Does ureteral obstruction cause renal infarcts in cats?
Renal infarcts in cats are common incidental findings on abdominal ultrasonography in cats. Hickey and others (2014) reviewed disease associations in cats with renal infarcts diagnosed on ultrasonography or necropsy.
http://www.ncbi.nlm.nih.gov/pubmed/24528199
A significant association with cardiomyopathy was observed.
However, that doesn’t explain for me why so many cats have apparent infarcts. Certainly in our population the overwhelming majority of such patients don’t have any cardiac changes.
Now look at these kidneys…..
This is a cat with classic ‘big-kidney, little-kidney’ presentation. This is the big one demonstrating pyelectasia. There are multiple calculi in the left ureter:
One in mid-ureter.
…and one in the terminal ureter at the bladder neck.
There’s a lot of inflammation around the left kidney and a small retroperitoneal effusion which also suggest that this kidney is acutely obstructed.
OK, so now the right kidney…
It’s small, it has focal mineralisation and it has discrete, ‘sunken’, hyperechoic wedge-shaped cortical lesions with the characteristic appearance of infarcts.
And unsurprisingly, the right ureter also is obstructed by a calculus:
In my experience, this is typical of the appearance of kidneys with chronic ureteral obstruction.
This is another one:
I’ve not seen this written up anywhere but I wonder if some renal infarcts are due to unrecognised ureteral obstruction. Should be easy enough to test the hypothesis.