Intestinal echinococcosis in a dog from Missouri

We read with interest the recent report¹ of a 17-week-old German Shepherd Dog with no history of travel outside the state of Missouri in which Echinococcus multilocularis infection was documented through histologic examination of a full-thickness jejunal biopsy specimen and a PCR assay. This appears to have been the first documented case of infection with this zoonotic parasite in a dog in the contiguous United States. In previous studies,² 5 of 123 farm dogs in southwestern Minnesota were positive for E multilocularis coproantigens by means of an ELISA, and E multilocularis was recovered from 1% to 5% of farm cats in North Dakota. Echinococcus multilocularis is a well-known parasite of wild canids across the north-central portion of the United States and contiguous parts of Canada, and the fact that it is rapidly expanding its range across Canada, with spillover into dogs, cats, and humans, including possibly in urban settings, does not bode well.^3,4 Several European strains of E multilocularis have been found in Canada but differ from the one identified in this dog, indicating probable laxity in the importation of untreated foxes or dogs from Europe to North America.⁴

The case report described several diagnostic tests performed by the referring veterinarian, including a passive fecal flotation test with sodium nitrate solution for intestinal parasite eggs. However, it is not surprising that the passive fecal flotation test yielded no parasite eggs. Taenia-type eggs such as Echinococcus spp require the use of solutions with a higher specific gravity to yield good egg recoveries, and passive flotation is much less sensitive than centrifugal flotation for recovery of Taenia-type eggs.⁵ Although the dog had clinical signs for 4 weeks and eventually expelled numerous proglottids, it was not known whether the dog had a patent infection when initially evaluated at 13 weeks of age. It is possible that any eggs present at that time were missed owing to the low sensitivity of the passive fecal flotation test. Alternatively, the infection may have been prepatent; the prepatent period for E multilocularis is 26 to 30 days.

This case highlights the importance of using centrifugation and a solution with a high (eg, > 1.27) specific gravity when performing biannual fecal flotation tests as part of a comprehensive parasite control program for dogs and cats. It also highlights the importance of recognizing Taenia-type eggs as potentially dangerous. Both the Companion Animal Parasite Council and the American Association of Veterinary Parasitologists recommend the use of properly performed centrifugal fecal flotation tests to detect gastrointestinal parasite eggs.^6,7 Many studies have demonstrated that passive fecal flotation tests lack the sensitivity of centrifugal fecal flotation tests. The optimum solution for recovery of E multilocularis eggs is ZnCl₂, with a specific gravity of 1.45.³

Considering the expanding range of E multilocularis and the seriousness of zoonotic larval infection with this parasite, it is important for veterinarians and veterinary technicians to be aware of E multilocularis, especially in the north-central region of the United States and Canada, and to use appropriate precautions whenever Taenia-type eggs are seen in the feces of dogs and cats. They should also remember that Taenia-type eggs, even in the presence of large proglottids, may represent a mixed infection with Echinococcus spp.

Antoinette Marsh, PhD, JD

College of Veterinary Medicine The Ohio State University Columbus, Ohio

Brian Herrin, DVM, PhD

College of Veterinary Medicine Kansas State University Manhattan, Kan

Kevin Kazacos, DVM, PhD

Professor Emeritus Purdue University West Lafayette, Ind

The authors respond:

On behalf of my co-authors, I want to thank Drs. Marsh, Herrin, and Kazacos for their interest in our case report¹ and for providing vital information regarding flotation techniques for recovery of Taenia-type eggs and interpretation of flotation test results. We agree that it is very important for veterinarians and veterinary technicians to use proper fecal examination techniques for a better yield and to be aware that this zoonotic parasite is present in the contiguous United States. They should also be aware that in animals with intestinal echinococcosis, eggs may be shed intermittently in feces and that detection of eggs in the feces is not specific for echinococcosis, because the eggs of Echinococcus spp and Taenia spp, common tapeworms in dogs and cats in the United States, are morphologically indistinguishable.² Consequently, fecal flotation testing followed by confirmatory testing, such as with a PCR assay, is often needed for diagnosing intestinal echinococcosis. Regular deworming with praziquantel should be considered for dogs and cats that have access to wild rodents in regions where Echinococcus multilocularis is endemic.

