_Treatment_: If from cold, give frequently one[1] or more teaspoonfuls of glycerine and water; if from over-barking, pacify the dog by removing the cause. =Hydrocele=: _Symptoms_: A swelling of the scrotum, which may be either hard or soft. _Treatment_: Apply following lotion often:— _Recipe_: Goulard’s Extract of Lead, 1 drachm. Tincture of Opium, 2 drachms. Distilled Water to 6 ounces. Mix. In some cases the application of tincture of iodine is necessary, or even the tapping of the swelling. =Hydrocephalus: Water in the Head=: _Symptoms_: May be seen in young unweaned puppies; in some cases it occurs later. The head, especially the top of the skull, is large and rounded, and the puppy waggles it from side to side as if it was too heavy to hold up. The gait is unsteady, and the puppy frequently walks in circles generally in one direction, is constantly whining and crying, does not thrive, and later generally has convulsions and dies. _Treatment_: There is really nothing to be done in these cases, and the kindest thing to do is to put the puppy out of its misery. =Hydrophobia=: _See_ RABIES. Though practically the same disease as rabies or canine madness, hydrophobia is a misnomer when this disease affects the dog, as he is not afraid of water; in fact, he will try to drink, but is unable to swallow little or none of the fluid in consequence of the condition of the throat. =Hypodermic Syringe: How to Use=: The proper quantity of medicine or stimulant, or whatever is going to be given, having been drawn up into the syringe, and the needle adjusted, a small fold of skin should be pinched up between the forefinger and thumb of the left hand, and the needle for about half an inch should be quickly thrust into the skin at one end of the fold, and then by pressure on the piston the contents of the syringe should be evacuated. If the operation is done quickly, the dog knows nothing about it. It does not in the least matter where the injection is made, so long as the place selected is where the skin is loose, as over the ribs. It is most important that the syringe and needles be kept very clean; and each time after being used it should be washed out with a five per cent. solution of carbolic acid or spirit. A wire (slightly vaselined), several of which are supplied with the syringe, should always be kept in the needle. =Hysteria=: Young puppies, especially at the time when they are changing their teeth, have sometimes a form of hysteria brought about by excitement, especially in hot weather. _Symptoms_: The puppy rushes about here and there, not knowing where it is going or what it is doing, biting and snapping at everything within reach, and screaming and howling as if it was being unmercifully beaten. Saliva pours from the mouth, and many a one has been destroyed during such an attack, it being supposed to have gone mad.