Intraosseous contrast administration for coelomic computed tomography angiography in green iguanas (Iguana iguana): Preliminary findings show promise as an alternative to the intravenous route.

Computed tomography is commonly used to evaluate the reptile coelom. One challenge in the acquisition of contrast-enhanced CT studies in reptiles is the difficulty in placing intravenous catheters due to the poor conspicuity of peripheral vessels. To overcome these limitations, intraosseous catheterization of the long bones (humerus, femur, and tibia) can be used. The purpose of this prospective study was to assess the feasibility and diagnostic value of contrast-enhanced CT of the coelom using a femoral intraosseous route for contrast administration. Twelve healthy juvenile green iguanas were enrolled. In 9 of 12 iguanas, vascular phases were obtained, providing strong, homogeneous enhancement of the arterial and venous tree concurrently. In these nine cases, Phase #1, acquired 60 s after beginning the injection of contrast medium, provided maximal contrast between the hepatic parenchyma and hepatic vasculature. In the remaining three cases, injection failure resulted from intracortical placement of the catheter tip. Histological examination of the liver, kidneys, and femur was performed to determine the pathomorphological correlates of the CT findings; in a third of patients, some degree of contrast-induced renal toxicity was documented, which in mammalians shows potential for reversibility. Four iguanas had iatrogenic structural damage to the femoral growth plates attributed to intraosseous catheter placement. A femoral intraosseous route can be used in green iguanas for iodinated contrast medium administration for CT angiography. For the greatest contrast between coelomic organs and vascular structures, at least one postcontrast acquisition 60 s after initiation of contrast administration is recommended when using this technique.

A remnant kidney surgery model in cats induces acute and chronic outcomes that mimic spontaneous chronic kidney disease.

OBJECTIVE: To report acute and chronic outcomes of cats with chronic kidney disease (CKD) induced by a remnant kidney model. ANIMALS: 32 purpose-bred cats (n = 15 female, n = 17 male). PROCEDURES: Cats underwent a 2-stage reduction in renal mass through partial arterial ligation of 1 kidney (day 28) and delayed contralateral nephrectomy (day 0), targeting an 11/12th functional nephrectomy. Acute (days -28 - 29) survival and renal function parameters were compared over time, and the latter were evaluated as predictors for acute mortality. Chronic (days 30 to >1,100) survival, renal function, and morphology were described. RESULTS: Acutely, renal function deteriorated in all cats (mean ± SD baseline and day 28 serum creatinine mean concentration, 1.13 ± 0.23 mg/dL and 3.03 ± 1.20 mg/dL, respectively; P < .001; and GFR, 3.22 mL/min/kg ± 0.12 and 1.21 mL/min/kg ± 0.08, respectively; P < .001). Seven (22%) cats were euthanized after because of clinical signs of uremia after contralateral nephrectomy. Prenephrectomy renal function tests were not significant indicators for survival during this acute phase. Twenty-five cats entered the chronic phase. Ten cats were euthanized at a median of 163 days from nephrectomy because of progressive renal dysfunction. Median survival times were significantly different when stratified by acute kidney injury grade at day 29. Cats in the chronic phase had clinical courses similar to cats with naturally occurring CKD, and most (13/15) were in CKD stage 2. CLINICAL RELEVANCE: The remnant kidney model is effective at reducing kidney function to an extent that mimics important characteristics of spontaneous CKD in cats.