Part 60

TABLE 24. _Incidence of Parasites in Animal Groups._ ══════════════════════╤═══════════════════════════════╤════════════════════ Animal │ MAMMALIA │ Remarks ──────────────────────┼───────────┬────────┬──────────┼──────────────────── „ │ Number of │ Number │Percentage│ „ │Autospecies│Infested│ │ ──────────────────────┼───────────┼────────┼──────────┼──────────────────── Primates │ [126]538│ 51│ 9.4│ Cercopithecidæ │ │ │ │ Sooty Mangabey │ 34│ 4│ 11.8│ Cercocebus │ │ │ │ fuliginosus │ │ │ │ Rhesus Macaque │ 60│ 6│ 10.│ Macacus rhesus │ │ │ │ Callitrichidæ │ │ │ │ Marmosets │ 43│ 7│ 16.3│ Cebidæ │ │ │ │ Squirrel Monkeys │ 8│ 3│ 37.5│ Other Cebus │ 87│ 10│ 11.5│Eight had Filaria Monkeys │ │ │ │ gracilis. Lemures │ 86│ 6│ 7.│ Carnivora │ 498│ 84│ 16.9│ Felidæ │ │ │ │ American Wild Cat │ 28│ 11│ 40.│Stomach and │ │ │ │ intestines, 22; Felis ruffus │ │ │ │Bronchi, 4; Muscles, │ │ │ │ 7. Spotted Wild Cat │ 5│ 4│ 80.│ Felis ruffus │ │ │ │ texensis │ │ │ │ Canada Lynx │ 10│ 4│ 40.│Ascarids only. Felis canadensis│ │ │ │ Lions │ 10│ 3│ 30.│Ascarids in stomach │ │ │ │ and Felis leo │ │ │ │intestines. Ocelot │ 15│ 5│ 33.│Uncinaria. Felis pardalis │ │ │ │ Canidæ │ │ │ │ Gray Fox │ 28│ 1│ 4.│Cestodes. Canis cinereo │ │ │ │ argenteus │ │ │ │ Red Fox │ 17│ 2│ 12.│Uncinaria. Canis vulpes │ │ │ │ pennsylvanicus│ │ │ │ Swift Fox │ 5│ 2│ 40.│Uncinaria. Canis velox │ │ │ │ Gray Wolf │ 18│ 2│ 11.│Ascarids. Canis mexicanus │ │ │ │ Mustelidæ │ │ │ │ American Badger │ 17│ 7│ 41.│Physaloptera. Taxidea taxus │ │ │ │ Procyonidæ │ │ │ │ Raccoon │ 42│ 2│ 5.│ Procyon lotor │ │ │ │ Ursidæ │ │ │ │ Bears │ 37│ 6│ 16.│Ascarids. Otariidæ │ │ │ │ Hair Seal │ 20│ 1│ 5.│Uncinaria. Zalophus │ │ │ │ californianus │ │ │ │ Rodentia │ 198│ 32│ 16.│ Sciuridæ │ 44│ 4│ 9.│Scattered through │ │ │ │ four Castoridæ │ │ │ │different genera. American Beaver │ 17│ 4│ 23.│In three cases │ │ │ │ oxyuris Castor │ │ │ │and flukes in cecum. canadensis │ │ │ │ Hystricidæ │ │ │ │ Canada Porcupine │ 47│ 17│ 36.│Cestodes 8, filaria │ │ │ │ 11, oxyuris 9, Erythizon │ │ │ │in peritoneal cavity dorsatus │ │ │ │ also intestine. dorsatus │ │ │ │ Hyraces │ 7│ 2│ 28.│Cestodes in bile │ │ │ │ ducts. Cape Hyrax │ │ │ │ Procavia capensis │ │ │ │ Ungulata │ 365│ 44│ 12.│ Equidæ │ │ │ │ Zebras │ 7│ 7│ 100.