Dr. Roberta Relford, DVM, MS, PhD, Chief Medical Officer of IDEXX Laboratories who helped to research and develop the SDMA biomarker test, talks about kidney disease in cats. In a Q&A interview she addresses the impact of the new IDEXX SDMA test, the technology behind it, and the importance of screening your pets earlier than veterinarians were able to do before.

Tell us about yourself. How did you get involved in veterinary medicine, and what lead you to become actively involved with kidney disease in pets, particularly cats.

As a small animal veterinarian practicing in Florida and then Tennessee, I became very interested in diagnostics and decided to pursue a doctorate degree in veterinary pathology. While on the faculty of Texas A&M University, I focused my studies on veterinary pathology and small animal internal medicine. It was there that my interest in kidney disease and its impact on pets really grew.

Would you explain in layman’s terms what kidney disease is?

As a leading cause of suffering and death, kidney disease is to pets what heart disease is for humans. In their lifetime, over 1 in 3 cats and 1 in 10 dogs will get kidney disease. As pets get older, the likelihood they will develop kidney disease increases. In fact, more than half of cats over age 15 are afflicted.

Put simply, kidney disease means your cat’s kidneys have stopped functioning as well as they should. Kidneys are vital to your cat’s overall health since they perform an important role in removing waste and regulating water in your cat’s body. Cats have two kidneys that share the work of filtering out waste products in the blood and creating urine to carry wastes and fluid from the body. In kidney disease something disrupts and damages the kidneys, compromising their function.

From our understanding, there are 2 types of kidney disease, acute, which comes on from a traumatic event like ingesting anti-freeze or some toxic substance, and chronic, which is the result of the aging process?

Kidney disease may occur very suddenly as you have described due to an acute kidney injury, otherwise known as AKI. Or it may occur slowly, over time as the cats ages. In both instances there is an underlying process that is contributing to development of the disease. Different processes can cause chronic kidney disease (CKD) including infections, kidney stones, inflammation, even congenital conditions. For more about common causes of kidney disease, check out this article on PetHealthNetwork.

What happens when all these toxins aren’t filtered out of a cat’s system? Can kidney disease lead to other diseases?

When your cat’s kidneys start to slow down, waste products increase in the blood stream and can cause several other issues, including: mouth ulcers and stomach changes which can result in your cat not wanting to eat. They can also become weak from anemia that can develop from both GI ulcers and the loss of the kidney’s ability to produce a hormone that stimulates red cell production. Neurologic changes can result in weakness and seizures. High blood pressure is a common complication of kidney disease which can contribute to heart disease, bleeding into the eye and even blindness,

You say, 1 in 3, that’s 30 percent of all cats get kidney disease. That’s a pretty large number. Are there any other diseases, say thyroid disease or diabetes that are more rampant in cats? Will better diagnostics see the number increase?

As pets age, the percentage of cats with kidney disease worsens. In fact, more than half of cats over age 15 can have kidney disease. While many pet parents seem to be aware of diabetes and thyroid issues in cats, it is important to know that kidney disease is much more common than either of those conditions.

Now IDEXX SDMA™, a breakthrough new test that screens for kidney disease, can detect this devastating disease months to years earlier. With over 2 million tests now run, IDEXX SDMA™ has been able to detect up to two times the number of pets with kidney function loss. This gives you and your veterinarian the chance to take action and give your pet the best shot for a healthy, happy, long life — even with kidney disease.³For more detailed information, check out this article on PetHealthNetwork.

What causes kidney disease?

There are a number of causes that may affect different age groups and have different consequences. Ultimately though, chronic kidney disease (occurs over time) or acute kidney injury (occurs suddenly) will always have the same result—a sick kitty. The signs of illness in your cat reflect the failure of the kidneys to do their many jobs well enough. Although not a complete list, here is a list of common causes of kidney disease in pets.

