Parasites and Parasitic Diseases of Dogs 21 



fection takes place, but have been said to appear as early as 16 days 

 after infection. In all probability prenatal infection of pups in the 

 uterus of the mother occurs occasionally, and perhaps frequently. 



Symptoms. — Owing to the fact that hookworms are bloodsuckers 

 and that such worms not only remove blood from an animal but also 

 appear to produce poisonous substances which exert an injurious ef- 

 fect on the blood, dogs heavity infested with hookworms usually show 

 anemia ( a condition in which the blood is thinner and paler than nor- 

 mal, which is shown by a pale color of the mucous membrane in the 

 lining of the mouth and eyelids) and edema (a condition in which 

 there is an accumulation of serum which seeps from the thinned 

 blood into the tissues and accumulates in pendant portions of 

 the body, as under the jaw) . The disease is sometimes referred to as 

 kennel anemia. In early stages of the disease there are digestive 

 disturbances, and in later stages there is often diarrhea, sometimes 

 with blood visible in the feces. Owing to the impoverished condi- 

 tion of the blood and to other disturbances due to the worms, the 

 infested dogs become weak and emaciated, the resistance to disease 

 and to unfavorable conditions is diminished, and the vitality is re- 

 duced. In severe cases the following symptoms may be observed : A 

 sunken eye, foul breath, unthrifty coat, reddening of the skin inside 

 the thighs and elbows, pronounced dullness or depression, and a slow 

 healing of operative wounds or accidental injuries, with a tendency 

 to ulcer formation in such cases. The larval worms going through 

 the lungs have been reported as the cause of a fatal pneumonia in 

 pups. Pups are highly susceptible to infection with hookworms and 

 to the bad effects of such infestations and many of them die from 

 hookworm disease, especially in the South. 



^^^len the symptoms noted above are present, hookworms may be 

 suspected as the cause, but it is inadvisable to allow dogs to go to 

 the stage where they show clinical evidence of hookworm disease, as 

 such dogs have a diminished resistance to the drugs used in removing 

 the hookworms. In regions where hookworms are prevalent, espe- 

 cially in the South but also in many parts of this country outside of 

 the South, the feces of dogs, and especially of pups, should be ex- 

 amined occasionally for, worm eggs, and, if they are present, suitable 

 treatment undertaken at once without waiting for ill effects to be- 

 come evident. 



Treatment. — ^Until comparatively recently no satisfactory treat- 

 ment for removing hookworms from clogs was known, but as a re- 

 sult of numerous experiments carried out in the Bureau of Animal 

 Industry in a search for a satisfactory treatment, a very effective 

 and quite safe treatment has been discovered. The drug used is 

 carbon tetrachloride, which in suitable doses will remove all the 

 hookworms from infested clogs in practically every case. A chemi- 

 cally pure drug must be used. Most dogs tolerate enormous doses of 

 this drug, but an occasional animal proves highly susceptible to bad 

 effects from its use. For this reason it is advisable to employ a 

 veterinarian to administer it whenever possible. 



The dose of carbon tetrachloride is at the rate of three-fourths 

 fluid dram (3 cubic centimeters) for a 22-pound dog. This may be 

 given in hard capsules with entire safety in most cases, but care 

 must be exercised in administering such a capsule, as the drug is 



