Abnormalities in the axial skeleton of a Risso's dolphin,Grampus griseus

As the first step in the development of a cervine IFN-γ assay for the diagnosis of tuberculosis in deer, cervine IFN-γ cDNA was amplified by polymerase chain reaction using primers based on the bovine IFN-γ sequence. A high level of amino acid homology was found between the cervine and the ovine and bovine sequences (94% and 91% respectively). There was less identity with the porcine, human, mouse and rat sequences (78%, 62%, 37% and 39%, respectively). The amino terminus of the mature IFN-γ protein, which is critical for interaction with its receptor and for triggering biological activity, is highly conserved between the cervine, bovine and ovine proteins. A monoclonal antibody-based sandwich enzyme immunoassay (EIA) specific for bovine IFN-γ also detects ovine but not cervine IFN-γ. This suggests that the antibodies recognise epitopes common to the bovine and ovine protein but not cervine IFN-γ. Seven amino acid residues that were common to the bovine and ovine sequence differed in the cervine sequence, suggesting that the specificity of the monoclonal antibodies may be dependent on one or more of these residues. The possibility of the development of an EIA for cervine IFN-γ as a commercial in vitro diagnostic assay for tuberculosis in deer is discussed.     

A morphological study of the thyroid gland in Risso's Dolphin,Grampus griseus

To accumulate histological information of cetaceans and basic information about metabolic systems of marine mammals, the thyroid gland of Risso's dolphins was examined by gross anatomical and light and electron microscopic observations. Gross anatomically, right and left lobes of the thyroid were not clearly discriminated, and no isthmus was observed. By light microscopy, irregular or oval follicular lumens were seen, and surrounded by follicular epithelial cells. By electron microscopy, the rough endoplasmic reticulum (rER) was seen adjacently to mitochondria at the basal and lateral regions of the follicular epithelial cells. RERs at the basal side of the cells sometimes contained flocculent material with the same electron density as the follicular lumen component. Microvilli were poorly developed at the apical surface of the cells. In the apical regions of the cells, there were typical Golgi complexes, multivesicular bodies, and granules with various size and electron density. The parafollicular cells were recognized among the follicular epithelial cells and in the interstitial regions but never protruded into the follicular lumen. These cells were present singly and/or formed clusters among the follicular epithelial cells, and often located adjacent to capillaries. They were obviously discriminated from follicular epithelial cells by higher electron density of their granules. In their cytoplasm, well-developed rERs, primary lysosomes, secondary lysosomes, multivesicular bodies, and phagosomes were recognized.     

Use of human recombinant erythropoietin for the treatment of nonregenerative anemia in a rough-toothed dolphin (Steno bredanensis).

Erythropoietin, a glycoprotein growth hormone that is produced primarily in the kidneys, promotes mitosis and survival of erythroid progenitors. The recent synthesis of the human form of the hormone by recombinant technology has provided a new therapeutic option, which is being used in both human and veterinary medicine for treatment of various anemias. A mature male rough-toothed dolphin, Steno bredanensis, was treated with human recombinant erythropoietin in an attempt to resolve a nonregenerative anemia. Two i.m. injections 48 hr apart were associated with an almost immediate increase in circulating immature reticulocytes, total reticulocytes, and nucleated erythrocytes. Over the next several weeks, the hematocrit, hemoglobin, and erythrocyte counts returned to normal, and the animal was subsequently released back into the wild. Endogenous erythropoietin concentrations were determined for this animal as well as three other conspecifics by an enzyme-linked immunosorbent assay for human erythropoietin. These measurements showed circulating erythropoietin concentrations (5-20+ mU/ml) similar to those of most other mammals. This study suggests that human recombinant erythropoietin can be safely and effectively used in this species and may have applicability to other cetacean species for the treatment of nonregenerative anemia. Caution should be exercised during long-term use because production of antibodies to human recombinant and endogenous erythropoietin may lead to potentially serious side effects.     

Echocardiographic evaluation of the bottlenose dolphin (Tursiops truncatus).