1. Infection of kidney tissues
2. Kidney stones (nephrolithiasis)
3. Kidney blockage (ureteral obstruction due to stones, inflammation, strictures)
4. Damage to kidney tubules (toxins, infectious or immune mediated)
5. Damage to the kidney filters (infectious, immune medicated, hereditary)
6. FIP (feline infectious peritonitis)
7. Cancer (multiple types of cancer)
8. Protein metabolism problem (amyloidosis)
9. Hereditary
10. Heart disease and high blood pressure

These are discussed in some detail on Pet Health Network:

What are the signs I should look for to see if my cat may have kidney disease?

With early kidney disease, there are rarely any clinical signs, although there may be some subtle indicators that are easy to miss. As a natural defense against predators, cats actually hide disease, even when it is advanced. While this serves them in the wild, it makes it very difficult for you to know they are sick. This is why screening with the IDEXX SDMA test is so important – it offers cat parents the opportunity to detect problems with the kidneys much sooner than before. In later stages, symptoms can include increased drinking, increased urination, diminished appetite, subtle weight loss, lethargy, dehydration and vomiting. Pets with more advanced kidney disease may also have bad breath associated with mouth ulcers.

Is there a particular cat breed or age who are more prone to kidney disease?

While spontaneous kidney disease can occur in any breed, and in outbred cats, there are some inherited conditions that cause kidney disease. Certain families of Persians, Abyssinians, Siamese and Orientals may be affected with congenital kidney disease at a young to middle age. Chronic kidney disease due to other causes is more common in older cats, but can occur at any age.

Is there a particular place in the world where kidney disease is more common? Do cats in Europe, Japan, or Canada contract the disease any less than American cats?

At this time, we don’t have data to say if kidney disease is more common in certain countries. But we do know that it is a common problem facing cats around the world.

What are the stages of kidney disease, from early to late stages, and can it be cured, or treated to extend the cats life? (Make this more general, and include more details when you talk about the new test that’s available)

Once kidney disease is diagnosed it is then staged by severity into four stages. In the early stages of kidney disease (stages 1 or 2), kidney function is typically good enough for the pet to have a great quality of life.  Often times there are no obvious clinical signs so routine check-ups are often the only way to know something is going on with your cat.

The good news is kidney disease can be identified on routine blood work and a urinalysis performed by veterinarian during preventive care visits or prior to anesthesia for routine procedures like a dental.

Recently the IDEXX SDMA test has been made available to all veterinarians to help identify early stage disease. This test is helping to detect stage 1 better. Further tests such as an ultrasound, urine culture, blood pressure or a test for urine protein may be needed to help categorize stage 1 or 2. Identifying stage 1 & 2 is very important as this is when cats still feel good and are more accepting of new medications and diet changes that will be necessary to properly manage their disease. Using the IDEXX SDMA test for early recognition of kidney disease offers veterinarians an opportunity to investigate for underlying treatable conditions that may reverse or spare remaining kidney function.

As kidney function further declines and kidney disease becomes more advanced in Stages 3 & 4, the wastes accumulate in the blood, urine production is altered in quality and quantity with the urine often being very dilute and with larger amounts of urine being produced. Cats often develop anemia which adds to them not feeling well.

During these advanced stages, clinical signs such as weight loss, not eating, inactivity, vomiting, and bad breath may become noticeable. Cat owners may not realize that by the time patients show visible signs, there has usually been significant and permanent loss of kidney function. Not finding kidney disease until stage 3 or 4 presents more limited opportunities to change the big picture for your kitty. Early detection and screening with IDEXX SDMA gives you and your veterinarian the chance to take action and give your pet the best shot for a healthy, happy, long life — even with kidney disease.

Are there any treatments other than special diets to treat kidney disease? I had a long-haired Tabby Maine Coon look alike that had kidney disease years ago, and I treated her with a special K-D food from Hills.

