Association between solar radiation and ocular squamous cell carcinoma in cattle

The association between ocular squamous cell tumors and various measures of solar radiation was evaluated for 2,775 contemporaneous Hereford cattle. The animals were from 34 herds located in 21 states in the United States and in one Canadian province. Examinations and photographs were made of the eyes of all cows and heifers in a herd; 33 herds were examined between June and August 1957 and 1 herd was examined in 1958. Solar radiation was measured by altitude and mean annual hours of sunshine applying to an individual herd, and global radiation, a cloudiness index, and elevation of nearby National Weather Service stations. All measures of solar radiation provided evidence of a significant association between increasing risks of developing cancer eye and increasing levels of radiation; adjustments were made for possible confounding effects of age and corneoscleral pigmentation. Associations were evident whether affliction was defined as the occurrence of any type of tumor (ie, plaque, papilloma, or carcinoma), or as the occurrence of only papilloma or carcinoma. Average ages of affected cattle also tended to be lower at high radiation levels than at low levels, further supporting the hypothesis that solar radiation has an important role in the development of this disease. In view of the heritability of eye pigmentation and its inhibitory effect on lesions, cancer eye may be controlled by selective breeding for increased pigmentation in and around the eye to afford protection against the harmful effects of incident UV radiation.     

Intracavitary Cisplatin Chemotherapy Experience with Six Dogs

Six dogs with a median age of 7 years (range = 5-14 years) were presented for signs referable to thoracic or abdominal effusion associated with neoplasia of the body cavities. Intracavitary cisplatin was administered at 50 mg/m2 every 4 weeks for a median of 2.5 treatments (mean = 3, range = 1-6). Three dogs with pleural mesothelioma had complete resolution of effusion for 289, 129, and greater than 306 days without evidence of tumor growth. Resolution of effusion occurred after one treatment in two dogs and after two treatments in one dog. In three dogs with carcinomatosis of unknown origin, complete responses was seen in two dogs after one treatment for 255 and greater than 807 days, respectively. Intracavitary chemotherapy with cisplatin was associated with palliation and control of malignant pleural and/or abdominal effusion in five of six dogs. Toxicity was minimal, and this method of therapy should be further explored in dogs with similar malignancies.     

Acute and chronic hormone and metabolite changes in lambs fed the beta-agonist, cimaterol

The objective of this study was to determine if acute and chronic changes in circulating metabolic hormone and metabolite concentrations are associated with β-agonist-induced nutrient repartitioning in young growing lambs. Two groups of 12 Dorset and Dorset-Finn cross ram lambs weighing 36 or 33 kg live weight were assigned to 3- or 6-week treatment intervals, respectively, to achieve similar slaughter weights. Six lambs within each treatment interval were fed ad libitum a complete mixed high-concentrate diet containing either 0 or 10 ppm cimaterol. During the first 12 hr of cimaterol administration plasma somatotropin (ST), thyroxine (T₄), and triiodothyronine (T₃) concentrations were not altered by treatment, but plasma insulin, glucose, non-esterified fatty acids (NEFA) and glycerol concentrations were elevated 2 hr after ingestion. These acute responses suggest direct stimulation of glycogenolysis and lipolysis by cimaterol, which is characteristic of β-adrenergic alteration of carbohydrate and lipid metabolism. Chronic administration of cimaterol significantly decreased insulin concentrations by 36% and 52% at 3 and 6 weeks, respectively, while glucose concentrations remained unchanged. Serum IGF-I concentrations were not significantly altered by cimaterol. T₄ levels were reduced 22.1% after 3 weeks of cimaterol treatment. Although plasma NEFA concentrations were chronically elevated 56% to 65% in lambs fed cimaterol, plasma glycerol concentrations remained at baseline levels. The relative changes in plasma NEFA and glycerol concentrations are consistent with a decreased rate of lipogenesis, rather than an increase in lipolysis.     

Exposure of Ankole and crossbred cattle to theileriosis in Rwanda

Summary Susceptible Ankole (Sanga:Bos indicus/Bos taurus) and crossbred Ankole x Jersey (B. taurus) and Ankole x Sahiwal (B. indicus) cattle derived from a farm in Rwanda with no recent history of theileriosis, were infected withTheileria parva stocks from Rwanda either by feeding infectedRhipicephalus appendiculatus ticks on the ears, inoculation of tick derived stabilate or natural exposure to tick challenge. The Ankole cattle originated from local stock born and bred in East Coast fever (ECF) endemic areas of Rwanda. Disease, followed by spontaneous recovery, was observed in 49 of the 72 Ankole cattle after infection withT. parva (68%); the other 23 animals (32%) died of ECF. In contrast 21 of the 33 infected crossbred cattle (64%) died of ECF. It is concluded that the partialTheileria tolerance of the Ankole is, to a great extent, genetic. The basis of this partial tolerance seems to be their ability to limit the explosive multiplication of macroschizonts during the acute phase of the disease.

---

Resumen Se infectó ganado Ankole susceptible (Sanga:Bos indicus/Bos taurus) y ganado cruzado Ankole x Jersey (Bos taurus) y Ankole x Sahiwal (Bos indicus) proveniente de una finca en Rwanda sin historia reciente de theileriosis, conTheileria parva procedente de Rwanda, mediante la adhesión en la oreja deRhipicephalus appendiculatus infectado, inoculación de estabilados derivados de garrapatas, o exposición natural a la enfermedad a través del vector. El ganado Ankole era originario de un área endémica de theileriosis en Rwanda. Se observó la enfermedad seguida de recuperación, en 49 de 72 animales Ankole infectados conT. parva (68%); los otros 23 animales murieron (32%). En contraste, 21 de los 33 animales cruzados infectados (64%), murieron. Se concluye, que la tolerancia parcial del ganado Ankole es de origen genético. Las bases de ésta tolerancia genética, parece debida a la habilidad para limitar en cierto modo la multiplicación explosiva de macroesquizontes, durante la fase aguda de la enfermedad.

---

Résumé On a infecté du bétail sensible, de race Ankolé (Sanga:Bos indicus/Bos taurus) et des croisés Ankolé x Jersey (B. taurus) et Ankolé x Sahiwal (B. indicus), provenant d'une ferme au Rwanda sans cas récents de theilériose, avec des souches deTheileria parva du Rwanda, par l'application de tiques (Rhipicephalus appendiculatus) infectées sur les oreilles, par inoculation de stabilat de tiques infectées ou par l'exposition à un challenge naturel de tiques. La souche d'Ankolé était originaire du cheptel local Rwandais, né et élevé dans les régions où la theilériose est endémique. La maladie suivie par la guérison spontanée fut observée dans 49 des 72 Ankolés (68%), les autres 23 animaux (32%) ont succombé à la theilériose. Par contre 21 des 33 croisées infectées (64%) ont succombé à la theilériose. Nous concluons que la tolérance partielle des Ankolés contre la theilériose, est génétique. La base de cette tolérance semble être leur capacité de limiter la multiplication explosive des macroschizonts pendant la phase aigu de la maladie.