Alan D. Liggett

Endometritis in Postparturient Cattle Associated with Bovine Herpesvirus-4 Infection: 15 Cases

Suppurative, ulcerative endometritis associated with bovine herpesvirus-4 (BHV-4) infection was identified in 15 postparturient dairy cows from 5 separate dairies. Characteristic eosinophilic to amphophilic intranuclear viral inclusion bodies were identified within degenerate endometrial lining epithelium and endothelial cells. Bovine herpesvirus-4 was confirmed as the etiology by a combination of fluorescent antibody assays, viral isolation, heminested PCR, ultrastructural examination of the uterus and inoculated tissue culture cells, and negative-stain electron microscopy of tissue culture supernatant. Viral particles measuring 70–95 nm were demonstrated in uterine epithelial and endothelial cells by electron microscopy. Bacteria including Arcanobacterium pyogenes, Escherichia coli, and an α-Streptococcus isolate were isolated from all uteri. Bovine herpesvirus-4-associated endometritis has been previously reported in sporadic cases in Europe but has not been previously reported in the United States. Endometritis associated with BHV-4 appears to be an emerging syndrome in Georgia dairy herds.

Seroprevalence and Comparison of Isolates of Endometriotropic Bovine Herpesvirus-4

Sixty-eight cases of suppurative, ulcerative endometritis associated with Bovine Herpesvirus-4 (BHV-4) in postparturient dairy cows (62 Holsteins and 6 Jerseys, mean age 4.2 years) were confirmed by a combination of histopathology, fluorescent antibody assays, electron microscopic evaluation of uterus, and polymerase chain reaction (PCR). All cases occurred in the 3- to 28-day postpartum period, and histologic lesions among various cows were consistent when compared with postpartum interval. The endometrial lining epithelium was necrotic and ulcerated from 3 to 7 days postpartum, with only mild inflammation in the lamina propria and submucosa. From 1 to 4 weeks postpartum, the ulcers were confluent to diffuse. Epithelium was replaced by fibrinonecrotic, suppurative mats, resulting in severe bacterial pyometra by day 24. Seroprevalence to BHV-4 in one dairy with a history of 18 mortality cases was 36% (107 of 296). In a random sample of 8 cows from this herd, none had serologic titers in blood sampled 2 weeks prepartum, but 3 of 8 seroconverted with significant titers of 1:8 to 1:16 at 2 weeks postpartum. By 10 weeks postpartum, all 8 cows returned to negative serologic status. Two of 6 cats from the premises also had positive titers. Random serum samples taken from 480 dairy cattle at sale barns indicated 76 (16%) were positive by serum neutralization. Clinical signs, postparturient timing, and histologic lesions were very similar to those previously reported in Belgium with BHV-4. But sequence analysis of PCR products of the glycoprotein B region of 4 separate field isolates of endometriotropic BHV-4 suggests these field isolates were more closely related to the North American nonvirulent strain DN-599 than to the endometriotropic European strain V.

Gastrointestinal cryptosporidiosis in a puppy.

An 8-week-old female Yorkshire terrier with a history of weakness, diarrhea and intestinal isosporiasis was euthanized and a post mortem examination performed. Histologically, there was severe gastrointestinal cryptosporidiosis, severe intestinal isosporiasis and thymic lymphoid depletion. PCR revealed visible bands for the actin and 18S rRNA genes but not for the acetyl CoA synthetase gene for Cryptosporidium spp. The PCR product for the actin gene was sequenced and found to have a 97.6-99.8% similarity to that of Cryptosporidium canis. To our knowledge, this is the first report of gastric cryptosporidiosis in a canine.

Protection of pigs by vaccination of pregnant sows against eastern equine encephalomyelitis virus.

