Clarify the situation: The significance of history and signaling When it comes to creating a list of possible causes of inappropriate elimination for a differential diagnosis, Germain advised, “Never underestimate the power of a good history.” She continued, “Confirming the presence of lower urinary tract signs is one really important thing I think we miss.” Pollakiuria, dysuria, stranguria, overgrooming of the abdomen, and vocalization during urination are lower urinary tract (LUT) symptoms. LUT signs may or may not be present in all cats with uroliths, but their presence or absence will alter the differential list. Although it is not pathognomonic, hematuria is another clinical sign of uroliths.
Germain also reminds veterinarians that they must communicate with clients in the same language. When a pet owner claims that their cat is urinating more frequently, it is essential to determine whether they are referring to the volume or frequency of the urination. Germain suggests making a comparison between the sizes of the urine balls in the litter box and known objects like fruits. Both polyuria and pollakiuria may present with uroliths, but the other differentials will differ between the two presentations.
The differential diagnosis list should also be influenced by cats’ signaling. Struvite uroliths are more common in cats under the age of 7 and uncommon over the age of 10.3 There is a breed predisposition for urate stones There’s a gigantic disparity in what we do in principle and what we really do,” said Germain. Ultrasound, which is frequently used in conjunction with cystocentesis to obtain urine samples, can assist in determining the presence of stones and may be the only method for diagnosing non-radiopaque stones like urates.
the chance of successful dissolution. On the other hand, radiographs are essential for the diagnosis of uroliths because they can aid in predicting the composition of the stone and permit the measurement of stones Calcium oxalate stones are the most radiodense, tend to be round to spiculated, and frequently have multiple stones (more than 3-5).4,5 Additionally, the vast majority of renoliths are calcium-based, so patients with renoliths are more likely to have calcium-containing uroliths in the bladder.5 Struvit
Urinalysis results can also help determine the type of stone, but they should be interpreted in light of how the specimen was collected, stored, and handled. A stone’s type can be determined by its pH, as struvite stones typically form at a pH close to neutral.5 Crystals may or may not be present. Germain reminds professionals to “Never preclude a stone on the off chance that there aren’t gems in the pee.”
Dissolution diets are effective for struvite uroliths, and clinical signs should improve quickly after starting the diet.4,5 Medical management of uroliths should always be attempted first. They can disintegrate as quick as multi week,” shared Germain. The majority of struvite stones will disappear within four weeks, with a 50% reduction in the first two weeks. Germain would rather take radiographs of patients every two weeks to keep an eye on their dissolution, but she pointed out that not all clients can afford this. If the patient’s clinical signs are improving, it is appropriate to wait 4-6 weeks before taking a radiograph.
To alleviate the pain and discomfort caused by stones, a dissolution diet should be followed. In addition, despite the fact that the majority of struvite stones in cats are sterile, stones do make them susceptible to infection, which should be treated if it occurs. Last but not least, environmental modification to alleviate patient stress ought to be implemented.
Stone removal should be pursued if medical dissolution fails despite appropriate dietary compliance, environmental management to reduce stressors, and confirmation that a urinary tract infection is not present. Cystotomy should be the last intervention, but it is necessary in some patients, particularly male cats, whose anatomy limits the use of many non-invasive options.4,5 These procedures include voiding urohydropulsion, cystoscopic basket retrieval, intracorporeal lithotripsy, and percutaneous cystolithotomy.4,5 The American College of Veterinary Internal Medicine and the AAFP consensus statements on urolith management recommend minimally invasive procedures as the preferred option.
Preventing urolithiasis Knowing the kind of stone the patient had is an essential piece of information for preventing urolithiasis. Quantitative analysis should be performed on all stones taken from a patient in a laboratory. “That sand and grit is precious,” Germain stated, “There’s no urolith too small.”
An appropriate therapeutic maintenance diet can be chosen after the type of stone has been determined. There are numerous diets available, some of which manage multiple conditions simultaneously. “Reach out to the different companies because [diets] aren’t all the same,” Germain advises veterinarians. In addition, knowing the kind of stone might lead to an examination for other medical conditions that may be present at the same time, like hypercalcemia or portosystemic shunts. The treatment of these conditions might help avoid uroliths in the future.
Dilution of the urine, which increases urination frequency, produces a flushing effect, and reduces the concentration of stone precursors, is a primary goal of urolith prevention. There are numerous ways of attempting to weaken pee. The primary strategy is to try to get cats to drink more water on their own, which can be hard for some. Utilizing running drinking fountains, adding water to the food, taking care of a canned eating routine, expanding the recurrence of dinners, and diminishing calories can all be procedures to weaken pee. Using pain medication for arthritic cats and increasing the number of litterboxes available may also help to increase the frequency of urination. For some cats, diluting the urine can be difficult, and multiple methods may need to be used simultaneously to achieve the best results.
