The kidneys in both humans and dogs are best known for balancing bodily fluids and filtering waste products out of the blood in the form of urine. They also help your dog maintain proper salt and water levels. Kidneys are also responsible for controlling blood pressure, sustaining phosphorous levels, and assisting in the metabolism of calcium. They are necessary to your dog’s health. Any dysfunction in your dog’s kidneys can lead to the buildup of toxins in your blood, causing some serious illnesses.
Kidney diseases in dogs cover a wide range of disorders with varying symptoms. This article will take a closer look at different forms of kidney disease in dogs, their causes, and effective treatments and prevention strategies.
Acute Kidney Disease in Dogs
Acute kidney disease, or acute renal failure, is the most common form of canine kidney disease. It happens suddenly and over the short period of a few days. Acute kidney injury is not specific to any breed, but it is more common in older dogs.
It is often a result of severe dehydration, a reaction to medication, or severe blood loss from an injury or surgery. It can also be caused by ingestion of poisons, particularly antifreeze, which contains the chemical ethylene glycol, a highly toxic substance in the kidneys.
Symptoms of acute renal injury can vary based on the dog and the severity of the disease, but some symptoms to keep an eye out for include:
- Coordination issues
- Increases or decreases in thirst
- Increases or decreases in urination frequency
- Straining while urinating
- Loss of appetite
During a physical examination, your dog’s vet may also find:
- Ulcers in the mouth, on the tongue, gums, or inside the cheek
- Swelling of the limbs
- Pale mucus membranes, like in the gums
- High blood pressure
- Retinal changes
Your dog’s vet will likely perform a variety of tests to determine what exactly is causing the acute kidney issues. These tests may include:
- Urine tests to determine how well the kidney can concentrate urine
- A blood count to determine if your dog has enough red blood cells
- Electrolyte tests to determine how well your pup is hydrated
- X-rays and ultrasounds to see the actual kidney structures
Treatment for acute kidney disease varies based on the underlying issue. Some common treatments include
- Fluid therapy – This is the initial treatment for kidney disease. It involves rehydrating the dog for up to 10 hours through an IV. This is followed by normal hydration afterwards. The IV fluids are often enough to return urine output to normal. If the IV fluids aren’t successful, the vet may administer medications like mannitol or furosemide.
- Diet – While your pup is being rehydrated, his appetite will likely return and his nausea will go away. Whether your pup eats willingly or requires tube feeding, he should be fed high-quality food with lower quantity protein. This helps to give his kidney the nutrients they need without putting too much demand on them. If the kidney disease has become too severe, your vet may need to administer parenteral nutrition through the IV line.
- Antibiotics – If the acute renal disease is tied to a bacterial infection, your vet will likely recommend some form of
- Dialysis – If your dog doesn’t respond to normal therapies, is not producing urine, or has ingested a toxin, he may benefit from dialysis.
Chronic Kidney Disease
Unlike acute kidney disease, chronic kidney disease happens over a longer period of time, developing slowly. It mainly occurs in older pups. The causes of chronic kidney disease are harder to determine, though instead of any immediate cause, it’s usually a result of an underlying disease or congenital or hereditary condition.
Surprisingly, one of the most common causes of chronic kidney disease in dogs is dental problems. Bacteria involved in severe dental diseases can easily enter your dog’s system and invade the kidneys, lungs, heart, and other organs.
One of the most common signs of chronic kidney disease is urinating and drinking more than usual. This often means that dogs will have to urinate at night or suffer accidents in the home. Many of the other symptoms are similar to acute kidney disease and include:
- Urinary incontinence
- A lack of appetite
- Weight loss
- Pale appearance
- Ulcers in the mouth
- Bad breath that has a chemical odor
Testing for chronic kidney disease usually starts with a physical examination. During this exam, your vet can spot any pain in the flank or back, changes in the prostate or urinary bladder, and enlarged, painful kidneys. A rectal examination can also help your vet determine if the chronic kidney disease is caused by an underlying bladder, urethral, or prostatic disease.
