This section is from the book "The Dogs Of Great Britain, America, And Other Countries. Their Breeding, Training, and Management in Health and Disease", by John Henry Walsh (Stonehenge). Also available from Amazon: The Dogs Of Great Britain, America And Other Countries.
Worms are a fertile source of disease in the dog, destroying every year more puppies than does distemper itself; and, in spite of every precaution, attacking the kennelled hound or shooting dog, as well as the pampered house pet and the half-starved cur. In old and constantly used kennels, they are particularly rife, and I believe that, in some way, their ova remain from year to year, attached either to the walls or to the benches. All of the varieties met with are propagated by ova, though some, as the Ascaris lumbri-coides are also viviparous, so that the destruction of the worms actually existing at the time the vermifuge is given does not necessarily imply the after clearance of the animal. He may be infested with them as badly as before, from the hatching of the eggs left behind. Besides the intestinal worms, there are also others met with in the dog, including the large kidney worm, and the hydatid, which is in all probability the cause of turnside. I shall, therefore, first describe the appearance of each kind of worm; then the symptoms of worms in general; and, lastly, the best means for their expulsion.
The Maw-worm is much larger than its representative in the human subject, which is a mere thread, and is hence called the "thread-worm" In the dog it is about an inch in length, having a milky white color. Maws-worms exist in great numbers in the dog, chiefly occupying the large intestines. They do not injure the health to any great degree, unless they exist in very large numbers. They are male and female, and are propagated by ova.
Fig. 47. - Maw-Worm.
The Round-worm is from four to seven inches long, round, firm, and of a pale pink color. The two extremities are exactly alike, and are slightly flattened in one direction at the point. See engraving. Figure 47 shows a group of three round worms as actually discharged from the intestine of a dog in which they were thus knotted. I have often seen from six to a dozen round worms thus collected together, so as when discharged to form a solid mass as large as an egg. Like the last species, they are propagated by ova, but sometimes these are hatched in the body of the parent, so that a large worm may be seen, full of small ones. This species occasions much more inconvenience than the maw-worm, but still far less than the tape-worm.