Anorexia is the medical term for a lack of appetite. Not eating is one of the most common reasons worried pet-owners bring their pets to veterinarians. A day or two in which your pet turns up its nose at food is not that unusual. Sometimes it can be associated with recent events: a trip to the groomer or animal hospital, a new brand of diet, turmoil in its day-to-day living (most dogs and cats do not appreciate change), separation anxiety, etc. But when this occurs over more than a day or two or if your pet actually looses weight, runs a fever or develops any physical signs of illness, it is time to pay attention to the problem.
This is a very common problem. I see it particularly in smaller and toy breeds of dogs. Cats are not immune to it either. Dogs and cats are quite intelligent – particularly when it comes to the taste of their food. After their first bite of table food (particularly meat items), they instantly know that your food tends to taste better than theirs. Even if it doesn’t always, they remember the time it did and assume it will. I am as guilty as anyone. Our cat Oreo and Labrador retriever, Maxx, wait patiently for anything to “fall” from the dining room table. It is only when they realize that they are not going to get anything that they wander back to their food dishes. I have no problem with you giving your pets treats of human food. But you must not let these scraps constitute more than 20% of your pet’s diet and there are certain foods that must not be given. They include, grapes, raisins, avocado, chocolate, anything with small or sharp bones or sugar substitutes like xylitol or heavily spiced foods. If anything you gave caused diarrhea, a tummy ache, vomiting or constipation, never give it again. It may not be that toy breeds are any more guilty of this problem than large breeds. It could be that the owners of toy pets just tend to baby them more and that there are rarely enough table scraps to constitute more than 20% of a large dog’s diet.
Some pets - like some humans – are just born finicky eaters. This can be a blessing. Scientists have found that the length of life in many species is lengthened by the consumption of fewer calories. But when a nurturing person is disturbed by a picky eater, it can become a perceived curse. Some pets just enjoy the attention that a worried owner pays to them when they hover over their food dish not eating. They can quickly pick up on this. If a disinterested party, such as a groomer, pet handler or neighbor tells you that your pet is too thin, a visit to your veterinarian (and perhaps a diet change) is in order. Many picky eaters will go a day or two without eating much. It is no cause for alarm if that is the confirmed constitution of your pet and its weight remains normal and steady. When clients call me after hours at home for advice for a pet that will not eat, I often try my Vienna Sausage Test. Vienna sausages are small smoked, canned wieners. They would be a horrible diet choice for pets – but few pets can refuse one. I tell owners to offer half a link to the pet and call me back if he won’t eat it. If the pet doesn’t eat it, its time to set an appointment the following day or for me go back to my animal hospital and examine it immediately.
Many of the serious diseases that our cats and dogs suffer from are accompanied by a drop in appetite or weight. There are too many of them to list here - although you will find an article about most of them on this website. However, they are all accompanied by one or more abnormal findings other than lack of appetite.
If your pet is loosing weight it should be promptly examined by your veterinarian. Sometimes, a physical examination is all that is required. Things such as infections of the skin, eyes and ears can often be diagnosed and treated - without further complicated testing.
Many owners think their pet is loosing weight because of intestinal worms. In my experience, this is very rarely the case in a well-kept adult dog or cat. Pet stores, patent remedy merchandisers like Hartz, Walmart and PetSmart encourage this myth because worm medications are big sellers. But I have seen a lot of pets whose owners waited way too long to take their pet to their veterinarian because of this myth. When intestinal worms are involved in weight loss, it is due to a severe infections caused by unsanitary conditions, high-stress environment, crowding, concurrent other diseases or the feeding of low-quality generic pet foods or inadequate amounts of pet foods. You can read about those parasites here and in dogs specifically here. There are dogs that are particularly fond of nibbling on the stools of other dogs while visiting doggy parks. I have never seen a similar problem in cats. If you pet shares those habits. The best way to prevent worm infections is one of the monthly heartworm/flea preventatives that contains an intestinal worm medication as well. Tapeworms, although disgusting, rarely cause weight loss in dogs and cats.
