To determine the transdermal absorption of 1,25(OH)₂D₃ and its effects, 1,25(OH)₂D₃ solutions were applied drop-wise onto the skin of the ventral root of the tail (1,25(OH)₂D₃ treatment) of five growing Jersey cattle. The plasma concentrations of 1,25(OH)₂D₃ in the 1,25(OH)₂D₃ -treated animals increased significantly from 2 hours after the treatment, peaked at 12 hours, and fell thereafter. There was a transient increase in the plasma Ca concentration during 2 to 4 hours post-treatment, and it remained significantly higher during 12 to 72 hours. The iP concentration in the plasma was significantly higher during 24 to 120 hours post treatment. These observations appear to be evidence for transdermal absorption of 1,25(OH)₂D₃ and its physiological activity in cattle.

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The effect of perfusion of hCG, PGF_2α, vasoactive peptides, and Ringer's solution (control) on the ovaries of mares (Percheron, Breton and crossbred) during early and functional luteal phases of the ovarian cycle was studied using an in vitro microdialysis system. There was no increase in P₄ secretion as a result of the perfusion of 10 IU or 100 IU of hCG during the early or functional luteal phase. But both the levels of hCG significantly increased PGF_2α release, compared to the control, during early luteal phase (p<0.05). During functional luteal phase, 100 IU hCG caused significantly higher secretion of PGF_2α than 10 IU hCG or the control (p<0.05). P₄ release was significantly higher than in the control (p<0.05) with PGF_2α perfusion in both the early and the functional luteal phases. Vasoactive peptides (angiotensin-Ⅱ, endothelin-Ⅰ and atrial natriuretic peptide) did not cause a significant difference in P₄ release during the early or the functional luteal phase. However, PGF_2α release was significantly increased compared to the control (p<0.05) in both phases. These results suggest that hCG and vasoactive peptides had a profound effect on PGF_2α release but did not stimulate P₄ secretion during the early or the functional luteal phase in equines.

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An 11-year-old nursing Japanese Black cow was admitted to the Large Animal Treatment Center of Kitasato University, for treatment of astasia. She had been treated for anorexia by a local veterinarian 7 days earlier, but had developed astasia 60 days after calving. Anorexia, depression, dehydration and hard stools were seen at the initial visit, and blood tests showed severe hypocalcemia (4.8mg/dl) and hypomagnesemia (0.6mg/dl). Continuous intravenous infusion of a fluid containing mainly calcium and magnesium solutions was performed, and a gastrointestinal drug was administered orally. As a result, the hypocalcemia and hypomagnesemia improved gradually, the animal stood up on the 11^th day after admission, the symptoms improved, and normal feed intake and water intake were restored by the 19^th day. This case suggests that nursing cows of advanced age can develop hypocalcemia and hypomagnesemia even after the immediate post-partum period.

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A female Japanese Black calf presented with dwarfism, extremely small limbs, hydrocephalus-like head, and abnormal gait. It was reared from the age of 5 days to about 6 months to observe its development, and to conduct blood chemistry tests, endocrinological tests, and epidemiological tests. At age 5 days, the calf weighed 25 kg, and had the very small height of 50 cm, and the body length of 52 cm. X-ray examination revealed blurring of long bone epiphyseal growth plates, and enlarged articular cavity of the knee. CT showed separation of the femoral head from the acetabulum. The calf's subsequent development was poor, and it weighed only 45kg at age 5 months. Afterwards, it developed astasia, and died at the age of 196 days. The gene that causes dwarfism in Japanese Brown cattle was the homozygous normal genotype in this subject. Endocrinological tests revealed elevated plasma growth hormone, decreased insulin-like growth factor-1, and decreased thyroid hormones (T₃ and T₄). Pathological tests showed chondrodysplasia of the epiphyseal plates. The thyroid showed variability in the size of colloidal follicles and sloughing off of the follicular epithelium into the colloid. Although the animal was diagnosed with chondrodysplastic dwarfism, the cause could not be fully elucidated.

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A 12-year-old multiparous Holstein cow weighing 710 kg that had shown no signs of estrus after the last calving on July 16, 2007 was subjected to clinical and pathological observations. On October 16, rectal palpation showed a large mass in the left ovary, and a distended and flaccid uterus. Vaginal examination and ultrasonography revealed pyometra with a cystic left ovary and a right ovary with corpora lutea. The administration of a prostaglandin F_2αanalog alleviated the pyometra by November 6 ; the left ovary cyst grew to about 20 cm diameter, and maintained that size. An autopsy on December 18 revealed chronic inflammation of the endometrium and a single large cyst (18×15.5×12 cm) in the left ovary. The cyst (1980 g) contained 1983 ml of a limpid yellowish-brown liquid. The ovary became flattened and weighed 77 g after aspiration of the liquid. The cyst wall was less than 1mm thick and the ovary had no follicle or corpus luteum. The right ovary had a regressing and a functional corpus luteum. The left ovary cyst was diagnosed as granulosa-theca cell tumor by histopathological analysis. This cow was considered to have a unilateral monocystic granulosa-theca cell tumor accompanied by pyometra, with a functional corpus luteum in the right ovary.

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