In different parts of Europe and America, and especially in the warmer regions, or in sheltered gardens, shrubberies, and pastures, different species of the trombidium abound, and the young hexapod larvæ attack man and beast, burrowing under the cuticle and giving rise to extreme itching and persistent and irritating rubbing of the affected part. These parasites belong to the family of acari or mites, so that the condition they produce is one of acariasis or mange, only the offender is not a compulsory parasite, but appears to survive in certain soils and in the vegetation independently of animal hosts. Their parasitism is therefore accidental and non-essential to their survival.
The trombidian parasite usually found in Europe is the Trombidium Holosericeum or silky trombidium, so small (in its larval state) that it is just visible to the naked eye as a bright scarlet point when moving on a dark background. It was formerly called Leptus Autumnalis and is familiarly known as the red beast, bete rouge, harvest bug, etc. The common American species is of a dull brick red, so that it is less easily detected even on a dark background. It is familiarly known as the jigger, though quite distinct from the chigoe or burrowing flea of the West Indies.
The domestic herbivora get these parasites on the nose and lips while browsing on the pastures and contract an intolerable itching which may lead to violent rubbing, abrasions and scabby exudations. The skin becomes thickened, scabby and rigid, and as new accessions are constantly received the malady continues until cold weather sets in. The affection is not in any sense dangerous, and the attacks may be warded off by a daily application of one of the common parasiticides—decoction of tobacco, tar water, solution of creolin, naphthalin, etc. The mere seclusion of the infested animal indoors, without green food, will cure, as the larvæ pass through their parasitic stage in a few days and drop off.
GENERAL CATARRHAL STOMATITIS. BUCCAL INFLAMMATION.
Mature animals most subject: Causes in horse, mechanical, chemical, microbian irritants—alkalies, acids, caustics, hot mashes, ferments, fungi, rank grasses, excess of chlorophyll, clover, alfalfa, acrid vegetables, bacterial infection secondary, acrid insects in food; symptomatic of gastritis, pharyngitis, diseased teeth, specific fevers. Symptoms: Congestion and tumefaction of buccal mucosa, lips and salivary glands; Epithelial desquamation; fœtor; salivation; froth; papules; vesicles. Prognosis. Treatment: Cool soft food; antiseptics; wet applications to skin; derivatives.
This is much more common in the adult than in suckling domestic animals. None of the domestic mammals or birds can be considered immune from it, but as its causes and manifestations differ somewhat it seems well to consider it separately in the different genera.
GENERAL CATARRHAL STOMATITIS IN SOLIPEDS.
Causes. These may be classed as mechanical, chemical, microbian and other irritants. In the horse it is often due to the reckless administration of irritant liquids as remedies. Owing to the length of the soft palate the horse can refuse to swallow any liquid as long as he chooses, and some of the worst cases of stomatitis I have seen resulted from the retention in the mouth of caustic alkaline liquids given under the name of “weak lye.” Strong acids and caustic salts dissolved in too little water or other excipient, or suspended in liquids in which they cannot dissolve, or made into boluses which are crushed between the teeth are not infrequent conditions. Too hot mashes given to a hungry horse is another cause of this trouble. Fermented or decomposed food is often most irritating. Coachmen will sometimes induce it by attaching to the bit bags of spicy or irritant agents, to cause frothing and make the animal appear spirited.
Fungi in fodders are among the common causes. The rust of wheat (puccinia graminis), the caries of wheat (tilletia caries), the blight (erysiphe communis), ergot (claviceps purpurea), the fungus of rape (polydesmus excitiosus) and the moulds (penicillium and puccinia) have all been noticed to coincide with stomatitis, and charged with producing it. On the other hand, at given times, one or other of these cryptogams has been present extensively in the fodder without any visible resultant stomatitis. The apparent paradox may be explained by the fact that these fungi vary greatly in the irritant or harmless nature of their products according to the conditions under which they have grown, and the stage of their development at which they were secured and preserved. Ergot notoriously differs in strength in different years, on different soils, under various degrees of sunshine, shade, cloud, fog, etc. In different States in the Mississippi valley it is not uncommon to find stomatitis in horses in winter, fed on ergoted hay, while cattle devouring the same fodder have dry gangrene of feet, tail and ears. Yet in other seasons the ergot fails to produce these lesions. Rank grown, watery vegetation, especially if it contains an excess of chlorophyll is liable to cause stomatitis. Red and white clover, trefoil, hybrid and purple clover, and alfalfa have all acted more or less in this way, though in many cases, the food has become musty or attacked by bacterial ferments. Some of the strongly aromatic plants, and those containing acrid principles (cicuta virosa, œnanthe crocata, mustard, etc.) cause buccal inflammation and salivation.
The irritation in many such cases is not due to one agent only, the vegetable or other irritant may be the starting point, acting but as a temporary irritant, the action of which is supplemented and aggravated by the subsequent attacks of bacterial ferments on the inflamed, weakened or abraded tissues. The bacteria present in the mouth, food or water would have had no effect whatever upon the healthy mucosa, while they make serious inroads on the diseased. On the other hand the vegetable, mechanical or chemical irritant would have had but a transient effect, but for the supplementary action of the bacteria.