Vet Dermatology Q

~2yo, 7# Havanese runt (litter of 4 by primagravida) w/ h/o bots @ ~12-13wks extracted w/o complication & microdontia, @ ~22mo, was noted to have a 1.5cm diameter patch of alopecia w/ slightly elevated, freely movable pale area w/in, that feels cartilaginous. The area is non-tender, non-pruritic & there are no behavioral or other noted changes other than usual development /learning. Normal I/Os, on Diamond Naturals Small Breed Puppy [just overbought]. DDx🧐:

• Congenital hypotrichosis due to an ectodermal defect (tx sx PRN) 🤔maybe? ie a developmental error like a human teratoma? Theory jives w/ the microdontia I happened upon.
• Watchful waiting 👀⏳or
• Enough ABCDEs for a biopsy (neoplasia?! Ca?!🫣)?
• level of urgency?
• need specialist tx? (skip GP & go👉🏽 straight to University?)
• What else does it look like?
• Potential prognoses?
• Or it's nothing... quit being a hypochondriac🤓 by proxy, put away the Merck📖& get a life!

🙋🏻‍♀️Help 🙏🏽Please?! 👩🏽‍⚕️Advise? ❤️THANK YOU❤️!!! Téo the foster failure service dog 🦮 & his anxious human ~22mos (note phone charger cord lower left, for scale), RT flank just in front of haunch

Hello - and thank you for this interesting case.  Please could you give me some context?  You provide a veterinary-style description of a lesion including some suggested differentials, although there doesn't appear to be a full differentials list; I assume that the vet has reccommended a plan which may involve investigations to distinguish between the various possibilities?   What is happening at the moment with this case?

My own thoughts are that there may be a range of potential causes, from ringworm (which usually has a wider cause) to demodex to self-trauma for pain or stress reasons.  Your vet should look at the wider context and help you to put this case into perspective, reccommending tests as necessary and usually starting with the more likely, common or easily ruled-out possibities.   Teratomas are quite rare although I would never rule one out over the internet.

We haven't 🙄 gone to the vet yet. The plan (such as it is) is to go when something else comes up with any of the animals & bring T along. We have an appt next wk. I hatched the above concoction in my own (human medicine trained) head.  Given that the bald spot:

1. doesn't seem contagious (yet) as our 3 dog nights (& day) as a pack have not yielded any other such patches the last couple months or so;
2. The bald patch is solo, besides having no mates on other close household members, no others have made themselves known on Téo either. It doesn't appear to have spread in the past couple + months on Téo, yet...
3. was an incidental finding on a long haired, non-shedding dog (read: requiring much regular grooming), and shows no sign of bothering him at all - no itching, no pain, no change in movement or activity level, no change in diet or sleep habits or any other behaviors noted (other than he seems to be occasionally letting me bring him in the house @ night, likely only when he's exhausted)
4. Téo leads quite a carefree, fun-centric life. The most traumatic events since his weaning have been baths (like he's melting & shrinking!) and coming inside (maybe going anywhere...?) by anyone else's (esp mine) will.
5. feels somewhat cartilaginous in an area that shouldn't have anything cartilaginous
6. the microdontia (poor wee thing couldn't chew even the tiniest sliver of any type of chew, even puppy chews) happens to fit the teratoma theory. The deciduous molar I happened to find was tiny compared to a 1/6 sliver of a teeny Greenie & the smallest size safety pin & the apple logo on the phone back (see photo). And it had a hole in lieu of a center, like a volcano.
7.  I believe the pinkness is the pink skin of a pink dog with white hair, just as my Carmen was.

this bald spot doesn't seem contagious,  traumatic or stress-related 🤔. I do recall being told many, many times "When you hear hoofbeats..." I think I investigated, put the information together, and did a layman's job of researching best match possibilities (rather than ruling out the most likely first) only to find myself on safari in 🦓Namibia 🤷🏻‍♀️ rather than @ the 🏇Kentucky Derby. By way of example: I had thought the 'puncture wounds' @ ~ 13wks were due to his brother rough-housing, as they wrestled most of their waking hours. In retrospect, it was curious they never bled, and I never heard him complain about being bit (being their only guardian). Only when the inhabitant wiggled, did it occur to me that they might not be puncture wounds, but even then, I didn't know if the wigglers took advantage of pre-existing holes or if they were causal.  I didn't even know such a creature existed in North America, somehow I had an idea in my head that botflies were tropical, S. American or African, ie zebras, but I only recalled the name, not the gruesome life stages. Téo seems to attract zebras 🦓. Thoughts? Otherwise, more after Tues pm....