Urinogenital surgery

1) Kidney surgery
There are 2 relatively common operations performed on the kidney.
-Nephrotomy. An incision is made in the kidney, usually to recover a kidney stone. (Similar in origin to bladder stones - see below.) Because the kidney is so well supplied with blood (1/7th of the heart’s output) it is necessary to restrict blood supply temporarily to the kidney using vascular clamps.
-Nephrectomy. The kidney is removed. This procedure is usually performed to remove damaged or tumorous kidneys, but may become more common as transplantation becomes an option in pets.

2) Ureters
Some animals are born with ureters entering the bladder in the wrong place ( the normal place is the Trigone. ) These animals leak urine constantly and nurses may well be consulted about “house training” problems, as if only one ureter is involved the animal will also be urinating normally. Surgery is necessary to re-implant the abnormal ureter.

3) Bladder Surgery
Cystotomy is performed for tumours on the bladder wall, or for removal of cystic calculi. The bladder is opened on its dorsal side as this is the least mobile so less likely to disturb sutures. Two layers of inverting sutures are usually used to close with a watertight seal, and a Foley catheter is often left in place to relieve pressure. When removing calculi it is important to flush hidden ones up out of the urethra. Remember some struvite calculi can be dissolved with the appropriate diet (s/d).
If the bladder is very full and the urethra is blocked, then a needle may be introduced through the body wall to relieve pressure (cystocentesis). This is done through a clipped and prepped area just in front of the rim of the pelvis in the ventral midline.

4) Urethral Surgery
In the dog, there is a bone in the penis - the os penis- and the urethra runs through this. This is often where stones from the bladder grind to a halt. The preferred technique currently for dealing with these is to flush them back into the bladder and recover them with the rest from here. It is occasionally necessary do a urethrotomy over the ventral midline of the penis to recover calculi. The hole is left to granulate and heal, and nurses need to advise owners about the likelihood of some bleeding, and urine coming from an unusual place.
If there is repeated blockage or some other penile damage then urethrostomy may be necessary to form a permanent stoma.
This is a reasonably common procedure in Tom cats, in which the penis narrows at the tip, allowing frequent problems with obstruction even with very small amounts of calculi. Urethrostomies are formed in the perineum, at a point where urine will not contaminate the surrounding coat or skin. Dogs will then always urinate to the rear, providing an endless supply of jokes and wet feet.
Nursing care will often be sought for the need to keep the skin clean and healthy around the stoma. Bathing and the use of waterproofing ointments such as vaseline are recommended.

5) Neutering
a) Female
Spaying = Ovariohysterectomy, or removal of the uterus and ovaries. Owners will need to be advised exactly what this operation entails, as the human equivalents are very different, and clients may assume that spaying is the same as hysterectomy or “tying the tubes” Ovariohysterectomy is now routinely performed in many pet species, not just dogs and cats.
Risks associated with spaying:
Surgical / anaesthesia risks
Possible association with urinary incontinence in later life
Occasional increase in territorial guarding in some dogs
Benefits of spaying
Prevention of oestrus / pregnancy
Prevention of false pregnancy
Prevention of mammary tumours if performed before the second oestrus
Possible benefits in treatment of mammary tumours

It should always be emphasised that spaying is major surgery. Certainly anybody attending a spay procedure on a large breed dog can be in no doubt as to the size of blood vessels and the risk of haemorrhage. The ovarian vessels are relatively minor, but the uterine arteries can easily allow an animal to bleed to death if a ligature slips.
When to spay a Bitch: The bitch should be in anoestrus. In Pro-oestrus and oestrus the uterus is too vascular for safe surgery. In metoestrus, the problem is that false pregnancy (due to the brain hormone prolactin) can be started or prolonged by spaying. Spaying should therefore be performed from about 3 months onwards after a season.

Other domestic species:
Rabbits- female rabbits or does should be spayed at about 3 -6 months. This prevents a number of behavioural problems associated with oestrus. In addition, 80% of females will suffer from a malignant uterine cancer by the age of 5 years, and this is a very good reason to recommend neutering.
Ferrets- Jills will die of a fatal anaemia if allowed to maintain persistent oestrus. Vasectomised males or spaying are used to prevent this.

b) Male
Except for vasectomy in ferrets, as above, Castration is the procedure peformed on males, i.e. removal of the testicles. Once the scrotum is incised the testis is exposed inside a sac which is actually an extension of the lining of the abdomen. In dogs and cats this is cut open and open castration is performed. In small pets such as Rabbits and small rodents, the sac is not cut open as there is open communication with the contents of the abdomen, and open castration leads to herniation of intestines etc. through the incision.

Drawbacks of castration:
Surgical risk

Benefits of castration:
Reduced libido leading to less tendency to roam, less territorial aggression, increased attention to commands.
Reduction in “sexy” behaviour often complained of in small dogs.
Unfortunately many owners will seek castration as a cure for all behavioural ills. Castration removes sexual motivation, hence the less sexually motivated a behaviour, the less likely castration will remedy any faults. Unschooled boisterous Labradors will become castrated unschooled boisterous Labradors.

It is a common complaint that neutering in both sexes causes weight gain.
It is true that overall metabolic rate may decrease slightly (NOT the same as becoming in any way more lethargic). It is also true that certain breeds have appetite problems regardless of whether they are neutered or not. Weight problems can always be controlled by appropriate feeding, thus it is often an owner problem. Remind them that Guide dogs are all neutered to reduce distractions whilst working. Overweight guide dogs are very rare, mostly because their owners feed appropriate amounts, and their pets are unable to give visual “feed - me” cues.

6) Other urinogenital surgery
Vaginal polyps are oestrogen dependent tissue areas on the wall of the vagina. At oestrus, the tissue hypertrophies massively and a finger- like projection sticks out through the vulva, often becoming sore and damaged. It is often a big surprise to the owner. The cure for this is surgery to remove the polyp, then spaying to prevent recurrence

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