Feeding a prescription kidney diet has been shown to extend the lives of cats and dogs with chronic kidney disease. It may also reduce the frequency of periods of significant illness associated with having advanced kidney disease.

In addition to a high quality kidney-supportive diet, general treatments of kidney disease may include:

• investigating the underlying cause,
• keeping plenty of fresh water available and enticing your pet to drink;
• treating high blood pressure (if necessary) and
• treating any secondary signs, if noted.

For the fortunate patients whose kidney disease is caught early, special emphasis may be placed on:

• investigating for underlying conditions,
• monitoring closely and regularly
• adjusting for changes or worsening parallel conditions
• implementing good kidney-care practices (like monitoring hydration)

All of these may help protect your cat’s kidneys, slow down progression of the disease and extend life.

If diet is the best treatment, what are your recommendations, for a multi-cat home?

Balancing the needs of multiple pets can be challenging but also gratifying. Your pets’ veterinarian can help you choose a diet or diets that will benefit your pets with kidney disease without harming other cats.

Will getting my cats to drink more water help prevent kidney disease?

Keeping pets well hydrated tends to make most conditions better by improving circulation, even if that benefit is difficult to objectively measure. For example, good hydration has been shown to help protect against acute kidney injury in certain circumstances.

Are cats that have had urinary tract infections more prone to kidney disease?

Urinary infections and chronic lower urinary obstruction can be risk factors for developing kidney disease.

Is there anything I can do to prevent my cats from getting kidney disease?

While prevention may not be possible, early detection is key. The most important thing you can do is take your cat for regular check-ups and ask for the IDEXX SDMA test to be included as part of the annual blood work. The good news is an estimated 2 in 5 veterinarians in the U.S. are already including SDMA in their routine blood testing, almost always at no added cost. If your veterinary hospital is not doing so, simply ask them to send your pet’s blood samples out to IDEXX’s Reference Laboratories.

IDEXX SDMA, a breakthrough new test that screens for kidney disease, can detect this devastating disease months to years earlier. This gives you and your veterinarian the chance to take action and give your pet the best shot for a healthy, happy, long life — even with kidney disease.

At home, daily observation of thirst, urination and appetite are big markers of your cats’ well-being, get any changes or irregular behaviors checked out.

If one of my cats is diagnosed with kidney disease, how long can I expect him to live? And what can I expect his quality of life to be? Will the cat be in pain from this disease?

Cats that are diagnosed with mild or early kidney disease can live for years with a good quality of life. Cats that are diagnosed after the disease is moderate to severe and are showing outward signs, have a much shorter life expectancy may only live for a few months.

How do I know the disease is progressing? What should I be looking for, and what should I do?

Since cats typically show no signs of illness until their kidneys have lost most of their function permanently, IDEXX SDMA testing is important to help to monitor disease progression. If you are one of the many cat parents with a cat impacted by kidney disease, IDEXX SDMA can help your veterinarian determine how advanced the disease is, enabling your pet to get the right treatment plan while there is still time to impact their quality of life.

At later disease stages there are some things you may notice at home. Kitties may sleep more and eat less. They may lose weight and groom less. Vomiting, constipation and chronic dehydration may also indicate progressive kidney disease.

If one of my cats is diagnosed with kidney disease, how often should I visit my veterinarian? Should I visit more than the 2 semi-annual visits when there’s not an emergency?

There’s really no simple answer here. The ideal monitoring schedule depends on your pet’s stage of kidney disease and overall health. Some cats in good condition with early disease may only need to visit twice a year, others (with more advanced conditions or complications) may need to visit weekly for non-emergency care.

Often times s monitoring your cat’s weight can help you stay in touch with your cat’s overall health—you might want to invest in a digital scale to keep tabs at home too.

Have you ever had a cat with kidney disease? Does your veterinarian offer the new IDEXX SDMA testing or would you request having it done. Paws for Reflection certainly is thinking about having our Siamese Linus tested? Please weigh in with your thoughts and comments.