While the underlying condition may not be curable, your dog can still live a happy, full life even with chronic kidney problems. Most of the treatment goals involved with chronic kidney issues involve:
- Ensuring your dog is properly hydrated at all times
- Providing a healthy, nutritious diet that specifically aims at promoting good kidney health
- Balancing your dog’s internal salt and pH levels
- Treating high blood pressure, protein issues, or any other health problems that may contribute to kidney damage
- Keeping a ready supply of fresh water available at all times
Chronic kidney diseases also often mean that your dog will have to go to the bathroom more often throughout the day. Build this into your schedule, whether that means hiring a professional dog walker or asking a neighbor or friend to drop by in the middle of the day while you’re at work. Your dog can’t help it, and it’s better than coming home to stains in the carpet.
Fanconi Syndrome in Dogs
Named after Swiss pediatrician Guido Fanconi, Fanconi syndrome is a disorder of the proximal renal tubules in your dog’s kidneys. The syndrome prevents these tubules from properly absorbing electrolytes and nutrients, including water, bicarbonate, phosphate, glucose, potassium, sodium, and amino acids. These nutrients instead end up in the dog’s urine.
About 75 percent of the reported cases of Fanconi syndrome all occurred in Basenjis. Within the Basenji breed, the syndrome is prevalent in about 10 to 30 percent and is reported to be an inherited trait. However, other breeds may also have Fanconi syndrome, including:
Fanconi syndrome can be diagnosed at any age with cases discovered between 10 weeks and 11 years of age.
The symptoms of Fanconi syndrome vary based on the severity of the disease, but the most common symptoms include:
- Sudden excessive urinating
- Increased thirst
- Weight loss
- Loss of appetite
- General poor health and body condition
- Reduced or abnormal growth in young pups that are still growing
There is no treatment for reversing defects in dogs who have inherited Fanconi syndrome. Most dogs will require individual treatments for each nutrient defect, including potassium deficiencies, renal failure, too much acid in the kidneys, and rickets and growth issues. Younger pups may require calcium, vitamin D, and/or phosphorous supplements.
The best way to prevent Fanconi syndrome in your dog is to avoid drugs that are toxic to canine kidneys. Certain medications have been found to potentially cause Fanconi syndrome. These include:
- Amoxicillin (common antibiotic)
- Gentamicin (common antibiotic)
- Streptozotocin (chemical treatment for certain forms of cancer)
Azotemia and Uremia
Both azotemia and uremia are disorders that cause increased levels of nitrogen in your dog’s blood. Azotemia specifically involves excess urea, creatinine, and other waste products in the blood caused by gastrointestinal bleeding, a high protein diet, or other higher than average ingestion or production of substances containing nitrogen.
It may also be caused by reabsorption of urine back into the bloodstream or improper kidney filtration. Uremia is similar but caused by the improper excretion of waste products through urine.
Symptoms of azotemia and uremia include:
- Weakness and fatigue
- A red or purple spot on your dog’s skin caused by hemorrhaging blood vessels
The main goal of treatment is to stop azotemia or uremia altogether. This may involve the administration of fluids if your dog is dehydrated. If the disorder is caused by a urinary obstruction, your vet will remove the obstruction to encourage proper urination.
Pyelonephritis refers to an infection of the renal pelvis. Generally, when your dog gets a urinary tract infection, it will have been treated before it can reach your pup’s kidneys or ureters. If your dog’s kidneys do get infected, it’s usually a sign that your dog’s defenses might be impaired.
It may also point to kidney stones or another form of blockage in the kidneys. Kidney infections are most often caused by Escherichia coli and Staphylococcus bacteria.
Common symptoms of kidney infections include:
- Difficulty urinating
- Urine that is bloody, discolor, or foul-smelling
- Frequent urination
- Pain in your pup’s abdomen or lower back
- Frequent thirst
Antibiotics are generally the first line of treatment for kidney infections, but infections that are severe or caused by an obstructed urinary tract may require surgery. Kidney stones can be removed by surgery, fragmented using shock wave therapy, or dissolved with diet changes.
The best way to prevent kidney infections is to make sure your pup gets treated immediately for a urinary tract infection before it spreads up to the ureters and kidneys.
How to Prevent Kidney Problems in Dogs
Keep an eye on your dog and make sure that he cannot get to any poisons or potentially dangerous substances, especially antifreeze. Supervise your pup when you are outside. Furthermore, do not give your dog any over-the-counter medications without first getting approval from your vet.
Some hereditary or congenital kidney diseases cannot be prevented, but by maintaining a healthy diet with plenty of fresh water and regular vet visits, your dog should be able to live a long, comfortable life.