│Nematodes, │ │ │ │ intestine. Cervidæ │ │ │ │ Axis Deer │ 6│ 1│ 17.│C. tenuicollis. Cervus axis │ │ │ │ Barasingha Deer │ 8│ 0│ │ Cervus duvanceli│ │ │ │ Eld’s Deer │ 6│ 0│ │ Cervus eldi │ │ │ │ Fallow Deer │ 20│ 1│ 5.│Echinococcus cysts. Cervus dama │ │ │ │ Hog Deer │ 21│ 0│ │ Cervus porcinus │ │ │ │ Japanese Sika Deer│ 14│ 0│ │ Cervus sika │ │ │ │ typicus │ │ │ │ Red Deer │ 14│ 0│ │ Cervus elaphus │ │ │ │ Elk │ 29│ 2│ 7.│Trichocephalus. Cervus │ │ │ │ canadensis │ │ │ │ White tailed Deer │ 33│ 2│ 6.│Echinococcus in lung │ │ │ │ (2). Mazama │ │ │ │ virginiana │ │ │ │ Mule Deer │ 8│ 5│ 62.│Four Cyst. │ │ │ │ tenuicollis. Mazama hemionus │ │ │ │ Camelidæ │ │ │ │ Llama │ 14│ 2│ 14.│ Lama glama │ │ │ │ Camels │ 9│ 4│ 44.│Hydatid cysts. Suidæ │ 19│ 2│ 10.│ Edentata │ 16│ 2│ 12.5│ Armadillos │ 10│ 2│ 20.│ Marsupialia │ 175│ 45│ 26.│ Didelphyidæ │ │ │ │ Common Opossum │ 84│ 40│ 48.│Physaloptera, 38; │ │ │ │ oxyuris, 5; │ │ │ │ cestodes, 5; │ │ │ │ nematodes in │ │ │ │ lungs, 3; cysts in │ │ │ │ peritoneal areolar │ │ │ │ tissue, 2; │ │ │ │ trematodes in │ │ │ │ ileum, 1. Didelphys │ │ │ │ virginiana │ │ │ │ Macropodidæ │ │ │ │ Kangaroos and │ 70│ 0│ 0.│ wallabies │ │ │ │ ──────────────────────┼───────────┴────────┴──────────┼──────────────────── │ AVES │ Passeres │ │ │ │ Corvidæ │ │ │ │ Common Crow │ 16│ 7│ 44. }│Tropidocerca and │ │ │ │ occasional │ │ │ │ intestinal │ │ │ │ cestodes. Syngamus │ │ │ │ in crows. Few │ │ │ │ filaria. Corvus │ │ │ }│ brachyrhynchos│ │ │ │ brachyrhynchos │ │ │ }│ Magpies │ 28│ 18│ 64. }│ Jays │ 41│ 22│ 55.│Periproventricular │ │ │ │ filaria, │ │ │ │ strongylus. Pies, choughs, │ 35│ 12│ 33.│There is a striking etc. │ │ │ │ consistency of │ │ │ │ infestment in the │ │ │ │ different members │ │ │ │ of Corvidæ both as │ │ │ │ regards degree of │ │ │ │ infestment and │ │ │ │ species of │ │ │ │ parasite present. Sturnidæ │ │ │ │ Starlings │ 63│ 19│ 30.│Periproventricular │ │ │ │ filaria largely. Turdidæ │ 25│ 8│ 33.│Periproventricular │ │ │ │ filaria largely. │ │ │ │Thrushes and Robins. │ │ │ │ None in American │ │ │ │ thrushes, one in a │ │ │ │ robin. │ │ │ │Finches. Not │ │ │ │ examined closely │ │ │ │ at autopsy, but │ │ │ │ there is a │ │ │ │ scattering of │ │ │ │ periproventricular │ │ │ │ filaria and │ │ │ │ intestinal │ │ │ │ cestodes through │ │ │ │ most of the │ │ │ │ species. Canaries │ 24│ │ │Were free from │ │ │ │ parasites. Picariæ │ │ │ │ Picidæ │ │ │ │ Woodpeckers │ 4│ 2│ 50.