Welcome to Justanswer! I am Dr. Altman and happy to assist you both today!
Ideally until you are able to get to your veterinarian, please increase water intake. You can do this by supplementing the dry food with water and flavoring the water (maple syrup for example) as well. Increasing the water intake will help "flush" out the bladder and reduce the pain associated with urination.
Collecting a first morning sample in a tupperware container and refrigerating the sample if more than an hour old to have your vet evaluate the sample will help determine the cause of the increased straining to urinate.
Your vet will run a urinalysis, potentially do a urine culture to look for bacteria, an X-ray to rule out a bladder stone, and bloodwork to ensure there is not a metabolic cause or kidney issues causing the symptoms
Diagnosing the issue will help determine how best to treat the straining to urinate to get your pet comfortable swiftly
Please let me know if you have any additional questions I can assist with!
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