10 a distinct breathing effort that may be fast or slow, but usually shallow because of pleuritic
pain. Treat suspected cases with antibiotics, isolate in a well ventilated area if practicable and maintain hydration. Low stocking rates, good ventilation and vaccination against
respiratory pathogens can markedly reduce morbidity and mortality from pneumonia.
2.2.2 Heat stress
British and European Bos taurus breeds are affected by heat stress when entering the high temperatures and humidity of the equatorial band. Tropical breeds Bos indicus and their
crosses remain largely unaffected. Unacclimatised Bos taurus cattle, particularly if fat, have long hair coats, are in crowded pens and have difficulty accessing water, can die within
hours of onset of hyperthermia. Heat stress is probably one of the main predisposing factors for pneumonia. Rectal temperatures may reach 43.0
o
C
2.2.3 Bloat
Bloat causes respiratory distress by the tightly distended rumen compressing the thoracic cavity. Bloat is discussed further under the syndrome of Abdominal distension.
2.2.4 Physical exertion
Physical exertion will cause temporary respiratory distress.
2.2.5 Hypoxia from engine exhaust gases
Carbon monoxide and carbon dioxide poisoning may occur in poorly ventilated pen areas where portable combustion engines are being used for repairs or maintenance.
2.2.6 Hypoxia from exposure to toxins in feed
Shipboard cattle are normally fed hay, chaff or pellets which carries very low risk of nitrate- nitrite or cyanide poisoning compared to the silage and green chop from certain pastures
and crops. Nitrate- nitrite poisoning may occur if feeding hay made from plants that have been fertilised with nitrogen, cut when stressed by heat or dampness, or improperly cured.
Hay made from wilted forage sorghum and fed to hungry cattle may cause cyanide poisoning. There will be weakness and ataxia, brown cyanotic mucous membranes with
nitrite poisoning, cherry red mucous membranes with cyanide poisoning, before collapse and death in asphyxial convulsions. Treat cyanide poisoning with intravenous sodium nitrite and
or sodium thiosulphate if available.
2.3 Lameness
