Equine Herpesvirus 2-Associated Granulomatous Dermatitis in a Horse

Granulomatous dermatitis in horses has been linked to many etiologies, including various parasites, fungi, and bacteria. Idiopathic forms of granulomatous inflammation-producing diseases, some of which are localized to the skin, also have been reported in horses. Herein we describe a case of recurrent equine granulomatous skin disease characterized by intranuclear viral inclusions within macrophages and giant cells. The histologic changes were primarily noted in the deep dermis and included multifocal to coalescing areas of necrosis marked by histiocytic cell infiltration and presence of giant cells. Electron microscopic examination revealed intranuclear and intracytoplasmic viral particles consistent with herpesvirus. Sequence results of the polymerase chain reaction product were consistent with equine herpesvirus 2, adding another possible etiology to the list of differentials in cases of equine granulomatous skin disease.

Ultrastructure of the spermatozoa from three odontocetes: a killer whale (Orcinus orca), a Pacific white-sided dolphin (Lagenorhynchus obliquidens) and a beluga (Delphinapterus leucas)

Semen was collected from three captive odontocetes: a killer whale (Orcinus orca); a Pacific white-sided dolphin (Lagenorhynchus obliquidens) and a beluga (Delphinapterus leucas). Semen was collected from the killer whale and Pacific white-sided dolphin using behavioural commands, whereas semen from the beluga was collected postmortem. Ultrastructure of the spermatozoa was examined using scanning and transmission electron microscopy. Species differences were more pronounced in the head sections followed by the midpiece and finally, the tail sections. Spermatozoa from the killer whale and beluga were similar but differed from the Pacific white-sided dolphin spermatozoa.

Angiolipomatous tumors in dogs and a cat

Variants of lipoma are uncommon, although fibrolipoma and infiltrative lipoma have been well documented. This report describes two cases of rare angiolipoma in dogs and the first documentation of angiofibrolipoma and infiltrating angiolipoma in a cat and a dog, respectively. Tumors were solitary, and most were located on the thorax of middle-aged patients. Angiolipomas were composed of mature adipose tissue mixed with variable numbers of blood vessels. In addition to the adipose and vascular components, the angiofibrolipoma contained bundles of collagenous connective tissue. The infiltrative angiolipoma had a primary mass external to the muscle and was histologically similar to a mixed intramuscular hemangioma that was confined to the muscle. Both disrupted bundles of striated muscle and were associated with segmental degeneration and loss of myofibers.

The potential toxicity of Ilex myrtifolia in beef cattle

Spatial and temporal patterns of death loss in a beef cowherd indicated a possible relationship between the loss of 11 cows and the consumption of Ilex myrtifolia (myrtle leaf holly). To investigate this relationship, plant material from Ilex myrtifolia was harvested and 2 feeding trials were performed. The 1st trial involved intermittent feeding of plant material to 4-mo-o calves for 2 w, and the 2nd trial was continuous plant feeding to 2-mo-o calves for 35 d. No significant clinical pathology, histological or gross lesions resulted and no clinical signs consistent with the original herd problem were observed, suggesting that berries, leaves and stems from Ilex myrtifolia were not sufficiently toxic to induce clinical effects under these experimental conditions.

Effects of macrophage inhibitory factor-A3 (MIF-A3) on cytokine secretion and phagolysosome fusion in murine macrophages

Macrophage inhibitory factor-A3 (MIF-A3) is a fraction derived from Mycobacterium avium serovar 2 (Mav2) that consists of a small amine containing compound (peptide), trehalose and two or three short chain fatty acids. MIF-A3 has been shown to inhibit candidacidal activity of murine thioglycolate-elicited peritoneal-derived macrophages and bovine peripheral blood monocytes, and scavenge reactive oxygen intermediates. In this study, MIF-A3 was evaluated for its effect on secretion of IL-1beta, IL-6, IL-10, TNFalpha and GM-CSF in C57BL/6 murine thioglycolate-elicited peritoneal-derived macrophages, with and without pre-incubation with affinity purified goat anti-MIF-A3 IgG, using ELISA cytokine kit analysis. Results of this study suggest that anti-MIF-A3 IgG does not enhance clearance of Mav2, alter phagocytosis or alter phagosome-lysosome interactions as determined by electron microscopy in Mav2 infected macrophages. MIF-A3 does induce secretion of IL-6, but does not induce secretion of TNFalpha, IL-1beta, and GM-CSF. TNFalpha has been previously shown to reduce growth, while IL-6 has been shown to enhance growth of M. avium. Since IL-6 appears to enhance growth of M. avium and MIF-A3 induces IL-6 secretion, MIF-A3 may be responsible for enhanced intracellular growth in M. avium infections and be a factor in the pathogenesis of M. avium infections.

Multiple persistent vitelline duct cysts in a dog

Persistent vitelline duct remnants, with the exception of Meckel's diverticulum in pigs and horses, are rare in animals. During an ovariohysterectomy of an 8-month-old Labrador Retriever, multiple fibrous nodules with cystic centers were found attached to the ileal serosa and in a mesodiverticular band attached to the abdominal wall. Histologic and ultrastructural evaluation revealed that the cysts were composed of well-differentiated intestine with mucosa, submucosa, and muscularis layers surrounded by a thick layer of fibrous connective tissue. The morphology and arrangement of lesions were consistent with multiple persistent vitelline duct cysts, a distinct condition related to Meckel's diverticulum. This case in a dog represents a unique presentation of this congenital anomaly in domestic animals.

