Cystitis

By Colin & Lorna Lazenby

(Veterinary Surgeons) (An archive article)

Blood in the “wet” corner of the cage or a red staining of the fur under the tail is often the first sign of something being amiss with the hamster’s urinary system. Blood in the urine (known technically as Haematuria) is found in both sexes and we have seen it in hamsters from as young as six weeks right through to 2¼ years old. The blood usually comes from the vessels in the wall of the bladder, although on rare occasions it may originate in the kidneys. Inflammation of the bladder or Cystitis usually results in haematiria as the blood supply to the organ is increased whilst small vessels in its wall become more fragile.

Urine is normally sterile as the bladder wall is relatively resistant to attack by bacteria, but any trauma to the wall or stasis of urine results in a loss of this resistance. Infection may be carried into the bladder either from the kidneys in the urine, in the blood stream or directly from the outside via the urethra. In female hamsters the urethra is shorter and wider than in the male so infection from the outside is more usual in the female. Infection is nearly always bacterial, but fungal infections can occur.

The pH is the degree of acidity or alkalinity of the urine. 7 is midpoint and therefore neutral. Hamster urine is usually slightly alkaline – around pH 8. pH is closely linked to infection. Some bacteria can only survive within very strict limits of pH and so can only initiate an infection if the pH has already been altered. Other bacteria ferment sugars to acid and hence reduce the pH of the urine. Usually when the infection is treated the pH returns too normal and conversely if the pH is altered the bacteria are often unable to survive. Excessively acidic or alkaline urine irritates the bladder and may lead to haematuria without the involvement of infection.

Apart from the urinary symptoms a hamster with a bladder infection is usually well in its self, bright and eating. Only if the infection spreads, for example to the kidneys, will the hamster become ill.

If a hamster suffers a fall, especially with a full bladder, the sudden resulting increase in pressure may cause a vessel to burst. Another form of cystitis occurs if the nerves to the bladder are damaged, either after a knock or as a result of a disease process. This causes urine to collect in the bladder as the hamster is unable to pass it of its own accord; the urine becomes stagnant and cystitis results. Eventually when full enough the pressure in the bladder forces urine out (urinary overflow). In an incontinent hamster such as this the rear end will become sodden with urine.

Bladder stones are due to the settling out of crystals of minerals normally found dissolved in the urine. Sometimes this is due to an upset in the hamster’s body mechanisms leading to an excess of a certain type of urinary crystal. Here to, an alteration in the pH infection predisposes to precipitation of certain substances. In hard water areas there is an increased mineral concentration in the water and it is said that these too may settle out in the bladder, just compare it to a kettle furring up.

If only tiny stones are formed the hamster may be able to pass them. If they are large and unable to leave the bladder, their presence damages its interior. Middle-sized stones pass partway down the urethra (the passageway from the bladder to the outside) and may become stuck causing a complete or partial blockage. This type is more common in males with their narrow twisting urethra. If the stone is large enough it is possible to feel it through the abdominal wall. If the blockage is total no urine is passed at all and the abdomen will become slightly enlarged and very tense. The hamster will be continually positioning itself to urinate and there will be a lot of straining. With a partial blockage, as with other forms of cystitis, small amounts of bloodstained urine are passed very frequently with a great deal of effort.

Tumours of the bladder are another source of haematuria.

These are not as common as the other causes and we would only expect to see them in older hamsters. For these there is no treatment as radical surgery is impractical in so small an animal.

Most of the others do, however, respond to treatment.

For an infection an antibiotic, which is secreted into the urine, is needed. This criteria is met with in the sulphonamides, but overdosage with these will in itself cause crystals to form in the urine within the kidneys. Penicillin and its derivatives, although secreted into the urine well are not advisable due to their toxic affects on hamsters. Antibiotics such as the tetracycimes can be used successfully. Bladder infections often need a much longer course of antibiotics than would be used for infections in other parts of the body.

Urine can be tested to ascertain the pH, if it is too low i.e., acidic, sodium bicarbonate in the drinking water will help.

If it is too high, rosehip syrup (which is high in ascorbic acid-vitamin C) should be put into the water.

In the case of a partial blockage treatment may result in dissolving the stone. With total blockage it is necessary to anaesthetise the hamster to try and dislodge the offending stone in the hope that it may be passed and allow the hamster to urinate, as loss of this function allows the build-up of harmful substances within the body.

It is always a risk that having removed one obstruction another may come down from the bladder to take its place.

If several hamsters are affected it may well be the diet which is at fault and thus should be investigated. Foods containing high levels of some minerals such as magnesium should be avoided.

Where the cause is traumatic, in many cases rest is all that is needed.

Small, ruptured blood vessels rapidly heal themselves.

Where the nerves are damaged, if it is only bruising the paralysis will be of a temporary nature and function will gradually return. Until such time it may be necessary to empty the hamster’s bladder manually, by squeezing the abdomen gently but firmly towards the tail. Drugs, which reduce inflammation such as steroids, may help in these cases. If the nerves have actually been cut, as with a broken back, the outlook is very poor, especially if urinary paralysis is associated with hind limb paralysis.