Chronic lameness caused by vascular compression of the iliac artery and vein by a malignant melanoma in the pelvis of a grey Spanish gelding

An 11-year-old grey Spanish gelding was presented with chronic lameness of the right hindlimb, with abduction of the limb during the swing phase. Based on a comprehensive lameness examination, the problem was localised to the pelvic region. Rectal and ultrasonographic examinations revealed a mass in the pelvic region in close association with the iliac artery and vein, and ultrasonographic indications of vascular compression. Considering the clinical presentation of a grey middle-aged horse with multifocal melanoma-like nodules at the level of the perineum, tail base, preputium and penis, a malignant melanoma with secondary vascular or neurological compression was suspected. Post-mortem and histological examination confirmed the diagnosis of malignant melanoma with vascular compression of the iliac artery and vein and infiltrative growth in the iliac vein.     

Osteosarcoma in the proximal humerus of a mare

A 15‐year‐old Quarter Horse mare was examined for significant and progressive lameness in the right front limb. On physical examination, muscle atrophy over the scapular and pectoral regions were noted. A pain response was elicited on palpation of the scapulohumeral joint. No other abnormalities were noted on examination of the limb. Diagnostic nerve blocks ruled out a source of lameness in the distal limb. Arthrocentesis of the scapulohumeral joint was performed and results were within normal limits. Radiographs of the right scapulohumeral joint revealed an extensive, aggressive bone lesion in the proximal humerus, suspected to be an osteosarcoma. After a course of nonsteroidal anti‐inflammatory therapy, minimal improvement to the lameness was noted. The owner elected to subject the horse to euthanasia due to the lack of significant response to treatment. Post mortem radiographic and histological examinations determined a definitive diagnosis of an osteosarcoma in the proximal humerus.     

Gigantic Cutaneous Myxoma at Equine Distal Limb

An extremely large-sized neogrowth of myxoma was observed at the cannon region in a 3-year-old Arabian mare. The mass developed during the course of 4 months. The mass mechanically hindered the animal movement, exposing the mare to multiple external injuries and subsequent blood loss. The clinical parameters, morphology, and hematological and histopathological examinations of the myxoma were recorded. The body condition score of the mare was 1. The hemogram revealed moderate to severe degree of anemia. Histopathological sections assessed after surgical removal identified the mass as a myxoma. To the authors’ knowledge, this is the first report of cutaneous myxoma at equine limb in an Arabian horse.     

Management of hydrops amnion in a mare resulting in birth of a live foal

CASE DESCRIPTION: A 19-year-old Thoroughbred mare was evaluated at 265 days of gestation with a markedly distended abdomen and edema of the ventral portion of the abdomen. CLINICAL FINDINGS: The uterus was distended over the pelvic rim, making transrectal palpation of the fetus impossible. Transabdominal ultrasonography revealed excessive amounts of fetal fluid. Results of analysis of fluid obtained via amnio- and allantocentesis confirmed that the amniotic cavity was large. TREATMENT AND OUTCOME: The mare was monitored for signs of weakness of the prepubic tendon and abdominal wall. The fetus and placenta were monitored for signs of stress and pending abortion. Flunixin meglumine and altrenogest were administered to the mare. Parturition was attended and occurred at 321 days' gestation. Postpartum complications in the mare included hypovolemic shock and cardiac arrhythmias. Both conditions were treated, and the mare recovered. The foal was considered small, had bilateral angular limb deformities, and was unable to nurse. The foal was given plasma for failure of passive transfer of immunity. Ten months later, the foal underwent procedures to correct limb deformities. CONCLUSIONS AND CLINICAL RELEVANCE: Hydrops conditions are rare in horses, with hydrops allantois occurring more frequently than hydrops amnion; reportedly result in fetal or neonatal death; and may result in death of or injury to the mare. Close monitoring of maternal and fetal health in combination with supportive treatment of the mare can result in the safe progression of a hydrops pregnancy and the birth of a live foal.     

Characterization of the renal portal system of the common green iguana (Iguana iguana) by digital subtraction imaging.

Digital subtraction angiography was used to map the venous blood flow from the pelvic limb and the tail in the common green iguana (Iguana iguana). The majority of blood returning from the pelvic limb bypassed the kidney and entered the general circulation, whereas venous blood flow from the tail entered the renal portal circulation. No evidence was found of a renal portal valve.     

