Cystitis and bladder stones are two of the most common urinary diseases and lead to various clinical signs that are sometimes poorly understood by the owner. The main role of urine is to eliminate body wastes and toxic products that accumulate in the bloodstream. It also plays a role in maintaining the body’s equilibrium by regulating the quantities of water and minerals that are excreted.
Produced in the kidneys where nephrons carry out blood filtration, urine passes through both ureters to the urinary. It is released to the outside via the urethra when the pet feels the need to urinate.
How can I detect a urinary disorder in my pet?
The clinical signs of urinary disorders are various and sometimes subtle. Irrespective of their intensity, they always indicate discomfort or pain.
Your pet may show one or more of the following signs:
- urinates more often and passes small quantities, or fails to urinate
- licks the genital area frequently
- crouches longer in the urinating position
- strains or shows signs of pain while urinating
- pinkish urine, indicative of the presence of blood
- loss of appetite
- behavioural changes
Does a urinary disorder necessarily mean a urinary stone?
NO. Low Urinary Tract Disease (LUTD) may have various causes and there are also some differences between cats and dogs. In fact it may be caused by:
- cystitis (bladder inflammation) of infectious origin
- urinary crystals/stones: these aggregates mostly form in the urinary bladder of pets.
- neoplasm (tumour)
- behavioural disorder etc.
To make his/her diagnosis, your veterinarian may suggest performing further examinations such as urinalysis to determine the urine pH, detect the presence of inflammatory cells, blood or protein…
What is a urinary stone?
These crystals occur when urine is saturated in minerals, either because the pet’s metabolism is abnormal or because his diet makes the urinary environment favourable to crystal formation. Urinary stones consist of aggregates of urinary crystals that are present in the bladder. They can be of four types: struvite stones (very common), calcium oxalate stones (most common), ammonium urate stones (much less frequent) and cystine stones (rare).
These stones may vary in size, be alone or associated with other stones, be of one type or mixed. Identification of the stone is very important in planning the most appropriate treatment.
What are the factors that promote stone formation?
As a general rule, the factors involved in stone formation are:
- the degree of urine acidity (pH)
- urinary concentrations of minerals
- infectious cystitis
Small breeds such as Bichon Frise, Miniature Schnauzer, Poodle, Shih Tzu and Yorkshire Terrier are known to be more prone to developing urinary stones. Dalmatians have a higher risk of ammonium urate stones due to a metabolic abnormality leading to excessive urinary excretion of urate. In general, male dogs are more affected by urinary calculi than female dogs (except for struvite calculi).
What is the treatment for urinary stones?
Treatment may consist of the administration of antibacterial agents to fight against a possible bladder infection, anti-inflammatory drugs to reduce inflammation of the urinary tract, or urinary pH modifiers.
Some calculi, such as struvite, can be dissolved by a specific diet, such as Royal Canin. This diet is higher in sodium (in proportions safe for the pet’s health), resulting in increased water intake and therefore urine dilution. Moreover, this diet is specifically designed to reduce the urinary concentrations of minerals (magnesium, phosphorus) and urea, and to acidify urine.
Ammonium urate and cystine stones can also be dissolved. Dissolution requires a diet that alkalinises urine. Royal Canin diet is particularly indicated.
Other stones, like calcium oxalate, cannot be dissolved. Therefore they need to be removed by your veterinarian, under general anaesthesia.
What can I do to prevent stone recurrence?
- If your pet has already had urinary crystals/stones: do not change his diet before consulting your veterinarian, even if he seems to be cured.
- Do not withdraw the medical treatment prescribed by your veterinarian before the end of the treatment period. If you encounter difficulties in administering drugs to your pet, consult your veterinarian: he/she will give you some advice and may adjust the prescription. Your pet may seem to be completely normal even though crystals are forming again.
- Ideally, divide your pet’s daily feeding amount into several small meals: this minimises fluctuations in urine pH.
- Make sure that your pet has fresh and clean water available at all times.
- Ensure that your pet does not have to wait to urinate. When your pet holds on, it concentrates its urine as well as the minerals that are contained in urine. Remember to take your dog out often.