Testing for Inappropriate Urination (Urinating in the house)

Why is my house-trained pet urinating in the house?

Inappropriate urination or urinary “accidents” happen in well trained pets for many reasons, including:

• inflammation or infection of the urinary or reproductive tracts  
• diseases that cause increased urination such as kidney failure, diabetes mellitus (“sugar” diabetes), diabetes insipidus, and hyperadrenocorticism (over active adrenal glands - “Cushing's disease”)  
• neurological disease affecting control of the bladder
• behavioral problems such as submissiveness or territoriality

Some medications, especially corticosteroids may cause increased thirst and urination leading to urinary accidents

How do we investigate the problem of inappropriate urination in my pet?

The search for answers starts with a complete history and physical examination. A pet’s “history” is the information you give the veterinarian about your pet’s illness. A detailed history can provide important clues about the underlying problem.

Physical examination involves looking at all parts of the body, and typically includes listening to the heart and lungs with a stethoscope and “palpating” the abdomen (gently squeezing or prodding the abdomen with the fingertips to detect abnormalities of the internal organs). In a pet that is having urinary accidents, the physical examination may reveal such things as vaginal discharge in a female suggesting vaginitis; large tense bladder suggesting urinary obstruction; or abnormal kidneys suggesting kidney disease.   

If history and physical examination are unhelpful then further testing will likely be needed and your veterinarian may recommend doing screening tests. These are a series of simple tests that provide information about the overall health of the pet and often provide further clues about the underlying problem.

What screening tests are recommended? 

The basic screening tests include complete blood count (CBC), serum biochemistry profile, and urinalysis. To complete these tests, two blood samples and a urine sample need to be collected from your pet.

What can these screening tests tell us?

(a) Complete Blood Count: This is a simple blood test that provides information about the different cell types in blood. These include red blood cells, which carry oxygen to the tissues, white blood cells, which fight infection and respond to inflammation, and platelets, which help the blood to clot. The CBC provides details about the number, size and shape of the various cells types, and identifies the presence of abnormal cells in circulation.   (See article Complete Blood Count).

The CBC is often normal in pets that are urinating inappropriately. However, changes that may be seen include:

• anemia (decreases in red blood cell number and hemoglobin) - may be due to chronic kidney disease or other chronic illness including cancer
• increased numbers of white blood cells – may indicate infection of the kidneys or secondary infections due to diabetes mellitus or Cushing’s disease
• Increased numbers of neutrophils (a type of white blood cells) - may indicate underlying infection, corticosteroid medication, or Cushing’s disease.

(b) Serum Biochemistry Profile refers to the chemical analysis of serum, which is the pale yellow liquid part of blood that remains after the cells and clotting factorshave been removed. There are many substances in serum, including proteins, enzymes, fats, sugars, hormones, electrolytes etc. Measuring the levels of these substances in the blood provides information about the health of the body’s organs and tissues as well as the metabolic state of the animal. Changes and abnormalities found in the biochemistry profile can help to diagnose a variety of diseases and disorders. (See article Serum Biochemistry).

In pet that is urinating inappropriately the serum biochemistry profile could show:

• elevated glucose – suggesting diabetes mellitus
• elevated kidney values – suggesting kidney disease
• decreased urea – may indicate diabetes insipidus or liver disease
• mild elevation of liver enzymes – often seen with Cushing’s disease and corticosteroid medication

(c)  Urinalysis is a simple test that analyzes the physical and chemical composition of urine. It measures how well the kidneys are working, identifies inflammation and infection in the urinary system, and helps to detect diabetes and other metabolic disturbances. Urinalysis is important for the proper interpretation of the serum biochemistry profile and should be done at the same time as blood testing. (See article Urinalysis).

In a pet that is urinating inappropriately, a urinalysis could show:

• dilute urine (pale watery urine): associated with conditions such as kidney disease, diabetes insipidus, diabetes mellitus, Cushing’s disease, and use of corticosteroid medication.  
• red blood cells, white blood cells: indicates inflammation of the kidneys, urinary, or reproductive system. 
• white blood cell casts (tubular clusters of white blood cells): indicates inflammation of the kidneys    
• crystals: may indicate underlying bladder stones
• bacteria, fungi, yeast: can indicate bladder infections. Bacterial bladder infections are common while yeast and fungal infection are uncommon. 
• abnormal bladder cells: may be a sign of underlying bladder cancer

What if all the screening test results come back normal?

If all the tests results come back normal, then the inappropriate urination may be due to:

(a) behavioral problems:

• Territorial marking – if there are multiple pets in the household, competition between animals may lead one or more of them to urinate inappropriately to “mark” territory.
• Cats and their litter boxes  
  • some cats prefer not to use a dirty litter box and may urinate elsewhere.
  • a male cat with a history of painful urinary blockage may associate pain with using the litter box and will choose to urinate somewhere else.

(b) “Hormone responsive urinary incontinence”.  In this condition, there is a slow involuntary “leaking” of urine from the bladder when the pet is lying down or sleeping.

What additional tests might be recommended for a pet that is urinating inappropriately?

There are several additional tests that might be recommended depending on the results of a pet’s history, physical examination and screening tests.

Some examples of additional tests would include:

• testing for diseases that cause increased thirst and urination: these include diabetes mellitus, Cushing’s disease, diabetes insipidus, and renal failure.
• culture and sensitivity: this test helps to determine if bacterial bladder infection is present and identifies which antibiotic should be used to treat the infection.
• cytology: bladder cells taken from urine are examined under the microscope to diagnose bladder cancer.
• imaging studies: X-rays or ultrasound of the kidneys and urinary system may be recommended to look for stones or tumors.
• stone analysis: bladder stones are sent to the laboratory to be analyzed for their mineral content. Based on the results, appropriate dietary changes can often prevent recurrence of bladder stones.