Surgical Treatment of an Abdominal Abscess Caused by a Migrating Iron Wire From the Ventral Colon,a Case Report

A 13-year-old mare presented for evaluation of recurrent colic episodes. The horse was diagnosed with a mass within the spleen at the ultrasound examination of the abdomen; the levels of Serum Amyloid A and the fibrinogen were high and so a presumptive diagnosis of an abscess involving the spleen was made base on clinical, ultrasonographic and laboratory findings and it was decided to perform n exploratory laparotomy for a definitive diagnosis and possible treatment. Upon abdominal exploration a mass involving the spleen, the lateral wall of the ventral colon adherent to the left abdominal wall was diagnosed and with an intraoperative ultrasound examination a linear hyperechoic foreign body was diagnosed within the mass. It was removed through an enterotomy of the left ventral colon that allowed the digital exploration of the mass without spilling of pus within the peritoneal cavity. The horse was discharged and the long term follow-up revealed no complications and no more signs of abdominal pain.     

Pleuroscopic diagnosis of disseminated hemangiosarcoma in a horse

A 7-year-old Thoroughbred mare was examined because of persistent bilateral epistaxis and respiratory distress. Evidence of bilateral pleural effusion was found during physical examination, and a large amount of serosanguineous fluid was drained from the right side of the thorax. Cytologic examination and bacteriologic culture of the transtracheal aspirate and pleural fluid did not yield evidence of sepsis. A coagulation profile was unremarkable. Radiographic and echographic changes were seen in the lung parenchyma. Pleuroscopy, with the horse standing, revealed numerous dark nodules on the pleura, diaphragm, and lung surface. On the basis of biopsy and necropsy findings, the histopathologic diagnosis was disseminated hemangiosarcoma.     

Extreme eosinophilia with disseminated eosinophilic granulomatous disease in a horse

Extreme eosinophilia with disseminated eosinophilic granulomatous disease is described in a 4-year-old Arabian mare. Clinical signs included weight loss, coughing, jugular distention, and ventral edema. Cutaneous lesions were not observed. Eosinophilic inflammation was observed in cytologic specimens from the respiratory tract, body cavities, and lymph nodes. At necropsy, a 20-cm diameter intrathoracic mass was observed. Smaller nodules were present in the lymph nodes, liver, spleen, adrenal glands, pancreas, and skeletal muscle. Histologically, these masses and nodules were characterized by infiltrates of eosinophils, macrophages, and multinucleated giant cells, reactive fibroplasia; and multifocal eosinophilic coagula. Microscopically, mild eosinophilic infiltrates were observed in sections of stomach, small intestine, colon, and pleura; however, gross lesions were not observed in these tissues at necropsy. The etiology of the extreme eosinophilia and disseminated eosinophilic granulomatous disease in this horse was not determined.     

ECHOCARDIOGRAPHIC DETECTION OF A DISSECTING AORTIC ROOT ANEURYSM IN A THOROUGHBRED STALLION

A 12-year-old Thoroughbred stallion was referred with a history of acute pain and tachycardia immediately after breeding a mare. On presentation, the horse showed no evidence of pain and routine examination of the abdomen failed to yield any abnormalities, however, a persistent tachycardia remained. A base-apex ECG examination revealed sustained ventricular tachycardia which resolved spontaneously within 12 hours of hospitalization. During this period, the stallion developed a grade 4/6 heart murmur. An aortic root aneurysm in the right sinus of Valsalva was diagnosed using two-dimensional echocardiography. Pulsed-wave Doppler evaluation revealed turbulent flow within the aneurysm. Repeat echocardiographic examination 10 months after the onset of signs revealed no change and the horse continues to perform as a breeding stallion.     

Septic peritonitis due to colonic perforation associated with aberrant migration of a Gasterophilus intestinalis larva in a horse

An adult quarter horse mare was presented with acute colic and fever. Physical examination and abdominocentesis showed septic peritonitis, and the mare was euthanatized. Necropsy and histopathologic examination revealed a focal partial perforation of the right ventral colon, which contained a single bot fly larva, identified as a third-instar larva of Gasterophilus intestinalis. This larva was embedded deep within the muscularis and the submucosa. Although bot fly larvae are known to attach to aberrant sites within the digestive tract, this is the first known report of deep penetration of the colon by a gasterophilus larva, with the resulting leakage of intestinal content leading to septic peritonitis.     

