Taenia crassiceps Cysticercosis in a Wild Muskrat and a Domestic Dog in the Northeastern United States

Abstract

Taenia crassiceps is a parasite of wild canids and dogs that serve as definite hosts, harboring the adult cestode, whereas rodents are the intermediate hosts in which the metacestode/cysticercus/larval stage occurs. Fecal-oral transmission ensures the parasite’s lifecycle. At times, dogs and humans act as accidental intermediate hosts. Despite the public health concern this parasite warrants, its epidemiology remains unclear. In this report, we document the occurrence of metacestodes of T. crassiceps in a muskrat (Ondatra zibethicus) and a domestic dog from the northeastern United States, a development that necessitates increased awareness and surveillance to tackle this disease of “one health” significance. Taenia crassiceps cysticercosis was confirmed in an adult male muskrat in February 2018 and in a 4-year-old female spayed Staffordshire Bull Terrier in December 2020. Parasitological and histopathologic examination of both cases revealed cysticerci with the characteristic rostellar hook morphology that aided in Taenia species identification. In the muskrat case specifically, partial sequencing of the mitochondrial cytochrome oxidase gene confirmed the species identity as T. crassiceps. We report T. crassiceps occurrence in a muskrat in New York State for the first time and document a case presentation in a domestic dog from New Jersey that was infected with metacestode stages of this parasite. Given the detection of this parasite in the northeastern United States, T. crassiceps infection, which otherwise is considered a rare disease, should be on the radar of veterinary, medical and wildlife biologists for timely diagnosis and interventions.

Pets, Wildlife and Parasites

“…Taenia crassiceps is a parasite of zoonotic significance, as humans may act as accidental intermediate hosts [14][15][16]. The article by Zhang et al [17] documents the occurrence of cysticercosis caused by T. crassiceps in a muskrat (Ondatra zibethicus) and in a domestic dog from the northeastern United States (New Jersey). The infection was identified via parasitological and histopathological examinations in both cases, while in the case of the muskrat, a molecular identification of the parasite species was also performed.…”

“…The infection was identified via parasitological and histopathological examinations in both cases, while in the case of the muskrat, a molecular identification of the parasite species was also performed. Cysticercosis caused by T. crassiceps in dogs had already been described in the same area, but it was considered a rare disease; the first description of muskrat infection in the area, by Zhang et al [17], suggests that veterinarians and medical doctors should increase their awareness regarding this parasite in order to achieve timely diagnosis, interventions and surveillance, in relation to the "One Health" concept.…”

Comprehensive Diagnosis, Treatment, and Outcome of Taenia crassiceps Cysticercosis in a Ring-Tailed Lemur (Lemur catta) from a Croatian Zoo: No Longer Unusual?

“…Natural infections with T. crassiceps have also been described in arctic foxes ( Vulpes lagopus ), sand foxes ( Vulpes ferrilata ), wolves ( Canis lupus ), golden jackals ( Canis aureus ), raccoons ( Procyon lotor ), raccoon dogs ( Nyctereutes procyonoides ), wild cats ( Felis silvestris ), stone martens ( Martes foina ), domestic dogs ( Canis lupus familiaris ), and cats ( Felis catus ) (reviewed in [ 17 ]). Although rodents and rabbits are primarily intermediate hosts, numerous other mammals, including humans, can also harbour the larval stage [ 6 , 17 , 18 , 19 ]. In intermediate hosts, upon ingestion of a taeniid egg, an oncosphere, also called a hexacanth embryo, hatches from the egg, penetrates the intestinal wall, and migrates through the bloodstream or lymph flow to the tissues or organs of predilection, such as the subcutis, muscles, and body cavities.…”

“…As a consequence, severe cysticercosis can develop in intermediate hosts, leading to a fatal outcome. Several studies reported that carnivores such as dogs, cats, and foxes can also develop cysticercosis caused by C. longicollis , presuming that immunocompromised status was the main cause of disease occurrence [ 19 , 20 , 21 , 22 , 23 , 24 ].…”