June 2009 - Ernest Jollop
Ernest Jollop - Can wee, will wee!
Ernest Jollop is a 2 year old German Wirehaired Pointer, who has been diagnosed with diabetes insipidus. This is very different to diabetes mellitus and does not involve glucose. Diabetes insipidus is very difficult to diagnose and is similar to another hormone related disease known as Cushing’s. Diabetes insipidus is a very rare condition.
At the end of May Ernest’s owner noticed that he was urinating excessively, his water intake also increased dramatically drinking up to ten litres in one afternoon! Ernest’s weight also began to plummet.
No abnormalities were found on clinical examination so further tests were performed. Ernest’s bladder was still extremely full despite his frequent urination so an ultrasound was performed but did not reveal any abnormalities apart from an increase in diameter of the bladder even after urinating. A blood sample was then collected to assess the liver and kidney functions and determine if a infection was present. A urine was collected through a procedure called a cystocentesis to ensure a sterile sample, a long needle was passed into the bladder through the abdomen and urine was then drained into a syringe. This was sent to an external lab for tests. Cushing’s Disease was ruled out by an ACTH stimulation test which measures the amount of cortisol (a natural steroid) produced in response to ACTH. Ernest was sent home on broad spectrum antibiotics to cover for any infection with instructions to return the following day for radiographs. Again these all came back showing a large, normal bladder.
At this point, the only 2 conditions Ernest could have were psycogenic polydipsia (excessive thirst for no medical reason) or diabetes insipidus. Traditionally the test to distinguish between these conditions is a water deprivation test where, under very close observation, a dog is deprived of water until it becomes dehydrated. During this test the urine is monitored very closely to see if the dog can concentrate it urine. With Ernest’s recent weight loss this test was considered too dangerous so treatment was started for diabetes insipidus.
When a dog or cat is has diabetes insipidus it renders them unable to concentrate their urine. This is because the anti diuretic hormone released by the main hormonal gland in the body fails, or the kidneys do not respond to the hormone .
This treatment is supplementation of antidiuretic hormone by intranasal drops. Ernest responded almost immediately to these drops and over the next few weeks returned to his normal cheeky extremely bouncy self.
Ernest no longer drinks the river dry so there wont be a water shortage this summer at least!
