"r .0 .WBLTON, PRES . ,
CAHPUS .
A50-440-7M-L180

TEXAS AGRICULTURAL EXPERIMENT STATION

p’ A. B. CONNER, DIRECTOR
COLLEGE STATION, BRAZOS COUNTY, TEXAS

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BULLETIN NO. 585 APRIL 1940

DIVISION OF VETERINARY SCIENCE

IN COOPERATION WITH THE BUREAU OF ANIMAL INDUSTRY, PATHOLOGICAL
DIVISION, UNITED STATES DEPARTMENT OF AGRICULTURE

 Poisoning in Sheep and Goats by Sacahuiste

 (Nolina Texana) Buds and Blooms

 

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AGRICULTURAL ANSI): METJHANICAL COLLEGE OF TEXAS
T. O. WALTON, President

[Blank Page in Original Bulletin]

The buds and blooms of sacahuiste (N olina, teocana) are poison-
ous for sheep, goats, and cattle, while no untoward results have
been noted when cattle graze upon the leaves of the plant. Sheep
and goats have not been observed to graze on the rather coarse
leaves of the plant but are very fond of the tender buds and
blooms. When these are consumed by sheep and goats in amounts
greater than one per cent of their body weight the animals become
sick and usually die. If only dry feed is available at this time
the animals will be very much depressed and icteric due to a
marked degeneration of the liver cells and by obstruction of the
bile ducts. If some green feed is consumed at the same time
then in addition to the symptoms and lesions just noted, the
animals will become photosensitive and if they are now exposed
to the sun will develop itching of the skin and a marked swelling
of the skin and subcutaneous tissue of the head, including the
ears. Losses from this source may be prevented by removing
the animals from the infested pasture during the blooming season
or by concentrating the animals on a smaller area in the pasture
or removing them to less heavily infested areas so that they will
not be able to consume a toxic dose during a day’s grazing.

CONTENTS

rage
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Botanical description of Nolina Texana . . . . . . . . . . . . . . . . . . . . . . . . . .. 6

Natural occurrence of the disease  . . . . . . . . . . . . . . . . . . . . . . . . . . .. 8

Symptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Pathology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Experimental Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 10

Results of experimental feeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11

Intermittent feeding . . . . . l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 13

Symptoms and pathology of experimental cases . . . . . . . . . . . . . . .. 14

Toxic Principle of Sacahuiste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Leaf of the plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 16

Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Literature cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 19

BULLETIN NO. 585 ' APRIL 1940

POISONING IN SHEEP AND GOATS BY SACAHUISTE
(NOLINA TEXANA) BUDS AND BLOOMS

By
Frank P. Mathews, Veterinarian, in Charge Loco Weed Laboratory, Alpine

IN COOPERATION WITH THE BUREAU OF ANIMAL INDUSTRY, PATHOLOGICAL
DIVISION, UNITED STATES DEPARTMENT OF AGRICULTURE,
WASHINGTON, D. C.

Although sacahuiste is a relatively common plant on the ranges of
Western Texas, the toxicity of the buds and blooms is a controversial
subject among the ranchers of this region. Due to the fact that the
blooming season occurs at a time when other succulent feed is scarce
many ranchers maintain that they are good feed and look forward to
this season. On the other hand, the rancher who appreciates the potential
danger from this part of the plant approaches the blooming season with
considerable apprehension. Given enough time and suitable conditions, the
rancher who considers this part of the plant suitable forage will eventually
learn the fallacy of such a belief. This statement applies only to the buds,
blooms, and ripe fruit; the leaves of the plant are another story and one
upon which more will be said later in this publication.

Sacahuiste poisoning is generally referred to as “swellhead” or “fevered.”
The former term is applied when photosensitizat-ion is a prominent part
of the clinical picture, the latter when this lesion is absent and in which
case icterus is the only outstanding symptom. Sheep, goats, and cattle are
affected. The disease occurs during the blooming season of the plant,
which, in the vicinity of Alpine, is shortly after the first of April, but
may be earlier or later depending on variations in seasonal conditions;
at lower altitudes the season is somewhat earlier. The average blooming
season generally covers a period of about three weeks,’ although this may
be shortened or lengthened by late freezes which frequently occur in the
Trans-Pecos region of Texas. A late freeze at the beginning of the bloom-
ing season may be followed by a blooming season of about the normal
length; a freeze during the middle of the blooming season is generally
followed by the appearance of but. few blooms.

