It is very important that your pet keeps eating. After all, via nutrition the necessary proteins for the immune system, which the dog needs to fight cancer, are being provided. Proteins also strengthen the body in general.
The first signs of chronic malnutrition often manifest themselves via the skin, the digestive system and the blood. Signs of a disturbed food intake are therefore visible as a bad fur quality, regular digestive problems (e.g. diarrhoea), excessive sebaceous discharge, apathy and pale mucosae (due to a low level of haemoglobin).
If your dog eats well, you can possibly optimize the food intake. For example, if your dog has kidney issues, he will ideally receive high-quality proteins, but in a reduced quantity. If your dog receives a home-cooked meal, it is advised to consult a veterinary nutrition specialist to check whether the meal consists of all the necessary elements in the right proportions.
Causes of decreased appetite
It is not uncommon for cancer patients to abstain from eating or eat less. This is often the result of an increased inflammatory process linked to the tumour which suppresses the appetite.
A decreased appetite can also be the consequence of the tumour’s location (e.g. in the digestive system) or a side effect of a treatment.
Furthermore, chemotherapy can temporarily change the sense of smell and taste. As dogs and cats rely heavily on these to eat, this can also reduce their appetite.
Handling digestive issues
- Vomiting
This is a symptom that should be reported to your treating veterinarian. Vomiting once or twice is acceptable, but not more than that. When this happens, take away nutrition and water during 12h. If your dog does not vomit after drinking water, you can give him small amounts of more or less tasteless nutrition such as boiled chicken and cooked white rice. If your dog still does not vomit after eating this solid food you can slowly (over 3 days) re-administer his usual food. If the vomiting continues and/or your dog has a fever of over 39.5°C during more than 24h (normal body temperature: 38-39°C), you should alert your veterinarian.
- Diarrhea
Diarrhoea can occur during some treatments. Offer your dog more or less tasteless and easily digestible food such as cottage cheese, boiled chicken and boiled white rice. Offer slowly (over 3 days) again his regular food. If the diarrhoea persists for more than 72h, if your dog is sick and/or has a fever over 39.5°C (normal body temperature: 38-39°C), you should alert your veterinarian.
Vomiting, diarrhoea, fever or urinating excessively can lead to dehydration resulting in a prolonged recovery. The gums of your dog should feel moist and the skin soft and elastic. If your dog is not vomiting, always provide fresh drinking water. If the gums are continuously dry or the skin does not feel elastic, you should contact your veterinarian. It could be necessary to administer liquids to speed up the recovery.
- Recognizing an infection
Symptoms of an infection can be: fever as from 39.5°C, fatigue, vomiting, diarrhoea and/or a poor appetite. If your dog presents with one of the mentioned symptoms, his temperature should be measured. When the temperature exceeds 39.5°C the veterinarian should be alerted.
How to increase appetite
There are a number of aids to stimulate your dog to eat. One of these is heating up the food (until just below body temperature, so until 38°C). This releases more aroma allowing your dog to smell the food.
There are dogs who prefer to be handfed, as opposed to eating from a bowl. When handfeeding, it is very important to be very patient and not force anything. One can very gently apply easily spreadable food on the inside of the lip. When the dog takes this in and asks for more, this process can be repeated. If the dog remains apathetic or turns himself away, you must stop to avoid creating negative associations with the food.
Offering food occurs preferably in a quiet environment, without the bustle of other pets/children/visitors.
Dogs have taste receptors for salt and sweet. Adding sugar, syrup or other sweet compounds (no chocolate!!!) can improve the appetite.
If your dog is nauseous, it is best to avoid offering a whole array of different food sources because your dog can develop an aversion towards these.
Weight and diet follow-up
If you regularly weigh your dog and keep track of his eating habits, this will help your veterinarian make decisions. For example, this way the veterinarian can make a distinction between anorexia (not wanting to eat) and cachexia (lose weight despite having a good appetite). The former can be altered by adapting the nutrition or by giving medication that improves the appetite, while the latter may require change in the treatment approach.