Nutritional Support for the Feline Critical Care Patient
My cat is receiving intensive care in the hospital and she’s not eating on her own. I know not eating is a bad thing, but I don’t understand why.
Hospitalization can have a profoundly negative impact on a cat’s nutritional status. Hospitalized cats are commonly malnourished due to decreased food intake which can lead to decreased immune system function, decreased ability of the body’s tissues to repair and restore themselves, and abnormal drug metabolism.
How can the immune system be affected by nutrition?
The immune system cannot function normally if the body is not receiving appropriate amounts or an appropriate distribution of nutrients. Compromised immune function increases the risk for infection, which can lead to anorexia, and this further compromises the immune system. Protein deficiency decreases the number of immune system cells circulating throughout the body, as well as decreasing their functional capacity.
The immune system cannot function normallyif the body is not receiving appropriate amounts
or an appropriate distribution of nutrients.
The immune system is quite responsive to nutritional intake, so restoring adequate intake can restore the immune system to competence fairly quickly.
Can you explain the relationship between nutrition and tissue healing?
Wound healing and tissue repair are intimately interrelated with nutrition. Amino acids from protein, as well as carbohydrates, contribute to muscle and tendon repair. Energy from nutrients is required for all the body’s cells to function effectively. Rebuilding tissues following injury or surgery requires increased protein production that must be fueled by adequate nutritional intake.
How can nutrition influence medication metabolism?
All medications that enter the body must be distributed throughout the tissues, metabolized, and ultimately, eliminated from the body in order for them to be effective. In a hospitalized critical care feline patient receiving inadequate nutrition, normal cellular metabolic activities are disrupted. This can lead to problems with medications resulting in either inadequate drug activity, or creating a relative overdose if drug elimination is slowed.
What other negative effects are related to disrupted nutrition while hospitalized?
Malnutrition while hospitalized may contribute to a cat needing a longer hospital stay and a prolonged recovery. The word “anorexia” means losing interest in food before satisfying the body’s calorie needs. In “partial anorexia” the cat eats some food, but not enough. In “complete anorexia” the cat eats nothing. Anorexia while hospitalized may be caused by:
- Emotional distress
Cats who are recovering from illness, surgery, or injury are often in a hyper-metabolic state in which the body’s nutritional needs exceed normal baseline requirements. A hospitalized cat who has had partial anorexia for three days, or complete anorexia for 48 hours, may need a nutritional intervention. Whenever possible we want to use the GI system for nutrient delivery rather than intravenous feeding (also called “parenteral feeding,”. a discussion of which is beyond the scope of this article). Nutritional interventions that utilize the GI tract may be as simple as placing food in the mouth to stimulate the swallowing reflex, or as complex as surgically placing a feeding tube into the stomach or small intestine.
What are the various methods for feeding a critically ill or hospitalized cat who won’t eat on her own?
Placing a bolus of food in the mouth may be enough to stimulate the swallow reflex, appetite, and eating. Alternately, a large-tipped syringe may be used to deliver a liquid or semi-solid food into the mouth. If the cat refuses to swallow food delivered this way there is a risk for aspiration pneumonia, so oral feeding attempts should cease.
Feeding tubes can truly mean the difference between life and death. There are many types of feeding tubes available for the feline critical care patient. For one or two days of tube feeding, your veterinarian may choose a simple oro-gastric (mouth-to-stomach) tube. No anaesthesia is required to slip the tube down the esophagus, deliver the meal via syringe, and then pull the tube out. This method is well tolerated, but can only be used for a day or two. For longer periods of tube feeding, an in-dwelling tube is required.
- Naso-esophagostomy tube:
The naso-esophagostomoy tube is placed via one nostril down into the esophagus near the opening to the stomach. Liquid nutrition can then be delivered. These tubes are typically used only in the hospital.
- Pharyngostomy, esophagostomy, and gastrostomy tubes:
These tubes are placed using a short-acting general anaesthesia. The pharyngostomy and esophagostomy tubes enter the side of the neck and end in the esophagus near the opening to the stomach, are sutured in place, and can be used for long periods of time. When it is best to deliver food directly into the stomach, a gastrostomy tube is placed through the abdominal wall into the stomach and secured into place. Home care of these tubes is generally quite easy.
- Jejunostomy tube:
Jejunostomy tubes are not as commonly used. They are surgically placed under general anaesthesia into the small intestine through the abdominal wall and secured in place. Cats requiring a jejunostomy tube are fed a liquid diet delivered by a slow continuous drip.
How do I feed my cat using a tube?
Your veterinarian will develop a feeding plan with a nutrient profile specific to your cat and the tube type, and will teach you how to do the feedings at home. Multiple small meals are preferable, and your veterinarian will provide a total per day volume to avoid over-feeding. Processing your cat’s regular food in the blender may facilitate the smoothest transition back to eating on her own. It is critical to flush the tube with a small amount of warm water at the end of each meal to prevent the tube from clogging.
How long will my cat need a feeding tube?
Your veterinarian will work with you to decide how long a feeding tube is needed. Cats with feeding tubes are typically offered food periodically, looking for that time when they are willing to eat on their own. They can eat on their own with the tube in place. As they eat more on their own, the amount being tube fed will be decreased proportionately. Once they are eating adequately on their own, the feeding tube can be removed, usually without sedation or anaesthesia.
With good planning and early intervention, critically ill cats can be spared the detrimental effects of malnutrition during hospitalization and healing.