2020 AEMV Student Case Report Contest

Introduction

Lafeber Company was proud to sponsor the Association of Exotic Mammal Veterinarians (AEMV) Student Case Report Contest. Veterinary students from all over the world were encouraged to write a 2-page case report (1500 words or less) about an exotic companion mammal seen at their college of veterinary medicine or during a clinical experience.

Submissions closed March 27, 2020. Fifteen cases reports were received from eight countries, including the Czech Republic, India, Switzerland, Australia, USA, Canada, Portugal, and Romania. Judges from the Research Committee evaluating the case reports were blinded to the students, mentors, co-authors, and institutions at which the cases were seen.

Posted below are brief summaries of each winning case report. Each student has also been encouraged to submit their paper for peer-reviewed publication.

First place

Shanna Wong (Student – Oklahoma State University, USA):                                              Intra-abdominal torsion of a neoplastic testicle in a rabbit (Oryctolagus cuniculus) with cryptorchidism

A 7-year-old Dutch rabbit was examined for sudden anorexia and lethargy. The rabbit was previously diagnosed with unilateral cryptorchidism 5 years earlier; however, the owner declined surgical treatment at that time. Transabdominal ultrasonography showed a structure consistent with an enlarged testis, with decreased echogenicity, and absent blood flow upon color Doppler ultrasonography. After induction of general anesthesia and during preparation for surgery, the patient had an episode of cardiac arrest. After successful resuscitation, bilateral cryptorchidectomy continued as planned. A ventral midline laparotomy was performed and confirmed presence of an enlarged, dark red left testicle torsed on its spermatic cord. The contralateral testicle was atrophic. Both testicles were removed after standard hemostasis. Recovery was uncomplicated. Histopathologic examination revealed a diagnosis of Sertoli cell tumor and extensive hemorrhage and necrosis in the torsed testicle. Based on literature search, this is the first reported case of intra-abdominal torsion of a neoplastic testicle in a cryptorchid rabbit. Early elective cryptorchidectomy before the potential development of life-threatening complications may be beneficial in rabbits as in other species.

Second place

Nicole Pauli (Student – University of Zürich, Switzerland):
Diagnosis and successful treatment of discospondylitis in a rabbit (Oryctolagus cuniculus) using MRI

A 2.5-year-old 5.3kg male neutered rabbit (Oryctolagus cuniculus) was presented for lameness and progressive exercise intolerance. In the clinical and neurological examinations, the rabbit showed an unphysiological hindlimb position and a non-ambulatory paraparesis with absent proprioception and increased spinal reflexes. Radiographs revealed an aggressive lesion of the endplates of the lumbar vertebrae L4-L5. Under general anesthesia (hydromorphone (0.3mg/kg IM), midazolam (1 mg/kg IM), ketamine (2.5 mg/kg IV), isoflurane in oxygen after intubation, flumazenil (0.05 mg/kg IM) as a reversal), an MRI scan was performed. The MRI study revealed typical signs for discospondylitis at the vertebrae L4 and L5, including T2-hypointense endplates, a T2-hypointense intervertebral disc and contrast enhancement of the surrounding soft tissue and vertebral bodies. Initially, the patient was not able to pass urine. Ultrasound of the urinary system and urine analysis were indicative of a cystitis. Blood analysis revealed an increased CRP (392 mg/l) and other unspecific signs of inflammation. The patient was treated with injectable penicillin (60’000 IU/kg; BID for 7 days, afterwards q2d) and marbofloxacin (5 mg/kg; SID) orally for a total of eight weeks, as well as meloxicam (1 mg/kg PO, SID) for the first three weeks. During treatment, the patient regained normal function of the hindlimbs and was able to pass urine again. On recheck exam after eight weeks of treatment, radiographs revealed signs of ongoing healing and the CRP returned to a normal level (10 mg/l).

