Working with a dog who behaves inconsistently -- walking well on leash one day, exploding in fury at the sight of another dog another day, for example -- can be frustrating, to say the least.
Having success one day and not another is pretty typical when dealing with complex issues such as reactivity. Many variables affect behavior, including the dog's mood, recent events, environmental stimuli, even diet.
So I advise my clients to expect this type of inconsistency, especially when working with fearful or anxious dogs.
It's important to work with the dog you have now, in this moment; not the dog you had yesterday (or last year), or the dog you think you have (or hope to have), or even the dog you expect to have in the next moment.
And that dog can change moment to moment -- for the better if you're doing things well and for the worse if your timing's off or you're not reading the dog well or external factors intrude.
So observation and flexibility are key.
Analysis of past sessions is also key -- if you take a look at what you were doing, how the dog was responding, what changes there were in the environment, etc. you'll be better able to set future sessions up for success.
Learn to read the body language and emotional state of the individual dog you're working with really well. This will take some education on your part. There are some good books and videos out there on learning to "read" Dog. I've reviewed a couple on my website although I have several others I haven't reviewed yet that are also really good. You can find them in Dogwise's "Behavior/Body Language" category.
But mostly it will take practice. Observe your dog (videotape is great!), but also observe every dog you come across.
And by "observe" I mean put on an ethologist's hat, noting behavior and body position but not trying to put a label or interpretation on it at first.
Train yourself to notice things like lip position and relaxation or tightness, breathing, facial expressions and the minute changes in facial muscles, minute changes in eye shape and especially pupil shape and size, and other really tiny signals.
But also pay attention to the overall picture -- the center of gravity (is body weight shifted forward or back, or centered), whether the dog's straight lines and right angles or curves and soft angles and bent joints (especially elbows), etc.
And all those shift from moment to moment.
Once you get good at actually seeing those things, able to focus on specific body parts but also see the picture as a whole, you'll begin to be able to make judgments about the dog's emotional state of mind and possible thought patterns.
That may sound difficult, but it's not really -- it just takes education and practice.
For that, I recommend using the "Dog Body Language 101" information from the Dog Scouts of America: http://www.dogscouttroop107.com/BodyLanguage101.html
Record a session of "The Dog Whisperer" and watch it with the sound turned off, focusing on the dogs.
Make liberal use of the "pause" and "slow" buttons.
Note down every behavior & body posture & expression that you can match with anything from the Dog Scouts' Dog Body Language 101 list.
Also note down anything in the environment that you can see that may be affecting or causing that particular behavior/body language. Pay special attention to where the dog's focus may be. (And sometimes that "focus" is actually the very thing the dog's trying studiously to ignore or tune out.)
Since Cesar Milan works with so many different dogs with so many different issues, his show is great for learning how to read dogs -- especially confused, stressed, anxious, fearful, frustrated, or angry dogs.
When you've "translated" the dogs' narration of one or two of his shows in slow motion, try doing it at regular speed.
If you can make these observations without getting yourself all stressed out (this will get harder the better you get at reading the dogs on Cesar's show, as you'll become keenly aware of the stress some of his techniques can cause), it's a good idea to "translate" as many segments with different dogs as you can.
Then start doing the same in real life situations (observing your dog and other dogs) -- although of course you're not likely to have a "slow motion" feature.
This will help you develop the ability to "read" dog body language on a conscious level while educating your subconscious mind as well. With enough practice you'll stop noticing the "left brain" logical, detailed observations and start feeling the "right brain" intuitive observations -- which is when you can truly make real-time observations with an educated "gut feeling" that is probably the closest anyone can come to truly understanding what dogs are "saying."
And then, if you need to (as I often do with clients), you can point out the specific postures, expressions, movements (or lack thereof) and behavior that led to your conclusion.
"Conflicted" dogs are difficult to read, because some of their body language says one thing while other body language says something entirely different. These are the dogs that you really need to be flexible with, dancing around the line of their conflicts, reinforcing the body language you want (which will affect emotion) and trying to change emotions to something closer to what you're hoping for (which will affect the body language and behavior).
Once you're good at reading the dog, you'll be able to easily tell when it's time to raise criteria (decrease distance or increase distraction or whatever):
When the dog's easily handling the current situation. :-)
And don't be afraid to take a step back if you overstep and raise criteria too quickly! Shifting back immediately will be far more productive in the long run than trying to "push through" the next step if the dog's not ready for it.)