Merogonic stages of Theileria cervi in mule deer (Odocoileus hemionus).

In February 2012, 12 farmed mule deer (Odocoileus hemionus) were moved from a facility in southwestern Oklahoma to a facility in southeastern Oklahoma that housed 100 farmed white-tailed deer (Odocoileus virginianus). Between the third and fifth weeks, 9 of the 12 mule deer had died, 4 of which were submitted for necropsy. The deer were heavily infested with Amblyomma americanum (lone star ticks).

Gross lesions of alimentary disease in adult cattle.

The purpose of the gross necropsy examination of the gastrointestinal tract is to recognize the presence of lesions, thus requiring a basic understanding of its normal appearance and anatomy. This article highlights gross changes to the gastrointestinal tract of adult cattle that help place the disease processes into broad categories. Although few gross lesions reach the zenith of pathognomonic, there are numerous lesions that, when considered in aggregate with history (eg, number of animals affected, environment, duration of signs, time of onset relative to management changes, previous management) and clinical signs, can help narrow the spectrum of causes, provide a basis for a strong presumptive diagnosis, and focus diagnostic test selection.

Genetic diversity of Hepatozoon spp. in coyotes from the south-central United States.

To better define the strains and species of Hepatozoon that infect coyotes in the south-central United States, whole blood and muscle samples were collected from 44 coyotes from 6 locations in Oklahoma and Texas. Samples were evaluated by a nested polymerase chain reaction (PCR) using primers amplifying a variable region of the apicomplexan 18S rRNA gene as well as histopathology (muscle only) for presence of tissue cysts. Hepatozoon spp.

Heat-related injury in lambs.

The broad spectrum of heat-related injury (HRI) and its associated lesions is well described in the human literature, with rare reports of similar findings in farm animals. In the current case series, lesions from 4 of 8 lambs that presented with clinical signs of heat stress are reported. Gross lesions at necropsy consisted of acute renal swelling and pallor in 2 of 4 lambs, muscle pallor in 2 of 4 lambs, and chronic bronchointerstitial pneumonia in each of the 4 lambs.

Detection of Trichinella murrelli in coyotes (Canis latrans) from Oklahoma and North Texas.

We determined the prevalence and mean intensity of Trichinella sp. infection in coyotes from six counties in Oklahoma and one in northern Texas. Tongues from 77 coyotes were examined using histology and artificial tissue digestion.

Novel Hepatozoon in vertebrates from the southern United States.

Novel Hepatozoon spp. sequences collected from previously unrecognized vertebrate hosts in North America were compared with documented Hepatozoon 18S rRNA sequences in an effort to examine phylogenetic relationships between the different Hepatozoon organisms found cycling in nature. An approximately 500-base pair fragment of 18S rDNA common to Hepatozoon spp.

Treatment of Hepatozoon americanum infection: review of the literature and experimental evaluation of efficacy.

There is no labeled treatment for dogs with American canine hepatozoonosis (ACH), but the drug therapies discussed in this article, although not rapidly curative, may be successful in alleviating acute clinical signs, prolonging life, reducing the number of clinical relapses, and enhancing quality of life. This article also describes a pilot trial conducted to assess the efficacy of a novel treatment approach with ponazuril as a stand-alone parasiticide administered for 4 weeks without follow-up decoquinate treatment. Although extended ponazuril treatment in combination with NSAID administration did ameliorate acute clinical signs associated with ACH, the parasite was not completely cleared with this treatment protocol alone.

Hyperphosphatasemia and concurrent adrenal gland dysfunction in apparently healthy Scottish Terriers.

Objective: To determine causes of hyperphosphatasemia (high serum alkaline phosphatase [ALP] activity) in apparently healthy Scottish Terriers.

Design: Prospective case-controlled study.

Animals: 34 apparently healthy adult Scottish Terriers (17 with and 17 without hyperphosphatasemia).

Pathogenesis and pathology of bovine pneumonia.

Pneumonia is a major cause of death and economic losses to the cattle industry. Recognizing the patterns of pneumonic lesions and understanding the pathogenesis of the various types of pneumonia are important for correct diagnosis and interpretation of the lesions. Bacterial pneumonias consist of bronchopneumonia, fibrinous pneumonia, and pleuropneumonia as well as caseonecrotic, aspiration, and tuberculous pneumonias.

Light and transmission electron microscopic characteristics of a novel Hepatozoon spp. in naturally infected cotton rats (Sigmodon hispidus).

A novel species of Hepatozoon was recently reported in cotton rats (Sigmodon hispidus) collected from an area of Oklahoma where American canine hepatozoonosis is endemic. In this study, the various stages of merogony of the parasite were characterized by light and electron microscopy. Meronts occurred within parasitophorous vacuoles in hepatocytes and ranged from mononucleated spherical forms to large, mature forms in vacuoles that contained approximately 50 peripherally arranged merozoites.

Lung pathology and infectious agents in fatal feedlot pneumonias and relationship with mortality, disease onset, and treatments.

This study charted 237 fatal cases of bovine respiratory disease (BRD) observed from May 2002 to May 2003 in a single Oklahoma feed yard. Postmortem lung samples were used for agent identification and histopathology. Late in the study, 94 skin samples (ear notches) were tested for Bovine viral diarrhea virus (BVDV) by immunohistochemistry (IHC).

Experimental transmission of Hepatozoon americanum to New Zealand White rabbits (Oryctolagus cuniculus) and infectivity of cystozoites for a dog.

