The dog owner who brought her terrier mix to the emergency clinic said the animal was covered with bugs. She reported that she and her children, a boy and a girl around 8 and 10, were infested, too.

The client handed a small plastic bag to the veterinary technician. The technician inspected its contents. The bag contained hair and dander, but nothing alive.

Stepping out of the exam room, the technician apprised the veterinarian of the situation and observed, “I think this woman is insane.”

That’s how Dr. Kate Brammer came to learn about delusional infestation by proxy. Coming from a family of registered nurses, Brammer was familiar with psychological conditions in people but this was the first time as a veterinarian that she’d seen a client project a pest delusion onto the family pet. It left quite an impression.

A few years later, Brammer discovered that many of her colleagues have had similar encounters. On a message board of the Veterinary Information Network (VIN), an online community for the profession, dozens of clinicians recently related anecdotes about clients who presented pets that they imagined to be ridden with parasites. Brammer shared her experience, adding, “To this day, I feel really bad for that dog and those two little kids.”

The discussion wasn’t the first on VIN about the subject. Delusional parasitosis has come up at least 20 times since 2000. The multitude of cases surfacing in the professional forum suggests that what may appear to be a rare oddball situation really isn’t, said Dr. Mark Rishniw, VIN’s director of clinical research and a visiting scientist at Cornell University College of Veterinary Medicine.

“It’s something that an individual will see very, very occasionally but a collective audience will see it substantially more frequently than is being reported (in scientific literature),” Rishniw said.

It was Rishniw who started one of the latest VIN discussions after he heard from a colleague in February about a client who believed that her entire family, including the dog, suffered from a condition popularly known as Morgellons. Morgellons patients believe fibers sprout from their skin. Rishniw asked his colleagues: Anyone else seen something like this?

The resulting flurry of posts led Rishniw to conduct a formal survey of VIN members, which drew more than 700 responses. The data are being analyzed now. Rishniw and his collaborators hope to report the findings in two scientific papers — one aimed at informing psychiatrists of the condition, the other at veterinarians who are confronted with clients suffering from the condition.

Affliction occurs around the world

Collaborating with Rishniw on the studies are Peter Lepping and Roland Freudenmann, psychiatrists in Wales and Germany, respectively. As clinicians and researchers, Lepping and Freudenmann have broad knowledge of delusional infestation. Among the studies they have authored is a review summarizing 508 publications on the topic.

The review, published in Clinical Microbiology Reviews in October 2009, documents references to delusional infestation dating back more than 100 years, and case reports from all continents except Africa and Antarctica.

Women, elderly people and those with sensory impairments are most likely to be affected, although men and women alike are susceptible to the illness, as are young and old, often intelligent and otherwise rational people.

The condition comes by assorted names — Ekbom syndrome, delusional parasitosis and Morgellons among them. Whatever the name, the condition is characterized by patients’ firm belief that their skin or bodies are beset with small, perhaps virtually invisible, pests or filaments — irritants for which no medical or biological evidence exists.

Psychiatrists have thought the condition rare but Freudenmann and Lepping found that may be because patients tend not to seek the help of psychiatrists, believing their problem is physical, not mental. In dermatological practice, by comparison, delusions of infestation aren’t rare. Several surveys suggest that most dermatologists have seen one or more cases.

Patients also consult entomologists and pest control companies, according to Nancy Hinkle, a veterinary entomologist at the University of Georgia in Athens.

Hinkle has been fascinated by the subject ever since her major professor in graduate school in Florida handed her a Baggie of debris with the direction, “Look through this and see what kind of bug you find.”

For hours, she sifted through the detritus looking in vain for a creature. They’re going to throw me out of grad school, Hinkle thought. At last she admitted sheepishly to the professor that she’d found nothing. “That’s what I thought,” he replied.

Fascinated and inspired by the incident, Hinkle applied for and received a grant from the Florida Entomological Society to survey pest control operators on whether they’d encountered clients with undetectable pests. “It turned out all the pest-control companies run into it frequently,” she said.

