Feline Chronic Kidney Disease

Video Link from The Cornell University College of Veterinary Medicine: Cat owners guide to kidney disease. Includes tests used to diagnose it, what it is, medications used to manage it and instructions on giving fluids under the skin (subcutaneous fluids).

Kidney disease implies that one or both of the kidneys are not working as they should. It can go undetected until the disease is severe enough to cause clinical signs or changes in blood and urine tests. Other terms used include renal or kidney failure. Kidney disease can be acute (recently occurred and may be reversible) or chronic (has been occurring and progressing for a long time and is not reversible). Sometimes it can be a combination where a patient with stable chronic kidney disease has an acute worsening of kidney function, termed acute on chronic kidney disease.

The kidneys are important for daily function as they eliminate the waste the body produces, make sure electrolytes and water balance and they produce a variety of important hormones including one that helps prevent anemia. Luckily the kidney is made with plenty of “back-up” help. 66% of the kidneys must be damaged to lose the ability to concentrate urine and 75% of the kidneys must be damaged to see elevations in levels of wastes the body clears from the blood. This is why people and animals can donate one kidney and continue to live a normal life, as both kidneys are not necessary if they are completely healthy. One disadvantage is that the “back-up” help makes it difficult to detect kidney disease early on.

The goal of identifying kidney disease early is to attempt to slow its progression. How can you tell at home if your cat may have kidney disease? Early on, your cat will appear normal and healthy. Once 66% of the kidneys are damaged, concentration of the urine (a way the body conserves water) is not possible. A sign of this is that your cat begins to drink more water and urinate more often. You may notice that your cat is always at the water bowl or that you fill it more often than usual. You may also notice that your cat is using the litter box more often or that you are scooping the litter box more frequently.

As the disease becomes more advanced your cat will lose weight, have a poor hair coat and may not eat as well. As the kidney damage progresses body wastes are not eliminated properly and they accumulate in the blood and body. This elevation of toxins can be measured with blood work and when these levels are increased the condition is called uremia which literally means urine in the blood. Signs of uremia include loss of appetite, vomiting, ulcers in the mouth, weakness and bad breath due to the accumulation of ammonia.

Other abnormalities that can occur include anemia (the kidney produces a hormone called erythropoietin that is responsible for making red blood cells), and high blood pressure. The anemia makes the weakness and loss of appetite worse. High blood pressure can cause blindness, stroke-like signs such as changes to behavior or seizures, injury to the heart and worsening of the kidney disease itself.

So how can you identify this disease earlier rather than when your cat is sick? This is where the importance of yearly urine and blood tests during your senior cat’s annual visit comes in. A urine sample will show whether the kidneys can concentrate it appropriately (remember loss of this ability is one of the first indicators of kidney disease). If the kidney is damaged enough or there is high blood pressure proteins will also accumulate in the urine and this can be detected as well. Sometimes, urinary tract infections can affect the kidneys and a urine test can also identify if this is present. A complete blood test is important to monitor not only for two main indicators of toxin accumulation in the body (BUN and creatinine) but also to make sure that anemia is not present. A blood test can also identify electrolyte abnormalities which may require special supplements to correct.

Other tests that should be done during your senior cat’s exam should include a blood pressure. Once kidney disease is identified x-rays and ultrasound are needed to evaluate the kidneys. This evaluation is important in identifying possible kidney stones, abnormalities in size and shape of the kidneys.

Although chronic kidney disease is irreversible, for most cats treatment can “assist” the kidneys and allow a good quality of life for months or years. There is no single treatment for kidney disease. Your veterinarian will tailor make a plan for your cat based on the severity of the changes in the blood work and the signs that your cat is experiencing. Treatments include a “kidney friendly” diet, hydration therapy by giving fluids under the skin, supplements and medications to vomiting, nausea, poor appetite and high blood pressure. If your cat becomes anemic injections of the hormone erythropoietin may be recommended.

Your veterinarian will formulate a schedule for exams that will include re-checking blood work, urine tests and blood pressure. This will assist in making adjustments to the treatment plan.

In humans chronic kidney disease is sometimes managed with hemodialysis (where a machine acts like a kidney and cleanses the blood of wastes) or by kidney transplant, both of which are available for cats but usually not a realistic option for the general cat population due to limits in availability, costs and specific criteria to be an ideal candidate. It is important to remember that hemodialysis is not a cure and those receiving kidney transplants require long-term medication administration to try and avoid rejection of the donated kidney.

Remember, just because your cat seems healthy at home, it is important to see your veterinarian at least yearly for younger cats, every 6 months for senior cats (>7 years old) and that blood work and urine tests be performed in senior patients to try and spot changes before your cat is actually sick!