Abstract Serum-virus neutralizing antibodies were detected in serum and colostrum of sows vaccinated during pregnancy with commercially available vaccines against eastern equine encephalomyelitis virus (EEEV), and antibodies were detected in serum from nearly all pigs from vaccinated sows flllowing colostrum uptake. Serum-virus neutralizing antibody (SVN) test titers were measured in colostrum and pigs at the next farrowing, and additional vaccination of sows prior to the third farrowing led to elevated SVN titers in serum, colostrum and all pigs. Six pigs from vaccinated sows challenged at 8 to 9 days of age with 1 × 106 TCID50 EEEV did not develop the high temperatures or signs of central nervous system disease that 6 pigs from non-vaccinated sows developed. Virus was isolated from blood and oropharyngeal swabs from all pigs from non-vaccinated sows with blood virus titers as high as 9.3 × 104 TCID50, while only low levels of virus were detected in blood and oropharyngeal swabs from pigs from vaccinated sows. Virus was also isolated from tonsils collected at necropsy from 3 pigs from non-vaccinated and 1 pig from vaccinated sows. Vaccination of pregnant sows leads to development of maternal antibodies that are transmitted via colostrum to pigs and are protective against clinical EEEV related disease after experimental challenge with EEEV. In addition, vaccination prevents amplification of virus in infected pigs and could result in protection of animals and farm labor in the environment of infected pigs.

Prevalence of Exposure to Eastern Equine Encephalomyelitis Virus in Domestic and Feral Swine in Georgia

Eastern equine encephalomyelitis (EEE) is endemic in the eastern United States. The number of cases during the summer of 1991 reached epizootic proportions in horses, and 2 human cases were diagnosed in Georgia (Fig. 1). In addition, 2 outbreaks of EEE virus infection were diagnosed in swine and confirmed by isolation of EEE virus at the Veterinary Diagnostic and Investigational Laboratory (VDIL) in Tifton, Georgia. Eastern equine encephalomyelitis virus infection in pigs has been described in Georgia, and antibodies to EEE virus in swine have been reported from other states in the USA. The clinical disease in swine probably is underdiagnosed in swine-producing areas with high incidence of EEE in horses or other species because cell lines routinely used to isolate virus from porcine tissues do not readily propagate EEE virus. Financial losses to swine producers due to EEE have not been estimated but were substantial in cases reported in Georgia and in 1994 in Florida. In the Florida outbreak, a 16-year-old farm worker also had clinical signs consistent with EEE virus infection. The objective of this study was to determine prevalence of exposure to EEE virus in selected populations of domestic swine in Georgia and in feral swine on Ossabaw Island, a barrier island in the Atlantic Ocean off the Georgia coast. Serum samples from domestic swine received in accessions for pseudorabies and brucellosis testing at the VDIL from June to September 1991 and from April to July 1992 were analyzed for neutralizing antibodies to EEE virus. An accession is defined as a collection of specimens from 1 locale (farm or stockyard) on 1 date. Accessions were selected nonrandomly for testing to reflect close spatial (same or neighboring county) and temporal (within 1 week) proximity to clinical EEE cases in all species (Fig. 1, 2). A total of 1,247 specimens in 65 accessions were tested: 46 accessions with 1,064 specimens were from 45 farms, 16 accessions with 151 specimens were from 6 stockyards/salesbarns, and 3 acces-

Canine parvovirus-2b-associated erythema multiforme in a litter of English Setter dogs

Erythema multiforme (EM) was diagnosed in a litter of English Setter puppies. The puppies developed erythematous cutaneous lesions at the age of 2 weeks. Microscopically, there was individual keratinocyte apoptosis associated with lymphocyte exocytosis in all layers of the epidermis. Intranuclear viral inclusions were seen in multiple tissues and organs. Tissues from the tongue, lymph node, spleen, skin, and small intestine were positive for Canine parvovirus-2 (CPV-2) and negative for Canine distemper virus (CDV) and Canid herpesvirus 1 by fluorescent antibody test. Negative-staining electron microscopy detected parvovirus particles in the intestinal contents. The skin and small intestine were positive for CPV-2b and negative for CDV by polymerase chain reaction. The mucocutaneous junctions and small intestines stained positive for CPV by immunohistochemistry. The present report documents CPV-2b–associated EM in a litter of English Setters and substantiates the single previous report associating EM with CPV-2. The finding suggests that CPV should be considered as a possible cause of EM in dogs.

