The Diagnosis Is In: Jasmine Has An Interdigital Cyst

The wait for Jasmine's appointment felt endless. But the circumstances were such that it had to wait till Friday afternoon.

I did send the photos of Jasmine's swelling and the lump found on the toe to her vet and we talked on Thursday morning.

He reviewed it all and said that it looked like interdigital cyst to him.

(Actually interdigital cyst is a common way to refer to this kind of bump, though technically incorrect. Generally, a cyst is a fluid/semi-fluid filled sac. An abscess, in comparison, is filled with pus. An abscess is formed when foreign organisms are attacking the tissues. What is referred to as interdigital cyst is really an interdigital furuncle, in other words, a boil.)

Either way, it was a relief to hear. This would not pose any immediate or future serious threat.

Interdigital cysts are quite common and we kept our fingers crossed that's what it was. I did some research into the subject and there were couple things that worried me.

1. I didn't find any mention of associated swelling
2. There seemed to be no evidence of pain or lameness (these are supposed to be painful and cause lameness)

Of course this thing is pretty tiny compared with photos I found online, so perhaps that's why the lack of evidence of pain.

The swelling, though, kept worrying me.

No mention of a swelling resulting from interdigital cyst anywhere I could find, while mast cell tumors do have the ability to cause swelling. They don't seem to look the same, but pretty darn close, particularly when you're looking at something very tiny. All reference photos of either condition feature large lumps. And I still havd to wait before we could find out.

VetLive:  I have never seen edema caused from a cyst but if it is irritating her body enough then I can see the logic there.

I was a basket case.

I kept checking the lump, which seemed unchanging, and staring at the swollen leg. The more I was staring at it, the more swollen it seemed ...

The lack of any other symptoms was somewhat comforting.

I did look up potential causes behind an interdigital cyst, several were possible. I was leaning toward either ingrown hairs or foreign body, or yeast infection. I did notice that Jasmine's feet smelled kind of salty (for lack of better interpretation of what I was smelling)

I didn't really feel that allergies would be behind this, I keep saying this all the time but it's true--Jasmine is not an itchy dog.

I found that typical treatment would be Cephalexin (antibiotic used to treat skin infections), along with topical treatments. That would be good, Jasmine was on Cephalexin in the past with no adverse effects.

I found out that the most useful diagnostic tests include skin scrapings (for mites), impression smears, or fine-needle aspirates to confirm the presence of an inflammatory infiltrate.

Source: Merck Veterinary Manual

I wanted to be sure we know exactly what we're looking at.

I wasn't certain whether we could do an needle aspirate on such a tiny thing, but I made a list of all the things I wanted to do to confirm anyway. I really do feel sorry for Jasmine's vet.

Finally we made it to the time of Jasmine's vet appointment.

The diagnosis is in: Jasmine indeed has an interdigital cyst, secondary to Malassezia infection (yeast).

So now I know what that salty smell means.

This was confirmed by physical examination and cytology results. We also sent some of it to the lab for further bacteriology.

All four feet are actually affected by the yeast infection, possibly some virulent strain than Jasmine had previously encountered. The vet was asking whether Jasmine met any new dogs; well, she didn't meet them per say but there are a lot of new dogs in our complex now...

The rest of Jasmine's body is infection free, the vet check her all out inch by inch.

The treatment, as I suspected, is Cephalexin and antifungal shampoo.

So I guess I should be able to breathe again. Still obsessing about the swelling, though, so I hope it'll go down some time soon. Of course it would go down faster with steroids but my gut tells me that is not a good idea. So unless things get worse, I'd rather stay away from that.

When I shared the results with VetLive, I realized that I really was not overly paranoid about the mast cell tumor at all.

VetLive: I am SO glad it's not a mast cell tumor! She really has the worst luck so I was hoping it would not continue to this. Some of the sweetest patients have the worst health luck, if there is such a thing.

I was paranoid alright. I even fasted Jasmine prior the visit, just in case she needed any diagnostics or treatments that would need her fasted.

I trust our vet 98%. But the remaining two are enough to drive me out of my mind in a case like this.

And the long wait only fed my worry. I figured that combining his expertise with the cytology results we can be reasonably sure that it indeed is the interdigital cyst. I was glad to get a confirmation.

VetLive: Mast cell tumors practically scream their names on a slide.

So that ought to be enough even for my ever-worrying heart. 

The swelling still bothers me, so hopefully it's not going to be there for much longer.

Jasmine's birthday is coming up next Friday, I so hope she can enjoy it fully with nothing bothering her.

Related articles:
Jasmine's Mysterious Swelling And Another Experience With VetLive

Jasmine's Acute Lameness
Jasmine Doesn't Like "Doing Time"
Our Of Jail Free Pass
When It's Looks Too Good To Be True … The Lameness Returns
The Day Of The Treatment
First Time For Everything: A Healing Crisis(?)  
From Zero To Sixty In Four Days: Stem Cells At Work
The Calm After The Storm 
If It Was Easy, It Wouldn't Be Jasmine
This Is What Jasmine's Episode Looks Like
Gotta Try Everything Once (Or Twice): On The Quest To Figure Out Jasmine's Episodes 

***
Meet Jasmine
I'm Still Standing! (Happy Birthday, Jasmine)
How Dogs Think (Well, Jasmine Anyway)
How The Oddysey Started: Jasmine's ACL Injury
Jasmine is Vet-Stem's poster child!
Rant About Quality Of Life Versus Quantity, And Differential Diagnoses
Jasmine Is Headed For Her Next Stem Cell Treatment
Jasmine's Stem Cells Are In
Arthritis? What Arthritis? 
Guess Who Is An Ever-Ready Bunny And Really Liking The Bit Of Snow We Got? 
Don't Knock It Until You Tried It: Animal Chiropractic 
Jasmine's Fur Analysis
Back At Chiropractic Care

Further reading:
Jasmine’s Story: Can Chronic Diarrhea and Soft Tissue Injuries be Normal?
Jasmine’s Story: An ACL Injury and a Cancer Scare
Jasmine’s Condition Deteriorates: Another ACL Injury and an Abdominal Abscess
Jasmine Recovers from Surgery and Jana Discovers TCVM
Who’s Minding Your Pet’s Health?
Pet Owner Perspective On Stem Cell Therapy
Difficult to Manage Lameness Treated with Physical Therapy
Our Journey to Traditional Chinese Veterinary Medicine