In specialist medical jargon, loss of appetite is also known as anorexia or inappetence. This is a pathologically reduced food intake, which can be triggered by different causes. However, the term has to be differentiated from what is known as pseudo-anorexia. This condition describes a sense of hunger with simultaneously disturbed food intake (e.g. due to injuries to the jaw or difficulties swallowing).
In order to be able to understand how a loss of appetite can arise with cats, it helps to take a closer look at feline physiology:
The feeling of hunger is primarily controlled by the hunger centre in the brain. It receives important information like the expansion state of the gastrointestinal tract from the hunger receptors located there. If the stomach is extremely full, the expansion receptors are activated and send the brain the signal that no more food needs to be consumed. In contrast, a feeling of hunger comes to the fore when the stomach is empty and the expansion sensors aren't activated. Along with this signalling pathway, however, the sense of hunger is also activated by other factors like hormones or state of health, such as by the cat's acute phase reactions. This is an important immune system reaction in which the body reacts to diseases with an acute inflammation, which is meant to encourage wounds to heal, for instance.
Causes of a loss of appetite with cats
Along with pathological causes, there is in most cases a totally normal, harmless aversion to a cat food due to its taste. Nevertheless, many different illnesses can also be the cause of a loss of appetite with cats, which is why dividing them into primary and secondary causes is advantageous. Whilst primary causes influence the hunger centre in the brain, secondary causes describe the influence outside the brain, such as in the visceral organs or bloodstream.
The hunger centre in the brain reacts sensitively to psychological factors like stress or anxiety. Even small changes in the household like a new pet or the death of a family member can lead to your cat eating less or nothing at all.
Another factor is pain perception. Especially after surgery or injuries, cats can often have a decreased appetite.
Another negative influence can be disturbed nerve function of the senses of taste and smell.
In general, all underlying diseases can lead to anorexia with cats, including the following examples:
- Inflammations: e.g. stomach inflammation (gastritis) or bowel inflammation (enteritis).
- Due to a limited sense of smell, colds can lead to cats refusing food.
- Infectious diseases: e.g. feline immunodeficiency virus (FIV).
- Tumorous diseases
- Metabolic disorders: e.g. chronic renal diseases
Since a loss of appetite isn't an illness in itself, it is just a single symptom. Nevertheless, it can result in secondary symptoms depending on the primary disease and further consequences may occur due to the lack of food and nutrient deficiency.
- General symptoms: tiredness and frailty
- Weakened immune system: bacteria and other pathogens can multiply more strongly and, for instance, pass through the blood-brain barrier. This increases the risk of suffering from infectious diseases.
- Disturbance of the organs: decrease in cardiac muscle (atrophy), kidney damage to total organ failure.
If your cat has a decreased appetite, it should be thoroughly examined by a vet. Since the list of causes is very long, an exclusion diagnosis must be carried out, which can be very comprehensive depending on the cause.
In order to slightly narrow down differential diagnoses, the vet will ask when interviewing the owner (medical history) for important information on the duration, timing of the event and emergence of further symptoms. Along with the vaccination status and recent changes to the cat's environment (e.g. new arrival or change of food), the cat's interest in its food is also an important indication. If the cat does want to eat food, its inappetence is most likely caused by a masticatory disorder.
After the medical history, there is always a general clinic examination in order to establish the cat's current state of health. If the cat's circulation is too weak for a comprehensive examination, it must first be balanced by administering fluids and electrolytes.
If the cat's circulation is stable, the special examination can commence.
Firstly, a thorough inspection (adspection) of the head and mouth cavity is important. Perhaps sedation or anaesthesia are necessary. However, anaesthesia for an endoscopic examination is required anyway if it is suspected that the cause is the stomach or oesophagus.
Imaging procedures like X-rays or ultrasound as well as blood tests are also helpful for further diagnostics.
What to do if my cat no longer eats?
Inappetence is treated by a special (elimination of the cause) and symptomatic treatment too. The following therapeutic measures can also be required with inappetence:
- With infectious illnesses: possibly antibiotics, virostatic agents, antimycotics
- Severe hypoglycaemia: glucose substitution (e.g. via infusion)
- Force feeding: e.g. via nasal tube, parenterally into the vein or oral with a needle-free syringe
- Medication to prevent vomiting: antiemetics
- Medical appetite stimulation: e.g. Diazepam
- For limited taste of smell or taste: give foods with strong flavours (e.g. tuna)
What is the prognosis?
The prognosis of a loss of appetite with cats fluctuates greatly depending on the cause. Whilst mild infections can generally be fought off after a few days, acute intoxication or a too-low blood sugar concentration can turn out less well. An early diagnosis is important to allow effective treatment.
How can a loss of appetite be avoided with cats?
It's difficult to avoid cats suffering from a loss of appetite. Nevertheless, some of the ailments that cause it like infectious diseases or inappetence triggered by certain foods can be reduced with the preventive measures in the following list:
- Avoiding contact with sick animals and hygiene measures (e.g. regularly cleaning the litter box and food bowl)
- Balanced diet and portions based on weight
- Regular veterinary examinations