A 6-years-old, nulliparous, intact English Bulldog female was referred to the University of Antioquia Veterinary Teaching Hospital (Small animal clinic). The dog weighed 24.3 kg, had complete immunoprophylaxis and antiparasitic treatments, and was fed with commercial dog food. The owner reported no previous hormonal treatment, and 3 months had elapsed after its last standing estrus, that lasted 21 days. Two weeks before the consultation, the dog started with fetid vaginal discharge.
Rectal temperature, respiratory rate, heart rate, and capillary refill time were 38.3 C, 25 rpm (with increased vesicular murmur), 135 b.p.m., and 1 s, respectively, with a strong pulse, rhythmic, and concordant. The oral mucosa was found slightly pale, wet, and brilliant. The dog exhibited a docile attitude, had a 2.5 Body condition score (in a 1-5 scale), and was down although she was able to feed with commercial concentrate and drink water. An increased size of mammary glands, edematous vulva, and vulvar secretion of fetid sanguine-purulent aspect were observed. At palpation, the patient exhibited abdominal pain.
The dog was referred to with the results of blood cell counts (The blood cell counts are presented in Table 1). A blood sample was taken by radial vein puncture for measurements of plasma proteins, activated partial thromboplastin-time, ALT, and creatinine, using an IDEXX Pro Cyte Dx  automated equipment (DEXX Laboratories, Westbrook, MA, USA). The results of blood cell counts were indicative of normocytic normochromic anemia. Also, a vaginal cytology smear was prepared on microscopic slides and stained with Hematoxylin & Eosin, resulting in predominant degenerated polymorphonuclear neutrophils, and erythrocytes. All exams were performed in the Clinical Pathology Laboratory, School of Veterinary Medicine, University of Antioquia. No hormonal measurements were performed.
At the abdominal ultrasound examination, both ovaries showed increased size with fine-heterogeneous hyperechoic structure, a 3.0 x 2.5 cm cyst not compromising the ovarian silhouette. The uterine wall was tight, exhibiting irregular contour. Also, homogeneous intramural cystic structures and a hypoechoic luminal fluid associated with cystic walls were found (Figure 1). A presumptive diagnosis of open pyometra was established. Ovariohysterectomy was prescribed, and the dog was prepared for surgery.
For preparation, the dog was subjected to 12 h of solid food and 8 h of liquids fasting. According to the protocol of University of Antioquia Veterinary Teaching Hospital: Pre-anesthesia was performed with Tramadol (Tramadol, MK, 2 mg/kg/SC), Acepromazine (Tranquilan, Zoo laboratories, 0.02 mg/kg/IM), Meloxicam (Meloxic, Provet, 0.2 mg/kg/EV), Dipyrone (Colivet, Provet 28 mg/kg/EV). Cefalotine (Cefalotine, Vitalis, 20 mg/kg/IV) was administered before initiating the surgery. Anesthesia induction was achieved with Propofol (Propofol 1% MCT/LCT, Fresenius Kabi, 2.6 mg/kg/IV). The deep anesthetic level was maintained with 2 CAM isoflurane. Also, a lumbosacral epidural blockade was done with epinephrine-free Lidocaine (Lidocaine, Virbac Laboratories, 1 mg/kg). The surgical plans were according to the conventional approach through line alba. All the surgical plans were performed with no complications.
The uterus presented a slightly symmetrical distention, occupied with purulent material. The ovaries were found polycystic, measuring 3.0 x 2.5 cm, with normal color and aspect (Figure 2A). In a sagittal cutting of the right and left ovaries, hair, and bone tissue (Figure 2B), and polycystic structures were found, respectively. Samples taken from the uterus and both ovaries were fixed in 10% formaldehyde and were sent to the Laboratory of Animal Pathology, the University of Antioquia, and processed for histopathological evaluation with hematoxylin-eosin staining. Diagnosis was performed by an experienced pathologist with more than 20 years in microscopic histopathologic diagnoses.
Post-operative treatment included: Ampicillin, Metronidazole, Ranitidine, Tramadol, and Meloxicam at the recommended doses and treatment schedule. Also, 0.5% of topical chlorhexidine was prescribed for the healing of the surgical incision. The sutures were removed on the 20th post-operative day. The dog recovered with no complications up to the 20th post-operative day.
The histopathological exam evidenced a GCT in the left ovary, GCT in a solid tubular pattern containing Call-Exner bodies, tubular structures typical of a Sertoli pattern, surrounded by abundant stromal tissue (Figure 3). The neoplastic cells exhibited scare cytoplasm, cytoplasmic projections with rounded or oval nuclei, hyperchromatic or clear, having one or several nucleoli. Similarly, two mitotic figures per 400X field were observed.
In the right ovary, a well-differentiated teratoma was found (Figures 4, 5) that included fragments of perichondrium-containing hyaline cartilage (Figure 4A), trabecular and compact bone (Figure 4B), smooth muscle, sweat glands, hair follicles, stratified cylindrical, and simple plane epithelium. Abundant cavities covered by a stratified keratinized flat epithelium, containing abundant keratin, and supported by a dense connective tissue and adipose tissue were found (Figures 4C,D). Finally, a dentin-pulp complex containing dentine, pre-dentine, odontoblasts, and pulp was found (Figure 5). Accordingly, the definite diagnosis was teratoma of the right ovary, GCT of the left ovary, and open-cervix pyometra.