Standing transcutaneous surgical excision of a sialolith in an 11-year-old Thoroughbred mare

An 11-year-old Thoroughbred mare was diagnosed with sialolithiasis of the right parotid salivary duct. A firm nonpainful subcutaneous mass was palpable in the right maxillary region adjacent to premolar 4 (tooth 108). Radiographic and ultrasonographic examinations identified a discrete mineralised ovoid mass that was hyperechoic and produced an acoustic shadow. Surgical excision of the mass was performed under standing sedation using a transcutaneous approach and the excised sialolith submitted for histopathological and mineral composition analyses. Histological examination found no evidence of a nidus at the sialolith's core. Mineral analysis of the sialolith revealed its composition to be 40% calcium phosphate (apatite) and 60% calcium carbonate. The mare recovered with no post-operative complications and was clinically unremarkable 2 years later.     

Traumatic coccygeal luxation and distal amputation of the tail of an Appaloosa mare

A 17‐year‐old Appaloosa mare presented to the emergency service for acute, traumatic, partial amputation of the tail at the level of the ninth coccygeal vertebra. The patient did not have tail or anal tone and did not respond to sharp stimulation of skin in the perineal region. Two grade 1 rectal tears were found during rectal palpation. Radiographs revealed dislocation of the second (Cd2) and third (Cd3) caudal vertebrae. The patient was treated with antibiotics, an anti‐inflammatory drug and stall confinement. The ninth caudal vertebra was surgically removed to facilitate closure of skin over the wound. When the mare was discharged after 7 days of hospitalisation, she had regained partial sensation of the perineum and partial function of the internal and external anal sphincters. At re‐evaluation one year following injury, the mare was able to move her tail laterally and had regained sensation of her perineum and tail; however, she still was unable to lift her tail.     

Unilateral shunt formation with thoracic aortic dissection in a whippet

A three‐year‐old neutered male whippet was presented with intermittent, exercise‐induced paraparesis. Femoral pulses were bilaterally absent. Neurologic examination was suggestive of a thoracolumbar myelopathy. Blood pressure measurements revealed hypotension in both pelvic limbs, hypertension in the right thoracic limb and it was immeasurable in the left thoracic limb. Echocardiography was within reference limits. A clear vascular pulsation was palpable on the right ventral abdominal wall. Computed tomographic angiography revealed a dissection of the aortic wall between the left subclavian artery and the brachiocephalic trunk with subsequent thrombus formation. A shunt between the right internal thoracic, cranial and caudal epigastric arteries to preserve blood flow to the pelvic limbs was visualized. Necropsy was declined by the owner. This is the first case report describing the formation of a unilateral vascular shunt following a thoracic aortic occlusion, which presented as exercise‐induced paraparesis .     

Granulosa thecal cell tumour in a mare causing hypertrophic osteopathy

Hypertrophic osteopathy (HO) is a rare condition in the horse characterised by symmetrical proliferation of connective tissue and subperiosteal bone, along the diaphyses of limb bones. In this case, a 10‐year‐old Irish Draught cross Thoroughbred mare was presented for investigation of weight loss, lethargy and firm swelling of all 4 distal limbs. Radiographs of the distal limbs revealed palisade‐like periosteal new bone formation perpendicular to the cortex of the distal third metacarpal and metatarsal bones, proximal (P1) and mid (P2) phalanges. Rectal examination revealed a mass of approximately 20 x 30 cm in the right caudoventral abdomen. The mare was diagnosed with HO due to a granulosa thecal cell (GTC) tumour. The GTC tumour was removed and the diagnosis confirmed on histological examination. Clinical examination and radiographs of the distal limbs after surgery demonstrated reduction in size of the limb swellings and new bone formation. To the authors' knowledge this is the first report of HO due to a GTC tumour in a mare.     

Malignant melanoma of the pelvis as a possible cause of pelvic limb lameness in two gray mares

Two grey mares, a 12-year-old Arabian and a 13-year-old Lippizaner cross, were referred for chronic pelvic limb lameness and abduction of the limb during the non supporting phase of the stride. The clinical examination revealed melanomas under the tail and on the perineum, and oedema of the proximal lame limb. A mass in the pelvic area was detected on rectal palpation. Laparoscopy was performed and the provisional diagnosis of malignant melanoma was made. Histological examination of the biopsy taken under laparoscopic control from the mass in the pelvis confirmed the diagnosis of malignant melanoma. In the postmortem examination a large black mass in the pelvis and metastases in several organs were diagnosed. The process under the tail showed microscopically the characteristics of dermal melanomatosis. The metastases showed the appearance of a malignant melanoma. The lameness and abduction during the non supporting phase of the stride were possibly caused by a combination of pain, a mechanical limitation, and paresis/paralysis. When an older grey horse with melanomas on the predilection sites is submitted with pelvic limb lameness and abduction of the limb during the non supporting phase of the stride, a malignant melanoma in the pelvis is one of the differential diagnoses and a rectal examination should be performed. Diagnostic laparoscopy in the standing horse can be useful to confirm the provisional diagnosis.     

