Calling all vets -- What is this rash on my dog?

Hey everyone,

I have an appointment with my vet tomorrow, but I’d like opinions on what this rash might be. She has two of them, but they look very similar so I only took a picture of one. Any ideas? Ringworm? Eczema? Other fungus?

Yes, she is hairless, and yes, that is acne. Her breed (Xoloitzcuintle) is predisposed to it, especially when her previous owner fed her fatty table food and never bathed her.

TIA!

–FCOD

I’m no vet, but it looks like ringworm to me. Got it from the library patrons once.

Ringworm!!! Got it from the cats at the shelter once. You can catch it, too. Get thee to the vet, and stock up on Tolfanate for yourself. Highly contageous for other animals, too - do you have any?

Heh…yeah we have her four puppies…two rats…a ferret…a turtle…a bird…

I’m guessing the turtle and bird are safe…

–FCOD

Is it a rash that itches or an itch that rashes. IOW, was the dog scratching, leading to dermatologic change, or was the dermatologic change present prior to it being pruritic?

My guess (without a complete history) is a superficial pyoderma on the verge of being a deep pyoderma. Or, your veterinarian may call it a traumatic moist pyodermatitis.

It looks way too inflammatory to be ringworm, although I typically do a fungal culture on lesions like these.

She does have a tendency to scratch herself a lot. We try to keep clothes on her all the time because she has scratched herself raw before. On the other hand, one of the rashes is on her rear leg, and I think it’d be hard for her to scratch there.

What is a pyoderma?

–FCOD

Bacterial skin infection. Imagine what would happen if you had an itchy mosquito bite, and then took a day off of work just so you could sit around and scratch at it. The scratching damages the skin, normal skin flora bacteria multiply in the changed environment, and any primary skin lesions are obliterated.

Of course, your veterinarian can do a bunch of hands-on things to come to his/her diagnosis, including skin scrapings, acetate tape preps, etc.

Thank you. I moved the appointment to this afternoon because it turns out I am not busy like I thought I would be.

I thought the rash looked a little redder and not quite as “ringy” as pictures of ringworm I’ve seen. The only weird thing is I don’t know how she would have scratched the spot where one rash is, but then again she’s a stubborn little beast who loves to scratch/lick herself.

I will let you know what my vet’s diagnosis is!

–FCOD

That would be great.

The thing about dermatophytosis (ringworm) is that the organism does not do well in inflamed skin, which leads to it “moving” away from the bodies inflammatory response, creating a ringed appearance. In fact, an old time remedy for cows with ringworm was to apply a caustic agent to the skin, creating so much inflammation that the dermatophyte could not survive. Ouch.

The vet said it’s possibly ringworm, but she thinks it’s bacterial. She used some kind of light to look for the fungus, but said that even though she couldn’t see it glowing doesn’t mean it’s not there. She did take some scabs to do a fungal culture, but that takes up to two weeks.

–FCOD

The light is called a Wood’s Lamp.. In my experience, most ringworm that I see in dogs is Microsporum canis. Anywhere from 1/2 to 3/4 of all cases will fluoresce. It is a good screening tool.