PRINCIPLES OF VETERINARY SURGERY 617 



especially the maxillary bones, have been suffering from 

 the disease for a long tiijie. 



The disease often assumes an epizootic form. Theiler, 

 a veterinarian in Johannesburg, has described a veritable 

 epidemic of osteomalacia among tramway horses. The 

 bacteriological investigation of the disease has thus far 

 given only negative results, and its infectiousness therefore 

 remains unproven. It is supposed to be connected vi^ith 

 goiter. Dor has compared it with Paget's disease and Mar- 

 cone with osteomalacia of man. The latter regards it as an 

 inflammatory process beginning in the Haversian canals 

 and ending in rarefaction of the osseous tissue. 



SYMPTOMS.^The premonitory symptoms are vague 

 and are usually regarded as due to "muscular rheumatism." 

 Its beginning is obscure and evolution slow. The appetite 

 is preserved and the condition of flesh is well maintained. 

 The general condition is but little altered, but the vigor is 

 considerably depressed. They become weak and easily 

 fatigued without any evidence for attributing the change 

 to any definite disease. Some animals suddenly show signs 

 of either a slight or marked lameness, which is migratory 

 and remittent and often attributed to rheiunatic diathesis, 

 or of late years to osteitism, resulting from painful sensa- 

 tions in the bones. These pains are expressions of a dif- 

 fused rarefying osteitis, attacking the bones successively, 

 alternately or simultaneously. The lameness is accom- 

 panied with articular or tendinous tumefactions which 

 usually yield to the application of counter-irritants. Some- 

 times numerous and successive inflammations of several 

 synovial membranes and a large number of bones are ob- 

 served. These inflammations evolve without any percep- 

 tible rise of the temperature, and without leaving behind 

 any indurations and ankyloses as relics. The dorso-lumbar 

 region is stiff and painful on pressure and some animals 

 show paresis or paraplegia. 