Kei Kuroki, DVM, PhD

Veterinary Medical Diagnostic Laboratory

Department of Veterinary Pathobiology

College of Veterinary Medicine University of Missouri Columbia, Mo

Further discussion on declining wild bird populations and feral cats

We appreciate the comments from Bettinger et al¹ on our letter² concerning the role of feral cats in declining wild bird populations. However, we believe some additional clarification may be helpful.

Bettinger et al¹ correctly point out that the predation estimates we cited are based on a meta-analysis incorporating studies dating back many decades and counter with a more recent study³ showing that more cats are found in areas of dense human population where anthropogenic food sources are abundant. However, newer publications are not always better, and the small study³ cited represents the Florida Keys, whereas the earlier study⁴ includes data collected from many locations across North America over several decades. We agree that cats are more abundant in urban areas where anthropogenic food sources are available. The problem is that even well-fed feral cats kill birds and other small animals. It seems ineffectual to argue whether the number of deaths is in the hundreds of millions or billions. Bettinger et al¹ also state that “the model's estimates are incompatible with the most recent North American Breeding Bird Survey.” However, in our experience, many veterinarians involved in wildlife medicine or conservation would not agree.

Importantly, Foley et al⁵ found that for 2 large, sophisticated feral cat trap-neuter-release (TNR) programs in San Diego County, California, (n = 14,452) from 1992 to 2003 and in Alachua County, Florida, (11,822) from 1998 to 2004, there was no consistent reduction in per capita growth, the population multiplier, or the proportion of female cats that were pregnant in either county. In contrast, Bettinger et al¹ cite studies that describe modest progress in reducing cat numbers over 23 years in Key Largo, Florida, or on the campus of a single Florida university. Both of those TNR programs included extensive removal of cats, suggesting that TNR programs alone seldom, if ever, result in feral cat colony reduction or elimination and that removal for adoption or euthanasia is needed to bring the number of feral cats down.

Further, the report by Loyd et al⁶ is only one of many summaries related to deaths and injuries inflicted on wildlife by feral cats,^7–10 and there are many reports of the pernicious effects of feral cats on wildlife populations in non-island settings.^11–13

Bettinger et al¹ point to the DC Cat Count as a cooperative effort to better understand free-roaming cat populations. We applaud this effort, but would like to see greater efforts on decreasing, or at least mitigating, the killing and maiming of birds and small animals by feral cats, the feces and food waste generated by them, and the various public health risks they cause. For example, “catios” (cat patios) can be much larger than those built for pet cats. In fact, catios large enough to house feral cat colonies are possible and can protect not only wild birds and small animals but also the cats themselves, while also confining feces and parasites that affect the health of humans and other animals.

We continue to believe that the link between free-roaming cats and bird deaths is clear and that TNR programs, as typically structured, do not reduce free-roaming cat populations. The management of free-roaming cats is a complex issue that requires the integrated cooperation of population ecologists and specialists in animal welfare, feline behavior, social science, public health, and veterinary medicine. We are quite open to working with our colleagues and cat advocates to take responsible actions that can provide optimal one health solutions to the nation's feral cat problems.

David A. Jessup, DVM, MPVM

Wildlife Health Center University of California-Davis Davis, Calif

Sonia M. Hernandez, DVM, PhD

Warnell School of Forestry and Natural Resources

Southeastern Cooperative Wildlife Disease Study

College of Veterinary Medicine University of Georgia Athens, Ga

Questions of attire

I was, to put it mildly, shocked by the findings of Coe et al¹ in their recent study on companion animal owners’ perceptions of appropriate veterinarian attire. Being part of the baby boomer generation, I entered the University of Georgia College of Veterinary Medicine just as the floodgates opened for women. Jeans were not allowed. Men were required to wear neckties. Large animal veterinarians, including those on ambulatory duty, typically wore a shirt and necktie, even when they were in overalls.

Once women could wear pants in professional settings, it became more difficult to define and enforce dress codes. Nevertheless, to me, women do not look as professional as men when wearing pants. I suspect this is for one simple reason—the necktie. I am sure I am not the first person to wonder why slapping on a completely useless strip of fabric instantly “dresses up” a shirt and makes a man look more professional. I have accepted that the world is not fair.