You can read all about those various dental problems here. Although you might expect tooth and gum problems to affect your pet's appetite – they rarely do. This is because dogs and cats do not chew their food very much - at least not the kind of foods we generally feed them. It is only when dental problems are severe enough to cause systemic disease that they may affect the pet's appetite. Never the less, a veterinary examination should include an examination of your pet’s mouth. If it is found that your pet has severe periodontal gum disease or heavy tartar buildup, having its teeth cleaned is a very good idea. I have seen a few cases where this improved appetite - particularly in cats. In rare occasions, your vet may even identify an object lodged in the pet's mouth or throat. The more important benefit of dental hygiene in our pets is preventing infections that eventually hurt the heart, kidneys and liver. (ref) Veterinarians also become suspicious of a physical mouth problem when a pet will lap up it’s normal diet when it is blended into a liquid form. That can the novelty of a new form of presentation, but it can also be due to scaring (strictures) of the esophagus, tumors or developmental defects such as persistent right aortic arch.
If your pet has lost significant weight due to decreased appetite and the blood work comes back normal, the next step will probably be to x-ray or ultrasound your pet’s abdomen and chest. Some changes are quite obvious and easily detected. However, many are subtle and not easily recognized by a veterinarian in general practice. When that is the case, it is often best if the films or ultrasound image are reviewed or performed by a veterinarian specializing in reading those images.
The aroma of food is extremely important to your pet. In most cases, a little dressing of a premium gourmet canned pet food or home-cooked broth on top of your pet's regular food is all that it will take. Many cats appear to become addicted to pungent fish flavors, so I suggest that only turkey, chicken or beef-based foods be used for this purpose. It doesn't take much. Adding too much tasty topping simply begins another problem – refusal to eat a balanced diet.
Dogs and cats that are picky eaters will sometimes eat better when their food dish is placed in a new location. Sometimes, using a different container will help. This probably has more to do with scent than vision.
Often a pet is most interested in it’s food soon after it is put down. So taking the food bowel up after a reasonable period of time and replacing it later sometimes helps. However, there are other pets that are periodic munchers whose total food intake is much larger when the dish is always available. Only trial and error will tell for your pet.
Some pets eat better in the morning or at night or when you come home from work. Some eat more when undisturbed while others like your company or the company of other pets when they are eating.
Most pets will eat more and gain weight when fed canned diets versus dry food. This is because the odor of canned food is more attractive to most of them and also because canned diets tend to be higher in calories on a dry weight basis. However, I see many more pets with obesity and dental problems when they are fed canned diets. Read about that here.
If you are already feeding a canned diet, and are dissatisfied with your pet’s appetite or weight, try a different brand. Never make the change abruptly - do it gradually over a week or so. There are too many brands for me to make specific suggestions other than to say that you are always safer feeding a product produced by a large, national pet food company. These are the only companies with the resources for stringent quality control and with sufficient feedback from pet owners for them to recognize a problem when it does occur. There is no problem with homemade diets if they are nutritionally balanced. That is not an easy task – but it can be done. Read about them here. Fat pets here
Dogs and cats will often have more appetite after periods of activity. This can be play with a toy, fetching a ball, a walk in the park, or a simple trip in the car. Nothing too strenuous.
Pets that have been neutered tend to gain weight. That is particularly true when they were neutered too young. (ref) In most cases, this is a problem. However, if your pet is by nature a picky eater, it could conceivably be a benefit.
Growing pets need much more food for their size than adult pets. So the effects of not eating are much greater on them and occurs sooner. Also, puppies and kittens that are nutritionally deprived either by lack of appetite or starvation may never reach their full body-size potential. They may also develop soft teeth, floppy ears and bowed legs that can never be completely corrected. So take these youngsters to your veterinarian the moment you notice that their appetite has lessened. It is normal for a puppy or kitten’s appetite to gradually reduce once the majority of their growth has occurred. Try not to mistake that for a problem.
