CHAPTER VII. 



POISONING. 



Accidental poisoning is frequent in domesticated animals. It may 

 present no visible lesions, and it is therefore very important to recognise 

 the symptoms -which indicate the secret lesion. 



POISONING DUE TO FOOD. 



Under this title are included all forms of poisoning resulting from the 

 ingestion of bad fodder. Such expressions as "intestinal typhus" and 

 "typhic gastro-enteritis " only indicate a special stage in the condition, 

 which is never twice the same. 



Causation. The most important changes in the food ingested do not 

 consist in a mere modification in its chemical composition, but in the 

 presence of various parasites which develop in grain and forage, after 

 moistening, or after abnormal fermentation in the interior of the grains. 

 These parasites are chiefly represented by fungi belonging to the genus 

 Mucor : AsjicriiiUus or PenirilUum ; blight — Pmxinia (jraminis, Urcdo 

 liiiraris ; smut — Tillrtla caries, Ustilago seciehnu, Vstilaijo viayiUs ; 

 yeasts of different kinds resulting from the fermentation of brewers' 

 grains ; and, finally, unrecognised microbes Avhich act by means of the 

 poisons they secrete. 



The symptoms are always very vague. At first the only marked 

 symptom is loss of appetite, accompanied by dryness of the mouth and 

 muzzle, depression and constipation. The animals never clearly show 

 signs of gastro-enteritis ; nevertheless, the changes in general health 

 point very clearly to a digestive origin. 



In cases of acute poisoning the symptoms develop rapidly. Torpor 

 becomes more marlced, the movements of the heart tumultuous, and the 

 temperature rises to 105 ' Fahr. (40-5° C), diminishing later until death 

 occurs. 



In chronic forms of poisoning constipation is present at first, but is 

 soon followed by profuse, fcetid, blackish diarrhoea, sometimes containing 

 streaks of blood and accompanied Ijy abdominal pain. 



In exceptional cases these digestive symptoms are amplified by the 

 presence of broncho-pneumonia, pleuro-pneumonia, nephritis, and cystitis. 



