Hydronephrosis in Cats
Is a situation where the renal areas are overflowed by urine as the result of an obstruction

Hydronephrosis in cats can attack very quickly and can cause excruciating pain in your pet, especially in their flank areas.

The pain may be so sudden and acute that it can often lead to stupor in your cat.

If Hydronephrosis is gradual, your pet may do just the opposite and show no symptoms at all as the pain will be very dull until the condition becomes much worse.

If the situation is extremely severe in your cat, both their kidney and ureter may have to be surgically removed in order to save their lives.


Hydronephrosis in cats is the swelling of the pelvis of their kidneys when the flow of urine becomes obstructed in any part of the urinary tract and blocks your pet’s ureters.

The ureters are the long narrow tubes that transfer urine from the kidney to the urinary bladder in your cat.

It starts at the outlet from the pelvis, which is the center of the kidney and is the receptacle for the urine leaving the kidneys.

The two ureters in your cat are in the upper part of the bladder located symmetrically on both sides.

Between the two of them, they deliver the urine and will be the actual part of your cat’s body that will flare up with pain.

The actual term Hydronephrosis implies that your cat’s ureter as well as the renal areas has become overfilled with urine by caused by some type of an obstruction.

The kidneys in your cat filter urine out of the blood as a waste product. It will be extremely important to watch for any blood in your cat’s urine, as this may be the only actual symptom that you can spot.

The urine in your cat collects in the renal pelvis and flows down their ureters into the bladder.

The ureters are not just simple tubes; they are very strong muscular passages that actively proper the urine into your cat’s bladder.

There is a valve located in these tubes that that prevents their urine from flowing backwards. If unobstructed, the urine flows out of this muscular tube as a waste product.

Your cats urinary tract is closed other than one small opening at the bottom and as a result urine cannot escape but rather distend.

Cute KittensDoes vitamin C hurt or help with Hydronephrosis in cats ?

Any type of an obstruction along this drainage along this natural draining system can cause swelling to develop in the upper urinary tract.

If there is an obstruction below the bladder, the protective valve protects the upper tract to a certain point.

But even with this protection, there is now nowhere for the urine to go, so it naturally goes back to its original source.

This now becomes a very dangerous situation for your cat as it will start to cause deterioration of your pet’s kidneys.

However, this obstruction does not necessarily have to be a complete blockage; in fact, temporary or partial obstruction is far more common in your cat than complete.

However, this partial blockage can be just as damaging as it starts the process of enlarging and causing Hydronephrosis in cats


There can be several causes of Hydronephrosis in cats, but by far and away the most common cause will be Urolithiasis.

This is the process that occurs in your cat when stones are formed in their kidney, bladder, or the urethra or urinary tract.

These stones are the number one cause of blood in your cat’s urine.

The pain that will attack your cat is from these stones are j the same as they are in people, they will be very sudden and very severe.

The development of these stones is most often associated with decreased urine volume of an increased excretion of stone forming minerals and components such as calcium, oxalate and phosphate.


There has been speculation for several years that too much Vitamin C in your cats system from natural sources or supplements also causes the development of these stones.

However, it is exactly the opposite.

Three quarters of all stones that will develop in your cat are composed of calcium oxalate and unlike other stones, these stones form in acidic acid.

Although Vitamin C does increase the amount of oxalate in your cats system, there has been no documented evidence that it increase stone formations.

If fact, it does just the opposite for several reasons.

Vitamin C binds calcium, which decreases your cats system from forming calcium oxalate.

Vitamin C also has a diuretic action in that it increases your cat’s flow of urine.

The lack of urine flow is the major cause of stone formation, and Vitamin C supply’s your cat a natural environment that makes it much less likely for stones to from at all.

But there is one more advantage that this vitamin gives your cat in fighting these stone formations; high concentrations of Vitamin C are bactericidal, meaning that they kill bacteria.

This vitamin helps to remove the bacteria around the stones formations, actually helping to dissolve them and possibly preventing Hydronephrosis in Cats.


However, this vitamins fight against stone formations does not end there as it also helps to fight against uric acid stones, cystine stones as well as calcium phosphate stones.

Acid urine will naturally dissolve all of these stones and Vitamin C, long criticized for producing acid in the urine, actually helps your cats system.

The other potential causes of Hydronephrosis in cast can be masses in the retroperitoneal area which is the abdomen that surrounds your cat’s kidneys as well as balder masses.

Masses are tumors that form in your cat.

Tumors are swellings or lesions that are formed by abnormal growths of cells, but contrary to a lot of misconceptions, they are not always cancerous.

You will not have the opportunity to watch for a lot of symptoms with Hydronephrosis in cats.

They may initially show some increased drinking as well as urinating that will be intermediate based around the temporary blockage.

Blood in your cat’s urine is an indication that something is wrong, and that is very easy to spot.


In most all cases it will be some type of a stone that is blocking the urinary and causing the urine to back up.

The best preventive measures that you can take in preventing this potentially life threatening situation is to make sure your cat is supplemented with Vitamin C.

Although this vitamin is synthesized by your cat, if they develop stones, they need the additional supplementation.

Pet Medications for Hydronephrosis in Cats

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