Comparison of field-collected ascovirus isolates by DNA hybridization, host range, and histopathology

Six field-collected ascovirus isolates obtained from five noctuid species in the continental United States were compared with respect to the general relatedness of their DNA, host range, and histopathology. Two isolates were from Spodoptera frugiperda, and the other four were from Autographa precationis, Heliothis virescens, Helicoverpa zea, and Trichoplusia ni. DNA-DNA hybridization studies showed that the six isolates belonged to three distinct viral species, with the isolates from S. frugiperda composing one species, those from A. precationis and H. virescens a second species, and those from H. zea and T. ni a third species. The host range and histopathology of each isolate was studied in eight noctuid species, S. frugiperda, Spodoptera ornithogalli, Spodoptera exigua, Spodoptera eridania, H. virescens, H. zea, A. precationis, and Feltia subterranea. Though some variation existed between the different isolates of each viral species, distinct patterns were apparent for each. The viral species from S. frugiperda had a host range that was limited primarily to Spodoptera species and both isolates of this virus only replicated and caused significant pathology in the fat body, whereas the viral species from A. precationis and H. virescens had a much broader host range that included most of the species tested, but also had a tissue tropism primarily restricted to the fat body. The viral species from T. ni and H. zea readily infected all the hosts tested, where the principal site of replication and significant pathology was the epidermis. In many test hosts, however, this viral species also replicated and caused significant pathology in the tracheal epithelium and to a lesser extent in the fat body. Aside from contributing to knowledge of ascovirus biology, these studies indicate that DNA hybridization profiles combined with studies of host range and tissue tropism can be used as characters for defining ascovirus species.

Combined adenovirus and rotavirus enteritis with Escherichia coli septicemia in an emu chick (Dromaius novaehollandiae)

A 2-week-old emu chick (Dromaius novaehollandiae) of approximately 200 g body weight was presented for necropsy with a history of weakness, diarrhea, pallor of the head, and acute death. Hemorrhagic enteritis with mild hepatomegaly was noted on gross examination. Microscopic examination revealed necrohemorrhagic enteritis with intralesional intranuclear basophilic viral inclusion bodies in intestinal epithelial cells; splenic lymphoid necrosis and fibrin exudation; hepatocellular vacuolar change; and multiple clusters of small gram-negative bacilli in the liver, spleen, yolk sac, and intestine. Transmission electron microscopy of negatively stained fecal specimens and thin sections of small intestine revealed clusters of viral particles consistent with adenovirus and rotavirus. Attempts at viral isolation from pooled tissue specimens were unsuccessful. Escherichia coli was isolated from specimens of liver and intestine and from an abdominal swab.

Disseminated adenovirus infection associated with cutaneous and visceral hemorrhages in a nursing piglet

An unusual adenovirus infection in a conventionally raised nursing pig was characterized clinically by hemorrhagic diathesis of the skin and microscopically by disseminated viral inclusions in the endothelial, interstitial, and epithelial cells of the skin, kidney, spleen, liver, heart, and small and large intestines. This disease was confirmed ultrastructurally by demonstration of typical adenoviral particles in the nuclei of endothelial cells in the myocardium and of interstitial cells in the small intestine. This is the first report of disseminated adenovirus infection in a nursing pig in North America.

Isolation of Acanthamoeba sp. from a greyhound with pneumonia and granulomatous amebic encephalitis

Acanthamoeba were isolated from a naturally occurring animal infection of granulomatous amebic encephalitis. The amebas were grown from lung lesions from a 1-year-old greyhound puppy, which was 1 of several dogs in a kennel that was affected by a progressive fatal neurologic and respiratory disease. The Centers for Disease Control, Atlanta, Georgia, confirmed the disease to be acanthamebiasis and specifically identified the amebas as Acanthamoeba culbertsoni by fluorescent antibody testing on brain tissue from the dog. The amebas were cultured initially on potato dextrose agar and on nonnutrient agar plates that were seeded with a lawn of nonpathogenic Escherichia coli. The isolate was then transferred to nonnutrient agar plates containing killed Enterobacter aerogenes and subsequently to axenic medium and cell cultures. The isolate was highly pathogenic by intranasal inoculation into 2-week-old mice.

Fatal disease in nursing puppies associated with minute virus of canines

Thirteen cases of a previously undescribed parvoviral infection affecting puppies ranging in age from 5 to 21 days is described. The cases were originally thought to represent an unusual pathologic manifestation of canine parvovirus-2 (CPV-2) infection. However, failure to confirm CPV-2 infection in any of the cases suggested a different parvovirus was involved. Minute virus of canines (MVC) was subsequently isolated from a case by using the Walter Reed Canine Cell Line, the only cell line which will support the growth of MVC. The pathologic and virologic findings for these 13 cases are described in this report.

Clinical and pathologic features of ceroid lipofuscinosis in two Australian cattle dogs

A lysosomal storage disease was diagnosed in 2 Australian Cattle Dog siblings, using light and electron microscopic evaluation. Both dogs developed clinical signs of disease at about 1 year of age. Vision and motor function deteriorated over several months; by 2 years of age, the dogs were blind and had progressive ataxia. Cytoplasmic inclusions with ultrastructural patterns characteristic of ceroid lipofuscin were observed in most neurons examined and in the cells of several other parenchymatous tissues. Biochemical studies, including determination of lysosomal enzyme activities, excluded several other lysosomal storage diseases. In these dogs, the clinical and pathologic features of the disease were similar to those of the juvenile subtype of ceroid lipofuscinosis (Batten disease) in human beings.