Nested–polymerase chain reaction detection of Pneumocystis carinii f. sp. canis in a suspected immunocompromised Cavalier King Charles spaniel with multiple infections

Petini, Matteo; Furlanello, Tommaso; Danesi, Patrizia; Zoia, Andrea

A 7-month-old CKCS female, with a history of chronic coughing, was referred to the "San Marco Veterinary Clinic" (Padova, Italy) for further investigations. The dog was not vaccinated and had not received any heartworm prophylaxis in the previous 3 months. Consecutive antibiotic treatments with appropriate doses of doxycycline, metronidazole-spiramycin, and finally, a 10-day course of amoxicillin-clavulanic acid all had all failed to resolve or even improve clinical signs. Antibiotic treatment was discontinued 4 days before presentation. Two previous fecal Baermann's tests were negative for Angiostrongylus vasorum. PCR testing of a nasal swab for CDV, adenovirus 2 (CAV-2), herpesvirus 1, influenza virus, parainfluenza virus (CPiV), and respiratory coronavirus was also negative. On presentation, the dog was bright and alert, mildly tachypneic (40 r/min) with a bilateral mucous nasal discharge. The remaining physical examination was normal. A blood sample was taken for a complete blood count, including blood smear examination, serum biochemistry, and serum electrophoresis, and for a coagulation profile. Urinalysis was performed on a urine sample obtained via cystocentesis. Right lateral and dorso-ventral thoracic radiographs were also taken. Clinicopathological abnormal findings included a mild nonregenerative, normocytic normochromic anemia (5.27 × 10 12 /L; reference interval, 5.81-7.12), leukocytosis (35.8 × 10 9 /L; reference interval, 8.33-14.79) with neutrophilia (24.3 × 10 9 /L; reference interval, 4.0-8.1), lymphocytosis (10.0 × 10 9 /L; reference interval 2.1-4.9), and monocytosis (1.0 × 10 9 /L; reference interval, 2.9-7.0). On blood smear examination, there were activated lymphocytes and toxic neutrophils. Serum biochemical profiles showed an increase in serum C-reactive protein (6.9 mg/L; reference interval, 0.1-0.6), a mild hypoalbuminemia (27 g/L; reference interval, 29-33), and a mild hypoglobulinemia (21 g/L; reference interval, 24-32). Serum immunoglobulin fraction quantification showed a decreased immunoglobulin G (IgG) concentration (0.58 g/L; reference interval 0.9-3.72), while immunoglobulin M (IgM) and immunoglobulin A (IgA) concentrations were at the lower limit of the reference intervals (0.79 g/L; reference interval, 0.76-1.8 and 0.018 g/L; reference interval, 0.001-0.09; respectively). Serum globulin quantification was in agreement with those detected by micro-capillary electrophoresis diagram (Table 1 and Figure 1 ). Rod-shaped bacteria and pyuria were detected with urine sediment examination and therefore urine culture was performed. All the remaining clinicopathological tests were normal. The radiographs of the thorax showed a mild diffuse bronchial pattern (Figure 2 Rhinoscopy, bronchoscopy, and BAL were performed to further elucidate the clinical signs. The dog was pre-medicated with butorphanol (0.2 mg/kg, IM) and dexmedetomidine (0.002 mg/kg, IM), induced with propofol (2 mg/kg) and maintained using a propofol infusion (0.1-0.4 mg/kg/ min). Flow by 100% oxygen delivery was provided during the entire procedure until the dog was fully recovered. A small flexible fiberoptic bronchoscope was used. Pulse oximetry, electrocardiography (ECG), and blood pressure were monitored throughout the procedure. A diffuse, productive bronchopathy and a non-specific mucous-productive rhinopathy were identified. BAL was performed by instilling two aliquots of 5 mL of warmed sterile 0.9% saline by syringe, followed by approxim