48 



VETERINARY PATHOLOGY. 



1. Instantaneous production of thrombi. Crotalus (rattle- 

 snake). 



"2. Xeurdtoxic action. (Cobra.) 



:!. Produce capillary ruptures and hemorrhage. Crotalus 

 (rattlesnake). 



4. Produce liemolysis. Crotalus (rattlesnake). 



b. Produce scneral cytolysis. Crotalus (rattlesnake), 

 and viper berus (adder). 



The following- is the to.xicity estimate of venom per kilo- 

 gram liC'dv weight; — 



Coltra venom .0000!:) gram lethal dose for horse intravenously. 



Cobra venom .000.5 gram lethal dose for dog subcutanously. 



Rattlesnake .00.5 gram lethal dose for rabbit subcutanously. 



A'iper .0001 gram lethal dose for rabbit intravenously. 



Retrograde metamorphosis in the tissues of the animal body 

 frequently results in the production of leucomains which when 

 absorbed are extremelv poisonous and cause marked disturb- 

 ances. C)ver action of muscular tissue may cause the produc- 

 tion of leucomains, thus horses that are overworked, although 

 their food and water are first-class and their digestion is good, 

 are occasionally aiTected with a severe diarrhoea caused by the 

 action of leucomains. 



Parasitic or Infectious. During the last charter of a century 

 patholiigv has received an impulse by the knowledge of micropar- 

 asites accjuired during this time. Although parasitism has been 

 known since the dawn of the 19th century the importance of 

 microparasites has been recognized only since bacteriology be- 

 came a science. 



T'arasitism is an evolutionary condition. It is the result of a 

 long continued struggle, and the survival of the fittest, during 

 which there is a necessary adaptatictn to constantly changing en- 

 \ironniental conditions. Parasitic causes of disease include rep- 

 resentatives of both the plant and animal kingdom. Parasitic 

 plants (Phvtoparasites) are practicallv all microscopic in size 

 and are termed microphytes. Pathogenic plants are all fungi 

 and the following scheme gives their position in the plant king- 

 dom ; 



rECI-TABI.E PARASITES. 

 KINGDO^^ i:r,\nch class order family genus species 



1. Plant Thallophyta Hyphoiiiycetes Mucidineae Ooepora Porrigines 



(Achorlon 

 •choenleini) 



2. Plant ThailDphyta HyplnmyceteB Plecascineae Aspergillaceae Aspertrilhis Fumigatus 

 S. Plant Th.iUophyta Hyphoiiiycetes Plecascineae Afpergillaceae Aspergillus NlRer 



4. Plant Thallophyta Ascomyceles Protoasclntae Saccharomycetaceae SaccharomyceB Farclmlnosus 



5. Plant Thallophyta SchlzomyceteB ■ Actinomycea Bovls 



6. Plant Thallophyta Schizomyc«tes ,, , Bacterium TuberculOBla, etc 



