Emphysematous cystitis in cats

In previous posts, we have already discussed feline lower urinary tract diseases, more specifically struvite stones and oxalate and struvite stones.

In this post, we will focus on emphysematous cystitis (EC) in cats.

Emphysematous cystitis

Cystitis is the most common cause of bladder wall thickening. Emphysematous cystitis is a complicated lower urinary tract infection, characterised by the presence of gas-filled vesicles in the bladder wall and sometimes even gas bubbles in the lumen of the bladder. This gas formation is due to a bacterial infection that uses glucose, protein or tissue carbohydrates as substrates.

The gases found in the bladder are nitrogen, hydrogen, oxygen and carbon dioxide.

Multiple microorganisms have been isolated in such instances, with E. coli and Clostridium spp. predominating in over half of published cases. Other gram-negative bacteria, including Klebsiella and Proteus, or fungi, such as Candida, have also been reported in EC.

Diagnosis of emphysematous cystitis

Patients with diabetes mellitus and glycosuria in addition to emphysematous cystitis return confusing ultrasound images caused by intraluminal gas, which may even obscure the anatomy of the bladder. In such cases, an X-ray will provide more information because any gas is easily identified within the bladder wall.

A clinical suspicion of EC is sometimes aroused by a hissing or whistling when urinating or a crackling sound upon palpation of the bladder in the physical exam.

An early diagnosis is important because this type of cystitis is hard to treat and recurrence is frequent. The management of emphysematous cystitis, when introduced promptly, gives very successful outcomes. Effective urinary drainage, appropriate antibiotic therapy and good glycaemic control produce very good therapeutic results. Once the UTI has been eliminated, the gas is rapidly absorbed into the tissues. In rare cases, surgical debridement or a cystectomy may be necessary. Definitive resolution of the infection is confirmed by a follow-up X-ray and urinalysis.

Emphysematous cystitis and diabetes

Diabetic cats with associated glycosuria are known to have a greater predisposition to emphysematous cystitis. This is because the infection is caused by bacteria that use glucose, amongst other substances, as substrates. The absence of glycosuria is not a reliable criteria to rule out a diagnosis of diabetes mellitus. Therefore, the animal’s blood glucose should always be measured before excluding diabetes mellitus.

Emphysematous cystitis can also occur, albeit less frequently, in nondiabetic cats and these patients tend to suffer a more complicated evolution.