Marli's Chi's - AKC Longcoat Chihuahuas

of San Jose, California


-Barry McDonald

Coprophagia (aka, coprophagy) is a behavior that I have studied and treated extensively. I think I probably have the distinction of posting more about "poop" on-line than anyone else on the web. I guess you could say I am full of... it!

Here's more than you probably want to know about coprophagia.

1) In the short-term, if a dog is eating its own feces, coprophagia is both a normal and common canine behavior, and a harmless one. If the dog is ingesting the feces of other dogs or animals, it may run the risk of picking up a parasite or virus from the "donor." However, if the coprophagia is occurring among your own animals, there is little danger as long as you are keeping them healthy and providing the necessary vaccinations and heart worm medication. (The one exception may be young puppies that have not yet gained full immunity from parvo through vaccinations.) In the majority of cases, the behavior eventually stops on its own after a number of weeks or months. It is most commonly seen in pups between 4-9 months of age, who will most often outgrow the behavior without intervention. As a matter of fact, with dogs of all ages, early intervention of any kind is more likely to increase and sustain the behavior than eliminate it!

2) For dogs with short-term coprophagia (let's say, less than 6 months), I would simply ignore the behavior while taking a few steps to manage it and prevent it from being reinforced. As Nancy wisely noted, and as Kathleen suggested by mentioning "attention seeking behavior," many sustained cases of coprophagia are caused by the owner's unintentional reinforcement of the behavior.

A) Clean up the yard daily, but do not allow your dog to watch you doing so! Your pick-up efforts may be reinforcing to your dog. This is simple to understand: Your dog is "picking up poop," and now it sees you doing the same! What is it likely to conclude? Probably that you approve of, enjoy, and recommend this behavior! If the dog has an instinct telling it to "keep the yard clean," you are reinforcing it! Generally, the less you are associated with the feces, the less likely the dog's original urge will be complicated by owner attachment, reinforcement, or attention-getting.

B) DO NOT, as others have said, react to your dog's coprophagia in any way--no yelling, no correcting. As with any emitted behavior in clicker training, we want to ignore unwanted behaviors.

C) Reevaluate your dog's environment: Make sure she is getting enough mental stimulation, exercise, training, play, etc. Boredom and stress are definitely contributing factors in many cases of coprophagia.

3) There is a subset of dogs, however, that seem to develop coprophagia as a long-term behavior that continues unabated for many months or years. These are the only dogs that I would consider intervention or behavioral conditioning with. The behavior of these more obsessive consumers may warrant attention because first, the coprophagia may be a symptom of other underlying disorders such as anxiety or stereotypy; and second, due to the frequency and duration of their coprophagia, these dogs have a greater chance of picking up a parasite or infection over time.

4) For these long-time coprophagics, your chances of eliminating the behavior correspond inversely to the the length of time the dog has been coprophagous. It will be easier to break the habit in a dog that has been coprophagous for 8 months than in one who has been so for 2 years. The first step in intervention should be to follow the three rules already listed above. In addition, below are some comments about what other measures may or may not work. Remember, all dogs are not the same, so a method that may work wonders with your dog may not work at all for most other dogs.

A) Everyone and her brother has a magic food ingredient that supposedly will prevent coprophagia, from pineapple to spinach to pickles--including all the commercial additives. Although some of these "supplements" seem to work for particular dogs, there is no certainty or guarantee that they will work for your dog. Statistically, most of the time food additives fail to stop the behavior. A behavioral reason for this, which the members of this list can appreciate, is that eating the feces is simply more reinforcing than the "nasty taste" is punishing. There is also a possible physiological reason for the failure of food additives. Dogs have survived is by developing a tolerance for what we would consider nasty tastes. As Nancy points out, dogs are scavengers and opportunists. (See the Coppingers' book, "Dogs," and their village dump theory.) Some studies suggest that dogs that engage in coprophagia, especially long-term, have an even more forgiving sense of taste than the average dog.

B) Charlotte, MD, suggested ipecac and referred to the use of lithium chloride to deter coyotes and wild canids from attacking sheep. There are several reasons that this approach is unpromising with dogs. First, a number of studies have shown that it is not vomiting per se that acts as an aversive, it is the sustained feeling of nausea. It is therefore necessary to make the dog nauseous, not simply to make it vomit. I'm sure most people just said to themselves, "What's the difference?"--but here we bump into the species barrier and our tendency to anthropomorphize. Anyone who has watched their dog gag and upchuck its dinner can attest to the fact that most of the time dogs simply returns to what they were doing after they vomit, completely unimpressed by the messy episode. (That is, if they don't decide to eat the vomit first!)

