999. No smoke without fire: No scabies with mites

"My dog scratches her face vigorously, non-stop last night," the lady with red eyes showed me a young Shih Tzu with bright red cheek, ear and eye areas. "Is she suffering from an allergy?" Her friend had brought her in to Toa Payoh Vets on this fine Saturday morning, May 12, 2012.

I was present from 9 am as I was conducting a "trust and audit" process on Dr Jason Teo. This is part of effective management of a licensse to ensure a high standard of veterinary care and to rectify errors and ommissions of the practice.

"I remember your case," I said to the friend as I fished out the card assuming that the affected dog belonged to the introducer. The lady with the red eyes said: "I just want a second opinion. For the past one and a half week after treatment by Vet 1, my dog is not getting better. She is still very itchy and her skin is full of red sores."

I put the dog on the examination table and viewed the records and medication of Vet 1.
"Most likely, your dog has scabies," I pointed to the crusted lumps on the ear edges. "Just like your friend's dog I treated some 4 weeks ago."
"No," the lady with the red eyes showed me a bottle of an anti-fungal liquid medication which stated "for cats",  an ear drop bottle and an enzyme-based shampoo. "Vet 1 had written in the case sheet - no sarcoptic or demodectic mite seen. She said my dog has malassezia inside the ears." Vet 1 had confirmed by staining."

"It is possible that your dog has malassezia, a yeast infection." I said. "Negative skin scrapings do not mean there are no scabies. After all, your friend's dog, the sibling of this dog, had scabies."

"It is not possible as our dogs don't meet." she said.

"Scabies can be transmitted by owners' hand. Did you touch her dog earlier?"

"Yes, kiss and hugs."

"So your hands could have transmitted scabies mites to your own dog. When did you touch your friend's dog?"

"One to two months ago."
"How is the scabies dog now?" I asked the friend. "Do you remember seeing one scabies mite under the microscope?"
"Yes," the friend said. "My dog is fully cured now. I complied with all your instructions."
"Normally it will take 2 weeks and one injection to recover," I said.
"My dog recovered in 1 week as the hair grew (back on the ear edges)."

So, now I have to prove that this lady's dog has scabies. I asked Dr Jason and Mr Min to do a few skin scrapings. "Make sure it is deeper. There is no need to use oil. A drop of water will do." So both took the dog back room and produced a skin scraping as the case was Dr Jason. 

I examined the skin scraping. There was no scabies mites.
"I can't find any mite," I said to the lady. "I will have to do a deeper skin scraping to look for the mites." The lady cringed at the thought of drawing more blood from the ear edge skin scraping as she could feel the pain of her young dog.
Dr Jason shook his head when I told him there was no mites seen from the ear crust. "No mites, no scabies." Simple as that. "It could be ear trauma."

Yet the clinical signs of intense itchiness of the face, cheeks and ears over one and a half weeks meant some mites burrowing. The elbows and hocks were reddish and hairless. The backside had several ringworm like patches. So, there was some pathogens. Malassezia and ringworm medication was given and there was no improvement.

"Is the anti-fungal medication bottle that states 'for cats' safe for use in dogs?" the lady with red eyes asked me.
"Well, the liquid medication in the bootle is not produced by the drug company for dogs. So, it is marketed for cats. However,  the dog can take the medication if given appropriate doses."

The problem is that the young female dog is still scratching intensely.

On second thoughts, I reviewed the slide again instead of doing another skin scraping. Hoping against hope.  And there, a fat looking squarish mite was moving his six claws under the slide!
The owner saw it under the higher power. I got the power to the lower one and the mite was distinctly seen.

So, there was proof of scabies.

No smoke with fire. No scabies without scabie mites. I could find only one. But that is sufficient as it is sometimes very difficult to find them. Unless the skin scraping is deeper as the mites burrow under the skin.

Once the diagnosis is there, the treatment is routine. However, this sibling seems to have some systemic disease like hormonal disorder as the whole body is affected, except for the trunk. I needed a blood test and the owner consented. This may not be a simple case of scabies and malassezia. It may be related to a poor immune system or hormonal imbalance like  an early stage of "polycystic ovary syndome."  It is hard to say at this stage as more tests can be expensive. Two siblings. One had scabies only on the ear edges. This one had the whole body infested with skin disease. Why?