I am not a gecko doc. Actually, I was excited that I remembered how to pick the darn thing up, let alone complete an even cursory examination.

My reptile elevation elation may have contributed to my plummet into The Red Herring Trap (RHT). The RHT is an insidious thing; it looks like a clue, but it is actually a secret agent whose mission is to lead unwary diagnosticians down a dark and twisty path.

In my case the RHT snuck into an already crowded Monday morning in the form of a favor request from a friend. The RHT is an opportunist, striking when the victim – I mean veterinarian – has low resources.

Early morning gecko texts from frantic mothers don’t lend themselves to clear thought.

“Can you come take a look at M’s leopard gecko? He thinks he cut its toe when he was trimming its nails.”

After warning my friend that there was a good chance I’d be forwarding her and the gecko straight to a reptile vet – without passing GO or collecting $200 – I biked over, contemplating gecko toe trauma.

Like many before me (including practitioners I have been with), I got caught up in one aspect of the patient’s history and missed the bigger picture.

As I held the little lizard, I noticed that he was gripping my hand with all digits but one. Despite the lack of obvious wound or tissue discoloration, I decided that the toe must have been crushed by the clippers – squishing nerves and blood vessels.

Based on that conclusion, I sent my friend (with gecko) to seek a veterinarian with familiarity with reptile toes rather than ungulate hooves.

Had I not been led astray by scarlet fish in the guise of nail clippers and frantic mothers of 4th graders, I would have noticed the same thing upon exam as the reptile vet. There was no trauma. No damaged tissue that would indicate crushing. There was also no bone.

Yep. No bone.

The gecko had a birth defect. He never had a normal toe. It just happened that the first time anyone noticed was when my daughter’s classmate was trimming the nails.

Forehead slap. The Red Herring had caught me.

When fishing for information, it’s hard to know when you first reel in the net what’s a keeper and what to throw back so you don’t stink up the boat…I mean diagnosis.

Getting – and reporting – a good history on an animal sometimes feels like falling down a rabbit hole laced with thorns and psychadelics: nowhere safe to turn and you can’t always trust what you think you know.

The trick, sort of like falling down the aforementioned lagomorph hallucination tunnel, is to pay attention to all of the points without getting too hung up on any one thorn.

Human memory and observation are notoriously wonky. There is a reason eye-witness identification of suspects is considered unreliable. And the more people involved in the telling, the less likely that the story will come out straight.

“When did your horse start limping?”
“Last week. Right when we pulled up after the race.”
“No, remember? He was kinda off in the pasture a month ago.”
“Yeah, but he got better. Wait. He was fine after the race. It was when we unloaded him from the trailer; he slipped on that gravel and came up limping.”
“No. That was just the ground. I think it was after that new guy trimmed him a couple weeks ago.”

That conversation usually continues for a few more time-traveling rounds. The following factors are guaranteed to increase the convolution:

1. The participants are related. Bonus points for marriage or multiple generations.
2. One participant only recently became involved in the animal’s care.
3. The participants are currently fighting about some other issue linked in some weird way in their minds to the animal’s condition (e.g. the dinner they had the night after the rodeo where the horse may or may not have started limping.)
4. One or more of the participants feels guilty and is offloading that guilt. College students returning home to a family pet are notorious sources of historical red herrings.
5. The financially responsible person and the person doing most of the care do not live in the same body.

Red herrings love complicated histories. The more confusing the history, the greater the likelihood that all the people involved will seize on and stick with the most prominent feature in the story to keep from drowning in details.

Here’s another example:

“He’s always been a picky eater. Well, not really picky, he likes liverwurst and alfalfa sprouts. But not the liverwurst from the deli down the street. Well, he did like it, but not since they changed butchers. Anyway, he has this rash. But it wasn’t there last week. It started about a year ago. We put some ointment on it that we got from our friend’s neighbor who rescues water buffalo. We think he might be allergic to it, though, because he started throwing up and doesn’t eat his liverwurst. It all started after the man with the green hair and clown nose chased us down the street.”

“Aha! Did the green-haired, clown nosed man touch him?”

“Well, before he chased us, this tentacle thing sort of shot out of his forehead. I thought it went straight up, but it must have touched Fluffy. Otherwise why would he hate liverwurst now? And the rash!”

Before you know it, the veterinarian is researching alien tentacle-induced liverwurst loathing and Clown Attack Trauma Syndrome, and everyone has forgotten the other parts of the history.

The Red Herring cackles with fishy glee.

So how do we snag the Red Herring and cast it back into the Sea of Irrelevance?

It’s important to look at the entire catch – whole history and physical exam when fishing for a diagnosis. If one piece of the history doesn’t fit with the other evidence, for instance the nail clipper incident without skin trauma, there is a good bet it’s your Red Herring.