This might suggest to us what studies have shown: dogs do not seem to experience or fear nausea in the way that most humans do--and may not react to nausea in the same way as coyotes or other canids. This is consistent again with the dog's evolutionary past. Although scavengers need a keen sense of smell and taste to discriminate between good and poisonous foods, they also do best if they can tolerate a wide variety of grease, grain, goop, and glop! To put it frankly, if poop itself doesn't make a dog nauseous, what will? (:-)

Two other potential drawbacks, if you could get your dog terribly nauseous, are that you would have to assure that it happened consistently a number of times in a row for a strong enough association to be made, and in addition--my fellow clicker trainers--we are talking here about a clear case of positive punishment and aversion, which may be a moral concern to some.

C) Adding a bad taste (short of creating nausea and vomiting) to a dog's food does seem to help some dogs, but a problem with this approach is that with a long-term coprophagic dog, you will have to use the food additive long-term. Some commercial additives suggest that the product should not be used for more than a certain length of time. I would personally be worried about adding ANYTHING to my dog's daily meals regularly month after month. For example, spinach was one of the suggested additives. Spinach is high in oxalic acid, and oxalic acid binds with calcium in the gut and prevents it from being absorbed. There is no harm in a few serving of spinach each week, but there may be an adverse effect on calcium absorption if spinach is added daily for a long period.

Finding an additive that your dog will find distasteful enough to change its behavior may take many weeks of experimentation--if there IS an additive that will discourage your dog. For those lucky enough to find something that works, I would only use the additive in the short-term. If your dog cannot be deterred within a few weeks, food additives are not the best solution for long-term daily use, and there are likely other aspects of the behavior that need to be considered.

D) Although it was once thought that dietary deficiencies were a cause of coprophagia, most studies to date fail to show a clear or consistent correspondence between dietary deficiency and the unwanted behavior. Some dogs with nutritional deficiencies have ceased being coprophagic after their diet was improved, but as with the nasty tasting food additives, no particular nutrient seems to help all coprophagic dogs, and a majority of coprophagic dogs have no measurable deficiency. When a deficiency is associated with the behavior, it has most often turned out to be thiamin or one of a few trace minerals. So supplementation with a B-vitamin complex rich in thiamin may help some dogs. The link here is still tentative, though, because in a number of studies dogs that were deprived of nutrients did not become coprophagic. So while some coprophagic dogs have a nutritional deficiency, all dogs with deficiencies do not become coprophagic, and all dogs that are coprophagic do not have a nutritional deficiency.

E) A theory that has gained popularity recently is that coprophagia may be related to the action of digestive enzymes. A dog may eat its own feces or those of another dog because they contain undigested nutrients. Another version claims that dogs may actually be trying to consume the digestive enzymes themselves, not the undigested food. There has been some success from simply adding a digestive enzyme supplement to the coprophagic dog's diet, and/or the diet of other dogs in the household. (ProZyme, for example, is one popular and readily available brand.) Some of you may have heard the suggestion of adding meat tenderizer to the dog's meals to stop coprophagia. Meat tenderizers contain an enzyme called papain that helps to more fully digest the meal, so this tends to support the notion that it is enzymes that may be lacking, not nutrient themselves.

Other researchers have blamed the pet food industry for creating kibble that is high in carbohydrates and grain since dogs are primarily carnivores. A majority of a dog's diet should, IMO, consist of meat. Interestingly, while protein and meat rarely survive the digestive process, undigested factions of the meal are almost always non-meat ingredients such as grains. So it may be the inappropriateness of the foods we feed our dogs that has created an epidemic of coprophagia! (A study I would love to see done is to compare the frequency of coprophagia among kibble-fed dogs to that of dogs on a BARF diet!)

F) A number of theories have been offered to explain coprophagia. 1) Dogs, as scavengers, learned to eat whatever was available in times of famine. 2) Bitches will eat the feces of their pups--not just to keep a clean nest, but to eliminate the scent that would attract predators. 3) Adult dogs will eat their own feces when they are ill, or the feces of another pack member if it is ill, in order to conceal the "evidence" of this illness from fellow pack members and predators.

For the dog that is chronically coprophagous, these theories are interesting, but of little practical use in curbing the behavior. Chronic coprophagics are dogs that have taken the behavior far beyond its normal application, and are best treated as pets that have developed an obsessive-compulsive disorder (stereotypy), or that have an anxiety-related or perhaps conditioned (learned) behavioral problem. In other words, chronic cases of coprophagia are not being sustained by canine instinct, but are more likely sustained by displaced anxiety, abnormal brain activity, or other mechanism. (The human with OCD does not wash his hands 100 times a day because they need to be cleaned!)

