212. Any disease condition gives rise to welfare concerns for the animal(s) affected. A large range of therapeutic agents (including antibiotics, vaccines and anthelmintics) is available to prevent and treat bovine diseases. Infectious diseases of particular relevance such as mastitis, foul-in-the-foot, digital dermatitis, have already been addressed in other sections of this report. However, there are others which may have an impact on the welfare, especially the health, of animals in affected herds.
213. A significant number of infectious diseases are transmitted by contact between susceptible cattle and infected cattle and, wherever possible, a closed herd policy should be maintained. The purchase or hire of a bull to use by natural service on heifers or to act as a "sweeper" after AI is a common way of introducing infection to a closed herd. A planned approach should be agreed with the owner's veterinary surgeon to prevent and control the introduction of infectious disease to the herd by bought-in replacements or bulls.
214. Respiratory diseases may result in high morbidity within affected herds. Although some effective vaccines are available, these should not be used as a substitute for dealing with the underlying predisposing causes. Animals may be susceptible to other pathogens and succeeding batches of animals will be placed at risk if environmental or other management faults are not corrected.
215. Although a wide range of effective anthelmintics is available, diseases caused by internal parasites (intestinal worms and lungworms) remain potentially serious problems. A lack of understanding of the epidemiology frequently leads to poor grazing management or inappropriate worming regimes. Injury to animals has also arisen following the administration of long-acting anthelmintic boluses by unskilled people.
216. Diseases, especially mange, caused by external parasites have increased in prevalence since the ending of compulsory preventive treatment for warble fly. Mange causes considerable discomfort and irritation, with affected cattle often rubbing areas of skin raw, yet the presence of such disease is widely ignored. Ringworm, although causing less noticeable irritation, may affect large areas of the animal, particularly calves.
217. In 1988, BSE was made a notifiable disease and any animal showing clinical symptoms of the disease must be reported to the relevant authority immediately.
218. Other important infectious diseases, such as leptospirosis and TB, can have effects on the welfare of individual cattle or whole herds. However, animals with TB are normally identified and removed before clinical disease occurs.
219. Bovine virus diarrhoea (BVD) infection is a significant disease with welfare implications in infected herds. Calves born to dams infected in early pregnancy are persistently infected and are often poor-doers'. Such animals are frequently not culled until they become obviously ill and reluctant to rise and have gross soiling of the hindquarters. They also have the potential to infect other previously unexposed pregnant animals.
220. Johnes disease causes weight loss, soiling and debility. Animals are often not culled until too late in the disease process when they may be emaciated and weak.
221. A planned approach should be agreed with the owner's veterinary surgeon to prevent and control the introduction of infectious disease to the herd by bought-in replacement cattle.
222. The written health and welfare programme (see paragraph 62) should ensure that routine prophylactic measures which are required are given at the correct time and at the correct dose.
223. Infectious diseases should be controlled by good management and attention to detail. Measures include good hygiene, adequate ventilation and, in the case of calves, supervised colostrum intake. Vaccinations may be appropriate against certain infections.
224. Inexperienced or unskilled staff should be trained in the administration of treatments, such as injections or oral boluses, where damage may be caused to animals if given incorrectly.
225. Internal parasites should be controlled by grazing management and appropriate use of anthelmintics (or vaccine in the case of lungworms) based upon the epidemiology of the disease.
226. Diseases caused by external parasites, especially where irritation and rubbing are caused, should be controlled by appropriate parasiticides.
227. Animals suffering from debilitating, incurable diseases (such as BVD and Johnes disease) should be identified and culled as early as possible. They should not be left until they become emaciated and recumbent.