Explanation and Elaboration Document for the STROBE‐Vet Statement: Strengthening the Reporting of Observational Studies in Epidemiology – Veterinary Extension

The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement was first published in 2007 and again in 2014. The purpose of the original STROBE was to provide guidance for authors, reviewers and editors to improve the comprehensiveness of reporting; however, STROBE has a unique focus on observational studies. Although much of the guidance provided by the original STROBE document is directly applicable, it was deemed useful to map those statements to veterinary concepts, provide veterinary examples and highlight unique aspects of reporting in veterinary observational studies. Here, we present the examples and explanations for the checklist items included in the STROBE‐Vet Statement. Thus, this is a companion document to the STROBE‐Vet Statement Methods and process document, which describes the checklist and how it was developed.     

Clinical Features and Prognostic Variables in 109 Horses with Esophageal Obstruction (1992–2009)

Background: Esophageal obstruction is common in horses and can result in life‐threatening complications. Previous studies have described clinical findings in horses with esophageal obstruction, but there are no reports that attempt to make correlations of clinical findings with outcome. Hypothesis: Specific clinical features of horses with esophageal obstruction are associated with increased likelihood of complications. Animals: One hundred and nine horses with esophageal obstruction. Methods: Retrospective cross‐sectional study. All clinical records of horses admitted between April 1992 and February 2009 for esophageal obstruction were reviewed. The association among 24 clinical, hematological, biochemical, therapeutic variables and the likelihood of complications was investigated by a univariable logistic regression model, followed by multivariable analysis. Results: Multiple logistic regression analysis revealed that intact males (P= .02), age >15 years (P < .01), and a need for general anesthesia (P < .01) were associated with the development of complications after an episode of esophageal obstruction. Increased respiratory rate (>22 breaths/min) and moderate or severe tracheal contamination, although not associated with complications as a whole, significantly increased the risk of developing aspiration pneumonia (P≤ .01). Conclusions and Clinical Importance: Signalment, clinical variables, and endoscopic findings were confirmed as important tools in assessing the severity of the esophageal lesion and pulmonary involvement. Knowledge of risk factors for the development of complications will aid in making informed decisions to optimize treatment and assist in the assessment of prognosis.     

Risk factors for equine acute abdominal disease (colic): Results from a multi-center case-control study

Many causal hypotheses for acute equine abdominal disease (colic) have been proposed. However, few epidemiologic studies have been undertaken to identify risk factors for the syndrome. Risk factors for equine colic were identified using a hospital-based, multi-center, case-control study. Horses admitted with abdominal pain to Cornell, Guelph, Ohio State, Pennsylvania or Tufts university veterinary hospitals between March and December 1991 were selected. Control horses were randomly selected from a list of all other non-colic admissions. The person(s) responsible for the day-to-day care of the horse completed a telephone questionnaire. Risk factors were identified using multivariable logistic regression analysis.

A total of 406 colic and 406 control horses were used in the final analysis. Age, breed, outdoor access (pasture or drylot), outdoor water supply, use of a daily worming product, amount of concentrates and whole-grain corn consumed, type of person responsible for the day-to-day care of the horse and previous colic history were all significantly associated with colic risk. Arabian horses were more than twice as likely to be colic cases (OR = 2.0, 95% CI = 1.0–3.9), whereas Standardbred horses were nearly half as likely (OR = 0.6, 95% CI = 0.4–1.0) to be colic cases compared with the comparison Thoroughbred group. Horses that had access to outdoor enclosures without a continuous supply of water were more than twice as likely (OR = 2.2, 95% CI = 1.2–4.3) to be colic cases compared with horses that had an adequate supply of water on outside enclosures. The use of a daily worming product for at least 60 days during the 12-month period prior to presentation was associated with a significantly lower colic risk (OR = 0.11, 95% CI = 0.02–0.55). Colic risk increased with greater consumption of whole-grain corn; however, when all non-roughage concentrate feeds were combined, colic risk decreased with increased intake of concentrates. Significant interactions were identified between age and drylot use and between the type of care-person responsible for the day-to-day care of the horse (owner or non-owner) and previous colic history.

The findings of this study illustrate the complex multi-factorial nature of equine colic and point towards the importance of the overall quality of stable management and care, as well as the type of outdoor enclosure (pasture or drylot), water access, carbohydrate intake, parasite control and intrinsic (breed-related) factors.     

