Case report: Sarcocystis speeri, Aspergillus fumigatus, and novel Treponema sp. infections in an adult Atlantic spotted dolphin (Stenella frontalis).

A complete postmortem examination, including a computed tomography scan "virtopsy" (virtual necropsy), gross necropsy, cytology, histology, and molecular diagnostics were performed to investigate the cause of death of a deceased adult male Atlantic spotted dolphin (Stenella frontalis) that stranded on Pensacola Beach, Florida, USA in February 2020. Significant findings included chronic inflammation of the meninges, brain, and spinal cord with intralesional protozoa (identified as Sarcocystis speeri via 18S rRNA and ITS-1 sequences), suppurative fungal tracheitis and bronchopneumonia (identified as Aspergillus fumigatus via ITS-2 gene sequence) and ulcerative bacterial glossitis (associated with a novel Treponema species, Candidatus Treponema stenella, identified via 23S rRNA gene sequence). This is the first reported case of S. speeri in a marine mammal. Little is understood about the epidemiology of S. speeri, including the identity of its intermediate hosts. The findings of this case suggest that S. frontalis may be a capable aberrant host and experience morbidity and mortality from this parasite. It is suspected that the novel Treponema and Aspergillus fumigatus infections were opportunistic or secondary to immunosuppression, either due to S. speeri infection or other co-morbidities.

Ultrasonographic and radiographic features of a true gastrogastric intussusception with spontaneous resolution in a cat.

An 11-year-old, female spayed, domestic shorthair cat with a 1-week history of vomiting was diagnosed with a gastrogastric intussusception using ultrasound. Distinguishing ultrasonographic findings included invagination of the gastric fundus into the body and were correlated to radiographs acquired at the time of the evaluation. Spontaneous resolution of the gastrogastric intussusception was observed on a positive-contrast upper gastrointestinal fluoroscopic study done the following day. Due to worsening comorbidities, which most significantly included chronic renal disease and pancreatitis, and declining quality of life, the patient was humanely euthanized 10 months later. Necropsy revealed no gross and histopathologic abnormalities associated with the stomach. A definitive cause for the intussusception remains unknown.

What Is Your Diagnosis?

In collaboration with the American College of Veterinary Radiology.

Interpretation of cardiac chamber size on canine thoracic radiographs is limited and may result in the false identification of right-sided cardiomegaly in the presence of severe left-sided cardiomegaly.

Qualitative assessment of individual cardiac chamber enlargement on thoracic radiographs was assessed using echocardiography as the gold standard in dogs. Using this method, the presence of severe left-sided cardiomegaly was hypothesized to contribute to the false identification of right-sided cardiomegaly on radiographs. 175 dogs with three-view thoracic radiographs were retrospectively included in this diagnostic accuracy study if echocardiography was done within 24 h, and no rescue therapy was provided in the interim. All radiographic studies were reviewed by two groups of five board-certified veterinary radiologists with greater and less than 10 years of experience for grading of cardiac chamber enlargement as normal or mildly, moderately, or severely enlarged. The agreement, sensitivity, and specificity of the radiologists' interpretation of cardiac chamber size on thoracic radiographs to measured echocardiographic grades were evaluated. A total of 147 cases had complete echocardiographic data available for analysis. Intragroup agreement was moderate for the evaluation of left atrial enlargement and slight to fair for all other cardiac chambers. Between the mode of the radiologists' responses in the two groups and the echocardiographic grades, there was slight agreement for all cardiac chambers with higher severity grades reported using echocardiography. When moderate to severe left-sided cardiomegaly was identified on echocardiography, the sensitivity, specificity, and accuracy of radiographs were low, identifying dogs with radiographic evidence of right-sided cardiomegaly in the absence of corresponding right-sided cardiomegaly on echocardiography. Therefore, thoracic radiographs should be used with caution for the evaluation of cardiac chamber enlargement, particularly in the presence of severe left-sided cardiomegaly.

Radiographic characteristics of alveolar microlithiasis and pulmonary ossification following chronic corticosteroid therapy in a dog.

A 10-year-old, neutered female, Australian Shepherd was referred for acute respiratory distress and a history of chronic exogenous steroid administration. On thoracic radiographs, a severe increase in mineral opacity characterized as a generalized unstructured interstitial pulmonary pattern, diffuse calcinosis cutis, and moderate hepatomegaly were noted. Cor pulmonale was identified on echocardiography. The patient developed a pneumothorax following sampling and had a cardiac arrest. Postmortem histopathology of the lungs revealed pulmonary interstitial mineralization and alveolar microlithiasis. This report supports including generalized pulmonary mineralization due to chronic exogenous steroid administration as a differential diagnosis for dogs with these clinical and imaging findings.

Radiographic anatomy of the equine distal tibia.

The radiographic anatomy of the equine distal tibia is complex and is not widely described in the current literature. Superimposition and radiographic similarities between the different osseous structures of the equine distal tibia can make it difficult for anatomic localization of pathology. The purpose of this prospective, descriptive, anatomic study was to detail the normal anatomy of the equine distal tibia using routine radiographic projections and CT of the equine tarsus. Radiographic identification of the different osseous protuberances of the distal tibia on three cadaveric limbs was achieved using radiopaque markers and evaluation of multiplanar and 3D CT reconstructions to create anatomical maps. It was found that the lateral malleolus is composed of cranial and caudal protuberances that are superimposed over the intermediate cochlear ridge of the distal tibia on the lateromedial, dorsal 45° lateral-plantaromedial, and dorsal 65° medial-plantarolateral oblique views, thereby hindering visualization of the cranial protuberance of the lateral malleolus. The medial malleolus is a simple rounded protuberance with discrete margins. On the dorsal 65° medial-plantarolateral oblique, the medial malleolus is ill-defined due to superimposition with the talus. The intermediate cochlear ridge of the distal tibia extends in a craniolateral to caudomedial direction, with its cranial protuberance largely superimposed with the calcaneus and talus on the dorsoplantar view. In summary, the distal tibial anatomy is complex and a thorough anatomical reference is necessary when reviewing radiographs of the equine tarsus for pathology. A plantaro 15° distal 85° lateral-dorsoproximomedial oblique projection is proposed to isolate all distal tibial protuberances.