Inflammatory lesions containing parasitic cystozoites developed in multiple organs and tissues of laboratory-raised Oryctolagus cuniculus that were administered approximately 100 sporulated oocysts of Hepatozoon americanum (Oklahoma isolate, GenBank accession AF176836) orally. The predominantly granulomatous inflammatory lesions were detected histologically 8 weeks after exposure to oocysts. Cystozoites, recognized by cresent-shaped, uninucleated bodies surrounded by an accumulation of globular, PAS-positive polysaccharide material, were evident within macrophages as monozoic and dizoic cysts.

New developments in canine hepatozoonosis in North America: a review.

Canine hepatozoonosis is caused by Hepatozoon canis and Hepatozoon americanum, apicomplexan parasites transmitted to dogs by ingestion of infectious stages. Although the two agents are phylogenetically related, specific aspects, including characteristics of clinical disease and the natural history of the parasites themselves, differ between the two species. Until recently, H.

Infectivity of Hepatozoon americanum cystozoites for a dog.

Hepatozoon americanum cystozoites from experimentally infected, laboratory-raised rodents were fed to a Hepatozoon-free dog. Gamonts were detected by examination of blood smear 42 and 56 days post-exposure. PCR analysis of blood was positive for the 18S rRNA Hepatozoon gene on days gamonts were demonstrated.

Experimental transmission of Hepatozoon americanum to rodents.

Laboratory-raised cotton rats (Sigmodon hispidus), outbred white mice (Mus musculus), and C57BL/6J-Lystbg-J/J mice (M. musculus) that were administered approximately 50 sporulated oocysts of Hepatozoon americanum (AF176836) by gavage developed inflammatory lesions containing parasitic cystozoites in cardiac and skeletal muscle, kidney, and lung. Sprague-Dawley rats (Rattus norvegicus) similarly exposed showed no evidence of infection.

Field survey of rodents for Hepatozoon infections in an endemic focus of American canine hepatozoonosis.

Eighteen of 31 (58%) cotton rats (Sigmodon hispidus) and 8 of 24 (33.3%) white-footed mice (Peromyscus leucopus) that were wild-trapped from 4 American canine hepatozoonosis endemic sites in Oklahoma were infected with Hepatozoon species. The predilection organ for merogony of the Hepatozoon species in cotton rats was the liver.

Tympany, acidosis, and mural emphysema of the stomach in calves: report of cases and experimental induction.

Necropsy of 4 neonatal calves with a peracute syndrome of abdominal distention, diarrhea, dehydration, shock, and death revealed abomasal tympany, marked edema, hemorrhage, and emphysema of ruminal and abomasal walls and histopathologic lesions characteristic of forestomach acidosis. The presence of acid damage and the production of substantial quantities of gas strongly suggested that the pathogenesis of the syndrome involved exuberant fermentation of intragastric substrate. This supposition led to attempts to experimentally induce the syndrome by dosing neonatal calves with an alimentary tract flora, followed by milk replacer supplemented with excessive fermentable carbohydrate (D-glucose and cornstarch).

Hyperphosphatasemia in Scottish terriers: 7 cases.

Increased serum alkaline phosphatase (ALKP) activity in dogs is commonly encountered. In the study reported here, 7 Scottish Terriers were identified with hyperphosphatasemia, for which a cause could not be determined. The clinicopathologic findings of the syndrome are described and correlated with hepatic pathologic changes in biopsy specimens and in specimens obtained at postmortem examination.

Recombinant Mannheimia haemolytica serotype 1 outer membrane protein PlpE enhances commercial M. haemolytica vaccine-induced resistance against serotype 6 challenge.

Mannheimia haemolytica outer membrane protein PlpE, a major immunogenic outer membrane lipoprotein has identical sequences in serotypes 1 (S1) and S6. Recombinant outer membrane lipoprotein PlpE (rPLpE) from M. haemolytica S1 was added to commercial M.

Experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of Hepatozoon americanum (Apicomplexa: Adeleorina).

Each of five adult and four juvenile coyotes (Canis latrans) was exposed to an oral dose of 50 Hepatozoon americanum oocysts recovered from Amblyomma maculatum ticks that previously fed on either naturally infected domestic dogs (Canis familiaris) or naturally infected wild coyotes. All coyotes exposed to H. americanum became infected, regardless of isolate source, and all exhibited mild to moderate clinical disease that simulated American canine hepatozoonosis in naturally infected dogs.

Immunogenicity of recombinant Mannheimia haemolytica serotype 1 outer membrane protein PlpE and augmentation of a commercial vaccine.

Mannheimia haemolytica is the major cause of severe bacterial pneumonia associated with shipping fever in cattle. The gene for M. haemolytica outer membrane protein (OMP) PlpE was cloned into the expression vector pRSETA.

Determination of time of onset and location of early skeletal lesions in young dogs experimentally infected with Hepatozoon americanum using bone scintigraphy.

Canine hepatozoonosis caused by Hepatozoon americanum has periosteal proliferation on long bones, pelvis, vertebrae, and skull. The pathogenesis of the periosteal proliferation is unknown but may be similar to hypertrophic osteopathy. Objectives were to determine the time frame for onset of bone lesions, to characterize spatial distribution of early bone lesions, and to describe the scintigraphic appearance of bone lesions in six immature dogs infected with 400 H.