Liver Necrosis Caused by Mushroom Poisoning in Dogs

Mushrooms in Category A cause hepatic and renal damage after a prolonged latent period and are the most common cause of fatal mushroom poisonings in human beings. Category A is subdivided into 2 groups on the basis of the type of toxin produced. The genera Amanita and Galerina produce cyclopeptide toxins (Group I), and Gyromitra produces monomethylhydrazine toxins (Group II). Several Amanita species contain 3 kinds of cyclopeptide toxins: phallolysin, phallotoxins, and amanitins. 9 Of these toxins, only the amanitins play a significant role in poisonings. Mushrooms in categories B, C, and D have a rapid onset of clinical signs and effect the autonomic nervous system, central nervous system, and gastrointestinal tracts, respectively. Only one of the reported cases of mushroom poisoning in the dog was associated with a mushroom in Category A in which several animals were poisoned by ingesting Amanita phalloides. 6 Other mushrooms in this genus and category that have either been associated with human poisonings or contain amanitins are Amanita verna, Amanita virosa, Amanita bisporigera, and Amanita ocreata. 8 The purpose of this report is to describe the clinical and laboratory findings in 2 cases of canine mushroom poisoning. A 7-week-old male golden retriever had a sudden onset of extreme listlessness, ataxia, and petit mal seizures. The owner had observed the animal eating mushrooms on the day prior to onset of clinical signs. The puppy did not respond to intravenous Lactated Ringer’s solution and Valium and died within 6 hr of onset of clinical signs. Fresh and formalinfixed tissue, stomach contents, urine, clotted blood, and a mushroom were submitted to the diagnostic laboratory for evaluation. Strychnine was not detected in urine or stomach contents. The mushroom was identified as A. verna by a mycologist. The owner of the second case owned a small kennel and observed a sudden onset of yelping and a tense abdomen in a 12-week-old female Labrador retriever. The puppy became

Thymic Hematoma in Juvenile Dogs Associated with Anticoagulant Rodenticide Toxicosis

Ten cases of thymic hematoma in young dogs (9–24 weeks of age) were reviewed. Anticoagulant rodenticide toxicosis was confirmed in 5 cases. Histologically, hemorrhage caused variable expansion of thymic lobules and interlobular septa. The medulla appeared to be the primary site of hemorrhage. In areas of severe hemorrhage, normal lobular architecture was lost and lymphocytes were admixed in the hemorrhagic exudate. Vasculitis, necrosis of capillaries, and degeneration of the capsule were observed in infarcted areas. In 2 cases, angiofibroplasia indicated a longer interval between onset of thymic hemorrhage and death. The lesions are similar to those in 5 cases of idiopathic thymic hemorrhage. Appropriate samples were not available for anticoagulant rodenticide analysis in 3 of these 5 idiopathic cases. Lesions in confirmed cases of anticoagulant rodenticide toxicosis also are compatible with published descriptions of idiopathic and spontaneous thymic hemorrhage, but are inconsistent with normal thymic involution. Analysis for anticoagulant rodenticides is indicated in cases of thymic hematoma when an obvious cause is not detected at necropsy.

Multiple Cutaneous Metaplastic Ossification Associated with Iatrogenic Hyperglucocorticoidism

20 Other generalized signs reported in affected animals include polydipsia, polyuria, muscle weakness, hepatomegaly, and myopathies. Although calcinosis cutis in its broadest definition can encompass all forms of calcium deposition, it is most commonly used to denote the specific pattern of dystrophic calcification associated with hyperadrenocorticism or iatrogenic hyperglucocorticoidism. 8 The mechanism of this process has not been completely elucidated, but it involves phase transformation of calcium and phosphate ions from solution into crystalline aggregates, with deposition upon the matrices of dermal collagen and elastin under the influence of cellular factors. 3,8 The collagen fibers in these cases are variably mineralized, and root sheaths may also be affected. 8,20 The deposition of minerals in calcinosis cutis is often not associated with areas of inflammation and, when observed, typically consists of a histiocytic foreign-body-type reaction. In contrast, several dermatologic conditions of humans known as metaplastic ossification, primary or secondary osteoma cutis, plate-like osteoma, and acquired cutaneous osteomatosis are characterized by metaplastic bone formation in the dermis, where osteoid formation occurs with or without collagen mineralization. 2,4,7,10,12,15,18 Some of these syndromes are id