Cerebral cysticercosis in a woodchuck (Marmota monax)

Subcutaneous Taenia crassiceps Cysticercosis Mass Excision from an 11-Year-Old Mixed-Breed Dog

An 11 yr old mixed-breed dog presented with a 2 × 3 cm semimovable subcutaneous soft-tissue mass overlying the right hip region that grew to 8 × 5 cm over a 6 mo period. Two separate fine needle aspiration cytology samples showed marked pyogranulomatous inflammation with no cytologically apparent infectious etiology or neoplasia. Computed tomography imaging revealed a well-marginated, heterogeneous, contrast-enhancing soft-tissue mass extending into the adjacent fat, suggestive of neoplasia. A 14G needle biopsy showed similar chronic inflammatory changes without evidence of neoplasia or infectious etiology. Excisional biopsy of the mass was performed, and ex vivo sectioning revealed Taenia crassiceps cysticerci. Histopathology confirmed severe chronic pyogranulomatous cellulitis and myositis with intralesional cysticerci. Anthelmintic treatment was administered postoperatively, and no evidence of local recurrence has been noted as of 6 mo after the operation. To our knowledge, this is the first case report describing the cytological, histological, cross-sectional imaging characteristics and treatment outcome of T crassiceps cysticercosis in a dog.

First report of pulmonary cysticercosis caused by Taenia crassiceps in a Cape fur seal (Arctocephalus pusillus)

The cestode Taenia crassiceps parasitizes in the intestine of domestic and wild carnivores, especially in red foxes. Usually, the metacestode stage, also known as Cysticercus longicollis, is located in muscles, peritoneal and pleural cavity of wild rodents. In this case, larval stages were found in a female Cape fur seal, which lived in a German zoo since June 1998. In January 2019, the animal presented clinical signs in terms of inappetence and reduced mobility and, within a short time, it developed dyspnoea and died. Pathological and parasitological examinations were performed. In a large mass of the right thoracic wall and in nodular lung lesions, metacestodes with numerous protoscoleces were identified. Morphological and molecular analyses led to the diagnosis of a Taenia crassiceps infection. Probably, the urban fox population was the source of infection. Thus, regarding the zoonotic potential of this cestode, a regularly performed parasitological examination of pet dogs is recommended.

TAENIA CRASSICEPS CYSTICERCOSIS IN A NILGIRI LANGUR ( SEMNOPITHECUS JOHNII)

  A captive-born adult female Nilgiri langur ( Semnopithecus johnii) developed an edematous swelling of the left thigh and a firm mass around the right ankle joint. The animal also suffered from lethargy and anorexia and was euthanized because of poor general condition. Necropsy revealed that the skeletal muscle of the left thigh had been replaced by a multilocular cystic mass containing numerous sand-grain-sized whitish structures. Small cysts were also present in the lung and the myocardium. The mass of the right ankle joint was histologically consistent with a myxosarcoma. In contrast, the cystic masses from the left thigh, the lung, and the myocardium represented metacestode tissue with evidence of numerous larval cestodes consistent with cysticerci. Cysticerci showed morphological characteristics of Cysticercus longicollis, the larval form of Taenia crassiceps, which was confirmed by genetic analysis. This is the first documented case of a Taenia crassiceps cysticercosis in an Old World monkey species.

Fatal pulmonary cysticercosis caused by Cysticercus longicollis in a captive ring-tailed lemur (Lemur catta)

Here we describe fatal pulmonary cysticercosis caused by Cysticercus longicollis, the larval stage of Taenia crassiceps in a 15-year-old female ring-tailed lemur (Lemur catta) from Sarajevo Zoo. After sudden death, the lemur was subjected to necropsy and large multicystic structure, subdivided with fibrous septa and filled with numerous translucent, oval to ellipsoid bladder-like cysts (cysticerci), almost completely replacing right lung lobe was observed. In addition, numerous free and encysted cysticerci were found in the thoracic cavity. Histopathology revealed connective tissue outlined cavities that compress lung parenchyma. Each cavity contained several thin walled cysticerci with single inverted protoscolex, one or more suckers and rostelum with two rows of hooks. In many of the cysticerci one or several exogenous buds of daughter cysticerci were observed. Based on morphology and microscopic appearance the parasite was identified as C. longicollis. Subsequent molecular analysis and sequencing confirmed presumptive diagnosis. To our knowledge, this case represents the first report of T. crassiceps and cysticercosis caused by C. longicollis in Bosnia and Herzegovina.

Abdominal Cysticercosis in a Red Fox ( Vulpes vulpes )

A large abdominal mass containing numerous cysticerci identified as those of Taenia crassiceps (=Cysticercus longicollis) was found in the pelvic region of the abdominal cavity of a severely constipated and emaciated red fox ( Vulpes vulpes ) in Prince Edward Island, Canada. Cysticercosis has not previously been reported in a wild canid in North America.

