Kidney failure in dogs… Dogs too can suffer from kidney failure, especially senior dogs, and it can be either chronic or acute. Let's look at how to recognise this condition, what the symptoms of kidney failure in dogs are, and how it can be treated.

Causes of kidney failure in dogs

Kidney failure in dogs can develop in either a chronic or an acute form. The causes are not always easy to identify, partly because there can be many of them. Here are the most common:

  • Leishmaniasis in dogs
  • Leptospirosis in dogs
  • Dog diseases that cause immune-complex deposits
  • Lupus erythematosus
  • Tumours in dogs of various kinds
  • Dog poisoning
  • Kidney stones
  • Polycystic kidney disease
  • Urinary tract problems
  • Prolonged incorrect diet

How to recognise kidney failure in dogs

It is essential to detect kidney failure in dogs early in order to prevent kidney damage. The kidneys are made up of cells called nephrons, and only a small proportion of them are active at any one time — the rest serve as a reserve when the working ones become damaged.

Problems arise when kidney function has drawn on the reserve and that reserve runs out too. At that point the kidney is damaged and may go into renal shutdown. The symptoms of kidney failure in dogs are not always easy to spot. Nevertheless, the following signs may suggest the presence of this condition in general terms:

  • The dog drinks a great deal
  • Weight loss in the dog
  • Increased frequency of urination
  • Anorexia in dogs and lethargy
  • The dog stops eating
  • Bad breath in dogs

It is therefore important to recognise the symptoms of kidney failure promptly: if you have any suspicions, you can take your companion to the vet and ask for blood and urine tests.

Symptoms of chronic kidney failure in dogs

Chronic kidney failure is not a condition that develops overnight: the very word "chronic" tells us it has been present for a long time. Unfortunately, owners usually notice it when it is already too late, when the kidneys are already partially damaged.

Typically, a dog with chronic kidney failure is brought to the vet because it has not been eating for a few days, is vomiting, or showing other signs — and it then emerges that for weeks the dog has been eating less, drinking more, and urinating constantly. The symptoms of severe chronic kidney failure — that is, when the kidneys are functioning at a minimum — include, in addition to those listed above:

  • Non-regenerative anaemia in dogs
  • Vomiting in dogs and diarrhoea, sometimes with blood in the dog's stools
  • Ulcers in the dog's mouth and intestines.

Acute kidney failure in dogs

The acute phase of kidney failure in dogs is classified as:

  • Pre-renal
  • Renal
  • Post-renal

The first type, acute pre-renal kidney failure, is characterised by a reduction in the kidney's filtration rate and an increase in peripheral vascular resistance. The causes of pre-renal azotaemia are:

  • High-protein dog diets
  • Dehydration in dogs
  • Heatstroke in dogs
  • Shock
  • Burns
  • Gastrointestinal haemorrhage
  • Vasculitis
  • Hepatic insufficiency
  • Pancreatitis

Acute renal kidney failure is instead caused by direct damage to the kidney, and therefore occurs in cases of:

  • Thrombotic nephropathy
  • Kidney diseases caused by infections, immune-mediated conditions and tumours
  • Leishmaniasis in dogs
  • Pancreatitis in dogs
  • Tumours in dogs

Acute post-renal kidney failure is caused by obstructions or rupture of the urinary tract due to:

  • Tumours in dogs
  • Stones
  • Trauma

Symptoms of renal shutdown in dogs

Many of the symptoms of acute kidney failure are similar to those of the chronic form (anorexia, vomiting, lethargy, dehydration); the difference lies in the fact that the acute form may also involve renal shutdown, which prevents the dog from urinating.

The specific signs of acute kidney failure in dogs that distinguish it from the chronic form are:

  • Oliguria (the dog is not urinating),
  • Tremors and seizures in dogs
  • Metabolic acidosis
  • Nausea: the dog refuses to eat
  • Stomatitis in dogs
  • Heart failure
  • Pneumonia
  • Pulmonary oedema

Diagnosis of the acute form must be carried out by a vet, who may also perform an ultrasound scan. In acute kidney failure, restarting urine production is of the utmost importance.

Diet for dogs with kidney failure

In cases of kidney failure in dogs, it is important to bear in mind that the kidneys do not regenerate, meaning that nephrons can no longer be restored to function. This means that treatment for kidney failure in dogs will last for the rest of the dog's life. Therapy is based on reducing azotaemia with appropriate medications and treatments.

A correct diet for kidney failure will consist of foods that keep azotaemia and phosphataemia levels low. The kidney failure diet must be decided by the vet on a case-by-case basis. It is impossible to generalise, as it depends on the complete clinical picture of your dog.

However, food for dogs with kidney failure is available on the market — there are many options, both dry and wet — although the ideal solution is always to follow a tailored diet specifically designed for your dog by a qualified nutritionist.