Unless actively engaged in surgery, I have always worn a dress, blouse and skirt, or dress pants while working in a veterinary clinic. I dress the way I expect female physicians to dress. Similarly, I expect the male physicians and dentists I see to wear a nice shirt and pants and a necktie. The answer to the plea that as veterinarians, we frequently get dirty at work is, so do pediatricians. It amazes me that what the authors termed “formal attire” in the study (white blouse and black skirt for the female veterinarian and white shirt, black pants, and necktie for the male veterinarian) were ranked as least preferred by participants in the study.

Patricia Burke, DVM

Providence, RI

COVID-19 and FIP

Can domestic cats with feline infectious peritonitis (FIP) tell us something about human patients with COVID-19? Some of the more serious manifestations of COVID-19, such as stroke, heart failure, kidney failure, and Kawasaki-like syndrome, are at least reminiscent of clinical signs in cats with FIP. And, like COVID-19 in people, FIP in cats is caused by a coronavirus.

Feline coronavirus (FCoV) is a highly contagious, nearly ubiquitous virus that infects the intestinal epithelial cells of cats.¹ Most often, infection with FCoV does not cause any clinical signs. However, approximately 5% of cats develop FIP, with a mutation in the spike protein portion of the FCoV genome allowing replication in macrophages considered a possible cause.

The effusive or so-called “wet” form of FIP is characterized by effusion in the abdomen, thorax, or pericardium, whereas the noneffusive or so-called “dry” form is characterized by granulomatous changes in a wide variety of organs. Again, the similarity with signs in the most severely affected people with COVID-19 is striking. Current research on vaccination of cats against FIP is targeted at the nonmutated form of FCoV,² after years of attempts to target the mutated FIP variant.²

I hope that someone with the wherewithal and resources will use what we know about FIP to learn more about COVID-19, shrinking the number of unknowns during this time of crisis.

Stephanie Dorosko, DVM, PhD

Department of Science

Department of Veterinary Technology Vermont Technical College Randolph Center, Vt

I survived veterinary medicine

That may sound like a funny T-shirt or bumper sticker. But it's not. In November 2018, after 20 years in the profession, I left to save myself. This letter is for every veterinarian who feels stuck, trapped, or hopeless.

When I hear of veterinarians who die by suicide, I wonder what their backstory was. Was their childhood like mine? Were they expected to be perfect, to always do more? Did they grow up in a home with heightened and unpredictable negative emotions? When veterinary work activated those subconscious memories, did they share their struggle with anyone? Or did they hide behind a smile and a simple “I'm fine”?

In 2019, I looked up the definition of post-traumatic stress disorder to see whether I had the symptoms of it. I didn't. But what I did learn is that a dysfunctional upbringing that involved enmeshment, codependency, emotional parentification, and denial of autonomy affects your entire life until you do something about it. My brain was stuck in fight-or-flight mode. But I didn't know that. Had I talked to someone, it may not have taken me 20 years to figure it out. But when you become good at hiding emotionally as a child, you tend to maintain unhealthy, but previously protective, mechanisms as an adult.

I don't know what a veterinary school application looks like these days, but I think evaluating applicants for unresolved trauma and educating them on how trauma can affect the brain may potentially save a life. Trauma may not be limited to what you think it is. It's not just the big stuff. Informing applicants might cause some people to not apply. Or it might prompt people like me to figure out that being a veterinarian may not be a wise career choice unless they work to heal their issues.

If you're struggling emotionally and mentally despite being treated for anxiety or depression and your medical provider has never discussed childhood trauma with you, then bring it up with them. Because medication doesn't heal trauma and neither does time. Not all physicians and mental health providers are informed about the effects of trauma, so you may have to find someone who is.

Unresolved trauma combined with the stress of both life generally and the veterinary profession specifically may leave you with little to no resiliency or capacity to respond. I'm not a mental health professional, but I suspect this may be a key component in veterinarian suicide.

Shagufta Mulla, DVM

Independence, Ore