Antemortem diagnosis of external iliac arterial thromboembolism in a calf using contrast-enhanced computed tomography: a case report.

A 28-day-old Holstein calf with astasia (i.e., right hind limb flaccid paralysis) was referred to Large Animal Veterinary Educational Center. Thoracic radiographs showed an alveolar pattern and air bronchograms indicating pneumonia, whereas skeletal radiography showed muscle atrophy of the right hind limb but no abnormalities in the coxofemoral and stifle joints. Contrast-enhanced computed tomography revealed the pulmonary abscess in the right cranial pulmonary lobe and a thrombus (5 × 5 × 20 mm) in the right external iliac artery distal to the bifurcation of the abdominal aorta. These findings were confirmed via pathological examination. Streptococcus bovis/equinus complex colonies were isolated from the thrombus and pulmonary abscess. Thus, the pulmonary abscess was considered the infectious source of the thromboembolism in the right external iliac artery. Arterial thromboembolism should be included in the differential diagnoses in calves with astasia but without radiographic skeletal abnormalities.

Identification of Moraxella lacunata from pulmonary abscesses in three zoo herbivores.

Although Moraxella lacunata causes conjunctivitis, keratitis, endocarditis, and otolaryngitis in humans, its infection is rare in animals. We report three cases of asymptomatic pulmonary abscesses caused by M. lacunata in zoo herbivores, including two elks (Cervus canadensis) and a common eland (Taurotragus oryx). In all cases, macroscopic findings included coalescence of lung lobes and severe pulmonary abscesses filled with cheese-like materials in cysts. Microscopic findings included pneumonia characterized by marked fibrin exudates in alveolar spaces and infiltration of inflammatory cells. M. lacunata was identified in bacterial cultures from pulmonary abscesses using biochemical API 20NE system. M. lacunata is rarely isolated from zoo animals; however, herein, we describe the first report of pulmonary abscesses caused by M. lacunata infection.

Comparison of tulathromycin, azithromycin and azithromycin-rifampin for the treatment of mild pneumonia associated with Rhodococcus equi.

The objectives of the present study were to determine the relative efficacy of tulathromycin, azithromycin, or azithromycin with rifampin for the treatment of pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi. Foals with ultrasonographic evidence of pulmonary abscesses (abscess score 8.0-15 cm; n=120) were randomly allocated in four equal treatment groups: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy, orally; (3) azithromycin with rifampin, orally; (4) saline intramuscularly as a placebo. Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals that worsened were removed from the study. The proportion of foals that recovered without the need for a change in therapy was significantly higher for foals treated with azithromycin (29 of 30) or azithromycin with rifampin (28 of 30) than for foals treated with a placebo (20 of 30). Additionally, azithromycin or azithromycin with rifampin resulted in a significantly faster decrease in the number of abscesses and abscess score compared with a placebo. The proportion of foals treated with tulathromycin that recovered (27 of 30) was not significantly different from that of foals treated with a placebo. Azithromycin alone or in combination with rifampin was beneficial in the study population.

Diagnosis and successful treatment of a lung abscess associated with Brucella species infection in a bottlenose dolphin (Tursiops truncatus).

This brief communication describes the clinical presentation, antemortem diagnosis, and successful treatment of a pulmonary abscess associated with a Brucella sp. in a 27-yr-old female bottlenose dolphin (Tursiops truncatus). Ultrasound revealed a 3-cm diameter hypoechoic mass deep to the pleural lining in the left lung field. Multiple ultrasound-guided fine-needle aspirates were performed and tested for bacterial and fungal etiology. All cultures were negative, but the infectious agent was identified by MicroSEQ analysis in two samples and confirmed with real-time polymerase chain reaction (PCR) amplification using known Brucella sp. primers. Amikacin was infused into the abscess and was followed by an oral doxycycline and rifampin protocol. Follow-up diagnostic imaging, including radiographs and computed tomography, revealed a resolved lesion with minimal mineralization within the affected lung fields. Brucellosis should be considered for pulmonary disease in dolphins, and personnel who interact with marine animals should use caution to prevent zoonotic brucellosis.

Efficacy of mass antimicrobial treatment of foals with subclinical pulmonary abscesses associated with Rhodococcus equi.