Pelvic lymphoma as a cause of urethral compression in a mare

A 6-year-old mare was presented for evaluation of dysuria and pollakiuria. A pelvic mass, which caused obstruction of urinary outflow, was identified. Evidence of renal failure was also present. Due to poor prognosis the mare was euthanized. A postmortem examination revealed a pelvic lymphoma that surrounded and compressed the urethra.     

Myonecrosis and cutaneous infarction associated with Salmonella serovar Infantum infection in a horse

A 5-year-old Quarter Horse mare was referred for evaluation of oral ulcers, limb edema, weight loss, and weakness. There was marked diffuse swelling extending from the stifle region to the tarsal region of the left hind limb, and the horse had a left hind limb lameness. Firm swellings ranging from 2 to 15 cm in diameter and consisting of nodules, plaques, and discrete masses were palpated on both sides of the neck, over the right shoulder region, over the left elbow region, and over the left caudoventral aspect of the abdomen. Laboratory abnormalities included hypoproteinemia, neutrophilia, and hyperfibrinogenemia. Results of ultrasonographic examination of the left hind limb and masses were suggestive of muscle edema, necrosis, and hemorrhage. Histologic examination of a biopsy specimen from a subcutaneous mass revealed necrotizing, suppurative myositis. The horse's condition gradually deteriorated, and the horse was euthanatized. Necropsy revealed myonecrosis, cutaneous infarcts, hepatic abscesses, and cholangitis. Salmonella serovar Infantum was cultured from liver and muscle lesions, and a diagnosis of Salmonella myonecrosis was made.     

Long-Term Follow-up of Partial Limb Amputation in 13 Horses

Thirteen cases of partial limb amputation in horses were reviewed. Nine horses (69%) survived 18 to 111 months (mean, 41 months). Four unsuccessfully treated horses were euthanatized within 21 days of surgery. The horses' ages at amputation were 4 to 13 years (mean, 7.3 years). There was no predilection for the left or right limb nor for fore or hind limb involvement. Osteomyelitis in six horses (46%) was the most common cause for amputation. Severe, open, comminuted fractures of the third metacarpal bone that were impossible to stabilize by any currently available technique in four horses (31%) were the second most common cause for amputation. One gelding was salvaged because of his sentimental value, two horses were used as breeding stallions, and six were broodmares. One stallion lived 30 months, completed two breeding seasons, and started a third. The other stallion began breeding, but became sterile. Three of the mares have produced five foals. One mare died while in foal. One mare aborted near-term twin fetuses and died of uterine hemorrhage. One mare aborted twice before the femoral head ligament on the contralateral limb ruptured, and she was euthanatized.     

Carpal hyperextension in a Percheron mare caused by a palmar carpal ligament tear

A Percheron mare was presented for acute, severe lameness and marked swelling of the right forelimb after being cast. The mare was initially diagnosed with cellulitis of the forelimb but as her condition improved and the affected limb was able to bear more weight it became apparent that the limb was hyperextended at the level of the carpus. Widening of the palmar aspect of the middle carpal joint was observed radiographically. During ultrasonographic examination, excessive fluid in the carpal sheath and perithecal swelling were noted and tearing of the palmar carpal ligament was suspected. A dynamic brace was fabricated to prevent hyperextension of the carpus. After discontinuation of systemic antibiotics, the mare became febrile and forelimb lameness worsened. Cytology of fluid from the middle carpal joint confirmed joint sepsis and the mare was anaesthetised for arthroscopic examination. A tear in the palmar carpal ligament, characterised by focal fibre disruption and fibrillation, was identified during arthroscopic and tenoscopic examination. Communication between the carpal flexor tendon sheath and middle carpal joint was identified during these procedures. Both the middle carpal joint and carpal flexor tendon sheath were lavaged with physiological saline solution. Post operatively, swelling and lameness slowly resolved. Four months after discharge, the mare was sufficiently sound to be maintained at pasture. Viewed from its lateral aspect, the limb no longer appeared to be hyperextended from the carpus.     

