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.

[West-Nile-Virus infections in 12 horses in east-central Germany]. / West-Nil-Virus-Infektion bei 12 Pferden in Mitteldeutschland.

PURPOSE AND AIM: The presenting complaints, clinical signs, diagnostic evaluation, therapy, and outcome of 12 horses with clinically apparent West-Nile-Virus (WNV) infection are described. MATERIAL AND METHODS: Case series RESULTS: The adult horses (age 6-18 years, 7 mares, 5 geldings) from Saxony and Saxony-Anhalt were presented with various clinical histories between September 2018 and September 2020. All horses were presented in August or September and no horse was vaccinated against WNV. Fever as the most common general clinical sign was present in 8/12 horses. The most common neurological signs were muscle fasciculations (11/12 horses), ataxia (8/12 horses), hyperesthesia and head tilt (6/12 horses each). Diagnosis of WNV infection was confirmed by demonstrating IgM antibody and neutralizing antibody production in all horses; 2 euthanized horses also tested positive by PCR. Therapy was symptomatic and primarily included non-steroidal anti-inflammatories or dexamethasone as well as fluid therapy. Duration of hospitalization was 7.5 days on average. According to their owners, seven horses recovered completely, while information was missing for 2 horses. CONCLUSIONS AND CLINICAL RELEVANCE: In eastern-central Germany, WNV-encephalomyelitis must be considered a differential diagnosis for unvaccinated horses with acute neurologic disease occurring in summer and late summer. The reported clinical signs and the outcome of therapy are mostly congruent with reports from North America and other European countries.