Fibrosarcoma in the distal radius and carpus of a four-year-old Persian.

A four-year-old Persian was presented for evaluation of a nonweight-bearing, left forelimb lameness. Radioulnar and pancarpal osteolysis with minimal periosteal reaction were seen on radiographs of the antebrachium. Cytological examinations of fine-needle aspirates and impression smears were suggestive of sarcoma. After forequarter amputation, histopathological examination provided a diagnosis of fibrosarcoma with axillary lymph-node metastasis.

Bilateral tibial metaphyseal stress fractures associated with physitis in a foal.

A 7-month-old Appaloosa foal had bilateral hind limb lameness and was unable to rise from recumbency without assistance. Lameness could be exacerbated by tarsal flexion and a firm swelling at the distomedial aspect of the tibias was associated with a marked pain response when palpated. Radiography revealed enlargement of the distal tibial metaphysis physis (compared with normal), and radiolucent fissure lines extending proximally from the physis into the metaphysis at its medial aspect. Treatment included rest and dietary adjustment. Although clinical signs initially resolved following treatment, the problem recurred when the foal was 14 months old. Further treatment included 7 months of pasture rest without forced exercise, after which the foal was reported to be clinically normal.

Atlantoaxial malformation in a half-Arabian colt.

A 1-year-old half-Arabian colt was referred for evaluation of a cranial cervical abnormality. Physical examination revealed the left wing of the atlas to be more ventral than the right wing. A head tilt, with the pole deviated to the left, was present because of the malpositioned atlas. Neurologic examination identified symmetrical weakness, ataxia, and proprioceptive deficits in all four limbs. Radiographs of the cranial cervical region revealed fusion of the atlas and axis, and deviation of the atlantoaxial joint to the left of the median plane. Euthanasia was elected. Necropsy confirmed the radiographic findings. The atlas was rotated 20 degrees counterclockwise when viewed from the caudal aspect. Multifocal myelomalacia was present in the first and second cervical spinal cord segments. The malformation was believed to be due to a degenerative process or abnormal embryological development.

Clinical and clinicopathologic response of canine bone tumor patients to treatment with samarium-153-EDTMP.

Forty dogs with spontaneous skeletal neoplasia were treated with 153Sm-EDTMP (ethylenediaminetetramethylene phosphonic acid). Both primary and metastatic lesions were treated. Two treatment regimes, a single (37 MBq (1.0 mCi)/kg dose or two 37 MBq (1.0 mCi)/kg doses separated by 1 wk) were tested. Response to treatment was varied. Large lesions with minimal tumor bone formation responded poorly, while primary lesions with substantial ossification usually exhibited a transient response. Small lesions with minimal lysis, metastatic lesions, and axial skeleton lesions generally responded well. The major adverse side effects of treatment were platelet and white blood cell count depression below baseline values for up to 4 wk (p less than 0.05). Minor depression of packed cell volume and transient elevation of serum alkaline phosphatase were also noted (p less than 0.05). No significant differences (p greater than 0.05) between the two treatment groups, either in treatment effect or undesirable side effects, were detected.

Clinical and clinicopathologic effects of samarium-153-EDTMP administered intravenously to normal beagle dogs.

A study was undertaken to determine the degree of acute bone marrow and vital organs injury sustained when dogs were administered doses of 153Sm-EDTMP calculated to irradiate an acute bone lesion arising from cancer metastasis to a dose considered palliative or even therapeutic (20-160 Gy). The study revealed significant (p less than 0.05) temporary depression of the bone marrow in all doses in the therapeutic (greater than 40 Gy) range. Palliative (20 Gy) doses caused significant leukocyte depression but insignificant (p greater than 0.05) depression of platelet and packed cell volumes when compared to control animals. A mild transient rise in the levels of serum alkaline phosphatase occurred immediately following radioisotope administration. All hematologic parameters had returned to normal by six weeks after the last injection of radioisotope. The study indicates potential for this compound as a safe, therapeutic radiopharmaceutical for treatment of cancer bone metastasis.

50-Chromium labeled erythrocyte half-time disappearance from adult Sinclair (S-1) miniature swine.

Half-time disappearance of (51)Cr-labeled erythrocytes from 20 adult miniature swine was measured. Seven males and 13 females from 388 to 418 days of age, having a mean weight of 55kg were studied. Five ml of blood collected from each animal were labeled with 75 microCi (51)Cr at room temperature for 60 to 90 min. Following injection of the labeled erythrocytes into each animal, blood samples were collected every four to six days. Specific activity was measured and half-time disappearance determined by linear regression. The results were compared with values obtained from the same animals tested at two earlier ages. No significant (P <0.05) difference in erythrocyte half-time disappearance was detected between males and females at the three different ages. Mean (+/-SEM) erythrocyte half-time disappearance values were: 20 to 46 days of age, 19.58 (+/-0.59) days; 79 to 109 days of age, 23.56 (+/-1.18) days; and 388 to 418 days of age, 22.35 (+/-0.72) days. A significant (P <0.01) difference in erythrocyte half-time disappearance was found between the miniature swine tested at 20 to 46 days of age and those tested at either 79 to 109 or 388 to 418 days of age. No significant (P <0.05) difference in erythrocyte half-time disappearance was found between the two older age groups.

51-chromium labeled erythrocyte half-time disappearance from miniature swine.

Half-time disappearance of (51)Cr-laeled erythrocytes was studied in 39 Sinclair miniature swine at 20 to 46 days of age and again at 79 to 109 days of age. Mean erythrocyte half-time disappearance, disregarding age, was 21.29 (+/-0.77) days for males and 22.04 (+/-0.81) days for females. The half-time difference between males and females was not statistically significant (P<0.05). At 20 to 46 days of age the mean erythrocyte half-time disappearance was 19.56 (+/-1.41) days. The same pigs, tested at 79 to 109 days of age, had a mean erythrocyte half-time disappearance of 23.95 (+/-1.94) days. There was a significant difference (P<0.01) in erythrocyte half-time disappearance from miniature swine as the result of age and also for age within sex. The grand mean erythrocyte half-time disappearance, for all the miniature swine tested, was 21.67 (+/-0.54) days. The estimate of heritability was 0.61 for dam effect at 20 to 46 days of age and 0.06 at 79 to 109 days of age. Sire estimate of heritability was 0 at both age groups. It was concluded that the large heritability coefficient found only for dam component in young nursing pigs was the result of maternal environment rather than additive genetic variance.