T cell rich,B cell lymphoma in the small colon of a yearling horse

A one‐year‐old, Thoroughbred colt presented for evaluation due to a one month history of fever of unknown origin and progressive weight loss. On initial presentation, the horse was febrile and showed signs localised to the respiratory tract. These included bilaterally increased bronchovesicular sounds and a moderate, diffuse interstitial pattern on thoracic radiographs. A transtracheal wash yielded mucopurulent debris, culture of which grew small numbers of Staphylococcus epidermidis and Aspergillus spp. The horse was discharged with a diagnosis of bronchointerstitial pneumonia and placed on antibiotic therapy. Ten days after initial presentation, he developed abdominal pain that was unresponsive to on‐farm treatment. The horse was febrile, displayed increased respiratory rate and effort, and showed moderate signs of abdominal pain. On rectal examination, a firm, 8–10 cm mass was palpated on midline. The colt was admitted to the hospital and scheduled for exploratory laparotomy, but died a short time later before surgery could be performed. This report describes the clinical, diagnostic and histopathological findings of a case of alimentary lymphoma in a yearling colt.     

Use of chemotherapy for treatment of a mixed-cell thoracic lymphoma in a horse

A 4-year-old Oldenburg mare was evaluated because of signs of lower airway disease and subsequently developed bilateral pleural effusion. Neoplastic cells were not identified in the fluid sample obtained via the initial thoracocentesis. A thoracic mass was detected radiographically, but its location prevented collection of a tissue sample. A diagnosis of lymphoma was made on the basis of results of immunophenotyping of pleural fluid specimens. Treatment of thoracic lymphoma in horses has been attempted, but there are limited data regarding chemotherapeutic-induced remission. In this horse, remission was achieved by use of a chemotherapeutic protocol consisting of administration of cytarabine, cyclophosphamide, and prednisolone. No adverse drug reactions were encountered during treatment. Immunophenotyping of cells in specimens of pleural fluid could be used to determine lymphocyte lineage and may be a useful alternative diagnostic modality when morphologic and cytologic examination of tissue specimens obtained via invasive techniques is not feasible.     

ULTRASOUND AS AN AID FOR DIAGNOSIS OF OVARIAN ABSCESSES IN TWO MARES

This report describes two mares presented for evaluation of anorexia, fever of unknown origin, and weight loss. Clinical examination, laboratory findings, and transrectal ultrasonographic images suggested ovarian abscessation. One mare was successfully treated medically. Because of financial considerations, the second mare was euthanatized and a postmortem examination was performed. At necropsy, there was an enlarged right ovary with an adhesion to the large colon. Microscopic findings were characteristic of an ovarian abscess.     

Diaphragmatic herniation as a cause of lethargy and exercise intolerance in a mare.

A diaphragmatic hernia in which 90% of the large colon had herniated through a 16-cm linear tear in the diaphragm was found in a 12-year-old Quarter Horse mare. Clinical signs included lethargy and exercise intolerance. Diagnosis of diaphragmatic hernia was made based on careful thoracic auscultation, combined with ultrasonographic and radiographic examination of the thorax.     

Bilateral third eyelid ectopic cilia in an adult horse

A 15‐year‐old Cob mare presented with a 4‐month history of chronic epiphora and intermittent blepharospasm in the right eye. On ophthalmic examination, two translucent aberrant hairs were identified at the third eyelid margin corresponding to an area of corneal fibrosis and neovascularization. Partial excision of the third eyelid was performed, and histopathology confirmed ectopic hair follicles. Two weeks later, clinical signs recurred in the same eye. Examination revealed another pair of aberrant hairs on the bulbar surface of the third eyelid near its leading edge. This portion of the third eyelid was also excised, and histopathology confirmed two additional ectopic hair follicles. Eight months later, the horse developed similar clinical signs in the left eye. Ophthalmic examination showed a single aberrant translucent hair at the third eyelid margin associated with focal fibrosis and neovascularization of the ventromedial cornea. Partial excision of the third eyelid was performed, and histopathology confirmed an ectopic hair follicle within the third eyelid conjunctiva. Excision was curative at 4 years postoperatively with no further recurrence in either eye.     

Metastatic pancreatic polypeptide‐secreting islet cell tumor in a dog

Abstract: A 14‐year‐old female spayed Golden Retriever was presented to the University of Florida's Veterinary Medical Center with history of lymphoplasmacytic gastroenteritis, intermittent vomiting, watery diarrhea, and weight loss for over a year. CBC, biochemical profile, and urinalysis were within reference intervals. Abdominal ultrasonographic examination revealed mesenteric and jejunal lymphadenopathy and hyperechoic hepatic nodules. Cytologic examination of the enlarged lymph nodes revealed loosely cohesive cells with moderate nuclear pleomorphism and rare punctate eosinophilic cytoplasmic granules. The cytologic interpretation was metastatic neuroendocrine neoplasia. On surgical exploration, a mass was detected in the right lobe of the pancreas. Histologic evaluation determined the mass to be an islet cell tumor. Approximately 98% of cells were positive by immunolabeling for pancreatic polypeptide (PP), and only rare cells were positive for insulin or somatostatin. All cells were negative for glucagon, gastrin, vasoactive intestinal polypeptide, protein gene product 9.5, synaptophysin, and chromogranins A and B. Pancreatic tumors that primarily produce PP are rare in dogs, and this is the first report of both the cytologic and histologic features of an islet cell tumor predominantly secreting PP. Clinical signs for these tumors are typically absent or nonspecific; signs may include watery diarrhea, as noted in this dog, although the diarrhea may have resulted from lymphoplasmacytic gastroenteritis. Additional case studies are needed to further characterize the cytomorphologic features and clinical presentation of PP‐secreting islet cell tumor, or polypeptidoma, in dogs.     

