Gastrointestinal protectant use is ubiquitous in veterinary medicine. But is it always necessary? Learn more about new concepts regarding the use of gastric acid suppression in cats with chronic kidney disease.

It is a rare geriatric cat that doesn’t have some decline in renal function. Administration of gastric acid suppression has been considered an important component of treatment for chronic kidney disease. However, newer veterinary studies are calling this practice into question.

Chronic kidney disease (CKD) is one of the most common problems affecting older cats, with some estimates suggesting the disease affects at least 50% of older cats (defined as cats over 10 years of age). Other experts put the number even higher, at nearly 80% in cats over 15 years of age.

A lot of owners and veterinarians struggle to treat this complex illness. Although we’ve made great advances in helping cats with CKD live longer with a better quality of life, achieving this can require medication, diet change and fluid support. The multitude of treatments can be tough for cat owners to manage, which in turn can lead to poor compliance. Knowing which treatments are supported with strong evidence is key to a successful outcome.

In people, it’s long been recognized that chronic kidney disease can lead to gastric ulceration. However, gastric ulceration has never been firmly demonstrated in cats with CKD.

“There is a lot of dogma in veterinary medicine that comes from human medicine,” said Dr. Katie Tolbert, a Morris Animal Foundation-funded researcher and Associate Professor at Texas A&M University, in a recent interview. “We’re taught that CKD causes stomach ulcers in cats – it’s something that’s been passed down. However, when I talk to pathologists, they tell me they hardly ever see ulcers in cats with CKD.”

Dr. Tolbert took to heart what she heard from her pathology colleagues and studied acid secretion in cats with CKD and cats without the disease. She looked at a number of parameters including gastric pH and serum gastrin levels and found no differences between the two groups for either value. Dr. Tolbert concluded that, based on these results, cats with CKD might not need acid suppression. She published her results in the Journal of Veterinary Internal Medicine.

In her current Morris Animal Foundation-funded project, Dr. Tolbert is taking this observation one step further. She’s running a clinical trial where cats with CKD get omeprazole and others get a placebo for two weeks. After a two-week rest period, the groups switch. The research team is blinded to the treatment each cat is receiving. They’re collecting observational data as well on everything from activity to frequency of vomiting, since acid suppression is often given to improve appetite and decrease nausea and vomiting. Dr. Tolbert hopes that her results can add to the conversation around the use of these medications in cats with CKD.

Although gastrointestinal protectants have a wide margin of safety, they’re not without side effects. Mounting evidence demonstrates that the use of proton pump inhibitors (PPI) causes disruptions of the gut microbiome and, in people, there is a link between PPI use and an increased risk of Clostridium difficile infections. A recent paper looking at gut microbiome changes in healthy cats given omeprazole did not demonstrate dramatic changes after 60 days of use. While encouraging, these results might be different in cats with underlying disease or in cats that are given acid suppressors for even longer periods of time which is common in cats with CKD.

In addition to potential changes in the microbiome, long-term use of proton pump inhibitors can lead to gastric mucosal hypertrophy. There also is a rebound gastric acid hypersecretion that can occur after gastric acid suppression therapy is discontinued.

To provide greater clarity on when to use or not use acid suppressants and other similar medications, the American College of Veterinary Internal Medicine released a consensus statement in 2018 on the rational use of gastrointestinal protectants. The statement covers a number of clinical scenarios including renal disease in cats. The opinion of the panel was that cats with CKD should not receive prophylactic gastroprotectants if they are in International Renal Interest Society (IRIS) stages 1–3. They felt that additional studies are needed to determine if acid suppression is helpful for individuals in IRIS stage 4 renal disease.

Given the growing body of evidence that casts doubt on the routine use of gastric acid suppression in cats with CKD, withholding this medication in a cat with early stage CKD is reasonable. This especially holds true when other treatments, such as diet change, are available as a first step. If gastric acid suppression is instituted in a decompensated patient, weaning the patient off this medication when stable also is a reasonable alternative to long-term therapy.

To learn more about cats with chronic kidney disease and gastric acid suppression, listen to Morris Animal Foundation’s podcast with Dr. Tolbert discussing her studies on the control of gastric acid secretion in both dogs and cats.