Myosin heavy-chain myopathy in 2 American quarter horses.

A 1.5-year-old American quarter horse gelding (case 1) and an 11-month-old American quarter horse filly (case 2) were presented for acute onset pelvic lameness and lethargy. Case 1 had nasal discharge, while case 2 developed rapid muscle atrophy.

The effects of signalment, diet, geographic location, season, and colitis associated with antimicrobial use or Salmonella infection on the fecal microbiome of horses.

Background: The fecal microbiome of healthy horses may be influenced by signalment, diet, environmental factors, and disease.

Objectives: To assess the effects of age, breed, sex, geographic location, season, diet, and colitis caused by antibiotic use (antimicrobial-associated diarrhea [AAD]) and Salmonella infection on fecal microbiota.

Animals: Healthy horses (n = 80) were sampled from nonhospital environments across multiple geographical locations in the United States.

Alterations in the Fecal Microbiome and Metabolome of Horses with Antimicrobial-Associated Diarrhea Compared to Antibiotic-Treated and Non-Treated Healthy Case Controls.

Diarrhea is an adverse effect of antimicrobial therapy in horses. This matched, case-controlled study compared the fecal microbiome and metabolome of horses on antibiotics that developed diarrhea (AAD, = 17) to those that did not develop diarrhea (ABX, = 15) and to a control population not exposed to antibiotics (CON, = 31). Fecal samples were collected from horses that were matched for diet and antimicrobial agent (including dose, route, and duration of therapy).

Immersion Foot Syndrome in 6 Equids Exposed to Hurricane Floodwaters.

Prolonged exposure to water, known as immersion foot syndrome in humans, is a phenomenon first described in soldiers during World War I and characterized by dermal ischemic necrosis. In this report, we describe the pathologic findings of a condition resembling immersion foot syndrome in 5 horses and 1 donkey with prolonged floodwater exposure during Hurricane Harvey. At necropsy, all animals had dermal defects ventral to a sharply demarcated "water line" along the lateral trunk.

Signalment, clinical features, and outcome for male horses with urethral rents following perineal urethrotomy or corpus spongiotomy: 33 cases (1989-2013).

OBJECTIVE To describe the signalment, clinical features, and outcome for male horses with urethral rents following perineal urethrotomy (PU) or corpus spongiotomy (CS). DESIGN Retrospective case series. ANIMALS 33 horses.

Chagas disease in a Texan horse with neurologic deficits.

A 10-year-old Quarter Horse gelding presented to the Texas A&M University Veterinary Teaching Hospital with a six month-history of ataxia and lameness in the hind limbs. The horse was treated presumptively for equine protozoal myeloencephalitis (EPM) based on clinical signs but was ultimately euthanized after its condition worsened. Gross lesions were limited to a small area of reddening in the gray matter of the thoracic spinal cord.

Composition and Diversity of the Fecal Microbiome and Inferred Fecal Metagenome Does Not Predict Subsequent Pneumonia Caused by Rhodococcus equi in Foals.

In equids, susceptibility to disease caused by Rhodococcus equi occurs almost exclusively in foals. This distribution might be attributable to the age-dependent maturation of immunity following birth undergone by mammalian neonates that renders them especially susceptible to infectious diseases. Expansion and diversification of the neonatal microbiome contribute to development of immunity in the gut.

Gallium maltolate as an alternative to macrolides for treatment of presumed Rhodococcus equi pneumonia in foals.

Background: Macrolide-resistant isolates of Rhodococcus equi are emerging, prompting the search for clinically effective alternative antimicrobials.

Hypothesis: The proportion of foals with ultrasonographic evidence of pneumonia presumed to be caused by R. equi that had a successful outcome when administered gallium maltolate (GaM) PO would not be more than 10% inferior (ie, lower) than that of foals receiving standard treatment.

Ultrasonographic visualization of the liver in sites recommended for blind percutaneous liver biopsy in horses.

Objective: To ascertain the frequency of ultrasonographic identification of liver at sites recommended for blind percutaneous liver biopsy in middle-aged horses and to determine whether the liver is obscured by other organs or too thin for safe sample collection at recommended locations.

Design: Prospective case series.

Animals: 36 healthy middle-aged (between 3 and 18 years old) Quarter Horses or Quarter Horse crosses [Corrected].

Identification of genomic loci associated with Rhodococcus equi susceptibility in foals.

Pneumonia caused by Rhodococcus equi is a common cause of disease and death in foals. Although agent and environmental factors contribute to the incidence of this disease, the genetic factors influencing the clinical outcomes of R. equi pneumonia are ill-defined.

Risk factors associated with nasopharyngeal cicatrix syndrome in horses.

Objective: To determine risk factors associated with the development of nasopharyngeal cicatrix syndrome (NCS) in horses.

Design: Retrospective case-control study.

Animals: 242 horses referred for endoscopic evaluation of the upper portion of the respiratory tract (121 horses with NCS and 121 control horses).

Enthesopathy and desmitis of the medial collateral ligament of the cubital joint in 4 horses.

Case Description: 4 horses with enthesopathy and desmitis of the medial collateral ligament of the cubital joint were examined.

Clinical Findings: All 4 horses had a history of acute, severe, unilateral forelimb lameness and had signs of pain during manipulation of the affected upper forelimb; 2 also had swelling in the axillary region. There was no improvement in lameness after diagnostic local analgesia below the carpal region, and 1 of 4 horses had mild improvement after cubital joint analgesia.

