy may be considered. The article describes common indications for imaging techniques used to diagnose urinary tract disease as well as its anatomic and pathologic demonstration.

Clinical Management of Avian Renal Disease

Treatment of avian renal disease relies on supportive care, such as fluid therapy and nutritional support. Analgesia and adaptations of the environment are indicated in cases of renal disease associated with painful joints. Other treatments vary with the underlying etiology and may include systemic antibiotics, antifungal therapy, vitamin A supplementation, or chelation therapy.

Systemic Clinical and Metabolic Diseases

Like other animals pet and companion birds are also prone to systemic illness. This is presented in the form of certain clinical signs and symptoms which is known as “ sick-bird syndrome.”

Avian renal system: clinical implications

The avian renal system differs anatomically and physiologically from the mammalian renal system. However, it is affected by similar disease categories such as infectious, nutritional, degenerative, congenital, metabolic, and neoplastic conditions. The diagnosis of renal disease in birds can be challenging and, in many cases, diagnosis is made on postmortem examination. Successful treatment of avian renal disease requires early recognition of clinical signs and correct interpretation of diagnostic tools.

Diagnosis and treatment of avian renal disease

Reports on the incidence of renal disease in the avian patient vary,but renal disease is common in poultry and birds of prey. Clinical renal disease is probably under-recognized in the companion bird,with the notable exception of renal tumors in the budgerigar (Melopsittacusundulatus). Diagnosis of renal disease may rely on the identification of consistent clinical signs, clinical pathology, survey radiographs, and laparoscopic evaluation and biopsy of the kidneys. Treatment of avian renal disease relies on supportive care such as fluid therapy and nutritional support. Other treatments vary with the underlying cause and the clinical picture but may include systemic antibiotics, diuretics, parenteral vitamin A, and agents to lower uric acid levels such as allopurinol.

Clinical, clinicopathologic, radiographic, and ultrasonographic abnormalities in cats with ureteral calculi: 163 cases (1984-2002)

OBJECTIVE

To determine clinical, clinicopathologic, radiographic, and ultrasonographic abnormalities in cats with ureteral calculi.

DESIGN

Retrospective study.

ANIMALS

163 client-owned cats.

PROCEDURE

Medical records were reviewed, and information on signalment, history, clinical signs, and results of clinicopathologic testing and diagnostic imaging was obtained.

RESULTS

The number of cats in which ureterolithiasis was diagnosed each year increased progressively during the study period. Clinical signs tended to be non-specific and included inappetence, vomiting, lethargy, and weight loss. A combination of survey radiography and abdominal ultrasonography revealed ureteral calculi in 66 of 73 (90%) cats in which the diagnosis was confirmed at surgery or necropsy. Ultrasonography revealed that ureteral calculi were causing ureteral obstruction in 143 of 155 (92%) cats. One hundred thirty-four of 162 (83%) cats had azotemia, 84 of 156 (54%) had hyperphosphatemia, and 22 of 152 (14%) had hypercalcemia. Urinary tract infection was documented in 10 of 119 (8%). Fifty-eight of 76 (76%) cats with unilateral ureterolithiasis had azotemia and 33 (43%) had hyperphosphatemia, indicating impairment of renal function in the contralateral kidney or prerenal azotemia. Ultrasonographic imaging of the contralateral kidney in cats with unilateral ureteral calculi suggested that preexisting renal parenchymal disease was common in cats with ureterolithiasis. Ninety-one of 93 (98%) ureteral calculi contained calcium oxalate.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that abdominal imaging should be performed in all cats with chronic nonspecific signs or with acute or chronic renal failure to rule out ureterolithiasis. Preexisting renal disease may be common in cats with ureteral calculi.