|I would like to know; is surgery the only way to remove egg impaction. How do you know the difference between bladder problem and egg impaction?
Surgery is the only way to remedy egg impaction. There are folks who like to rupture the ovaries in the fish by massaging it. They sometimes even get an egg out of the fish as it dies. If the fish doesn't die right away, it will die within 48 hours of a rigorous massage. Trust me, I've killed my share trying this.
Egg impaction seems to be a functional failure to lay the eggs. Giving Carp Pituitary Extract won't UNBLOCK the fish. In fact, it will more than likely stimulate further ovogenesis and egg production and cause a greater energy deficiency and more distension.
Egg impaction can be distinguished from Cystic Kidneys by fine needle aspiration or exploratory surgery. For starters, we usually insert a needle into the fishes' abdomen and try to withdraw amber colored fluid, which is pathognomonic (clearly diagnostic for) for cystic kideny disease.
Eventually, the ultrasound may also shed light on internal pathology in fish, once more is know about "normal" and the regular appearance of the pathological conditions.
So for now, if you suspect egg impaction, it can be confirmed by needle aspiration and exploratory surgery. The surgical success rates are VERY high with this.
Egg impaction can be distinguished from regular gravid conditions by the ABSENCE of abdominal fat in the impacted fish, as well as "super distension" not seen in typical gravid females.