I must tell the the tale of my two dogs, Pinto and Cherokee, because it illustrates the part that medication or illness may have in causing temporary coprophagia. When my Basenji Pinto was about 6 months old, he started eating the feces of only one of my four other dogs--Cherokee, a Rottie/Husky mix of the same age. Cherokee, who was well housetrained, had had a few "peeing" accidents inside the house, which is usually a sign of a urinary tract infection. Sure enough, Cherokee had a UTI, and she was placed on an antibiotic for 2 weeks. About two days after Cherokee went on the meds, Pinto began eating Cherokee's feces. And only Cherokee's! Pinto continued this for a little more than 2 weeks. About five days after Cherokee was finished with the course of antibiotics, the coprophagia ended abruptly, and Pinto, over the past two years, has never exhibited the behavior again. I interpreted this as a clear case of one pack member concealing the evidence of an illness in another pack member. If anyone notes the onset of coprophagia at a time when a pet in the house is ill or on medication, this should be considered as a probable trigger for the behavior.

G) To summarize so far:

--There is more than one cause of coprophagia, and for many dogs, there are probably multiple influences.

--For any suspected cause--lack of enzymes or nutrition, for example--there is a wide variety of responses: Most dogs will not develop coprophagia at all due to digestive problems; others will temporarily exhibit coprophagia; and a few will become chronically and permanently coprophagic.

--While underlying causes such as stress or diet should be considered and addressed, you should realize that whatever the cause was originally, learning and reinforcement also play a part. Once the behavior has begun, the way that the owner reacts to it and other environmental factors may encourage the habit. So in all cases, we need to be cautious that we do not unintentionally reinforce what would have been a temporary and harmless behavior to the extent that it becomes a rewarding and long-term problem.

--Look for coprophagia to occur more often in puppies, stressed animals, malnourished animals, in households where there is a pet that is sick or on medication, and following a change in environment--such as the introduction of a new dog to the household. Rather than targeting the coprophagia, always start by enhancing the general welfare of the dog by increasing its exercise, reducing boredom and stress, and attending to any possible medical or dietary needs.

--Understand that as with other canine behaviors such as aggressive displays or guarding one's food, there is an appropriate and normal level of these behaviors in all canines that is instinctual and reasonable, but in some dogs there is an exaggerated and inappropriate escalation of the instinct which then becomes a behavior problem. When we leave it alone, coprophagia is usually just a doggy-thing that passes. But in some dogs, the behavior becomes much more than itself and may turn into an obsessive behavior that is driven by other forces such as fear or abnormal brain chemistry. If you can detach yourself from your initial disgust with the behavior, the difference between the common instinctual form and the less common obsessive form is quite obvious and striking. Only dogs in the latter category need your help.

--Ignore coprophagia at first, and understand that it is most often a normal and temporary behavior. Use management, not training, as the first line of attack for dogs that do show compulsive or long-term attachment to the behavior. Keep the area clean, but do not allow your dog to watch you picking up. Something as simple as one or two daily walks at the same time every day can encourage elimination while "on the road," and prevent access to the potential meal. Avoid leaving your dog unattended in dog parks or areas where opportunity may present itself. And if you feel it necessary to intervene, do it by distracting your dog--by inconspicuously redirecting its behavior rather than by overtly correcting or acknowledging the behavior.

5) Some experimentation with the various suggestions above should resolve the problem for the majority of dogs. This leaves the hard-core, compulsive and long-term coprophagic dogs. These dogs, IMO, fall into three categories: Those who have a physical cause for the behavior (malabsorption, brain chemistry, a lack of digestive enzymes, etc.); those that are prone to obsessive-compulsive behavior or stress-induced displacement behavior (what we might call neurotic dogs--who may benefit from drugs like Clomicalm, amitriptyline (Elavil), or Prozac and its companions (SSRI's); and those who have been unintentionally but strongly and consistently reinforced for the behavior over time.

Clicker training and OC is probably going to have little effect on the first group; owners of these dogs need to seek medical attention or nutritional guidance. The second group are in need of counterconditioning, and most often a combination of counterconditioning and mood-normalizing medication will be most effective. The third group, those who have been "taught" to carry on with the behavior (regardless of what its original causes are), can probably be taught to stop, but it will take a concerted and long-term effort for many of them. They will require counterconditioning and plenty of reward-based training.

But, again, to put these truly abnormal cases in perspective, probably 90% of coprophagous behavior is temporary, natural, and harmless--unless we as owners provide our dogs with reasons to prefer to continue the habit. Like the other "embarrassing canine behavior," mounting, it is usually only our typically human sense of propriety and aesthetics that elevates this common canine activity into "a problem."


Barry McDonald -------------------- DogSense =======================================