984 



Parasitic Insects. 



young pigs in which lice are numerous on the skin may die as a result of unrest and 

 disturbance of sucking (Sequens saw 40 head die out of 140; sarcoptic scab might, 

 however, have also been present at the same time). 



( b ) Hair Insects and Feather Insects. ( Mallophaga. ) These 

 are parasites similar to the preceding ones; they do not suck 



blood, but eat epidermal scales with 

 their pincer-shaped jaws and gnaw 

 through the fine hair. The females 

 also glue their eggs to the hairs. 

 They are mostly parasites on the 

 head, neck and legs of animals, and 

 cause itching and perhaps also 

 eczematous inflammation of the 

 skin. 



The varieties occurring in the domestic 

 animals are: Trichodectes pilosus in horses, 

 Tr. scalaris in cattle (Fig. 161), Tr. climax in 

 goats, Tr. sphaerocephalus in sheep (some- 

 times when present in great numbers they 

 produce itching, causing the animals to rub 

 their bodies vigorously and gnaw them; the 

 wool falls out and the affection may then be 

 mistaken for scab) ; Tr. latus in dogs, lastly 

 Tr. subrostratus in cats. 



The number of feather insects occur- 

 ring in domestic birds is very large. They 

 disturb the rest of the animal and cause 

 loss of condition when present in large 

 They comprise (according to Ziirn) : 



Fig. 160. Haematopinus equi. 

 Magnif. about 25. (After Kitt.) 



numbers. 



In chickens: Goniocotes hologaster, G. dissimilis, Lipeurus variabilis, L. 

 heterographus, Menopon pallidum. 



In ducks: Doeophorus icterodes. 



In geese: Doeophorus adustus, Lipeurus jejunus, Trinotus conspurcatum, Tr. 

 squalidum. 



In pigeons: Goniocotes compar, Lipeurus bacillus, Colpocephalum turbinatum. 



In turkeys: Goniodes stylifer, Lipeurus polytrapezius, Menopon stramineum. 



In peacocks: Goniocotes rectangulatus, Goniodes falciformus, Menopon 

 phaenostomum. 



(c) Bedbug. (Acantha lectularia.) These pass at times 

 on to birds, fowls and pigeons which are kept in rooms or near 

 to dwelling houses (Lucet). 



Treatment. Lice and hair parasites are killed by various 

 anti-parasitic remedies and removed from the body of the ani- 

 mal. According to the experimental investigations of Biihler 

 creolin liniment (creolin and soft soap, of each 1 part, alcohol 

 7 parts) ranks first of all on account of its astounding effect as 

 well as its cheapness and slight toxicity; the liniment is rubbed 

 into one-third of the body at a time, and after the third day a 

 bath in i/o to 1% liver of sulphur solution is given. In severe 

 invasion the process must be repeated 2 or 3 times. Cresol or 

 tar liniment is also very effective, but less innocuous, as is also 

 carbolic acid solution (5%) ; the somewhat more effective Peru- 

 vian balsam is comparatively expensive. Washing with 2 to 