Safe and effective echocardiography would represent a valuable tool for marine mammal veterinarians and physiologists evaluating the dolphin heart. Unfortunately, conventional ultrasound technology (transthoracic echocardiography) has been limited by logistic, anatomic, and behavioral challenges. Five mature male Atlantic bottlenose dolphins (Tursiops truncatus) were trained for echocardiographic imaging (four for both transthoracic and transesophageal imaging, and one for only transthoracic imaging). It was noted that transesophageal image quality transiently improved when the dolphins spontaneously exhaled. Subsequently, dolphins were conditioned to hold their breath following forced exhalation, and imaging proceeded during such behavioral breath holds. Over 25 transthoracic and 100 transesophageal echocardiographic studies were performed, including both two-dimensional imaging and color flow mapping. Transthoracic imaging yielded poor-quality images of only small portions of the heart. In contrast, transesophageal imaging, which improved dramatically with behavioral breath holding following exhalation, yielded consistently high-quality images of the entire heart (mitral, tricuspid, aortic, and pulmonary valves, atrial and ventricular septa, left and right atria, left and right ventricles, and ascending aorta and main pulmonary artery). Color flow mapping demonstrated mild tricuspid regurgitation in all dolphins, and mild aortic regurgitation in one dolphin found to have a pedunculated mass arising from the sinutubular junction just above the aortic valve. There were no complications in nonsedated dolphins. The heart of the bottlenose dolphin can be safely, effectively, and reproducibly evaluated with the use of transesophageal echocardiography in conjunction with behavioral breath holding following forced exhalation. This approach, and the normative echocardiographic data generated from this work, lays the foundation for future echocardiographic studies of cetaceans.     

Disseminated histoplasmosis in an Atlantic bottlenose dolphin (Tursiops truncatus).

An approximately 37-yr-old female Atlantic bottlenose dolphin (Tursiops truncatus) died after a 4-mo illness characterized by intermittent anorexia, lethargy, mild neutrophilic leukocytosis, and mild nonregenerative anemia. At necropsy, the lungs were diffusely consolidated, and histopathology of the lungs revealed severe pneumonia with macrophages containing clusters of numerous yeast cells. Inflammatory lesions and yeast also were found in pulmonary, mediastinal, prescapular, and duodenal lymph nodes, spleen, liver, kidneys, urinary bladder, pancreas, right adrenal gland, and the pyloric stomach. Histomorphology, fungal culture, and polymerase chain reaction analysis indicated that the fungus was Histoplasma capsulatum var. capsulatum. This is the first report of histoplasmosis in a cetacean.     

Non-purulent meningoencephalomyelitis of a Pacific striped dolphin (Lagenorhynchus obliquidens). The first evidence of morbillivirus infection in a dolphin at the Pacific Ocean around Japan

On March 22, 1998, a mature, male, hyposthenic Pacific striped dolphin (Lagenorhynchus obliquidens) was stranded at Aoshima Beach in Miyazaki prefecture, Japan. A necropsy performed 14 hr after death revealed mild diffuse congestion and edema of the leptomeninges and mild pulmonary atelectasis. Histopathologically, non-purulent inflammatory were observed throughout the cerebrum, thalamus, midbrain, pons, medulla oblongata, and spinal cord. Hematoxylin and eosin stain revealed no viral inclusion bodies. Immunohistochemistry using a monoclonal antibody against nucleoprotein of canine distemper virus (CDV-NP) revealed a number of CDV-NP-positive granular deposits in the cytoplasm and cell processes of the degenerating or intact neurons. The present paper is a first report of spontaneously occurred morbillivirus infection in a dolphin at the Pacific Ocean around Japan.     

Proliferative dermatitis associated with a novel alphaherpesvirus in an Atlantic bottlenose dolphin (Tursiops truncatus).

