Clarence is a 4 year old, male, neutered, domestic short hair cat. He lives indoors with 1 other cat. He has always been generally healthy and is not on any medications. Yesterday evening (Boxing Day) the owner noted spots of urine on the carpet, a couple of them seemed red. The owner was not sure which cat was having the problem, so isolated them to try to make this determination. The housemate urinated a large amount once over night in the litter box. Clarence urinated a small amount a few times in his litter box and several times on the rug in the bathroom he was isolated in. The urine appeared red when it was cleaned up. Clarence was brought in for evaluation. He has not vomited. His thirst seems normal and he continues to eat and have normal stools. On physical examination his vitals are within normal ranges, his body condition is considered normal at 5/9, his bladder is very small on palpation, and he is uncomfortable on bladder palpation. He immediately strained to produce only 2-3 drops of bloody urine.
What are the first 2 diagnostics to consider when presented with Clarence?
Clarence is a generally healthy young cat that is not drinking or urinating excessive amounts and continues to eat and drink normally without weight loss. Our initial main concerns are for the urinary tract, in particular the bladder. The kidneys cannot be ruled out as the source of the problem but would be much less likely in a cat of this age. Therefore, the first consideration would be for a urinalysis.
As he just emptied his bladder, we plan to keep him in the clinic for a few hours to get a sample. He is administered pain medications and placed in a kennel with a dish of water. About 3 hours later we are able to collect urine by cystocentesis (using a syringe to get urine directly from the bladder).
The urinalysis shows the urine to be well concentrated with a specific gravity > 1.040. There is a moderate amount of protein, no glucose, and pH 8 on the dipstick test. Microscopic examination shows a very large number of red blood cells, rare white blood cells, a small number of struvite crystals, a moderate amount of fat, and no obvious bacteria.
At this point we can rule out many hormonal problems, diabetes and chronic kidney disease. Kidney infection seems very unlikely as the kidneys were normal on palpation and no casts were seen in the urinalysis. A bladder infection has not been completely ruled out as there was so much blood in the specimen that seeing and differentiating round shaped bacteria from the fat droplets is difficult.
Now the problem is differentiating a bladder infection from a sterile cystitis. This leads us to the second diagnostic, urine culture. We send urine to an outside lab for culture and sensitivity. This test usually takes 2-3 days for final results. It takes time for the bacteria to grow.
Pending the urine culture results we place Clarence on pain medications to help with the symptoms. The results are returned 2 days later with no growth. The no growth result makes a bacterial urinary tract infection extremely unlikely. Therefore, we must look for causes of sterile feline cystitis (inflammation of the bladder with no infectious organisms identified).
The crystals in the urine could suggest that crystals or bladder stones are the cause of the inflammation. This is not a foregone conclusion as the crystals can form in the urine after collection as an artifact in urine with a higher pH like Clarence has. However, they could also be real and we cannot completely ignore them.
The other big consideration is what we call feline idiopathic cystitis (also known as feline interstitial cystitis). Remember, today is December 27. The midst of the holiday season. This is a very common time for cats to develop sterile cystitis and other urinary tract problems secondary to stress. The holidays are a stressful time for cats. They tend to be creatures of habit and do not like their routine changed. The visitors that were over on Christmas Day, the parties that the owners went to and stayed out late over the weekend, the flashing lights on the house across the street and that tree in the corner that the owner has been chasing him away from are all items of stress. Not to mention the kids running around like fools.
Studies have shown that about 90% of cats showing symptoms of lower urinary tract disease (frequent urination, small amounts of urine produce with straining, bloody urine, pain) are actually a sterile cystitis. Studies also show that reducing the stress for the cat can greatly reduce the frequency of these symptoms.
Acute phase treatment is aimed at controlling symptoms with control of pain and inflammation. Long term treatment is approached with diet and stress reduction. There are several prescription diets available with a label claim for treatment of sterile cystitis. One of these would be a good choice for Clarence given the crystals seen in his urine as these foods are primarily designed for control of the crystals.
Stress is typically addressed by trying to eliminate sources of stress and through environmental enrichment. Is there a cat outside that is upsetting Clarence? How do the housemates get along? Is it the tree, the lights, the company, the change in the schedules? Are there enough litter boxes? Is there enough space in the house? Sometimes it is difficult to determine the cause of the stress.
Environmental enrichment gets the cat more active within the house doing more numerous natural activities. These can include creating multiple perches around the house, hiding food around the house, feeding with a ball that dribbles the food out when rolled, creating hiding places, and many other activities. You can find a lot more information at https://indoorpet.osu.edu/cats.
We decided to place Clarence on a special diet. He was also treated with anti-inflammatory and narcotic analgesic medications for a week. His symptoms improved dramatically within a few days and he was found to be normal at his 2 week recheck. At that time there was no blood or protein in the urine, the pH was 6, and no crystals were found.
The owner knows that Clarence is not necessarily cured, but his symptoms seem to be managed at this time. We will continue to monitor and treat him as needed as symptoms commonly are cyclical. If he has problems in the future, he will need another urinalysis and possibly further evaluation, especially if symptoms are frequent.