Nephrectomy via ventral median celiotomy in equids.

Objective: To report technique for, and outcome after, nephrectomy through a ventral median celiotomy in equids.

Study Design: Case series.

Animals: Equids with unilateral renal disease (n = 6), aged 2 months to 18 years, weighing 90-434 kg.

Association of perinatal exposure to airborne Rhodococcus equi with risk of pneumonia caused by R equi in foals.

Objective: To determine whether the concentrations of airborne virulent Rhodococcus equi in stalls housing foals during the first 2 weeks after birth are associated with subsequent development of R equi pneumonia in those foals.

Sample: Air samples collected from foaling stalls and holding pens in which foals were housed during the first 2 weeks after birth.

Procedures: At a breeding farm in Texas, air samples (500 L each) were collected (January through May 2011) from stalls and pens in which 121 foals were housed on day 1 and on days 4, 7, and 14 after birth.

Abdominal abscesses in adult horses: 61 cases (1993-2008).

Objective: To determine clinical signs, diagnostic methods, treatment, and outcome for a series of adult horses with abdominal abscesses.

Design: Retrospective case series.

Animals: 61 adult horses.

Association of airborne concentration of virulent Rhodococcus equi with location (stall versus paddock) and month (January through June) on 30 horse breeding farms in central Kentucky.

Objective: To determine whether the concentration of airborne virulent Rhodococcus equi varied by location (stall vs paddock) and month on horse farms.

Sample: Air samples from stalls and paddocks used to house mares and foals on 30 horse breeding farms in central Kentucky.

Procedures: Air samples from 1 stall and 1 paddock were obtained monthly from each farm from January through June 2009.

Association of clinical signs with endoscopic findings in horses with nasopharyngeal cicatrix syndrome: 118 cases (2003-2008).

Objective: To characterize the associations between clinical signs of nasopharyngeal cicatrix syndrome (NCS) and endoscopic findings in horses.

Design: Retrospective, case-control study.

Animals: 239 horses (118 case horses and 121 control horses).

Rhodococcus equi: clinical manifestations, virulence, and immunity.

Pneumonia is a major cause of disease and death in foals. Rhodococcus equi, a gram-positive facultative intracellular pathogen, is a common cause of pneumonia in foals. This article reviews the clinical manifestations of infection caused by R.

Diagnosis, treatment, control, and prevention of infections caused by Rhodococcus equi in foals.

Rhodococcus equi, a gram-positive facultative intracellular pathogen, is one of the most common causes of pneumonia in foals. Although R. equi can be cultured from the environment of virtually all horse farms, the clinical disease in foals is endemic at some farms, sporadic at others, and unrecognized at many.

Heterobilharzia americana infection as a cause of hepatic parasitic granulomas in a horse.

CASE DESCRIPTION-A 22-year-old American Paint Horse gelding from the Gulf Coast region of Texas was evaluated for regrowth of a perirectal squamous cell carcinoma that had been surgically removed 11 months previously. CLINICAL FINDINGS-A necrotic and ulcerated mass was present below the anus. The horse had paraphimosis and was having difficulty with urination.

Starry sky hepatic ultrasonographic pattern in horses.

The starry sky hepatic pattern is an unusual ultrasonographic appearance of equine liver characterized by numerous small, hyperechoic foci, some of which cast an acoustic shadow, distributed randomly throughout the hepatic parenchyma. Our objectives were to describe the signalment, clinical signs, clinicopathological findings, primary disease process, and ultrasonographic findings of horses with this ultrasonographic pattern, as well as determine the associated gross and histologic changes. The starry sky pattern was identified in 18 adult horses of mixed gender and breed.

Evaluation of the efficacy of gallium maltolate for chemoprophylaxis against pneumonia caused by Rhodococcus equi infection in foals.

Objective: To determine the chemoprophylactic effect of gallium maltolate on the cumulative incidence of pneumonia caused by Rhodococcus equi infection in foals.

Animals: 483 foals born and raised on 12 equine breeding farms with a history of endemic R equi infections.

Procedures: Group 1 foals were treated with a placebo and group 2 foals were treated with gallium maltolate (approx 30 mg/kg, PO, q 24 h) during the first 2 weeks after birth.

Sonographic characteristics of intraabdominal abscessation and lymphadenopathy attributable to Rhodococcus equi infections in foals.

The sonographic characteristics of intraabdominal abscesses in 11 foals and intraabdominal lymphadenitis in five foals with Rhodococcus equi infections are presented. Intraabdominal abscesses were usually present in the ventral abdomen adjacent to the ventral body wall, well-marginated, and contained a mixed or complex echo pattern. Lymphadenitis appeared as singular or multiple clusters of lymph nodes of mixed echogenicity adjacent to any portion of the gastrointestinal tract or body wall.

Effects of location for collection of air samples on a farm and time of day of sample collection on airborne concentrations of virulent Rhodococcus equi at two horse breeding farms.

Objective: To determine whether airborne concentrations of virulent Rhodococcus equi at 2 horse breeding farms varied on the basis of location, time of day, and month.

Sample Population: 2 farms in central Kentucky with recurrent R equi-induced pneumonia in foals.

Procedures: From February through July 2008, air samples were collected hourly for a 24-hour period each month from stalls and paddocks used to house mares and their foals.