Herpesviruses and herpes-like viruses have been reported in only a small number of species of cetaceans, and, to date, clinical manifestations have been either as a life-threatening, disseminated infection or as a non-life-threatening dermatitis. A stranded juvenile Atlantic bottlenose dolphin, Tursiops truncatus, was admitted to the Dolphin and Whale Hospital for rehabilitation. On initial physical examination, the rostral skin had multifocal regions of hyperplasia, and the skin of the dorsum contained a large number of small papules. Histologically, epithelial hyperplasia was evident, and clusters of epithelial cells contained 5-15-microm intranuclear inclusion bodies. Transmission electron microscopic investigation revealed numerous 170-190-nm enveloped virions in both the intracellular spaces and the cytoplasm of epithelial cells, with numerous nucleocapsids noted in epithelial cell nuclei. Consensus primer polymerase chain reaction identified the presence of a novel herpesvirus associated with the lesions. Phylogenetic analysis of the deduced amino acid sequences of the herpesvirus DNA polymerase gene fragment showed it to align with alphaherpesvirus sequences from humans and domestic animals. Although clearly distinct, it was most closely related to two previously described alphaherpesviruses of dolphins. This case represents the first documentation of herpesvirus dermatitis in the Atlantic bottlenose dolphin.     

Bronchoscopic and serologic diagnosis of Aspergillus fumigatus pulmonary infection in a bottlenose dolphin (Tursiops truncatus).

A 4-yr-old male bottlenose dolphin (Tursiops truncatus) developed an Aspergillus fumigatus pneumonia. Fungal elements were identified by cytology and microbiology from endoscopic bronchoalveolar lavage and brushings of a raised yellow endobronchial lesion. The results of qualitative immunodiffusion serology, a technique that identifies specific circulating antibodies to Aspergillus fumigatus, were suggestive of an active infection. The dolphin was treated with itraconazole for over 2 yr, which resulted in remission of clinical signs. Pneumonia caused by Aspergillus sp. accounts for the large majority of pulmonary mycoses in marine mammals. Bronchoscopy facilitated an early definitive diagnosis, accurate treatment, and remission.     

Use of cone-beam computed tomography for advanced imaging of the equine patient

Access to volumetric imaging modalities, such as magnetic resonance imaging (MRI) and computed tomography (CT), has increased over the past decade and has revolutionised the way clinicians evaluate equine anatomy. More recent advancements have resulted in the development of multiple commercially available cone-beam CT (CBCT) scanners for equine use. CBCT scanners modify the traditional fan-shaped beam of ionising radiation into a three-dimensional pyramidal- or cone-shaped beam of radiation. This modification enables the scanner to acquire sufficient data to create diagnostic images of a region of interest after a single rotation of the gantry. The rapid acquisition of data and divergent X-ray beam causes some artifacts to be more prominent on CBCT images—as well as the unique cone-beam artifact—resulting in decreased contrast resolution. While the use of CT for evaluation of the equine musculoskeletal anatomy is not new, there is a paucity of literature and scientific studies on the capabilities of CBCT for equine imaging. CBCT units do not require a specialised table for imaging and in some cases are portable for imaging in the standing or anaesthetised patient. This review article summarises the basic physics of CT technology, including how CBCT imaging differs, and provides objective information about the strengths and limitations of this modality. Finally, potential future applications and techniques for imaging with CT which will need to be explored in order to fully consider the capabilities of CT imaging in the horse are discussed.     

Sublingual squamous cell carcinoma in an Atlantic bottlenose dolphin (Tursiops truncatus).

A 22-yr-old captive-born Atlantic bottlenose dolphin (Tursiops truncatus) presented with a nonhealing sublingual mucosal ulcer that was diagnosed histologically as a squamous cell carcinoma, the first such report in a dolphin. The lesion was excised completely and has not recurred.     

Effects of in vitro hemolysis on serum biochemistry values of the bottlenose dolphin (Tursiops truncatus).