Aberrant migration and surgical removal of a heartworm (Dirofilaria immitis) from the femoral artery of a cat

A cat was evaluated for an acute‐onset of right pelvic limb paresis. Thoracic radiographs revealed normal cardiac size and tortuous pulmonary arteries. Abdominal ultrasound identified a heartworm (HW) extending from the caudal abdominal aorta into the right external iliac artery and right femoral artery. The cat was HW‐antigen positive. Echocardiography revealed a HW within the right branch of the main pulmonary artery and evidence of pulmonary hypertension. An agitated‐saline contrast echocardiogram revealed a small right to left intracardiac shunt at the level of the atria. Surgical removal of the HW was performed with no substantial postoperative complications. There was return of blood flow and improved motor function to the limb. The cat remains mildly paretic on the affected limb with no other clinical signs.     

Medial collateral ligament desmitis of the distal interphalangeal joint in the hindlimb of a horse: treatment with cast immobilisation

A 12‐year‐old show‐jumping mare was presented for investigation of a chronic hindlimb lameness of 16 weeks duration. Perineural anaesthesia and ultrasonography localised the lesion to the medial collateral ligament of the distal interphalangeal joint of the left hindlimb. Treatment consisted of a heavily padded distal limb cast for 6 weeks, strict box rest and a strictly regulated hand walking program. Serial ultrasonographic examinations were performed throughout the rehabilitation period. Collateral ligament desmitis of the distal interphalangeal joint is a commonly diagnosed condition of the forelimb; however, hindlimb collateral ligament desmitis has been rarely reported. Ultrasonographic examination in this case was an invaluable diagnostic and follow‐up tool. Immobilisation of the foot by means of a heavily padded distal limb cast allowed excellent healing of the ligament and is presented as a novel treatment for collateral ligament desmitis. At the time of writing the mare had returned to her previous level of exercise and was showing no signs of lameness.     

Bilateral Dorsal Subluxation of the Proximal Interphalangeal Joint of the Hind Limb in a Mare: Case Report

Subluxation of the proximal interphalangeal joint is a rare and little studied condition in horses. We describe the case of a 12-year-old mare with bilateral dorsal subluxation of the proximal interphalangeal joint of the hind feet. Tenectomy of the medial digital flexor was performed in both limbs, and the patient showed signs of recovery within 14 days. Goniometry of the proximal interphalangeal joints 10 months after surgery showed diminution of 5° for the proximal interphalangeal axis of the left hind limb. However, no change was found for the joint angle of the right limb. Even so, the patient's gait and radiographic results were normal, and clinical abnormalities such as joint clicking and swelling were no longer observed.     

Computed tomographic and magnetic resonance imaging of a coup contrecoup traumatic brain injury in a horse

A 3-year-old Thoroughbred mare found recumbent in the field was referred for further assessment with suspicion of a skull fracture. Neurological examination identified compulsive tight circling to the left, and hypermetria in all four limbs. The mare was obtunded, with a mild head tilt to the right, absent menace response of the right eye and decreased facial sensation on the right. Standing computed tomographic examination revealed a subtle depression fracture of the dorsal calvarium and moderate intra-axial midline shift consistent with a traumatic brain injury (TBI). Despite supportive treatment, the mare deteriorated and was subjected to euthanasia. Post-mortem high field magnetic resonance imaging revealed findings consistent with a small cerebral contusion adjacent to the fracture site, and moderate to severe ipsilateral cerebral oedema within the caudal cerebrum and rostral brainstem, consistent with a coup contrecoup TBI. Brainstem lesions indicate a poor prognosis and support the decision for euthanasia. This is the first report of the imaging findings of a coup contrecoup TBI in a horse.     

Incompetent cervix and pneumouterus in a maiden mare

This case report describes an uncommon case of a congenitally incompetent cervix and a resulting pneumouterus in a 5‐year‐old maiden Quarter Horse mare. The mare was presented for artificial insemination at the Clinic for Animal Reproduction, Freie Universität Berlin, Germany. Routine vaginal and rectal examinations revealed a shortened cervix of 3 cm length and a dilated uterus filled with a considerable amount of air. During ultrasonographic examination, ovaries of normal size with regular cyclic activity were detected. Chromosomal analysis could not confirm any genetic anomalies such as an expected XO karyotype. The mare was excluded from breeding due to its anatomical constitution.