BACKGROUND: Mass antimicrobial treatment of foals with small subclinical ultrasonographic pulmonary lesions is empirical practice on many farms with endemic disease caused by Rhodococcus equi. HYPOTHESIS: Mass antimicrobial treatment of foals with subclinical ultrasonographic pulmonary lesions is unnecessary. ANIMALS: One hundred and eight foals on a farm endemic for infections caused by R. equi. METHODS: Controlled, randomized, and double-blinded prospective study. Foals with ultrasonographic evidence of pulmonary abscesses 5.0-10 cm in diameter (n = 108) were randomly allocated in 5 treatment groups: (1) tulathromycin IM; (2) doxycycline monotherapy PO; (3) doxycycline with rifampin PO; (4) azithromycin with rifampin PO, and (5) saline IM as a placebo. Physical examination and thoracic ultrasonography were performed by individuals unaware of treatment group assignment. Foals with evidence of disease progression were removed from the study and treated with azithromycin-rifampin. RESULTS: Overall, 22/25 (88%) foals in the placebo group recovered without the need for treatment. The proportion of foals that had evidence of disease progression did not differ significantly between the treatment groups (P > .05). Although the median duration of treatment was significantly (P < .05) shorter in foals treated with azithromycin-rifampin (46 days) compared with foals treated with the placebo (73 days), the time frame of ultrasonographic lesion resolution did not differ significantly between the treatment groups. CONCLUSIONS AND CLINICAL IMPORTANCE: The majority of foals with subclinical pulmonary abscesses <10 cm in diameter recover without antimicrobial treatment and treatment of affected foals does not provide a clear benefit over administration of a placebo.

Helcococcus ovis isolated from a goat with purulent bronchopneumonia and pulmonary abscesses.

The current study describes the recovery of Helcococcus ovis from an adult female Verata breed goat that was euthanized because of respiratory problems and emaciation. At necropsy, the affected animal showed a purulent bronchopneumonia with scattered pulmonary abscesses and fibrous pleural adhesions. A Gram-positive, catalase-negative, coccus-shaped bacterium was isolated from the lung tissue and confirmed as H. ovis by 16S ribosomal RNA gene sequencing.

Failure of antimicrobial therapy to accelerate spontaneous healing of subclinical pulmonary abscesses on a farm with endemic infections caused by Rhodococcus equi.

Mass antimicrobial treatment of foals with small ultrasonographic pulmonary lesions is common on farms with endemic disease caused by Rhodococcus equi. The objectives of this study were to compare the relative efficacy of three antimicrobial protocols for the treatment of pulmonary abscesses on a farm with endemic infections caused by R. equi and to determine the frequency of spontaneous resolution of subclinical pulmonary lesions. Foals with ultrasonographic evidence of pulmonary abscesses ≥ 1.0 cm in diameter (n=128) were randomly allocated to one of four equal treatment groups. Animals with respiratory distress or severe pulmonary lesions were excluded from the study. Treatment groups consisted of: (1) tulathromycin intramuscularly; (2) azithromycin monotherapy orally; (3) azithromycin in combination with rifampin orally; and (4) glucose orally as a placebo. Physical examination, thoracic ultrasonography and white blood cell (WBC) counts were performed weekly by individuals unaware of treatment group assignment. Foals that worsened were removed from the study and treated with azithromycin and rifampin. Overall, 14/32 (43.8%) foals in the placebo group recovered without the need for therapy. The proportion of foals that responded to the initial therapy, the duration of therapy, the kinetics of ultrasonographic lesion resolution, the proportion of foals that had to be removed from the study and the number of days to removal from the study did not differ significantly between treatment groups. The study showed that many foals with pulmonary abscesses recover without antimicrobial therapy. Moreover, treatment of sub-clinically affected foals with antimicrobial agents did not significantly hasten recovery.

Pulmonary fungal infection caused by Neoscytalidium dimidiatum in a Risso's dolphin (Grampus griseus).