Be sure to check out my articles on Entyce. When a pet is ill or injured and cannot or will not eat, you need to do all you can to supply it with critical nutrients. This is because those nutrients are essential for healing. Sometimes, encouragement and feeding the pet canned food from your hand is all that is needed. If this is to go on for a while, it is better to use a nutritionally balanced canned dog or cat food rather than unsupplemented boiled chicken or beef. Try a premium or gourmet brand or something you pick up from your vet. There is absolutely no problem in offering cat brands to dogs - cat diets are often preferred by dogs. The reverse is not the case – some dog foods are not be nutritionally adequate for long term use in cats. Pets, like kids, love to be pampered that way, so don't continue the practice longer than necessary or your dog or cat may resist a return to its regular diet.
If your pet can't or won't eat when offered food in this way, it will need to be fed a liquid or liquefied diet through a syringe or turkey baster. Various liquid and semi-liquid diets are available through your veterinarian. You can also prepare these foods just as well at home if you have the time. The food needs to be blended in a blender until it is fine enough to pass through the tube or syringe tip you are using. For tiny critters, I often enlarge the orifice in the syringe tip with a 1/8 inch drill bit so the food particles pass easily.
A visit to your veterinarian is the best way to determine if your
pet’s lack of appetite is a serious or minor problem. If the
exam and tests determine that the problem is minor, trying some
of the things I suggested should help. If an underlying disease
is detected, hopefully it can be cured with proper care and medicine.
If your pet has lost substantial weight, your veterinarian may try to stimulate it’s appetite with medications.
Some of the appetite stimulant medications I mention are prone to side effects - particularly when the pet's liver or kidney function is compromised. Many veterinarians believe that Remeron (Mirtazapine) and cyproheptadine have the least potential for generating worrisome side effects - as long as their dose is adjusted downward when illness prevents their normal metabolism and excretion. (ref1, ref2) I mentioned the link to Entyce twice before. In 2018, it is the newest appetite stimulant on the market. It is worth taking the time to read about.
Megesterol (Megace®) is a powerful appetite stimulant in pets. However, it has other undesirable effects including elevating blood sugar to unhealthy levels. I only suggest it when other medications fail.
Stanozolol (Winsterol-V®), an anabolic steroid, also has
powerful appetite-stimulating and weight-gaining properties. The medication can sometimes cause male
traits to a appear in female pets – similar to its effects
on female athletes – particularly when it is given at high
doses for long periods. It is no longer marketed in most countries due to the fact that it was a prime drug used by athletes (animal athletes as well) to gain unfair advantage. With continued use, side effects are as bad, or worse than megesterol.
In an animal hospital setting, delivering food via a tube is the most efficient way to feed your pet. It is also the least stressful way because even healthy pets often refuse to eat when hospitalized or kenneled. A small tube can be inserted up the nose or directly into the stomach through a small incision. Feeding in this way is not painful.
an animal stops eating, its body relies on mobilizing fat reserves
through the liver to provide needed calories. However, cats have
evolved to not have this ability well developed. When a cat eats
less than about half of what it normally does for a two week period,
it may develop hepatic lipidosis (fatty liver disease). This can
be fatal. So many veterinarians suggest supplemental feeding early
enough to avoid this problem. Another disadvantage cats have over
dogs is that their daily protein needs are higher. So while a dog
can live off of its stored fat for a considerable period of time,
a cat has more trouble subsisting on fat calories alone –
particularly when it is ill. Through 2018, Entyce is not approved by the FDA for use in cats. But you can read the experiences of cat owners who have used it here.
Pets are sometimes put on prescription diets because of a particular medical problem. Most pets accept these new diets – particularly if they are changed from their old diet gradually. But other pets never accept the new diet. When it has been suggested that your pet eat a prescription diet, I suggest you purchase only a few cans or a small bag first to see if the pet will eat it. If not, try a different brand or a different style of the same brand. But under no circumstances, force your pet to eat it to the point where it looses significant weight. The only exception is a diet formulated for weight loss. In some cases, the only prescription diet a pet will accept is one you prepare yourself at home.