Weight loss and specifically muscle loss is a concern in cats 11 years and older. It can be described as cachexia or sarcopenia. Cachexia is loss of muscle with the disease, e.g. congestive heart failure, chronic kidney disease, cancer and many other chronic conditions. Sarcopenia is the term used for muscle loss that occurs with ageing in the absence of disease. In recent years there has been more focus on understanding why this happens in humans and animals as loss of muscle is directly related to worsening disease and death. There is a change in the body with ageing and disease that causes the protein to be used for energy during periods of calorie restriction instead of fat. Why this happens depends on many complex reactions which are not completely understood at this time.
In the senior cat, nutrient absorption may be compromised where the gut is not working as well as it had in the past to metabolize and absorb protein. Also, appetite or energy intake is often less. There are many reasons a senior cat may be eating less. Some reasons may be the presence of painful dental disease, sore joints making moving toward food more challenging, medications that taste bad or cause nausea. Other reasons may include a younger, more powerful cat in the house guarding the food and decreased the ability to taste and smell are all reasons a senior cat may take in fewer calories. These changes can happen slowly. It is difficult for owners to recognize muscle loss before it is severe.
It is important for veterinarians to assess the body condition of senior cats. The cats total body weight is part of this assessment but it is common to have an overweight cat with excess body fat and poor muscle mass e.g. a “skinny fat cat.” The only way to determine this is to palpate the muscles. Tracking body weight alone is not enough.
Once your veterinarian identifies sarcopenia, a diet assessment can be done to determine if you are feeding your cat optimally. It is important to know what you are currently feeding, how much the cat is eating and your cat’s eating behaviour, e.g. where, when, and how you feed. With this information, your veterinarian can determine current calorie intake, your diet’s protein content and digestibility, and whether the diet is complete and balanced. Can small changes such as the location of food, type of dish, meal size and frequency be made? Is a diet change required to provide higher calorie food with more digestible protein?
Gone are the days of leaving kibble out or providing whatever is on sale at the local grocery store. Ask your veterinarian for body condition scoring and a diet assessment as part of every annual or bi-annual visit to help your senior cat live better and longer.
Written by: Dr. Dana Cini, DVM