Neoscytalidium dimidiatum was isolated from two 12-18 cm abscesses in the lung and the mediastinal lymph nodes of a stranded Risso's dolphin (Grampus griseus). Histopathologic examination of samples of these organs revealed the presence of hyphae and sclerotic body-like fungal elements. Photobacterium damselae subsp. damselae was recovered from the dolphin's organs which also were found to contain numerous Monorygma grimaldii cysts. No histopathological signs of morbillivirus infection were seen. To the best of our knowledge, this is the first report of N. dimidiatum infection in a sea mammal.

Efficacy of azithromycin in preventing pulmonary abscesses in foals.

The prophylactic application of azithromycin to prevent pulmonary abscesses in foals was evaluated on a stud with endemic Rhodococcus equi pneumonia. Forty-five foals served as untreated controls in two groups. Twenty-five foals were given azithromycin (10mg/kg) orally once daily for 4 weeks. The foals were examined once a week from birth to the age of 5 months. If clinical signs or leucocytosis were noted and pulmonary sonographic findings (diameter >10 mm) were observed, the diagnosis of abscessing pneumonia was made. The prevalence of pulmonary abscesses was similar in the control groups (31/45 foals), and in the azithromycin group (15/25 foals), but the foals in the azithromycin group were affected significantly later (median: day 83, range 67-123 days) (control groups: day 54, range 52-82; and 46, range 28-86 days). It was concluded that the application of azithromycin for 28 days post-natally does not reduce the prevalence of pulmonary abscesses in foals on a stud with endemic pneumonia.

Genotypic characterization of VapA positive Rhodococcus equi in foals with pulmonary affection and their soil environment on a warmblood horse breeding farm in Germany.

Pulsotypes of VapA positive Rhodococcus equi isolated from foals and soil on a farm in Germany were characterized on the basis of nasal and tracheal samples simultaneously collected in 2003 from 217 foals with sonographic evidence of pneumonia or pulmonary abscesses. Of the 217 double samples, R. equi was isolated in 118 (54%) of the tracheal samples and in 52 of the nasal swab samples (24%) (P<0.001). Furthermore, 37 and 55 isolates were also randomly selected from nasal swabs and the tracheal samples, respectively, and further processed to determine the presence of VapA by colony blot enzyme-linked immunosorbent assay. This method showed that 26 (68%) of the nasal swabs and 40 (73%) of the tracheal samples were VapA-positive. R. equi was isolated from 56 (87%) of the 64 soil samples taken from the paddocks and stables in March and from 17 (68%) of the 25 samples taken in July of 2003. Three (21%) of these randomly selected 14 isolates from March and 13 (81%) of the 16 from July were VapA-positive. The VapA positive isolates from foals and soil were genotyped by plasmid profiling, restriction fragment length polymorphism analysis and pulsed-field gel electrophoresis. Of the 83 isolates, 80 contained an 85-kb type I plasmid and three contained an 87-kb type I plasmid. Pulsed-field gel electrophoresis yielded four distinct VspI profiles dividing 83 isolates into three major (A1, 51; D, 14; and 11 isolates) and three minor (C, 4; A3, 2; and A2, 1 isolates) groups. These results suggest that the majority of foals were exposed to and infected with three pulsotypes of VapA positive R. equi containing an 85-kb type I plasmid.

Evaluation of tulathromycin in the treatment of pulmonary abscesses in foals.

Tulathromycin is a new injectable macrolide antibiotic used for the treatment of pulmonary diseases of swine and cattle. In this study, 37 foals with sonographic evidence of lung abscesses were treated with tulathromycin (2.5mg/kg intramuscularly [IM] once weekly, group 1) and 33 foals (group 2) with a combination of azithromycin (10mg/kg per os [PO] once daily for the first seven days of therapy, thereafter every other day) and rifampin (10mg/kg PO twice daily). The bacterial aetiological agent was not determined. The foals were only mildly sick and the median number of pulmonary abscesses was 1.4 (group 1) and 1.6 (group 2). Thirty foals in each group were treated without modifying therapy protocols until all clinical signs of disease had subsided. Tulathromycin was administered for a mean of 53 days, and azithromycin/rifampin for 42 days. The following side effects were associated with tulathromycin (279 IM injections): self-limiting diarrhoea in 11 foals; elevated temperature in six foals, and swellings at the injection site in 12 foals. This study provides some evidence that tulathromycin is well tolerated and appears promising for the treatment of pulmonary abscesses in foals.