Your animal is possibly having urinary tract obstruction or constipation. In order to diagnose the cause, it will need a vet to perform physical examination and diagnostic tests and evaluate if your animal is in pain.
Straining to urination is especially concerning as with urine continuing to accumulate in the bladder without being released, metabolic waste and pressure are built up backwards in the urinary tract. This can cause severe pain, renal damage and even death if patient is not treated on time. This is an emergency.
If you notice any of these signs or have concerns, please seek veterinary advice and care as soon as possible.
