Some respiratory and enteric diseases of cattle: an update.

Fibrinous pneumonia caused 40-45% of death losses in cattle shipped into Bruce County, Ontario. Feeding corn silage within the first 2 weeks of arrival increased mortality. Commingling cattle from different sources and keeping more than 110 cattle in a pen were detrimental. While use of antimicrobials in the starter ration was beneficial, prophylactic use of antimicrobials in the water was not. Mortality was directly proportional to morbidity and treatment costs. Vaccinating against any respiratory disease in the first 2 weeks after arrival was detrimental. Delaying vaccination for at least 2 weeks after arrival prevented the negative effects of vaccination in calves fed corn silage. Morbidity in cattle transported by train or truck did not differ. Bovine respiratory syncytial virus causes severe pulmonary edema-emphysema, with high morbidity and variable mortality, in confined calves in the fall and early winter. Death is usually from secondary bacterial pneumonia. Treatment involves use of pyrilamine maleate, dexamethasone and sulfamethazine. Salmonella muenster causes bloody diarrhea, abortion and death in cattle of any age. Treatment is with antibiotics selected by sensitivity tests. Cryptosporidium causes watery diarrhea in 1- to 2-week-old calves; infection is often fatal despite symptomatic treatment. Diagnosis is by identification of oocysts in fecal sugar flotation solution or May-Grünwald-Giemsa-stained fecal smears. Oral sulfamethazine has been used as a prophylactic.