Chronic copper toxicosis in a crossbred heifer calf

An 8-mo-old, crossbred, heifer calf was presented to the Heeke Animal Disease Diagnostic Laboratory with a history of ataxia and altered mentation. Grossly, the liver was diffusely yellow-orange, turgid, and exuded watery, thin blood on cut section. The cortex and medulla in both kidneys were diffusely and markedly dark brown to black. The urinary bladder was filled with dark red urine. Histologically, centrilobular hepatocellular degeneration was observed, but these sections lacked necrosis. In the kidney, numerous cortical tubules contained intraluminal bright eosinophilic fluid and red-orange granular casts that stained positive for hemoglobin with the Dunn–Thompson method. The gross and histologic lesions supported a high level of suspicion for copper toxicosis. Feed and water samples from the farm were submitted for mineral analysis. The copper concentration in the feed was 118 mg/kg, and the molybdenum concentration was 0.9 mg/kg. Chronic copper toxicosis is rarely reported in cattle. The gross lesions in our case are a departure from, although similar to, previously reported cases, including lack of histologic hepatocellular necrosis. Collectively, gross and histologic lesions were compatible with copper toxicosis in this calf, and copper concentrations in the feed samples suggest a feed-mixing error.

Spontaneous Appearance and Transmission of Polydactyly in Dexter Cattle

A 3-yr-old Dexter cow and her yearling Dexter heifer calf exhibited polydactyly. Neither animal was linebred within 5 generations. This cow-calf pair represented the first reported occurrence of polydactyly in Dexter cattle in the US or abroad. Based upon external examination, the cow was classified as having a spontaneous unilateral case of polydactyly with an extra digit along the medial digit of the right front limb and the heifer was classified as having bilateral polydactyly because both front limbs exhibited an extra digit along the medial digit. Radiographic examination confirmed bilateral status of the heifer and revealed bilateral status of the cow. The front feet of the cow and heifer had extra bone formation consistent with an extra digit along the medial digit. Neither animal suffered from limited mobility to date or required hoof treatments. The cow produced a second calf from a different sire, a bull calf that did not appear polydactylous per external examination and was not examined radiographically. The two polydactylous animals will remain in the breeding herd to produce more study calves unless their fitness becomes compromised. Genetic aspects of the cases are discussed.

Gas-filled urachal abscess with a pinging sound in a heifer calf

A 6-month-old crossbred of a Holstein and Japanese Black heifer calf weighing 95 kg presented with a history of intermittent abdominal distension and failure to thrive. The physical examination identified a pinging sound over the dorsal left flank. The abdominal radiography showed a huge gas-filled mass. The intravenous urography revealed no communication between the mass and the urinary bladder. Although the visual examination and palpation of the umbilicus did not reveal visible abnormalities, an umbilical disease was suspected because the animal exhibited poor growth, depression, and a hunched back posture. When the eschar adhering to the centre of the umbilicus was removed, the presence of a fistulous tract was revealed. The umbilical ultrasound examination revealed an intra-abdominal abscess and the fistulography demonstrated that the abscess communicated with the umbilicus. The abscess, compressing into the rumen, was observed by computed tomography. From these images, it was diagnosed as an umbilical cord remnant abscess and a definitive diagnosis of a urachal abscess was obtained by open abdominal surgery and the subsequent removal of the mass. The calf was discharged from the university hospital on day 14 after the operation. This case shows that a urachal abscess should be considered when a pinging sound is present, even if the animal exhibits no swelling or pain of the umbilicus.

Congenital amelanotic melanoma in a crossbred heifer calf

A large, pedunculated cutaneous mass protruding from the left flank fold and an enlarged left prefemoral lymph node were found on examination of a 3-d-old crossbred Aberdeen Angus heifer. The calf was asymptomatic aside from peripheral lymphadenopathy, and the mass, along with the left prefemoral lymph node, was surgically excised. Histologic examination of the mass and the lymph node revealed a homogeneous population of neoplastic cells that stained positively with immunohistochemical stains S100 and melan A, supporting a diagnosis of congenital amelanotic melanoma with nodal metastasis. Two months later, the calf became acutely recumbent and was euthanized after clinical examination revealed widespread metastasis. Gross autopsy revealed widely disseminated metastases that involved vertebral bodies, spinal cord, heart, kidneys, lungs, oral mucosa, multiple lymph nodes, and the marrow cavity of several long bones. Our case serves as a reminder that, although rare, congenital neoplasms occur in bovids and have the potential for aggressive, metastatic behavior.