Investigation of the prevalence of neurologic equine herpes virus type 1 (EHV-1) in a 23-year retrospective analysis (1984–2007)

A single nucleotide polymorphism in the equine herpesvirus 1 (EHV-1) DNA polymerase gene (ORF30 A₂₂₅₄ to G) has been associated with clinical signs of equine herpes myeloencephalopathy (EHM). The purpose of our study was to determine the odds ratio for this genetic marker and EHM using a panel of field isolates from North America collected over the past twenty-three years. EHV-1 isolates cultured at the Cornell University Animal Health Diagnostic Laboratory from 1984 to 2007 were retrieved along with their clinical histories. DNA was extracted from these EHV-1 cultures and allelic discrimination was performed using real-time PCR. The results were confirmed by sequencing of the target region in ORF30. PCR and sequencing were in 100% agreement and showed that 19 out of the 176 isolates had the ORF30 G₂₂₅₄ allele (11%), of which16 were EHM cases and 3 respiratory or abortion cases. The odds of having neurologic disease with the ORF30 G₂₂₅₄ genotype were computed as 162 times greater than those with the opposite allele ORF30 A₂₂₅₄ (95% confidence interval: 35–742). Despite this strong statistical significance, 24% (5/21) of horses with neurologic disease in our study population harbored the “non-neurologic” form of the allele (ORF30 A₂₂₅₄), suggesting that other factors may also contribute to the onset of EHM.     

The Association of Fibrinous Pleural Effusion with Survival and Complications in Horses with Pleuropneumonia (2002–2012): 74 Cases

Background

Fibrinous parapneumonic pleural effusions are associated with decreased efficacy of pleural fluid drainage and increased risk of medical treatment failure in people, but similar associations have not been established in horses.

Hypothesis/Objectives

We hypothesized that fibrin deposition in the pleural cavity of horses with parapneumonic effusions increases the risk of poor outcome.

Animals

Seventy four horses with bacterial pleuropneumonia diagnosed by culture and cytology of tracheal aspirates, pleural fluid, or both, and pleural effusion diagnosed by ultrasonographic examination.

Methods

Retrospective study of cases was from 2002 to 2012. Information obtained from the medical records included signalment, history, sonographic findings, treatments, and outcome. The primary outcome investigated was survival and secondary outcomes were development of complications and surgical intervention. Fisher''s exact test and logistic regression were applied for categorical variables. A t‐test was used to find differences in continuous variables between groups.

Results

Seventy four horses met study criteria and 50 (68%) survived. Fibrinous pleural effusion was associated with higher respiratory rate and pleural fluid height at admission, necrotizing pneumonia, increased number of indwelling thoracic drains required for treatment, and decreased survival.

Conclusions and clinical importance

Fibrin accumulation in parapneumonic effusions is associated with increased mortality. Direct fibrinolytic treatment might be indicated in affected horses.     

Treatment of oromaxillary fistulae in nine standing horses (2002–2006)

Reasons for performing study: There is minimal published information on equine oromaxillary fistulae that are unrelated to cheek teeth (CT) repulsion or on the conservative treatment of these atypical fistulae. Objectives: To report equine oromaxillary fistulae unrelated to CT extraction and describe their management in standing horses. Methods: Case details of oromaxillary fistulae of atypical aetiology occurring at 2 referral centres between 2002–2006, including their treatment and response to treatment were examined. Results: Nine cases of oromaxillary fistula were recorded, mainly in aged horses (median 22 years). Fistulae were associated with CT diastemata in 7 cases, fractured CT in one and a central defect in a worn CT in another. After removing food and exudate from the sinuses, 6 cases were treated successfully by filling the diastema or dental defect with polymethylmethacrylate (PMMA). Following dental extraction, the other 3 cases were treated successfully by use of PMMA alveolar packing. Conclusion: Older horses can spontaneously develop oromaxillary fistulae, usually secondary to CT diastemata. In the absence of apical infection, this disorder can usually be treated successfully in standing horses by treating the sinusitis and sealing the oral aspect of the diastema with PMMA. Potential relevance: Older horses with sinusitis should be assessed for the presence of CT diastemata and oromaxillary fistulae. If detected, these disorders can be treated successfully in the standing horse.     

Lymphangiosarcoma in 12 dogs: a case series (1998–2013)

Lymphangiosarcoma (LAS) is an uncommon malignant neoplasia arising from lymphatic endothelium; little information exists regarding therapy. Single institutional retrospective review for canine LAS histopathology diagnoses over a 15‐year period yielded 12 dogs. Ten dogs were presented for a mass and/or swelling at cervical, trunk or limb regions. Prior to diagnosis, 10 dogs received empiric wound therapy. Cytology performed in 10 consisted of mild inflammation. Survival ranged from 60, 168 and 876 days for three dogs with palliation; 90 days with prednisone in one; 182 days with chemotherapy in one; 240, 267, 487, 630 and 941 days for five receiving surgery; and 574 days for one receiving surgery, radiation and chemotherapy. One dog is alive with recurrence at 243 days following surgery and carboplatin chemotherapy. Clinical improvement existed in LAS dogs receiving multimodal therapies. Early tissue biopsies are recommended for progressive oedematous lesions of unknown origin.     