Third place

Joana Soares (Student – Lisbon University, Portugal):
Polyostotic lymphoma with vertebral involvement and spinal extradural compression in a ferret (Mustela putorius furo)

A 4-year-old implanted male domestic ferret (Mustela putorius furo) was presented with a sudden onset of hind limb paralysis and anorexia. Physical examination findings included dehydration, paraplegia with both limbs lacking proprioceptive and withdrawal reflexes, urine retention resulting in a distended urinary bladder, absence of perineal reflex and poor body condition. Radiographs revealed severe lysis of the L3 vertebral body with local invasion by a round soft tissue density mass. CT scan revealed an aggressive osteolytic bone lesion centered at the L3 vertebral body, with secondary vertebral canal invasion and ventral compressive myelopathy. The mass measured approximately 2 centimeters in diameter. It was also detected polyostotic osteolytic bone lesions involving the axial and appendicular skeleton and multifocal splenic nodules and masses. Due to the poor prognosis and in agreement with the owner, the animal was humanely euthanized. Histopathological examinations revealed infiltrations of continuous sheets of medium-sized lymphocytes with large nuclei, one or more nucleolus, and low mitotic index. A diagnosis of polyostotic lymphoma was made, the second report of this condition in a domestic ferret and the first in this species with vertebral involvement and spinal extradural compression.

Honorable mentions

• Nikola Sádovská (Student – University of Veterinary and Pharmaceutical Sciences – Brno, Czech Republic):  Anorexia in a ferret associated with a large infected biliary cyst and suppurative hepatitis

A 6-year-old neutered male ferret was presented to the veterinary clinic with acute onset of anorexia and nausea. On physical examination large spherical mass (6 cm in diameter) was palpated located caudally to the rib cage. Hematology and plasma chemistry showed anemia, monocytosis, uremia, hypocalcemia, elevated gamma-glutamyl transferase and bilirubinemia. Abdominal radiography revealed large soft tissue opacity mass indistinguishable from the liver parenchyma, which dislocated stomach laterally. On ultrasound, the cystic mass formed of one cavity originated from liver, anechogenic cyst content and hyperechoic sediment was identified. Exploratory laparotomy confirmed the presence of a large cystic mass, which was surgically excised (right liver lobe lobectomy). Total volume of the cyst content was 65 ml. Bacteriological examination revealed pure culture of multi-resistant Escherichia coli. The histopathological diagnosis was infected biliary cyst with peripheral suppurative hepatitis. Based on clinical signs and all the diagnostics, it was presumed that the infection was spread from the duodenum. Anorexia was caused by lateral displacement of the stomach with the large biliary cyst which prevented feed intake and also caused nausea. The presented case showed importance of thorough clinical examination, use of complimentary imaging methods and laboratory analyses which led to successful surgery and to the diagnosis confirmed by histopathology. Because liver disease can be part of a systemic disease, screening for concurrent disease and additional examination must be interpreted accordingly.

• Lenka Čejková (Student – University of Veterinary and Pharmaceutical Sciences – Brno, Czech Republic):  Uterine squamous cell carcinoma in a pet rat (Rattus norvegicus)

A 1-year-old female pet rat (Rattus norvegicus) was presented to the veterinary clinic with a 3-week history of mild hemorrhagic vaginal discharge. On presentation, the animal was inactive, dehydrated, and in poor body condition (BCS 1.5/5), with pale mucous membranes and a mucopurulent vaginal discharge. Abdominal palpation revealed an almost empty gastrointestinal tract and a large, ovoid, fibroelastic mass (4×3 cm) with two smaller tubular masses located in the hypogastric region. Abdominal ultrasonography revealed thickened and structurally changed uterine bodies and uterine horns of various echogeneity of the size 4×5 cm. Ovariohysterectomy was performed and the mass was submitted for histopathological examination that confirmed the presence of squamous cell carcinoma (SCC). The patient recovered uneventfully and further health checks, done after 10 days, 3 months, and 7 months, did not identify any metastatic lesions. The incidence of endometrial tumors increases with age. There is a 55% chance of identifying benign endometrial tumors in rats up to 31 months of age. In some strains of rats, the incidence of uterine tumors rises to 66% in rats older than 21 months. Therefore, ovariohysterectomy is the best prevention of uterine tumors in both laboratory and pet rats.

Prizes

Permission was obtained from the supervising clinician (required) and the owner (optional depending on local privacy laws or facility standards).

Learn more

Interested in learning more about exotic companion mammals? Visit AEMV.org or email aemv@navc.com for more information.