Urinary issues are a common concern for those who own cats, whether it is related to simple litter box management or a medical problem that needs to be managed. Caline is our Pet of the Month for May. She is a 6-year-old DSH cat with a spunky personality. She experienced her first episode of cystitis when she was barely 7 months old.
Caline had been boarding for 2.5 weeks while her owner was out of town. Once back home, the initial symptoms noticed were a significant increase in the frequency of Caline’s urination. On exam, she was healthy, and comfortable, but we were unable to collect a urine sample as the bladder was quite small. Caline was treated with antibiotics for five days and started on Hill’s Feline c/d Multicare Stress formula canned food. We added in Dasuquin® to help reduce any inflammation in the bladder wall. Caline responded well to treatment and seemed to be back to normal. Our plan was to recheck a urine sample in another month.
In early February 2020, we saw Caline for a routine examination. ‘Cali’ was not exhibiting any urinary issues, yet she was being a typical young kitten at home; getting into everything, digging in the potted plants, and getting into bags of treats. Per our request, her owner had collected a urine sample at home which she brought to the hospital. This sample was well concentrated, but the urine was alkaline (pH 8.5), there were a moderate number of red blood cells, and unfortunately, many struvite crystals were present. This was concerning.
The owner relayed that Caline was no longer eating the Hill’s c/d food exclusively. She didn’t realize that the food would make a difference since Caline was drinking well and using the litter box consistently. The new findings with Caline’s urine prompted a more in-depth conversation about the long-term management for urinary issues in cats.
- Every cat has the potential to produce crystals in the urine, of which there are several types. Knowing the type of crystal influences the medical advice and treatment options.
- Management almost always involves long-term diet modification along with adequate water intake to ensure the bladder is being flushed out on a regular basis.
- Maintaining ‘Five-Star’ litter boxes at home is essential – everyone, cats included, wants their bathroom to be clean, accessible, designed to your preferences and private. This was not an issue in Caline’s case as her owner was very diligent.
In chronic cases, or cases not responding to treatment as expected, it is important to ensure there are not other complicating issues, such as diabetes, physical abnormalities, or underlying diseases that might contribute to urinary changes. That means blood work, sometimes urine cultures, abdominal radiographs, and when needed, abdominal ultrasound.
Caline was put back on an exclusive prescription food and we continued to monitor urine samples every six months or so. Fortunately, she remained symptom free for years until April of this year when the owner noticed evidence of blood in Caline’s urine and the Litter Robot® had recorded she was urinating up to 10 times a day for the past 3-4 days. The owner indicated that Caline’s appetite was the same but she seemed ‘needier’ than usual. There were foster kittens in the house, which was not new, and there was no direct interaction between the cats. As an ‘indoor’ cat, Caline had access to a screened outdoor patio, but was otherwise living a very consistent and well-controlled life. This reduced the other factors that we had to consider when working up her current urinary symptoms.
During Caline’s evaluation, we were unable to collect a sufficient urine sample but did identify some ‘floating debris’ in the bladder and thickening of the bladder wall using our in-house ultrasound equipment. She was started on medication to ease her discomfort and a short course of antibiotics to address any infection. One week later we had her back in the hospital to collect a urine sample for evaluation and culture & sensitivity testing.
One of the advances we now have, is an A.I. assisted analyzer called the Imagyst® which allows us to run urine samples within minutes of collection. This has increased our accuracy as the urine doesn’t sit for hours before getting to the lab for evaluation, and the Imagyst evaluates 1000 hpf (high power fields) compared with traditional 10-100 hpf. We know that crystals can sometimes form when urine samples sit and that may not reflect what is actually happening in the bladder. 
In Caline’s case, the urine testing this time showed a significant amount of oxalate crystals and the presence of many red blood cells. The urine culture was negative for bacteria so infection was ruled out. Subsequent radiographs revealed a collection of bladder stones, also known as calculi, of various sizes. While struvite crystals are most often a consequence of infection, and can be dissolved with special diets, this is not the case for oxalate crystals and stones.
Caline would need surgery. We collected baseline blood work, which also revealed a mild increase in her blood calcium level. To ensure there wasn’t an underlying issue with her parathyroid glands, which control calcium balance in the body, we had an Ionized Calcium (iCa) level checked. This was thankfully normal, so we proceeded with surgery.
We are happy to report that Caline’s surgery went well. We removed several dozen small ‘stones’, many were a sand type grit, from her bladder and her recovery went well. Here is a photo of her waking up and a picture of the ‘stones’.
We submitted the bladder stones to the lab and they were confirmed to be composed of both oxalate dihydrate and oxalate monohydrate with no nidus. If a nidus, of infection or other, is present, think of how an oyster makes a pearl – the nidus triggers the body to lay down product around the item to isolate it. Without a nidus, our focus is on managing the crystal formation.
Going forward, our goal is to have Caline: 
- consume more water to help reduce the urine concentration; a specific gravity less than 1.030 is preferred
- increased fluid intake also increases urination and helps with flushing out crystals before they can form aggregates and calculi
- add in Purina HydraCare® which is a hydration supplement
- stay on a prescription food indefinitely and encourage a to transition to more canned food in the diet to maintain the urine pH in an ideal range of 6.8-7.5
- avoid any treats or other foods that might contain calcium or oxalate, the building blocks of calcium oxalate stones
- Her owner will work on getting Caline slimmed down as obesity is a risk factor the stone development.
There is nothing to completely prevent the oxalate crystals and potentially stones from forming again so we’ll need to monitor her urine and check the bladder with ultrasound and radiographs in the future. Some very small stones may be passed naturally by female cats, so we are hopeful that this was the only surgery Caline will need.
VeterinaryPartner.com – Bladder Stones (Oxalate) in Cats
VeterinaryPartner.com – Bladder Stones in Dogs and Cats
VeteirnaryPartner.com – Hypercalcemia in Dogs and Cats
Hill’s Feline c/d Multicare Stress food
VeterinaryPartner.com – Choosing the Right Litter Box for Your Cat
