162 



MODERN HORSE MANAGEMENT 



[CHAP. 



not extend to the crest of the neck where the 

 mane will reach. 



The thoracic and abdominal portion (known 

 as the cutaneus maximum) extends over the 

 whole chest and abdomen, over the forearm 

 above the knees, and back to the points of the 

 hips. It does not extend posterior to this, that 

 is, over the hindquarters, nor around the linea 

 alba or median line under the belly. 



Its action is to twitch the skin and drive away 

 offending flies, mosquitoes, etc. A few minutes' 

 study on a hot day in the fly season will give 

 anyone a good idea of the use of this muscle. 

 So it will be seen that the hindquarters of the 

 horse are unprotected from flies, a tail of 

 sufficient length to reach to the hips being neces- 

 sary to protect these parts. The mane also is 

 intended to protect the upper portion of the 

 neck. I discuss this subject fully in Chapter 

 XIII. 



There is also a thick, triangular piece of fascia 

 directly over the tail where the horse is unable 

 to reach. This fascia cannot be penetrated by 

 the proboscis of a fly. An undocked tail, with 

 only two or three inches on the end, will reach 

 very near to the hips, but a docked tail will not. 

 A tail of sufficient length to reach to the hocks 

 is necessary, though, to reach the belly and 

 in between the thighs. This is dealt with in 

 Chapter XIII. 



The skin at the end of the tail is very thick, 

 being over a quarter of an inch in many cases, 

 and it is from this alone that the long tail hairs 

 grow. Therefore, a docked horse will never have 

 a long tail. I have come across one or two very 

 rare exceptions with horses only slightly docked. 

 The hairs on top of the tail are short and finer. 

 Of course, a longer tail than described above is 

 better for the horse, as he will be able to keep 

 the flies from settling on his flanks, back and 

 abdomen, and be able, probably, to kill those 

 that do settle, instead of merely driving them 

 away with his fly muscle. 



Flies. 



636. Flies are a very active means of spread- 

 ing infectious diseases; they are filthy, dirt- 

 spreading insects, and cause no end of worry in 

 a score of ways during their short life. 



Reference to any book on insects will furnish 

 a good idea of the flies that attack the horse; 

 they are chiefly of a blood-sucking type, and are 

 mostly large. Steven H. Terry, in his " Crime of 

 Docking Horses," illustrates the commonest types 

 that attack the horse. Some of these flies have 

 been known to drive docked horses mad, as they 

 insert their lancets right into the horse's hide 

 where the tail will not reach, and there suck 

 blood until they are filled. 



637. Below is a list of some of the flies that 

 worry the horse : 



Tabanus equi, T. bovinus, T. autumnalis, T. 

 bromius, T. morio, T. rusticus, T. fulvus and T. 

 albipes. These are called breeze flies. 



Hippobosca equina. 



Simulia reptans and S. maculatum. 



Haematopota pluvialis (clegg fly), so called 

 because it lives on blood. 



Chrysops caecutiens (blinding fly). 



Stomoxys calcitrans, S. ferox, S. irritans and 

 S. serrata. 



Hydrotoea meteorica (storm fly). 



Glossina morsitans (tsetse fly), that causes 

 nagana. (See Sec. 616.) 



Musca domestica (common fly), M. bovina (ox 

 fly), M. vaccina (cow fly) and M. carnifex (fly 

 executioner) . 



Calliphora vomitoria (blue flesh fly). 



Sarcophaga carnaria (grey carnivorous, or 

 flesh-eating fly), S. magnifica. 



Lucilia csesar, L. sericata (causes maggots), L. 

 macillaria. 



Hypoderma equi (subcutaneous bot maggot). 



Gastrophilus equi (bot, gad or breeze fly, or 

 horse bee), G. haemorrhoidalis, G. pecorum, G. 

 nasalis and G. duodenalis. 



638. The common bot is the larva of a gad 

 fly (gastrophilus equi). This fly lays its eggs on 

 the horse's forelegs, etc., in the autumn, and in 

 two or three weeks these eggs hatch and form 

 small worms that cause irritation ; the horse 

 licks the part, and the worm gains access to the 

 mouth, and then to the stomach, where it 

 attaches itself to the mucous membrane of the 

 stomach by means of its little hooks. In nine or 

 ten months, i.e. the following summer, it quits 

 its hold and is expelled. It then lives in the 

 ground, is changed into a chrysalis, and after a 

 month becomes a gad fly. The female fly 

 becomes impregnated, and lays eggs on the horse 

 as described above. 



The bot fly, or gad fly, has a long quadratal 

 lancet that pierces the horse's skin, and then a 

 large sucker thart enters in between the four 

 lancets and sucks up the horse's blood. 



639. Mosquitoes. The common mosquitoes 

 are of the genera anopheles, culex, stegomia, 

 simulium, etc. Some of these attack the horse 

 and some do not. 



All these flies and mosquitoes belong to the 

 arthropoda phylum or form, and to the insecta 

 subphylum in the animal kingdom. 



Medical science has proved that a great many 

 diseases, as malaria, Texas fever (in cattle), 

 yellow fever, etc., are spread by flies ; therefore, 

 the more flies that are killed the better. If a 

 horse can kill a fly, or even drive away a bot fly 

 before it can lay its eggs, it has done a good 

 turn; a docked horse has very little chance of 

 driving it away from its hindlegs. 



640. The Spread of Disease by Flies. Having 

 considered the worry and pain caused to the 

 horse by the insect world, we will consider 