The effects of in vitro hemolysis on 23 biochemical analytes were assessed in sera from 14 clinically healthy Atlantic bottlenose dolphins (Tursiops truncatus). Each serum sample was divided into three portions for analysis: 1) nonhemolyzed control; 2) moderate hemolysis, simulated by adding hemolyzed serum to a final concentration of approximately 150 mg/dl Hb; and 3) severe hemolysis, simulated by adding hemolyzed serum to a final concentration of approximately 500 mg/dl Hb. Moderate hemolysis resulted in statistically significant increases in the mean values of iron, lactate dehydrogenase, potassium, and uric acid and a decrease in creatinine (P < 0.001). Severe hemolysis resulted in statistically significant changes in the mean values of the above analytes in addition to the following increases: alanine aminotransferase, calcium, and serum globulins (P < 0.001) and albumin and total protein (P < 0.01). Total bilirubin and gamma glutamyl transferase levels were lower in the severely hemolyzed sample (P < 0.001). Differences in mean values for alkaline phosphatase between nonhemolyzed and hemolyzed serum were not significant but did show a downward trend in the hemolyzed sera. The presence and severity of hemolysis must be considered in the interpretation of the serum chemistry values.     

Intraocular signet-ring cell melanoma in a hamster (Cricetulus griseus)

A two‐and‐a‐half year‐old male Chinese hamster (Cricetulus griseus) was referred for evaluation of an intraorbital mass involving the right eye. Based on ophthalmic examination and ultrasonography, a diagnosis of intraocular neoplasia was made. Enucleation of the affected eye was performed. The mass was histologically diagnosed as a primary malignant intraocular signet‐ring cell melanoma. No signs of recurrence were detected, and the hamster remained clinically healthy until it died 6 months after surgery. This case report attempts to contribute to the limited body of knowledge available in the literature on primary intraocular neoplasms in hamsters.     

Use of negative contrast computed tomography for diagnosis of a colonic duplication in a dog

A 24‐week‐old dog was presented with recurrent rectal prolapse because of colonic duplication. Colonic duplication is an extremely uncommon congenital abnormality, with only six cases reported in veterinary medicine, one diagnosed at necropsy and five after barium enema, colonoscopy, abdominal ultrasound, exploratory laparotomy either alone or in combination. In this case, these techniques failed to identify the abnormality and diagnosis was ultimately achieved via negative contrast computed tomography. The evaluation generated by the computed tomography images allowed a refined surgical approach. To the authors’ knowledge, negative contrast computed tomography has not yet been reported in the veterinary literature to diagnose gastrointestinal pathologies. Colonic duplication in this case was treated by removal of the intercolonic septum via colotomy.     

Use of computed tomography angiography for the evaluation of a cutaneous haemangioma in a Standardbred horse

Cutaneous haeangiomas are benign vascular neoplasms that arise from endothelial cells of blood vessels. Haemangiomas account for 0.6%–4% of all equine cutaneous neoplasms and the fetlock is the most commonly affected site. We describe the use of computed tomography angiography (CTA) for the evaluation of a cutaneous haemangioma located on the plantarolateral aspect of the left hindlimb fetlock of a 9-month-old Standardbred colt. Computed tomography angiography of the affected fetlock was performed under general anaesthesia. The medial plantar artery was catheterised and a total volume of 50 ml of iodinated non-ionic contrast medium (Iopamidol, 300 mg I/ml, Bracco Imaging Canada) was injected at a rate of 2 ml/s. Following contrast medium administration, the dorsal metatarsal artery and branches including the lateral and medial digital arteries were well demarcated. Two smaller lateral and medial arteries were also identified, forming the vascular network of the metatarsophalangeal joint. At the level of the haemangioma, two tortuous arteries arising from the lateral digital artery were identified, in addition to multiple small branches from nearby cutaneous arteries. These vessels supplied the homogeneously strongly contrast-enhancing cutaneous mass. The initial goal of the CTA study was to map the vascular anatomy for arterial embolisation in conjunction with pharmacological therapy. Considering the involvement of multiple small arterial branches, complete surgical excision along with ligation of the two main supplying arteries was alternatively elected, resulting in a successful long-term outcome.