Toxoplasmosis in a Woodchuck (Marmota Monax) and Two American Red Squirrels (Tamiasciurus Hudsonicus)

Toxoplasmosis was diagnosed in a woodchuck ( Marmota monax) and 2 American red squirrels ( Tamiasciurus hudsonicus). The woodchuck was euthanized by a wildlife rescue organization in New York after progressive clinical signs of head tilt, circling, and rapid weight loss. Necropsy examination revealed acute subdural hemorrhage over the right cerebral hemisphere. Histologic lesions included meningoencephalitis, myocarditis, and hepatitis. Protozoal cysts were present in affected and unaffected neuroparenchyma. The squirrels were found dead, emaciated, and moderately infested with fleas near a park in northern Indiana. In both squirrels, the lungs were consolidated with numerous nodules up to 2 mm in diameter. Histologically, pneumonia and encephalitis were associated with intracellular and free protozoa. Additional histologic lesions included multifocal lymphoplasmacytic encephalitis with intralesional protozoa in both squirrels. The protozoa were positive with Toxoplasma gondii-specific immunohistochemistry and had ultrastructural features consistent with T. gondii in both squirrels. A real-time polymerase chain reaction test using T. gondii–specific probes demonstrated protozoal DNA in the lung, brain, and kidney of the squirrels and in the brain and heart of the woodchuck. To the authors' knowledge, this is the first report of toxoplasmosis in woodchucks or American red squirrels. Because rodents are common near urban settlements, this finding underscores their role as important intermediate hosts for T. gondii.

When things go wrong: Cysticercus longicollis in an adult wild red fox (Vulpes vulpes)

First case of Cysticercus longicollis, larval stage of Taenia crassiceps, was diagnosed in a wild adult male red fox (Vulpes vulpes). The fox was killed by dogs at Nature Park Medvednica and presented to the University of Zagreb Faculty of Veterinary Medicine with history of being unable to run away and having skin lesions on legs that resembled to those of mange. Necropsy revealed whitish fluctuant mass full of cysticercus-like structures, surrounded by fibrous capsule and placed between the leg muscles, and numerous of spherical cysts in the subcutis and in the peritoneal cavity. Cysticerci were identified as C. longicollis based on their size, number and size of the rostellar hooks, mode of proliferation and DNA analysis. To our knowledge, this is the first case of T. crassiceps cysticercosis in a wild carnivore.

Clinical and MRI Findings in Three Dogs with Polycystic Meningiomas

One spayed female Labrador retriever and two castrated male golden retrievers were evaluated for chronic (i.e., ranging from 3 wk to 24 wk) neurologic signs localizable to the prosencephalon. Signs included seizures, circling, and behavior changes. MRI demonstrated extra-axial, contrast-enhancing, multiloculated, fluid-filled, cyst-like lesions with a mass effect, causing compression and displacement of brain parenchyma. Differential diagnoses included cystic neoplasm, abscess or other infectious cyst (e.g., alveolar hydatid cyst), or fluid-filled anomaly (e.g., arachnoid cyst). The cyst-like lesions were attached to the rostral falx cerebri in all cases. In addition, case 2 had a second polycystic mass at the caudal diencephalon. Surgical biopsy (case 3 with a single, rostral tumor via transfrontal craniectomy) and postmortem histology (in cases 1 and 2) confirmed polycystic meningiomas. Tumor types were transitional (cases 1 and 3) and fibrous (case 2), with positive immunohistochemical staining for vimentin. Case 3 was also positive for E-cadherin, s100, and CD34. In all cases, staining was predominantly negative for glial fibrillary acid protein and pancytokeratins, supporting a diagnosis of meningioma. This report describes the first cases of polycystic meningiomas in dogs. Polycystic meningiomas are a rare, but important, addition to the differential diagnoses for intracranial cyst-like lesions, significantly affecting planning for surgical resection and other therapeutic interventions.

Taenia crassiceps cysticercosis in a ring-tailed lemur (Lemur catta)

Subcutaneous and intraperitoneal cysticercosis due to Taenia crassiceps was diagnosed in a 5-yr-old male ring-tailed lemur (Lemur catta) in the Madrid Zoo-Aquarium (Madrid, Spain). Under laparoscopic examination, several septated fibrous cystic structures and numerous masses of small transparent vesicles (ca. 3 mm in diameter) were observed subcutaneously and inside the peritoneal cavity. Most of the structures were extirpated but, after 2 days of postsurgical intensive care, the animal died. The loss of body weight of the animal after surgical extirpation (566 g) represented 22% of the total weight (body weight before mass removal, 2582 g). The vesicles were identified under light microscopic examination as cysticerci and by molecular diagnosis as Cysticercus longicollis, the larval form of T. crassiceps. The present report represents the first detection of T. crassiceps in the prosimian genus Lemur.

Taenia crassiceps: in vivo and in vitro models

Taenia crassiceps is a cestode parasite of wild and domestic animals that rarely affects humans; it has been widely used as an experimental model. The asexual proliferation by budding is a useful attribute of T. crassiceps cysticerci, which allows the various strains to be maintained indefinitely in the peritoneal cavity of inbred mice. Over the last 50 years, experimental results using larval and adult stages of T. crassiceps have yielded much information on the morphology, infectivity, proliferation dynamics, host immune response, endocrinological responses and vaccine research, all of which have contributed to our knowledge of cestode biology.