Successful intra-abdominal resection of a 24 kg ovarian granulosa cell tumor in a Warmblood mare.

Background: Granulosa cell tumors (GCTs) are the most common ovarian tumors in mares. The classical presentation of a GCT is a unilaterally enlarged ovary appearing as a multicystic honeycomb mass. In rare cases, GCTs cause hemoperitoneum as a result of the rapid growth of the tumor. The clinical diagnosis of GCT is usually based on history, rectal examination, ultrasonographic examination, and serum hormone analysis, and surgical removal of the affected ovary is the treatment of choice. The different surgical approaches are based on the dimension of the GCT. Case Description: A 7-year-old mare was referred to the department for horses due to suspicion of a large colon impaction. The mare presented with clinical signs of colic, fever, and signs of hypovolemic shock. Rectal and ultrasonographic examination showed hemoperitoneum and a honey-comb mass within the abdomen, and a GCT as the cause of an acute hemoperitoneum was diagnosed based on the serum level of anti-Müllerian hormone. After stabilization of the mare, the GCT was removed through a ventral midline incision. Because of the enormous dimensions of the GCT, intra-abdominal partial resection of the tumor using a tenotomy knife was necessary to exteriorize the ovarian pedicle. At 3 months follow-up, the mare was ridden for her intended use. Conclusion: This report provides an approach to an uncommon case of a very large and heavy GCT.

Seroprevalence of Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum Infections in German Horses.

There are limited data on Lyme borreliosis (LB), a tick-borne disease caused by the Borrelia burgdorferi sensu lato complex, in horses. Seropositivity is not necessarily associated with clinical disease. Data on seropositivity against Borrelia burgdorferi and Anaplasma phagocytophilum in German horses are sparse. Therefore, serum samples from horses (n = 123) suspected of having Lyme borreliosis and clinically healthy horses (n = 113) from the same stables were tested for specific antibodies against Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum. The samples were screened for antibodies against Borrelia burgdorferi (ELISA and an IgG line immunoblot assay). Furthermore, the samples were examined for antibodies against B. burgdorferi and Anaplasma phagocytophilum with a validated rapid in-house test (SNAP® 4Dx Plus® ELISA). The clinical signs of suspect horses included lameness (n = 36), poor performance (n = 19), and apathy (n = 12). Twenty-three percent (n = 26) of suspect horses and 17% (n = 18) of clinically healthy horses were seropositive for having a Borrelia burgdorferi sensu lato infection (p = 0.371), showing that the detection of specific antibodies against B. burgdorferi alone is not sufficient for a diagnosis of equine LB. Anaplasma phagocytophilum seropositivity and seropositivity against both pathogens was 20%/6% in suspect horses and 16%/2% in the clinically healthy population, showing only minor differences (p = 0.108). Unspecific testing for antibodies against B. burgdorferi without clinical suspicion of Lyme borreliosis is not recommended since the clinical relevance of seropositivity against Borrelia burgdorferi sensu lato remains to be elucidated.

A Pilot Randomised Clinical Trial Comparing a Short-Term Perioperative Prophylaxis Regimen to a Long-Term Standard Protocol in Equine Colic Surgery.

BACKGROUND: For surgical interventions classified as clean or clean-contaminated, including laparotomy, guidelines in human and veterinary medicine recommend a short-term perioperative antibiotic prophylaxis (PAP). In equine colic surgery, however, PAP commonly exceeds 24 h. OBJECTIVES: The aim of this study was to compare a single-shot to a 5-day lasting PAP considering surgical site infections (SSI) and other adverse effects probably associated with the particular antimicrobial regimen. STUDY DESIGN: The study was designed as a randomised non-inferiority pilot study including horses subjected to colic surgery while receiving one of two distinct PAP regimens. METHODS: All horses (n = 67) included in the study received the standard physical examination before and after surgery. Colic surgery was performed according to the current standard of the clinic. Horses were randomly assigned to two groups, receiving either the "single-shot" or the "5-day lasting" antibiotic prophylaxis. The "single-shot" group (n = 30) received penicillin and gentamicin only once before and, if needed, during surgery, whereas the "5-day lasting" group (n = 37) received antibiotics for five days. In addition to the standard laboratory examinations, serum amyloid A and fibrinogen were determined preoperatively and during five days after surgery. SSI, postoperative colitis and haemolytic anaemia were classified as postoperative complications potentially related to antibiotic use. RESULTS: The outcome of this preliminary non-inferiority clinical trial showed that the occurrence of postoperative adverse events (i.e., SSI, postoperative colitis and haemolytic anaemia) lacked significant differences between the study groups. Main limitations: The main limitations of this study are the limited group sizes and our inability to blind the study. CONCLUSIONS: Single-shot PAP seems to be an alternative approach considering the 5-day lasting protocol commonly used in equine abdominal surgery. However, a proper hygiene management together with a close clinical and laboratory monitoring of the equine patient is indispensable.

Postoperative complications in equine elective, clean orthopaedic surgery with/without antibiotic prophylaxis.

OBJECTIVE: Retrospective analysis of postoperative complications in equines after clean, orthopaedic surgical procedures in order to detect differences between animals treated with antibiotics and horses without receiving these drugs. MATERIAL AND METHODS: Details on 652 patients, surgical procedures and surgery-associated complications were compiled from horses being operated between June 2011 and January 2015. Antibiotic-receiving patients (n = 259) were tested for differences in complication rates and characteristics to controls (n = 393). RESULTS: The total complication rate was 39.1 %. Increased swelling was observed most often (25.6 %), followed by exudation (7.5 %), fever without incisional alterations (2.3 %), suture dehiscence (1.8 %), and seroma (0.8 %). Seven patients (five treated, two controls) developed septic arthritis within a total of 463 arthroscopies (1.5 %). There were no significant differences in the development of postoperative complications, which were seen in 97/259 (37.5 %) antibiotic receiving patients and in 158/393 (40.2 %) controls. The application of perioperative antibiotics was significantly influenced by surgeon (p < 0.0001) and type of surgery (p = 0.0007) and increased with the number of surgical lesions (p = 0.03). In patients undergoing tendovaginoscopy/ bursoscopy, fasciotomy and neurectomy (n = 98), antibiotic prophylaxis was initiated less frequently than in other surgeries, e. g. combinations of surgeries, splint bone extraction, tenotomy, and arthroscopy (n = 554). CONCLUSION: Severe complications in equine clean orthopaedic surgery are rare and complication rates in patients either receiving perioperative antibiotics or not were not significantly different. CLINICAL RELEVANCE: Based on the results the use of antibiotics appears to be non-essential in uncomplicated elective orthopaedic interventions in the horse.