When nature provides two of something, it's a good indicator of its importance and how much work it does.
Kidneys are paired organs in the body that start working before birth and are critical for the life of dogs and cats. They work like furnace filters, but instead of filtering air they instead filter blood in the body. Unlike furnace filters, however, they cannot be easily changed out for a replacement!
What do kidneys do?
- Balance fluid levels in the body;
- Filter toxins and waste materials from blood and create urine;
- Balance and remove excess minerals in the blood; and
- Produce hormones that regulate blood pressure, red blood cell production and balance bone density.
Thankfully, not only are kidneys paired to have a backup system, they are also able to carry out all these important jobs without symptoms of disease until over 75% of the kidney is damaged. This can make it challenging to diagnose early kidney problems. Kidney problems are common, with one-third of senior cats (older than 7) being affected. Kidneys can be affected by a variety of problems at all ages of life so it's important to be vigilant at any age.
How are kidney problems diagnosed?
Veterinary examinations are the first step; yearly for animals less than seven years, and every six months for seniors. Further tests include: blood tests, urine tests, checking blood pressures, looking at the kidneys and bladder with an ultrasound, and possibly biopsies.
The need to do further testing varies with age and patient history. At least yearly lab screening of seniors is recommended to catch early changes and minimize progression. Screening of young animals at the time of their spay or neuter allows early detection of inherited kidney disorders. Screening any age animal before an anesthesia ensures that there is no detectable kidney disease, or that detected kidney disease is managed first.
Recently, a more sensitive test for early kidney disease called the SDMA test has become widely available. The SDMA test can be added to a regular blood panel, and reveals when the kidneys have as early as 25% damage, compared to only being able to detect nearly 75% damage with regular blood work alone. Early detection and intervention greatly improves outcome.
At home you can watch for:
- Changes in drinking and urination frequency
- Weight loss
- Decreased appetite or vomiting
- Bad breath
What can we do?
With early detection of kidney disease, management can be as simple as dietary changes and increased monitoring. Other medications or supplements may be adjusted or stopped as appropriate under the direction of your veterinarian.
With more advanced stages, there are medications that improve blood flow through the kidneys, and medications that manage the symptoms of kidney disease. Severe cases of kidney disease can require hospitalization and intravenous fluids until the patient is stabilized. Dialysis and kidney transplants are not readily available in the veterinary world at this time.
How can we prevent kidney issues?
Feed only approved foods, consult your veterinarian before starting supplements or using medications and ensure good access to fresh water. Maintain good dental health. Regular exercise helps with blood pressure and blood flow through the kidneys. Avoid toxins, or seek veterinary attention immediately if ingestion occurs.
The top kidney toxins include:
1. NSAIDs (non-steroidal anti-inflammatories) such as ibuprofen, aspirin, meloxicam. Always check with your veterinarian before giving any drugs. Only use medications as directed by your vet and if you aren’t sure, check first!
2. Grapes, raisins, or currants. Can cause sudden and severe kidney failure. Not a snack for pets!
3. Antifreeze. Very toxic.
4. Vitamin D3. Beware multivitamins.
5. Heart medications. Some human and veterinary medications can be harmful to the kidneys. Keep human medications out of the way and always follow your veterinarian’s directions on dosing heart medications and checking blood work while on the medications.
6. Toxic house plants such as lilies.
Maintaining good kidney health is important for a longer, more comfortable life for your pet. Consult your veterinarian to decide whether screening for kidney disease is important for your pet.
Dr. Katharine North (née Moody) has been a resident and active participant in the Fort St. John community since her family immigrated to Canada from the United Kingdom as a child. Her interest in medicine and animals led her back to the University of Liverpool in the U.K. to complete her Bachelor of Veterinary Science in 2000.