There are several types of urinary catheters available. The top catheter is a stainless steel catheter used only in female dogs. The second catheter from the top of the screen is a Foley catheter.
Foley catheters are too short to reach the bladder of male dogs.
This catheter type can be used in either sex. The bottom catheter is a red rubber feeding tube that can be used as a urinary catheter in either sex dog. The syringe is attached to an adapter which is attached to a thin tube within the catheter. Fluid or air is injected into this tube which terminates in a thin walled balloon. The intent is to retain the catheter in the bladder.