Feline Pancreatitis

Cats can be affected by inflammation of the pancreas known as pancreatitis. The pancreas is an organ in the abdomen located very close to the stomach, intestines and liver. The pancreas has multiple jobs that are very important to every day life. It produces insulin which is necessary for keeping the body’s blood sugar stable and it also produces important products necessary to properly digest food. When the pancreas becomes inflamed, the products that it makes to help digest food in the intestines are activated within the pancreas and the pancreas basically begins to “eat/dissolve” itself.

Usually the cause of pancreatitis in cats is not found. Some causes are believed to include trauma, infection and some medications. In cats chronic pancreatitis is more common in cats, where the acute form occurs more commonly in dogs. Signs of pancreatitis are very nonspecific and can be hard to notice. 80-100% of cats have decreased energy/actvity, 87-97% stop eating and 54% are dehydrated. In contrast to dogs and humans, vomiting (35%) and abdominal pain (25%) are not common signs in cats. Other conditions that occur with pancreatitis include hepatic lipidosis (fatty liver disease), inflammatory bowel disease (IBD-inflammation of the intestines), diabetes and inflammation/infection of the bile tract and liver.

Abdominal ultrasound is considered more useful that x-rays for the diagnosis of pancreatitis and should be the next test performed if x-rays of the abdomen do not provide a definitive diagnosis. A recently new blood test (fPLI-feline serum pancreatic lipase immunoreactivity) is being used to identify cats with pancreatitis. The only way to definitively diagnose pancreatitis is via biopsy, but this procedure is expensive and requires general anesthesia in patients that may be at higher risk complications. Using a combination of clinical signs, blood tests and ultrasound a strong suspicion that pancreatitis is affecting your cat can be attained.

If a cause for the pancreatitis is found, that cause must be treated. Other treatments are not directly targeted at the pancreatitis but more at helping the cat feel more comfortable and assist in balancing any secondary complications. This consists of providing intravenous fluids via a catheter to provide adequate hydration, electrolytes and blood flow to the pancreas. Medications that provide relief of nausea and vomiting as well as pain medications are given. In severe cases, protein levels drop and blood clots may form which require transfusions of plasma. Cats that have not been eating for a few days and do not begin to eat shortly after treatment is started may require a temporary feeding tube to be able to provide adequate nutrition. Cats that have inflammatory conditions of the liver/gallbladder (cholangiohepatitis) or intestines (IBD) require steroids to decrease the inflammation. If infection of the liver or gallbladder is suspected antibiotics may b administered.

The prognosis is very variable as some cases are more severe than others. Because the pancreatitis in cats is usually chronic, other bouts of pancreatitis will most likely occur at some point in time. If enough pancreatic tissues are damaged secondary complications can occur. One is diabetes as the insulin producing cells are damaged and the second is exocrine pancreatic insufficiency as the cells that make products that assist in digesting food are damaged. Sometimes the inflammation of the pancreas is so severe that the bile duct becomes obstructed.

Because cats hide disease so well, by the time they are showing signs they may already be very sick. It is important to remember that if you notice any non-specific signs such as lethargy or loss of appetite which do not improve after a day or two make sure you see your veterinarian. Pancreatitis may be only one of many possible diseases making your cat sick.

Why do puppies and kittens need a series of vaccines?

When a puppy or kitten is born its immune system has not yet matured. Kittens and puppies remain protected from infection because of the transfer of maternal antibodies in special milk from their mother called colostrum. Colostrum is only produced a few days after giving birth and it can only be accepted during the first days after birth before their intestines “close up” and can no longer absorb the antibodies.

Sometimes antibodies are not transferred either because the puppy did not drink the colostrum or the mother did not have certain antibodies, other times those transferred only last for a short period of time. If an appropriate number of antibodies are transferred there is protection for a longer period of time. However, the maternal antibodies that are transferred do not last forever.

What does this have to do with vaccinations? Well, there is really no way to tell if maternal antibodies were transferred, which were transferred or how long they will last and therefore a vaccination given early will help protect them.

So why not just give one vaccine early and forget about it? If a vaccine is given to a pet that still has maternal antibodies present it will be inactivated and new antibodies will not be made. How long maternal antibodies last in a pet varies with each individual and for specific diseases. We do know that maternal antibodies are gone or have decreased enough to not interfere with vaccines by 16-20 weeks of age. This is why the final booster is usually given at this time when there will be no interference and protection ensured.

So why not just give one vaccine when they are older, when we are pretty sure maternal antibodies will not interfere with vaccines? Again, since there is no easy way to tell if a pet has protection from maternal antibodies at birth or if protection will last until 16-20 weeks of age, waiting to vaccinate until that time puts them at risk of developing dangerous and deadly diseases.

Therefore, vaccinations are given in series every 2-4 weeks until age 16-20 weeks. This is done to protect those that lose maternal antibodies early while ensuring that those that have longer lasting maternal antibodies are protected as well.
What if the pet is older than 16 weeks of age? In this case there is no worry about interference from maternal antibodies, but one booster 2-4 weeks after the initial vaccine is necessary to ensure a better response.