Electrochemotherapy for the Treatment of Multiple Melanomas in a Horse

A 22-year-old Camargue mare was referred for showing signs of discomfort during chewing, building up of food in the mouth, and foul odor from the mouth. On physical examination, the mare presented bilateral pigmented labial masses affecting the upper and lower lips, more in the form of plaques at the mucocutaneous junction as well as multiple perivulvar and perianal lumps. The skin lesions were biopsied for histopathologic examination and the clinical suspect of melanoma was confirmed. The owner elected the lesions to be treated with electrochemotherapy using the drug cisplatin. After two sessions, the nodules were shrunk by 50% and the horse’s ability to feed normally was restored: at that time, the owner had the treatment discontinued because of financial issues. The horse is still in partial remission after 1 year from the end of the treatment. Electrochemotherapy can be successfully used to palliate large melanomas in horses.     

Leukemic small cell lymphoma or chronic lymphocytic leukemia in a horse

A 16‐year‐old, Irish Draft mare was admitted to the referring veterinarian for an annual health check. A mild generalized lymphadenomegaly was noted. Rectal palpation and transrectal ultrasonographic examination revealed prominent mesenteric lymph nodes. A transcutaneous abdominal ultrasonographic evaluation was unremarkable. A CBC revealed a marked leukocytosis (63.06 × 10³/μL) and lymphocytosis (58.2 × 10³/μL) due to increased numbers of small lymphocytes. No evidence of anemia or thrombocytopenia was found and neutrophil counts were low‐normal. Cytologic examination of fine‐needle aspirates of multiple lymph nodes and a bone‐marrow aspirate revealed the presence of a monomorphic population of small lymphocytes similar to those observed in the peripheral blood, suggesting a leukemic small cell lymphoma (SCL) or chronic lymphocytic leukemia (CLL). As the lymphadenomegaly and peripheral blood lymphocytosis were present simultaneously, the distinction between these 2 conditions was not possible. Immunophenotyping by immunocytochemistry and flow cytometry of the lymphoid cells in peripheral blood determined a T‐cell phenotype. As the horse was clinically stable, no treatment was initiated, but regular examinations were undertaken. A CBC repeated 120 days after the diagnosis showed a marked lymphocytosis (157.6 × 10³/μL) with no evidence of anemia or other cytopenias. The horse was euthanized 194 days after the initial diagnosis. Histopathology and immunohistochemistry of submandibular lymph nodes and bone marrow confirmed the diagnosis of leukemic SCL or CLL, and a T‐cell phenotype. SCL and CLL are rare in horses; previous immunohistochemical studies determined that the T‐cell phenotype is predominant. To the authors' knowledge, this is the first report of the combined use of immunocytochemistry and flow cytometry in a horse with leukemic SCL or CLL.     

Gamma delta T‐cell large granular lymphocyte lymphoma in a dog

A 2‐year and 6‐month‐old female neutered Labrador Retriever with Horner syndrome, megaesophagus, and a mediastinal mass was referred to the Queen Mother Hospital for Animals of the Royal Veterinary College. A large granular lymphocyte (LGL) lymphoma was diagnosed on cytology; flow cytometric analysis revealed a γδ T‐cell phenotype (CD3+, CD5+, CD45+, TCRγδ+, CD4?, CD8?, CD34?, CD21?). Chemotherapy was started with a combination of lomustine, vincristine, procarbazine, and prednisolone, followed by bleyomicin. Euthanasia was elected by the owners, due to progressive deterioration and lack of quality of life, 28 days after diagnosis. This is the first cytologic and immunophenotypic characterization of a canine γδ T‐cell lymphoma with LGL morphology and probably of mediastinal origin. The role of chemotherapy in delaying the disease progression remains unknown.     

Pseudomonas aeruginosa sepsis in an adult horse with enteric Salmonellosis

Objective: To report a case of enteric Salmonellosis and Pseudomonas aeruginosa bacteremia in an adult horse. Case summary: A 7‐year‐old mare presented for signs of acute abdominal pain. Exploratory laparotomy allowed surgical correction of right dorsal displacement of the large colon with a 180° volvulus at the cecocolic ligament. Postoperatively, the mare developed fevers, leukopenia, and diarrhea. Salmonella newport was cultured from the feces and P. aeruginosa from 2 consecutive blood cultures. The mare responded well to intensive medical therapy. New or unique information provided: Bacteremia associated with colitis is unusual in an adult horse, although the percentage of animals that may be bacteremic is unknown. The bacteria isolated, P. aeruginosa, a common pathogen of other sites in the horse, has not, to our knowledge, been previously reported as a cause of bacteremia and septicemia in an adult horse.     