Severe soft tissue infections in dogs: 47 cases (1996–2006)

Objective– To describe the patient population, microbiological findings, treatment and outcome in dogs with severe soft tissue infections (SSTIs) and to compare survivors to nonsurvivors. Design– Retrospective study. Animals– Forty‐seven dogs with confirmed soft tissue infections originating from the SC tissues, muscle or fascia. Interventions– None. Measurements and Main Results– Physical and clinicopathologic data on presentation, microbiological and histopathological findings, antimicrobial treatment and outcome. Dogs with SSTIs were predominantly large breed dogs with a median body weight of 35.6 kg. Incidence of pre‐existing conditions (immunomodulating diseases, blunt trauma, injections, clean surgical procedures) that could have contributed to development of SSTIs was 34%. Abnormal physical examination and diagnostic parameters on presentation included increased body temperature (median temperature 39.5 °C [103.1 °F]) and low arterial blood pressure (median systolic blood pressure 103.5 mm Hg). While Streptococcus species were the most commonly isolated bacteria, the incidence of polymicrobial infections differed between antemortem (38.7%) and postmortem (57.1%) cultures. The overall survival rate was 46.8%. Survivors had a higher body weight and higher respiratory rate on presentation than nonsurvivors. Nonsurvivors had a significantly lower WBC count and higher lactate, BUN, aspartate aminotransferase, and bilirubin concentrations. Histopathologic examination of tissue specimens showed that the degree of necrosis was higher in survivors compared with nonsurvivors. Conclusions– SSTIs in dogs are serious conditions associated with high mortality, significant inflammatory changes, and cardiovascular compromise. A number of conditions, including those that compromise skin integrity and immunomodulating diseases have been identified in our patient population and could have contributed to development of SSTIs. Polymicrobial infections occurred in many cases, necessitating broad‐spectrum antimicrobial coverage.     

Scapula stress fractures in Thoroughbred racehorses: Eight cases (1997–2006)

No case series exists in the literature describing scapula stress fractures. The purpose of this study was to review the clinical findings, diagnostic images and outcome of 8 horses diagnosed with scapula stress fractures. Scapula stress fractures were seen in Thoroughbred racehorses displaying acute moderate forelimb lameness. Nuclear scintigraphy identified the mid‐distal scapula spine and/or scapula supraspinous fossa as predilection sites. Conservative management resulted in a good prognosis for return to racing, but stress fracture recurrence may be seen.     

Evaluation of a new full‐body animal rescue and transportation sling in horses: 181 horses (1998–2006)

Objective– The goal of this study was to evaluate the reliability of the Animal Rescue and Transportation Sling (ARTS) for emergency and clinical use in horses. Design– A retrospective study of the use of the ARTS in the hospital and field. Setting– The medical records of 158 horses referred to the Equine Hospital, University of Zurich, and 23 records from the Large Animal Rescue. Animals– The ARTS was used in 121 standing and 60 recumbent horses. Seventy‐eight horses were sedated, 47 patients were under general anesthesia when the sling was applied and no sedation or anesthesia was required in 56 horses. Interventions and Main Results– The ARTS was applied in crane and helicopter rescue operations to stabilize horses that required lifting (n=41), during emergency transportation (n=24), to facilitate induction of general anesthesia (n=4) or recovery from general anesthesia (n=51). Additionally, the sling was used to immobilize horses with fractures (n=29), to reduce weight‐bearing in horses with severe lameness (n=12), to support horses with disorders of the CNS (n=7), to help recumbent horses rise (n=9), and to provide support for horses after repair of large abdominal hernias (n=4). Acceptance of the ARTS by the horses was scored as excellent (n=153), good (n=19) and poor (n=6), and the sling was not tolerated in 3 horses. Only after long‐term use (weeks) did the skin over certain pressure points become irritated, resulting in superficial pressure sores. Conclusions– The ARTS was reliable, safe, and easy to use. It proved to be ideal for a wide variety of emergencies.     

Distribution of alpha‐neoendorphin,ACTH (18–39) and beta‐endorphin (1–27) in the alpaca brainstem

Using an immunocytochemical technique, we have studied in the alpaca brainstem the distribution of immunoreactive structures containing prodynorphin (alpha‐neoendorphin)‐ and pro‐opiomelanocortin (adrenocorticotrophin hormone (18–39) (ACTH), beta‐endorphin (1–27))‐derived peptides. No peptidergic‐immunoreactive cell body was observed. Immunoreactive fibres were widely distributed, although in most of the brainstem nuclei the density of the peptidergic fibres was low or very low. In general, the distribution of the immunoreactive fibres containing the peptides studied was very similar. A close anatomical relationship occurred among the fibres containing alpha‐neoendorphin, ACTH or beta‐endorphin (1–27), suggesting a functional interaction among the three peptides in many of the brainstem nuclei. The number of fibres belonging to the prodynorphin system was higher than that of the pro‐opiomelanocortin system. A moderate/low density of immunoreactive fibres was observed in 65.11% (for alpha‐neoendorphin (1–27)), 18.18% (for ACTH) and 13.95% (for beta‐endorphin) of the brainstem nuclei/tracts. In the alpaca brainstem, a high density of immunoreactive fibres was not observed. The neuroanatomical distribution of the immunoreactive fibres suggests that the peptides studied are involved in auditory, motor, gastric, feeding, vigilance, stress, respiratory and cardiovascular mechanisms, taste response, sleep‐waking cycle and the control of pain transmission.