High Moisture Diets For Cat: The Rule Not The Exception

Author: Dr Katy Miller DVM, CVFT, CVNAN, CPFFCP, CPCQI, PAS

For most in the pet food industry, it is well known that kibble is a staple for many cat customers. But science indicates that it’s high time for that to change. By relying on dry diets we are inadvertently causing chronic dehydration, with harmful health effects. 

THE ISSUE: CHRONIC DEHYDRATION

Every living thing needs water to survive. It is vital for regulating temperature, lubricating joints, healthy digestion, and arguably most important for the domestic cat; it is needed for urine production. Urinary tract disease (idiopathic, infection, crystals, and stones) is at the top of the list of the most common diseases affecting cats, it is estimated that up to 20% of cats (30% of cats over the age of 10) will suffer from Chronic Kidney Disease.^2-3 Dehydration is a major risk factor in the development of these diseases.^5-6

We believe that because the domestic cat has evolved from populations of the African wildcats, Felis sylcestris lybica, the domestic cat has a low thirst drive. Their desert-dwelling ancestors evolved to live in the desert environment and are adapted to consuming water from their prey. In fact wild prey is about 70% water, providing ample hydration. Even when domesticated cats are seen drinking frequently from their water bowls, they are, in fact, chronically dehydrated if they are not consuming water in their food. A cat’s low thirst drive, is so low that they do not drink water until moderate dehydration is already present.¹ Cats compensate for this by producing highly concentrated urine, which unfortunately can lead to urinary tract and kidney disease.

THE SOLUTION: HYDRATE THROUGH DIET

While many references will suggest that fountains, running water, and multiple sources of water will increase water intake in cats, this may not be truly significant.⁴ Again, because they will not become “thirsty” until dehydration occurs.

So, how do we correct this dehydration in cats? Feed them foods high in moisture. A canned, sous-vide, or raw diet is 75-80% water. This significant increase in water intake through food has been shown to improve hydration and health and reduce disease in several studies.^7-8

While the transition period to get a “kibble” addict transitioned successfully from a dry diet to one high in moisture can be difficult and time-consuming, the benefit to a cat’s health and reduced medical costs are well worth the time and effort. One savvy tip: add a little warm water to increase the temperature of the food and increase the aroma (just a bit, ~ mouse body temp) to entice the persnickety feline to try a dab of new food.

Yet an even better approach is through early introduction in a cat’s life. Educate new customers with kittens to start on the right foot by immediately introducing different textures and formulas of high-moisture foods. It’s easy to wean kittens directly from their mothers’ milk to a high-moisture food and skip the kibble.

The benefits are far too great to ignore, and the time has come for the industry to embrace this benefit and shift the cat customer from a customary kibble diet to the rich benefit of a high-moisture diet for their beloved felines.

1. Anderson RS. Water balance in the dog and cat. Journal of Small Animal Practice 1982; 23: 588-598.
2. Burns, K. Creating brighter futures for cats with chronic kidney disease; JAVMA news. https://www.avma.org/javma-news/2021-02-01/creating-brighter-futures-cats-chronic-kidney-disease.
3. Top 10 Reasons Pets Visit Vets.  Retrieved from https://www.petinsurance.com/healthzone/pet-health/health-conditions/top-10-reasons-pets-visit-vets/
4. Grant DC. Effect of water source on intake and urine concentration in healthy cats. Journal of Feline Medicine and Surgery. 2010;12(6):431-434. doi:10.1016/j.jfms.2009.10.008
5. Greene JP, Lefebvre SL, Wang M, et al. Risk factors associated with the development of chronic kidney disease in cats evaluated at primary care veterinary hospitals. J Am Vet Med Assoc. 2014;244:320–327.
6. Rowe E, Browne W, Casey R, et al. Risk factors identified for owner-reported feline obesity at around one year of age: dry diet and indoor lifestyle. Prev Vet Med. 2015;121:273–281.
7. Buckley CM, Hawthorne A, Colyer A, et al. Effect of dietary water intake on urinary output, specific gravity and relative supersaturation for calcium oxalate and struvite in the cat. Br J Nutr. 2011;106(Suppl 1):S128–130.
8.  Xu H, Greco DS, Zanghi B, et al. The effect of feeding inversely proportional amounts of canned versus dry food on water consumption, hydration and urinary parameters in cats. In: Proceedings from the World Small Animal Veterinary Association, 2014; Cape Town, South Africa.

About the Author: Dr. Katy Miller works as the Director of Veterinary Services at BSM Partners. She brings her extensive background in companion animal nutrition (12 years) and her experience as a practicing veterinarian (7 years) together to help provide useful information to pet food manufacturers and pet parents. She shares a home with 2 cats, 9 dogs, and 5 horses.