Azotemia and Uremia in Dogs
Azotemia refers to an excess of nitrogen-based compounds like urea, creatinine, and other waste substances in the bloodstream. This condition can arise from elevated production of nitrogen-containing substances (often associated with a high-protein diet or gastrointestinal bleeding), impaired kidney filtration (as seen in kidney disease), or the reabsorption of urine back into the bloodstream.
On the other hand, uremia also results in the buildup of waste products in the blood, but it occurs due to ineffective elimination of these waste products through urine, primarily because of abnormal kidney function.
Symptoms and Types
- Weakness
- Fatigue
- Vomiting
- Diarrhea
- Depression
- Dehydration
- Constipation
- Weight loss (cachexia)
- Loss of appetite (anorexia)
- Bad breath (halitosis)
- Muscle wasting
- Hypothermia
- Poor hair coat
- Pallor (unnatural lack of color in the skin)
- Petechiae (minute red or purple spots on the skin due to tiny blood vessel hemorrhages)
- Ecchymoses (purple or black-and-blue spots on the skin caused by blood vessel ruptures and blood escape into surrounding tissue)
Causes
- Decreased blood volume or low blood pressure
- Infections
- Fever
- Trauma (such as burns)
- Toxicity from corticosteroids
- High protein diet
- Gastrointestinal bleeding
- Acute or chronic kidney disease
- Urinary obstruction
Diagnosis
To effectively diagnose your dog’s condition, it’s crucial to provide a detailed history of their health, including the symptoms’ onset and characteristics, to your veterinarian. Following this, the veterinarian will conduct a thorough physical examination along with several tests, including a biochemistry profile, urinalysis, and complete blood count (CBC). The CBC results might indicate nonregenerative anemia, a common occurrence in dogs with chronic kidney disease and failure. Hemoconcentration, leading to thickening of the blood due to decreased fluid content, may also be observed in some dogs with azotemia.
Biochemistry tests can reveal elevated levels of urea, creatinine, and other nitrogen-based compounds in the blood, along with possible hyperkalemia (high potassium levels). Urinalysis can detect changes in urine specific gravity, commonly used to evaluate kidney function, and abnormal protein concentrations in the urine.
Abdominal X-rays and ultrasound are valuable diagnostic tools used by veterinarians to assess azotemia and uremia. They aid in identifying urinary obstructions and evaluating the size and structure of the kidneys. Smaller kidneys are often associated with chronic kidney disease, whereas larger kidneys may indicate acute kidney failure or obstruction.
In some cases, a kidney tissue sample may be collected for further examination to confirm kidney disease and rule out other potential acute or chronic kidney conditions.
Treatment
The treatment plan recommended by your veterinarian will vary depending on the underlying cause of the conditions, with the primary aim being to address the root cause, whether it’s azotemia or uremia. For instance, in cases of urinary obstruction, the veterinarian will aim to alleviate the obstruction to restore normal urine flow. Additionally, if the dog is dehydrated, intravenous fluids will be administered to stabilize the animal and correct any electrolyte imbalances.
Living and Management
The prognosis for this disease hinges on the extent of kidney damage, whether the condition is acute or chronic, and the effectiveness of treatment. Since most medications are eliminated through the kidneys, dogs with kidney disease or failure require careful consideration when selecting drugs to prevent further kidney damage. It’s crucial not to administer any medication to your dog without consulting your veterinarian first. Furthermore, refrain from altering the brand or dosage of prescribed medications without prior consultation.
Monitoring your dog’s urine output at home is essential, and in some cases, owners may need to diligently record urine output. This record will assist your veterinarian in assessing disease progression and the kidneys’ overall function with current therapy. Your veterinarian may recommend repeating laboratory tests to measure urea and creatinine levels 24 hours after initiating intravenous fluid therapy.