Uremia is a condition characterised by the buildup of toxic waste products in the bloodstream. This occurs when the kidneys are no longer functioning properly and instead of removing wastes from the blood via the urine they build begin to build up in the blood, affecting many of the body systems. There are many reasons why kidney function may be impeded, it may be sudden (acute) or chronic (slow and progressive).
- Urinary blockage, when a blockage is present and urine backs up, the kidneys stop functioning and toxins begin to build up in the bloodstream.
- Kidney disorders such as inflammation, kidney stones, glomerulonephritis, polycystic kidney disease and diabetes.
- Bladder rupture due to the urine leaking back into the blood stream.
- Shock which can lead to blood loss or rapid dehydration.
- Heart failure which results in low blood pressure reducing blood flow to the kidneys.
- Drugs or other toxins which damage the kidneys.
The most common cause of kidney failure is due to age (chronic kidney failure). Most elderly cats will develop kidney diseased to some extent.
Acute kidney failure can occur for a number of many reasons, and is life threatening. Poisoning, infection, blood loss, dehydration, drugs and toxins, blockage and trauma are all possible causes of acute kidney failure.
What are the symptoms of uremic poisoning in cats?
Symptoms of uremic poisoning are similar to other types of poisoning and include:
- Lethargy and/or drowsiness
- Loss of appetite
- Difficulty breathing
- Increased urination and thirst (polyuria/polydipsia)
- Poor coat condition
- Mouth and tongue ulcers
- Intermittent diarrhea and vomiting
- Ammonia-like smell on the breath
Other symptoms may be present depending on the underlying cause of uremic poisoning for example if your cat is in shock he may have pale gums, appear confused and his breathing may be rapid.
A cat who has a urinary blockage will strain to urinate, visit the litter tray frequently, show signs of pain or discomfort and cry in the litter tray. Many pet owners mistake a urinary blockage for constipation due to your cat straining in the litter tray.
How is uremic poisoning diagnosed?
Your veterinarian will perform a complete medical history and perform a physical examination on your cat. He will need to know how long you have noticed symptoms and what symptoms are present. As we have already said, kidney failure may be acute (sudden onset) or chronic. Up to 70% of kidney function may be lost before outward signs of uremic poisoning become apparent.
He will need to perform some diagnostic tests, which may vary depending on the suspected cause. These may include:
- Biochemical profile to check BUN (blood urea nitrogen), phosphorus and creatinine levels. High BUN, phosphorus and creatinine levels can indicate poor kidney function.
- Urinalysis may show blood in the urine (hematuria) and urinary crystals.
- Complete blood count to look for signs of infection.
- Ultrasound to check for signs of urinary blockage.
- ECG (electrocardiogram) may be performed to evaluate the heart function. Elevated potassium levels can lead to abnormal heart rhythms.
How is uremic poisoning treated?
Treatment is aimed at addressing the cause of kidney failure and bringing down potassium, BUN and creatinine levels.
Chronic kidney failure is managed with a variety of ways such as a low protein and phosphate diet, phosphorous binders and supportive care such as fluids to treat dehydration.
Acute kidney failure is treated by addressing the underlying cause, such as poisoning, shock, urinary blockage, trauma etc.
If a urinary blockage has occurred, a catheter will be inserted into the urethra to enable urine to be removed from the bladder. An anti-inflammatory shot may be required to reduce inflammation, making insertion easier.
IV fluids to treat electrolyte imbalances and help flush out the system. Calcium gluconate to help stabilise the heart.