MVB CertSAM DipECViM-CA MRCVS
European Specialist in Veterinary Internal Medicine
Colin is a 7-year-old male neutered large cross breed dog who has had intermittent, recurrent episodes of haematuria lasting for several days to weeks at a time and ongoing for approximately a year.
He received various courses of antibiotics and was also given a urinary diet to alter the urine pH; together and separately these seemed to contribute to a resolution of the haematuria, although perhaps coincidentally. His haematuria sometimes persisted or developed despite antibiotic treatment suggesting that a primary urinary tract infection was not causative in every episode.
During one episode, he also passed large blood clots alongside the haematuria. The haematuria occurred throughout micturition, not necessarily at the beginning or end of urination. He was referred to the Internal Medicine Service and subsequently, the Interventional Radiology Service for further investigations to attempt to achieve a more definitive diagnosis and treatment.
Investigations and Diagnosis
Physical examination including rectal examination was unremarkable. Haematology and biochemistry were within normal limits. Serum iron concentrations showed no evidence of iron deficiency despite the chronic blood loss. Clotting times were normal and testing for Angiostrongylus Vasorum was negative. Abdominal ultrasonography was unremarkable with no visible renal, ureteral, bladder or urethral abnormalities.
Urethroscopy showed no abnormalities. Cystoscopy was performed via a miniature surgical laparotomy and cystotomy. This allowed the ureteral openings into the urinary bladder to be visualised. The left ureteral opening released yellow urine however the right ureteral orifice produced jets of red urine. Based on the results of the investigations, idiopathic renal haematuria seemed most likely.
Idiopathic Renal Haematuria
This is a relatively rare condition which is typically reported in young, large-breed dogs. It can occur bilaterally in around 25% of cases. Various renal vascular abnormalities, such as haemangiomas and minute venous ruptures, have been reported in humans with renal haematuria and these have also been identified in some dogs.
Long-term problems associated with chronic haematuria can include:
- Iron deficiency anaemia
- Ureteral pain Ureteral and urethral obstructions
- Predisposition to urinary tract infections
Colin was not anaemic however he did have several urinary tract infections over the course of the year, likely secondary to the haematuria rather than the cause of it. His owners were also concerned about the repeated presence of haematuria and so they were keen to find an effective treatment for this condition.
Nephrectomy is not recommended as the renal function is otherwise normal and haematuria can be or become bilateral in 20–30%of cases. Using retrograde sclerotherapy for haemostasis with a povidone iodine solution has been effective in humans with this condition as well as with chyluria. The treatment has been undertaken in many dogs with reportedly good success. The documented long-term success of the sclerotherapy was seen in around 62.5% of affected kidneys treated with dramatic improvement in the degree of haematuria in 75% and some improvement seen in all cases.
Colin was managed by Caroline Kisielewicz and Hervé Brissot of the Interventional Radiology Service. He was anaesthetised and positioned in dorsal recumbency in a Trendelenberg position (head lower than pelvis) such that gravity would assist with holding infused material in the renal pelvis.
A ureteral catheter was placed with cystoscopic guidance. Fluoroscopy enabled the balloon at the tip of the catheter to be inflated at the level of the ureteropelvic junction to block the renal pelvis. The renal pelvis was subsequently soaked three times, for 20 minutes each time, with a solution of povidone iodine, dextrose and meglumine diatrizoate (a contrast agent).
At the end of the procedure, any remaining solution was drained and a double pigtail ureteral stent was left in place to prevent ureteral oedema or ureteritis and subsequent ureteral obstruction. A minute ureteral tear was seen at the level of the balloon when this was deflated. As the ureteral stent is placed as a matter of protocol, it was likely that the tear would heal around this within a few days.
Colin was discharged the following day for further convalescence at home. Gross haematuria resolved within two days. Urinalysis undertaken two weeks later showed microscopic haematuria with <100 red blood cells per high power field. Although complete resolution was not achieved in this case, his owners and the clinicians involved with his case were delighted with the response and deemed sclerotherapy of the idiopathic renal haematuria to be a success.
Colin will continue to be closely monitored for the coming months to ensure that there is no progression to involvement of the contralateral kidney and to monitor for recurrence of urinary tract infections.