Clinical and ultrasonographic findings of a tear of the gastrocnemius muscle and enthesopathy of the origin of the superficial digital flexor muscle in a reining Quarter Horse mare

Proximal gastrocnemius and superficial digital flexor (SDF) muscle injuries are reported in the horse but are uncommon. In adult horses, the definitive diagnosis is more commonly based on clinical signs with or without the use of radiographic examination and/or nuclear scintigraphy. This case report describes the clinical and ultrasonographic findings of a tear of the gastrocnemius muscle in a 6-year-old reining mare. At standing physical examination, there was a sickled hock appearance, with the point of the hock of the left hindlimb lower (dropped hock) than that of the right hindlimb. At dynamic examination at walk, the mare had instability of the left hock characterised by medial rotation of the hoof and lateral rotation of the point of the hock (twisting motion); at trot, the horse showed mild/moderate left hindlimb lameness characterised by more downward movement of the pelvis during weightbearing of the lame limb compared with that of the sound limb. Ultrasonographic examination of the left thigh and crus showed a large irregular hypoechogenic area and irregularly shaped, retracted muscle stumps on the lateral aspect of the gastrocnemius muscles; the proximal insertion of the SDF muscle on the supracondylar fossa of the femur was irregular in its outline, hypoechogenic and thickened compared with that of the right side. Characteristic muscle fibre pattern was not identified in the left gastrocnemius muscle. On the radiography, a mild irregularity of the bone margin of the lateral supracondylar tuberosity was detected on the caudo 45° medial-craniolateral oblique view of the distal femur. Clinical and diagnostic imaging findings were consistent with partial failure of the caudal part of the reciprocal apparatus and injury of the gastrocnemius and SDF muscles/origin. The horse was managed conservatively by corrective shoeing, muscle relaxing drugs, controlled exercise and manual stretching.     

Bilateral lymphosarcoma of the nictitating membrane in a Quarter Horse

A 21-year-old Quarter Horse mare presented for a mass of the right nictitating membrane. The entire right nictitating membrane was surgically removed and diagnosed as a mixed cell lymphosarcoma and squamous cell carcinoma. The horse had no systemic signs of lymphosarcoma. Approximately 1.5 years later, the horse presented with a similar mass in the left nictitating membrane. The entire left nictitating membrane was surgically removed and diagnosed as a mixed cell lymphosarcoma. In this case, complete surgical removal of the masses resulted in a cure. The horse has remained free of systemic lymphosarcoma for over 3 years.

Case report

A 21-year-old gray Quarter Horse mare was presented to the Kansas State University Veterinary Medical Teaching Hospital for evaluation of a mass involving the right nictitating membrane. The mass was first noticed 5 weeks before presentation and had been treated by the referring veterinarian with a topical steroid solution twice daily. Administration of the topical steroid caused some decrease in the swelling, but it quickly returned once medication was discontinued. The horse had no other medical complaints and appeared to be otherwise healthy. On ocular examination, chemosis of the third eyelid and conjunctiva of the right eye was evident. Direct and indirect pupillary light reflexes, Schirmer tear test, and intraocular pressures were normal in both eyes. Fluorescein stain uptake was negative in both corneas. Cranial nerve and vision examinations did not reveal any abnormalities. On further examination of the right nictitating membrane, a firm mass was palpated under and protruding from the palpebral conjunctiva (Fig 1). No other abnormalities were found on physical examination.     

A case of giant cell tumor of soft parts in a horse

A 12‐year‐old British Warmblood mare was examined by the referring veterinarian for evaluation of a cutaneous lesion on the dorsal thorax to the right of the midline. Cytologic examination of fine‐needle aspirates from the mass was supportive of a giant cell tumor of soft parts (GCTSP). Laser surgical excision and postoperative methyl aminolevulinate (MAL) photodynamic therapy (PDT) were performed. Histologic examination of the mass confirmed the cytologic diagnosis. At 8 months from surgery, no evidence of recurrence has been observed. Giant cell tumors of soft parts are rare cutaneous neoplasms, observed in several domestic species, including the horse where they commonly appear as superficial cutaneous lesions without aggressive biologic behavior. Previously classified as giant cell variant of malignant fibrous histiocytoma, these superficial tumors have now been designated as giant cell tumors of soft tissue or giant cell tumors of low malignant potential within the category of fibrohistiocytic neoplasms.