│ Rhamphastidæ │ │ │ │ Toucans │ 30│ 9│ 30.│Spiroptera largely. Striges │ 142│ 2│ 7.│Remarkably free of │ │ │ │ parasites. Psittaci │ [127]774│ 124│ 16.│ Loriidæ │ │ │ │ Lorys │ 24│ 5│ 20.│3 spiroptera, 1 │ │ │ │ hemoproteus, 1 │ │ │ │ intestinal worm. Cacatuidæ │ │ │ │ Cockatoos │ 4│ 2│ 6.│2 spiroptera. Crested Ground │ 45│ 4│ 9.│4 spiroptera. Parrakeet │ │ │ │ Calopsitta novæ- │ │ │ │ hollandiæ │ │ │ │ Psittacidæ │ │ │ │ Old World (Totals)│ 453│ 65│ 14.3│ Undulated Grass │ 121│ 2│ 1.6│1 spiroptera, 1 Parrakeet │ │ │ │ coccidium. Melopsittacus │ │ │ │ undulatus │ │ │ │ Pennant’s │ 21│ 6│ 29.│6 spiroptera. Parrakeet │ │ │ │ Platycercus │ │ │ │ elegans │ │ │ │ Rosehill Parrakeet│ 48│ 21│ 44.│20 spiroptera, 1 │ │ │ │ cestode. Platycercus │ │ │ │ eximius │ │ │ │ Other old world │ 86│ 12│ 14.│12 spiroptera. parrakeets │ │ │ │ Old world parrots,│ │ │ │ lovebirds, │ 74│ 13│ 18.│13 spiroptera. eclectus. │ │ │ │ New World (Totals) │ 321│ 69│ 21.5│ Macaws │ 26│ 9│ 34.│9 spiroptera. Conures │ 62│ 16│ 26.│15 spiroptera, 1 │ │ │ │ hemoproteus, 1 │ │ │ │ blood larva. Amazons │ 164│ 27│ 16.5│24 spiroptera, 3 │ │ │ │ nematodes. Other new world │ 69│ 17│ 10.│7 spiroptera. parrots │ │ │ │ Accipitres │ [127]201│ 13│ 6.7│ Falconidæ │ │ │ │ Buzzards │ 55│ 4│ 7.3│ Eagles │ 44│ 1│ 2.3│ Serpentaridæ │ │ │ │ Vultures │ 29│ 1│ 3.4│ Miscellaneous │ 73│ 7│ 9.6│4 were blood │ │ │ │ protozoa. Galli │ 299│ 42│ 14.│ Phasianidæ │ │ │ │ Pheasants │ 95│ 20│ 21.│Heterakis in ceca. Partridges │ 14│ 3│ 21.│ Quail │ 70│ 10│ 14.│Heterakis. Megapodidæ │ │ │ │ Wild Turkeys │ 39│ 7│ 18.│Intestinal cestodes. │ │ │ │ Coccidia twice. Columbæ │ [128]163│ 14│ 9.│Mostly intestinal │ │ │ │ cestodes, but │ │ │ │ several │ │ │ │ spiroptera. Fulicariæ │ [128]38│ 7│ 18.│ Alectorides │ [128]41│ 10│ 25.│ Gaviæ │ [128]21│ 3│ 14.│ Steganopodes │ [128]22│ 1│ 5.│ Herodiones │ [128]105│ 21│ 20.│ Anseres │ [128]319│ 28│ 8.8│ Swans │ 48│ 7│ 14.│No significant │ │ │ │ groupings. │ │ │ │ Parasites │ │ │ │ scattering. Few │ │ │ │ intestinal │ │ │ │ cestodes. Geese │ 83│ 13│ 15.6│ Ducks │ 188│ 8│ 4.│ Struthiones │ 36│ 1│ 2.8│ ──────────────────────┴───────────┴────────┴──────────┴────────────────────

