Scabies Requires Immediate Attention; Microchips the Way to Go

My son was recently diagnosed with scabies on his hand. The
doctor said he probably got it from one our pets.
Q: My son was recently diagnosed with scabies on his hand. The doctor said he probably got it from one our pets. As it turns out, one of our dogs, Barney, recently lost a lot of hair. He itches a lot, and he looks like a patchwork quilt. Our vet can’t seem to figure out why. He did a skin scrape and said that he didn’t see anything under the microscope. But when I told him about our son’s skin condition, he immediately said we should give our dog an injection to treat for the scabies. Why should we treat the dog if there aren’t any mites on his skin? I think the scabies came from somewhere else.

A: This is a tough one, but I have to agree with your veterinarian’s plan. And if you have other dogs, I think they should be treated as well. Here’s why.

Scabies is a very contagious disease that can be easily transmitted from animals to people. It’s caused by a microscopically small mite called sarcoptes scabei. This mite burrows under the skin and causes an itch that can be very intense. It also causes hair loss, which can be accompanied by a lot of flaky dandruff. These mites prefer animals as a host, but can survive on the skin of humans for a limited time. I’ve seen diagnosed cases on the hands, scalps and torsos of people.

Since your son has this condition, and since Barney has suggestive skin lesions, he has to be considered highly suspicious.

Your veterinarian did the correct testing – skin scrapes are the proper way to identify this condition. But several characteristics of the sarcoptes mite make its diagnosis and treatment a little unique.

First, it takes only a few mites to cause a dog to itch and to show changes in his haircoat. In addition, these burrowing mites can be very difficult to find with skin scrapes. A veterinarian can do as many as five to 10 scrapings and sometimes never find a mite, only to confirm the condition later with a skin biopsy. Biopsies can help with the diagnosis, but they’re invasive and expensive. So, veterinarians will sometimes use the case history and clinical appearance to make a presumptive diagnosis before treating.

In this case, your son has a confirmed condition, and Barney has symptoms that are highly suggestive. This gives you several options. Your veterinarian could do more testing including deeper skin scrapings, blood tests and perhaps a skin biopsy. Or you could choose to treat for the mite and watch to see if Barney’s symptoms clear; we call this a therapeutic trial. If he has mites, his itch will disappear quickly after treatment.

Needless to say, the second option would be less costly and much less stressful for Barney and you. Over the years, I’ve treated several cases this way, monitoring response to treatment when diagnostics weren’t entirely conclusive. The injection used to treat sarcoptes, a drug called ivermectin, is relatively safe in most pooches. It occasionally causes problems in collies and collie-like dogs, so talk to your vet about its safety. There are other alternative treatments available including a dip that can be applied directly to the skin.

There is one other very important point to consider here. Because scabies is so very contagious, I’d recommend that all your dogs be treated simultaneously. Living together, Barney and his buddy could easily pass this mite back and forth. And even though your other dog might not show any symptoms, he could have the mites on his skin, and easily re-infect Barney and perhaps your son at a later time. So be sure to ask your vet to treat both dogs at the same time to eliminate the chance for this disease to resurface later on. That way, you’ll get rid of the itch for good.   

Q: How important is a microchip? I hear that many people have these placed in their pets, but I wonder what benefit they have. Is it worth the pain and expense?

A: Good question – and one that is asked often. The microchip is a very small device injected under the skin of a pet so that a scanner can read its number when passed over the pet’s shoulders. A chip provides permanent identification and works anywhere because the number is kept in a national registry.

The benefit? Let’s say your pet is lost, either in your neighborhood, or worse, when you’re traveling in another state. If someone finds him and takes him to a shelter or veterinary hospital, the staff will be able to scan and identify and return him to you within a very short time.

Before microchips, most of us relied on ID tags on the collar. But if those were lost, they were useless. Some dog owners had their pooch tattooed for identification. But most people know little about tattoos and don’t even look for them on a stray dog. And there is no national registry for tattoo numbers .

All in all, the microchip is the best method for permanently identifying your dog or cat. The procedure is relatively inexpensive, and while the needle used to inject the chip is somewhat large, it causes very little discomfort. Most patients don’t even know they’re getting poked if they have a cookie to chew during the procedure. I recommend microchips for everyone who wants a little more peace of mind for the safety of their pet.

Pete Keesling is a veterinarian at San Martin Veterinary Hospital. He writes a bi-weekly column for South Valley Newspapers. If you have questions about pet care, e-mail them to sm****@***oo.com or mail them to Lifestyles, 6400 Monterey Road, Gilroy CA 95020.