Selenium poisoning in dairy cattle

An outbreak of chronic selenium poisoning occurred in a mob of 30 Friesian dairy cows. These cows were all autumn calvers on a well-managed dairy farm.     

Digital dermatitis in dairy cattle

A condition of digital dermatitis causing lameness in a dairy herd is described. The lesion was a small circumscribed area of epidermal inflammation in the skin immediately above the coronet between the bulbs of the heel. Topical treatment, consisting of excoriation and application of a gentian violet and tetracycline aerosol spray, was effective. Although the high incidence and rapid onset of the condition suggested an infectious cause, no organism was isolated consistently.     

奶牛铅中毒

1　发病情况及流行病学调查1 999年 3月下旬 ,我市某区专业户郑某共养 4头黑白花奶牛 ,其中犊牛 1头 ,泌乳牛 3头。 3月 1 9日开始饲喂玉米秸杆 ,2 2日开始 1头奶牛产奶量下降 1 0 kg,2 3日 1头犊牛不采食 ,2 4日死亡 ;2 5日死亡 2头 ,2 6日死亡 1头。死前体温 3 8.2℃ ,脉搏 5     

Pendular nystagmus in dairy cattle

In a survey of 2,932 mature dairy cattle performed over a 1-month period, we found 15 with rapid oscillation in 1 or both eyes. Nystagmus had been present since shortly after birth in 2 animals, and the age at onset was unknown in the others. The nystagmus was not associated with any other physical or neurologic problem. Pendular nystagmus apparently is benign and should not be mistaken for a sign of serious neurologic disease.     

Mycoplasma mastitis in dairy cattle

The most important characteristics of Mycoplasma mastitis on dairy farms are described, based on two case studies. Clinical symptoms, diagnostics, epidemiology, and a plan of action are presented. In the herds investigated, Mycoplasma mastitis was characterized by multiple affected quarters unresponsive to treatment with antibiotic and/or anti-inflammatory agents. Most striking were a sandy sediment, brown colouring, and rice-like structure of the milk of affected animals. Clinical symptoms differed in the two affected herds. Diagnosis was based on bacteriological investigation of samples of milk and synovial fluid taken from infected cows. Affected animals were culled immediately, and the herds were monitored by repeated testing of bulk milk samples. It was concluded that a consequence of the increasing size of cattle herds in the Netherlands is that subclinical/clinical Mycoplasma mastitis may be diagnosed more frequently than in the past. In the case of Mycoplasma mastitis, farmers and veterinary practitioners are advised to draw up a plan of action together, incorporating aspects such as diagnostics at cow level, direct culling of affected animals, hygiene during milking, including post-milking teat disinfection, and routine monitoring of bulk milk. Unpasteurized milk should not be given to calves.     

Staphylococci from dairy cattle

Extract

Staphylococci are very important among the causes of bovine mastitis but little in-formation has been published about the possibility of a reservoir of the organisms in cattle apart from the udders. The aim of this study was to find the incidence of nasal carriage in herds with a staphylococcal mastitis problem and, by phage typing, to find the relationships, if any, between the strains carried in the noses to those causing mastitis.     

Bacterial endocarditis in adult dairy cattle

Thirty-one cases of bacterial endocarditis in adult dairy cows were reviewed. Clinical signs were reflective of the stage of the disease. Recurrent or persistent fever, tachycardia and a pounding heartbeat or systolic murmur, polypnea, and lameness were typical. With chronicity, weight loss and poor production developed. The end stage was congestive heart failure. Neutrophilia was typical in early cases. Low-grade anemia and high total serum globulin content developed with chronicity and seemed to be negative prognostic signs. Corynebacterium pyogenes was the organism most frequently identified by blood culture or at necropsy. Twenty cows were necropsied and 2 cows were sent to slaughter. Nine cows in which the diagnosis was made early in the course of the disease responded to long-term penicillin therapy.