Nor do all members of a genus necessarily show the same susceptibility, and the heterakis infestment in the pheasants illustrates this matter very well. It was limited almost entirely to two species—Amherst’s and Golden, whereas several frequently exhibited species showed none. The following table brings this out in more detail:

TABLE 25. _Heterakis in Pheasants._ ════════════════════════════════════════════╤════════╤════════╤════════ Species │ Total │Infested│ Per │ │ │ cent. │ │ │infested ────────────────────────────────────────────┼────────┼────────┼──────── Golden Pheasant (Chrysolaphus amherstiæ) │ 18│ 12│ 67 Amherst’s Pheasant (Chrysolaphus pictus) │ 16│ 5│ 31 Silver Pheasant (Gennæus nycthemerus) │ 19│ 1│ 5 Reeves’ Pheasant (Phasianus reevesi) │ 16│ 1│ 6 Ringnecked Pheasant (Phasianus torquatus) │ 12│ 0│ 0 Swinhoe’s Pheasant (Gennæus swinhoii) │ 10│ 0│ 0 ────────────────────────────────────────────┴────────┴────────┴────────

Enzoötics and environment played no part in the above figures. We have had no real heterakis enzoötics, for in but two instances did three heterakis deaths occur in a year, and two deaths per year have occurred in but four instances in the past twenty years. During this time there have been sufficient animals on exhibition and subjected to autopsy to indicate definitely that the two species named—Amherst’s and Golden, must be considered as more susceptible than the other varieties. Nearly all of the heterakis in quail likewise occurred in one species—seven of the ten cases occurred in a total of twenty-three Scaled Quail—but in these birds the infestment appeared in enzoötic form and cannot be viewed as indicating a preference for a species.

Psittaci are on the whole, not susceptible to worms. It is true that we suffered a serious outbreak of spiropteriasis a few years ago, but if we consider this a closed chapter we can accept the above generality as stated. Among 774 parrots autopsied we have encountered but one cestode and three intestinal round worms.

The deer, likewise, are singularly free from intestinal parasites. I gave the detailed records of these animals in Table 24 to emphasize the scarcity of parasites even when fairly numerous specimens had been available for examination.

Other interesting features in the table are the outstanding infestments of squirrel monkeys and marmosets among the monkeys, of gastric and intestinal worms in the wild cats, and intestinal worms in the zebras.

The foregoing has had to do with parasitism from the standpoint of the host. The next phase, that of the individual parasite itself, interests more the strict parasitologist than the general zoologist; however, both will see how it may have a very practical value.

TABLE 26. _Distribution of Parasitic Cases According to Parasitic Groups._ ═════════════════════════════════════╤════════════════╤════════════════ Nematodes │ 183[129]│ Spiroptera │ 145│ Filaridæ │ 138│ Ascaris │ 30│ Physaloptera │ 28│ Uncinaria │ 25│ Tropidocerca │ 23│ Heterakis │ 22│ Trichocephalus │ 11│ Syngamus │ 9│ Trichina │ 2│ Hepaticola │ 2│ Other Miscellaneous │ 4│ Total Nematodes │ │ 622 Cestodes │ 165[129]│ Echinococcus │ 9│ Cysticercus │ 7│ Tænia │ 4│ Miscellaneous │ 3│ Total Cestodes │ │ 188 Trematodes │ │ 22 Acanthocephalus │ │ 4 Protozoa │ │ 14 Arthropods │ │ 6 Unclassified │ │ 34 ─────────────────────────────────────┼────────────────┼──────────────── Grand Total │ │ 890 ─────────────────────────────────────┴────────────────┴────────────────

INCIDENCE ACCORDING TO PARASITIC GROUPS.

Inasmuch as it has been physically impossible to determine specifically and classify efficiently the accumulations of verminous material from our autopsies I will not be able to tabulate parasitic groups even as closely as I did in the “animal host” table. Nevertheless sufficient has been done to illuminate in part certain phases of parasitism and to prevent a summary dismissal of the subject. Reviewing our cross index I have distributed the data into the following Table 26, the parasites being listed in the order of their frequency. It may serve only as a panorama of the situation, inasmuch as determinative study of a group amounts to a research in itself, and the multiplicity of them precludes a consistent study of every one. The data are based upon “cases of parasitism.” That is, each and every worm species occurrence has been counted, regardless of whether it was the same species that has been concerned over and over again, or in different anatomical positions (of different individual hosts, of course) or whether it was in association with other parasites.

ANALYSIS OF TABLE 26.

There is a grand total of 890 cases of animal parasitism embraced in the above table, which is a sufficiently large number to give representative value to some phases of the analysis.

In the first place nematode worms occur about three times as frequently as all other forms of parasites. In gardens where spiroptera has not figured so largely the proportion might be reduced to about two to one. Cestodes rank a poor second, trematodes a worse third, and acanthocephali a very bad last. This order agrees with our figures of 1913[130] and with the small series of Nicoll.[131] The latter worker found that the order was not changed when pains were taken to include also such smaller worms as could only be obtained from the host by using sieves, etc. Cestodes were not likely to be overlooked, but very small trematodes and nematodes were easily passed over.

VISCERAL DISTRIBUTION.