Some 20 years later, after speaking and writing extensively on delusional infestation (using the name Ekbom syndrome), Hinkle has become an authority in her field, which has led colleagues to refer their cases to her. Consequently, she receives three to four “Baggies full of scabs” each week. “I’ve got dozens of them sitting right here next to my desk,” Hinkle said.

Despite her expertise around the subject, Hinkle said she’s developed no tricks for helping those with delusions obtain the treatment they really need. “There’s no graceful way to tell someone they need to see a psychiatrist,” she said.

Veterinarians struggle to safeguard pets

Veterinarians are in the same awkward position, with the added difficulty of needing to protect their animal patients, whose well-being may be endangered by the owners’ delusions.

Delusional owners can hurt their pets in ways small and large, whether it’s causing an animal’s skin to become dry and itchy from too-frequent bathing, or requesting euthanasia for a non-existent problem.

In a case seen a few years ago by Dr. Margaret Hammond-Lenzer, a veterinarian in Washington state, a middle-aged man picked at larvae he saw under his dog’s skin, causing wounds to which he then applied Frontline, a pesticide that kills fleas and ticks.

“It was painful to (the dog) and it made the lesions worse, which made (the owner) pick more,” Hammond-Lenzer recounted by email. “It was a vicious cycle for awhile until I gave him some Panalog ointment to smear on the lesions (told him it’d kill the ‘larvae’ as well as the Frontline) and convinced him to just put the Frontline on the dog’s neck.”

It worked. Hammond-Lenzer said the man lives with his mother, who seems to have taken responsibility for the dog’s care. The pet is 14 and overweight, “but still ticking along like a champ,” the veterinarian reported.

Providing a benign treatment of some sort is a common technique among veterinarians faced with clients having imagined infestations. Brammer, the practitioner who saw the terrier in the emergency hospital, first examined with a microscope the sample of fur and scurf brought in by the dog’s owner.

Brammer gently told the owner she saw nothing, but suggested putting the dog on Revolution, a topical parasiticide. “Revolution will kill everything,” she assured the client.

Brammer also recommended that the client call a doctor to address her own itching. With that, the woman, her son, daughter and dog left the veterinary hospital, though they lingered on the veterinarian’s mind. She doesn’t know how things turned out. “I’m hopeful she took my advice and called her doctor,” Brammer said.

Dr. Greg Upton, a veterinarian in Texas, had a similar experience. In one of two encounters with delusional parasitosis, Upton examined a plastic bag of samples the client provided. He found only carpet fibers.

“Even faced with this evidence, he was still convinced they were leeches,” Upton related on VIN. “I printed out an article on delusional parasitosis and suggested he get professional help. That was the last time I saw him.”

Some clients with infestation delusions are not easily sent on their way. Doctors at a clinic in Minnesota struggled for months with one very persistent pet owner who imagined her poodles were riddled with mites and other bugs.

At a loss for how to handle the situation, one doctor acquiesced to the client’s demands for treatment. “He ended up treating the dogs multiple times with broad-spectrum dewormers orally, and ended up going to injected ivermectin,” recounted his associate, Dr. Ingrid Bey, who witnessed his predicament with concern. “He felt he didn’t know what to do. Sometimes we’re not good at saying ‘no.’ ”

One day, the client ended up seeing Bey, who took a different tack. Asked by the pet owner to repeat the ivermectin injections, Bey declined. “She kept on pointing to the white flecks on the dog’s skin and saying that those were bugs. So I took a piece of Scotch tape and I picked some of them up on the tape and put them on a microscope slide,” the veterinarian said. “I drew circles around them with a felt-tip pen and I had her come and look at them.”

The client couldn’t be convinced. The conversation went “sideways,” Bey said, with the client insisting the veterinarian had picked up and was inspecting the wrong thing. Caught in a circular discussion that went on for 45 minutes, Bey grasped for an argument to persuade the client that the dogs didn’t need shots. “I was starting to fib a little bit. I started talking about ivermectin toxicity, not that I felt we were really in that realm,” she said.

The owner finally left the clinic without the treatment, although not before expressing displeasure at being charged for microscopic analysis. The ordeal ended after the elderly poodles were euthanized for other health problems.

