Animal Health Solutions

47 Q4 2020 | Animal Health Solutions mucosa (Figure 8). In an average- size cat, it is suggested to use 3.5 Fr catheters; those of larger diameter, for example 5 Fr, are associated with increases in UO due to a greater trauma and inflammation of the urethral mucosa. Catheter length is variable (11, 14 or 18 cm) depending on the size of the patient; the tip should reach the urinary bladder trigone (Figure 9). Maneuvers to release the UO and urethral catheter placement The olive-tip catheter should be selected based on the diameter of the urethra and the size of the patient's penis. It should then be connected to a venoclysis extension and a 3- or 5 mL syringe containing saline solution and water-soluble lubricant placed on the tip of the catheter. Because the penile urethra is at an angle of approximately Figure 7 Olive-tip catheters (Minnesota catheters) of different lengths. Figure 8 Different feline urinary catheters. A: Flexible polytetrafluoroethylene (Teflon); B: Flexible polyethylene with barium and stylet; C: Flexible polyethylene without stylet D: Semi-rigid polypropylene. Figure 9 Urinary catheter in a male cat. Top: The X-ray image showing the position of a urethral catheter. Down: Endoscopic image of the urinary bladder trigone, the urinary catheter emerging from the urethral lumen. Note how with magnification it is possible to observe the longitudinal grooves in the catheter walls; this characteristic of the Teflon catheter allows its insertion into the urethral lumen without trauma to the urethral mucosa. 45° in relation to the pelvic urethra, to insert the catheter the penis must be pulled in a caudo- dorsal direction to align the urethra parallel to the vertebral column 6 (Figure 10). Introduce the catheter gently into the urethra opening, turning it on it is axis and irrigating (washing) with saline solution while at the same time moving it forward with slight pressure on the penis around the catheter so the pressure of the fluid moves the element that is blocking the urethra 16 (Video 3). Avoid pushing the catheter sharply, as this may severely injure the urethral mucosa. Obstructions should be released only by irrigation of the urethra. Once the introduction of the olive-tip catheter is accomplished and there is no resistance to the solution, it is gently removed. If an olive-tip catheter is not available a flexible urethral catheter with frontal opening can be used. The tip of a flexible urethral catheter should be lubricated with a sterile water-soluble gel and introduced into the urethra, advancing with rotating movements on its axis and pushing it gently; insertion must be with relative ease (Videos 4 & 5).

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