Renal insufficiency in dogs 

Is your dog drinking more than normal or does it need to vomit? Then the problem could lie in its kidneys. Read here how the vet can help your dog and what you need to know about renal insufficiency in dogs.

How dangerous is renal insufficiency?

Survival chances vary depending on the cause and form of renal insufficiency. Whilst the acute form is generally curable, there is no cure for the chronic form. The disease can be fatal if total kidney failure occurs.

What are the symptoms of renal insufficiency?

Renal insufficiency can be sudden (acute) or long-term (chronic). Since the kidneys can no longer remove toxins contained in the blood (e.g. urea), they accumulate in the blood. This is also known as uraemia. The disease mostly progresses in several stages, in which the following symptoms emerge:

• Kidney patients appear weak and sleep a lot.
• Dogs drink more (polydipsia) and give off more urine (polyuria).
• The disturbed hormone balance can result in sufferers losing a lot of weight and their coat becoming lacklustre.
• Gastrointestinal symptoms like diarrhoea, vomiting and loss of appetite

Diagnosis: How do we recognise renal insufficiency?

If your dog is showing signs of renal insufficiency, you shouldn’t wait long to see a vet. They can use the following diagnostic measures to find the underlying cause for complaint:

1.     A urinalysis

The vet may ask you to collect your dog’s urine. If this isn’t possible, they can collect urine with the help of a catheter or an ultrasound-assisted needle (cystocentesis). The urine is then analysed for its specific gravity (dog < 1,025) and the concentration of protein, glucose and inflammatory cells. The urine can also be bacteriologically examined.

1.     Measuring the blood pressure and a blood test

Since the kidneys determine blood pressure, this increases due to renal insufficiency. A blood sample helps to measure the level of urinary substances (metabolites in the blood) like urea or creatinine in the blood. If their concentration in the blood increases, renal insufficiency must be assumed.

1.     Imaging procedures

The kidneys can be visualised by means of an ultrasound examination. This is how we recognise structural causes like tumours or injuries.

What treatment methods are available?

Since renal insufficiency can result from many different causes, a thorough diagnosis must take place before every treatment. This must then be targeted with medication or, if necessary, surgery.

Along with cause-specific treatment, symptoms can also be alleviated with the help of supportive measures. In order to do so, vets prescribe the following steps:

• Medication for high blood pressure (e.g. ACE inhibitors)
• Anti-nausea medication (antiemetics)
• Stomach protection tablets
• Fluid and electrolyte infusions
• Placing a urinary catheter
• Changing the food (low in protein, phosphate and sodium)

During the entire treatment, it is important to regularly monitor the dog’s blood pressure. Further blood success can also help to check if the treatment is successful.

If the kidneys are so severely damaged that they can no longer perform tasks alone, kidney replacement therapy (dialysis) must be carried out. This involves the blood being filtered in an external device and then added back to the bloodstream.

Prognosis: What are the chances of recovery?

The prognosis of renal insufficiency depends greatly on the underlying disease. It is generally more favourable with acute renal insufficiency, whilst chronic renal insufficiency is unfortunately not curable. If you follow the vet’s instructions and feed your dog with special kidney food, you can improve its quality of life and potentially its life expectancy.

You can also find suitable dog food for a kidney diet in the zooplus online store.

Causes: What are the triggers of renal insufficiency?

If a dog is suffering from renal insufficiency, its kidneys do not work as they usually do. Normally they ensure an even balance of fluids and electrolytes and regulate the blood pressure. In addition, they detoxify the blood and filter urinary excreted substances, which are then released into the urine. If these functions are disturbed, the body can be damaged in many ways due to the complex tasks involved.

The causes of renal insufficiency are divided into pre-renal (before the kidney), renal (inside the kidney) and post-renal (after the kidney) causes:

• Pre-renal causes: If too little blood enters the kidneys, they are not able to filter as much fluid. This can happen if your dog drinks too little water or its heart pumps too little blood into its circulation.
• Renal causes: These include tumours, injuries or inflammations (nephritis) of the kidneys themselves. Infectious diseases (e.g. leptospirosis) or toxins can also damage the kidneys.
• Post-renal causes: If the urinary tract is displaced or the ureter is torn due to trauma (e.g. after a car accident), the renal function is disturbed.

Acute kidney injury (AKI)

With acute renal insufficiency (also acute kidney injury, AKI), the kidneys suddenly receive less blood flow. It occurs within a few hours to days. If the cause is quickly identified and treated, complete recovery is possible.

Chronic kidney disease (CKD)

With chronic kidney disease (CKD), the renal corpuscle (glomeruli) in the functional units (nephrons) of the renal tissue suffers long-term damage. It isn’t always possible for vets to identify the exact cause.

Since the renal corpuscles cannot regenerate, chronic renal insufficiency is not curable. The dog’s condition often worsens over the course of the disease.