Practitioners want to know what to do

But the episode stayed with Bey. She’s thought about how her attempt to be “scientific/logical” with the client backfired. “I guess there is no logic to delusion. …” she said. “I would love to have had some better coping strategies.”

Although Bey felt her response was inadequate, psychiatrists confirm that it’s best not to yield to a client’s demand to treat a problem for which the doctor sees no evidence.

“It would be unethical and unhelpful to meet these irrational requests with the intention that the patient might learn from the lack of effect and gain insight into the nature of his or her symptoms,” Freudenmann and Lepping write in their review study. “This approach will not work, because the lack of effect is reinterpreted by delusional elaboration (e.g., ‘it was the wrong or too weak an anti-infective’). Hence, prescription of any anti-infective without clear indication is no option and reinforces the delusional belief.”

As Bey and Upton discovered, sharing negative results of an examination doesn’t dissuade a delusional client, either. “The physician should not expect that patients be ‘relieved’ by a negative finding. Instead, ‘nonfindings’ will be interpreted as ‘incompetence’ of the doctor, or patients will find another explanation to maintain their beliefs…” Freudenmann and Lepping write.

What, then, is a physician or veterinarian to do? Answers are elusive. Quoting from the first specific paper on the management of patients with delusional infestation, Freudenmann and Lepping note, “ ‘(T)here is probably no disorder in dermatology that is so difficult to treat ...’ ”

Knowing that veterinarians would like guidance, Rishniw, VIN’s director of clinical research, said he, Lepping and Freudenmann intend to develop recommendations for handling such cases. “It is a complex condition, requiring a variety of approaches. There are things we know not to do, but deciding what you should do can vary from client to client. We hope to address these issues prescriptively,” Rishniw said.

“There is clearly a role for vets in this complex problem when they may be the first people who realize that their client has a significant mental illness,” said Lepping, who, among other positions, serves as consultant psychiatrist and associate medical director at Betsi Cadwaladr University Health Board in Wrexham, Wales.

As a general approach, Bernard Rollin, a veterinary ethicist at Colorado State University, suggests that veterinarians encountering clients with mental illness be guided by their humanity. While it’s understandable that a practitioner may wish to end an appointment with a delusional client as quickly as possible, Rollins said taking the time to listen, to be kind and to try to help a client is the right thing to do.

“You do your best and you extend your area of obligation wider rather than narrower,” Rollin said. “That’s part of being a professional.”

Dr. Teri Oursler, a veterinarian in Wyoming, extended herself further than most when she personally escorted a client to the doctor. Oursler had been called several times to the home of the client, an elderly woman with a Manx cat. The woman thought the cat, herself and the furniture were infested. Oursler recounted on VIN: “Cat was normal-acting and (had) normal skin, although when he sat down to groom himself, owner was ‘See, he is all itchy.’

“I ended up taking her to the doctor, as I happened to have an appointment for myself that day,” Oursler said. “My M.D. took her in my place.”

In an interview by email, Oursler explained that she and the client happened to have the same physician. “She was more than willing to go to the doctor,” she recalled. “She was so tired of itching. … She had sores all over her arms from scratching.”

Veterinarians typically may not be willing or able to go as far as Oursler. But among medical professionals, they are in a unique position to potentially help such clients, says Dr. Frances Nicholson, a veterinarian in Georgia.

In a presentation published in the Proceedings of the 2012 National Conference on Urban Entomology, Nicholson posited, “As a cohort of the sufferer, working alongside them to help treat their ailing animal, there is a level of trust that might be taken advantage of. There’s a real possibility that we may be part of the professional community that has the best chance to reach out to that (population) that can experience successful remission of the disease.

“By simply going over the treatments done, the negative results, and the reality that all that could have been done, has been done, we may be able to reach out to them and convince them that there’s a possibility of mental illness,” she said. “ … This honest approach may help prevent euthanasia of the healthy pet and give the owner the peace they’ve been seeking. Some will never experience that peace but if we can bring it to some, we should do everything we can to recognize the disease and proceed cautiously and patiently.”