The morbidity of the animals varies from 1 to as high as 20 per cent,
depending upon the number of blooms. A heavy crop of blooms is asso-
ciated with a corresponding morbidity, and a light crop, with little or no
loss. Fortunately a heavy crop of blooms does not occur oftener than
about once every five or six years. If no losses occur it is obvious that
none of the animals obtained sufficient material to produce toxic effects,
a result that evidently accounts for the viewpoint of some ranchers.

The mortality is about the same as the morbidity since very few animals
recover if they have eaten sufficient of the toxic material to produce

6 BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

symptoms of the disease. In cattle the loss is seldom as serious as it is in
sheep and goats. However, in a herd of 100 head of cattle a loss of 20
head was observed and the animals in this case were removed from access

to the buds and blooms before the season was over. In the presence of

an abundant crop of blooms it is a common sight to see a ring of either
sheep or goats around a bunch of sacahuiste with their heads buried
among the leaves seeking the succulent feed. This picture is always asso-
ciated with a heavy loss.

The disease is characterized by icterus, liver and kidney lesions and
generally an edematous swelling of the face and ears, although the latter
manifestation is not a constant part of the clinical picture. The symptoms
and pathology are similar to that produced by the grazing of the leaves
of lechuguilla as well as several other poisonous plants, of which part of
the toxicology is a photosensitization. Tunnicliff (1) produced a swelling
of the head of one lamb by feeding the fruit, both ripe and immature, of
sacahuiste, which is evidently the only published report on the toxic nature
of this plant. A review of the literature on the photodynamic diseases
of the lower animals was presented by the writer in two recent publica-
tions and is omitted at this time (2, 3).

BOTANICAL DESCRIPTION OF NOLINA TEXANA*

Nolina texana S. Watson (sacahuiste), of the lily family is a perennial
plant with a thick, short caudex (woody base) usually 15 cm. tall or less
and mostly underground, which in well-developed plants is usually as much
as 3O cm. broad or more at or somewhat above the surface of the ground.

Fig. 1. A bunch of sacahuiste showing 1 bloom.

(*Botanical description by V. L. Cory, Range Botanist, Texas Agricultural Experiment
Station, Substation No. 14, Sonora, Texas.)

 

POISONING IN SHEEP AND GOATS BY SACAHUISTE 7

The caudex has many short branches, each bearing a cluster, as many
as 20 or more, of long, narrowly linear leaves. Under favorable condi-
tions a plant will bear several to many, up to 20 or more, stout, nearly
naked flowering stems. The leaves are dilated at the base, 60-160 cm.
long, 2-5 mm. broad, concavo-convex below, with a prominent ridge on the
concave upper surface, becoming sharply 3-angled towards the apex,
minutely roughish on the margins, and are spreading or drooping to cover
the ground. In the older foliage the apical portion, from a small fraction
up to as much as a third or half the length of the leaf, usually is dead.
The flowering stems are up to 60 cm. tall, towards the base as much
as 1 cm. broad, and bear~a compound, or branched, racemose, many-
flowered panicle, the main branches of which are subtended by long-
attenuate leaf-like bracts with dilated papery bases, and with the tips
of the lower bracts exceeding the inflorescence. The main panicle branches
are as much as 10-15 cm. long, each usually with 6 or more rather weak,
strongly ascending branchlets, each of which bear from a few up to 10
or more pedicels which are 4-6 mm. long, articulated well below the base,
and each bearing a solitary, small, polygamo-dioecious flower having small
white segments, which are withering-persistent. The fruit is dry, deeply
3-lobed, appearing almost as 3 separate globose carpels. The carpels are
thin and open tardily and irregularly after maturity, with usually only
one seed developing in a carpel. The seed is light-colored, nearly smooth,
somewhat depressed, 4 mm. high and 5-6 mm. broad.

The plant has not been reported as growing elsewhere than in Texas.
The early collections of the plant by botanists were mostly from the eastern
portion of its range, including Hamilton, Travis, Blanco, Comal, Gillespie
and Kerr counties. From this portion of its former occurrence the plant

Fig.’ 2. A bunch of sacahuiste almost killed by cattle grazing.

S BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

at the present time has disappeared for the most part, and its extermina-
tion on the range, under conditions of continuous grazing, is proceeding
steadily on westward. Inasmuch as the young plants are more palatable
than the older ones under ranching conditions the attempted reproduction
of the species is thwarted, hence, in the course of time, except where pro-
tected, it will cease to be a part of the range vegetation. At the present
time the plant is most abundant on the rolling hills or foothills of the
Trans-Pecos area of Texas. On the Edwards Plateau, towards the north-
eastern limit of its occurrence, sacahuiste blooms in the winter, usually
from January on into March, the time being influenced by moisture condi-
tions; in dry years it does not bloom at all. In‘ the higher elevations of the
Trans-Pecos area blooming is delayed until after the first of April.

NATURAL OCCURRENCE OF THE DISEASE
Symptoms

Manifestations of the disease are much the same in cattle, sheep and
goats. Loss of appetite appears to be the first evidence of intoxication,
followed within a day or two by a generalized icterus, which is of an
unusual intense yellow. The sick animals remain around the watering
places, make no attempt to follow the flock and are constantly seeking
shade. There is a gradual and progressive debilitation and the majority
of the cases do not live more than a week after the first symptoms appear,
although life may be prolonged as much as two weeks. Recovery is the
exception rather than the rule. Watering of the eyes which at first is
serous later becomes muco-purulent, adheres to the internal canthus of
the eye and to the wool or hair for a variable distance along the face.
There is a tenacious, yellow nasal discharge. A purplish band about one-
half inch in width is generally found around the top of the hoof below
the coronary band. Judging from observations on experimental animals
this band is probably a photodynamic response of unpigmented hoofs.
The urine is generally of a darker yellow color than normal, but at
times it has a port wine appearance. In such cases the staining of the
hair or wool suggests bloody urine but there are no red blood corpuscles
present. Otherwise, the nature of the pigment in the urine has not been
determined. Pruritis, which is an outstanding symptom in some of the
other photodynamic diseases is frequently observed, although it is not a
constant symptom. This symptom is evidently one of the first reactions
to sunlight exposure, decreasing with subsequent exposures until by the
third day it is no longer present.

Pathology

Upon autopsy, in addition to the intense and generalized icterus, two
lesions are constantly observed in all species of animals. The liver has
a light yellowish-brown to greenish cast and when cut has a slightly
greasy appearance. Pressure exerted along the edges of the cut surface
results in the expulsion of numerous viscid green plugs from the severed

POISONING IN SHEEP AND GOATS BY SACAHUISTE 9

bile ducts. No particular change is noted‘ in the gall bladder or the
contents thereof. The kidneys are always swollen, sometimes to as much
as twice their normal size, and are greenish-browmto greenish-black in
color. Upon incision urine drips from the cut surface and many of the
tubules are distended to the point that they can be distinguished with
the unaided eye.

Evidence of a photodynamic reaction may or may not be present as
this is not constant. Furthermore, in many cases the edematous infil-
tration of the corium and underlying connective tissue is soon absorbed.
If the edematous infiltration is soon absorbed very little necrosis of the
skin will result, thus leaving no evidence of the previous existence of the
infiltration. On the other hand the edema may be sufficiently extensive

Fig. 3. Sheep 64 showing the characteris-
tic swelling of the face and ears
24 hours after the first exposure

to light.

to produce a rounded appearance of the face and the ears, which may be
swollen as much as an inch in thickness, are drooped on account of the
excess weight. In such cases rupture of the skin of the ears is rather

common and a clear amber fiuid drips from the rupture. If the life of

such animal is prolonged for a sufficient time there is extensive necrosis
of the skin, thick, rigid scab formation and in the event of ultimate

recovery complete healing beneath the scab. During recovery, in the area

 

here under discussion, such cases are frequently subject to' screw worm
infestations. In the cases of recovery which have come to the attention of
the author, shedding of the wool has been a late sequel.

Microscopically the liver presents a uniform and pronounced albuminous
degeneration with distortion of the normal cord-like arrangement of the

10 BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

parenchymatous cells. Adjacent to the central veins the liver cells present
a foam-like structure due to fatty changes. These changes become less
noticeable as the periphery of the lobule is approached. Many of the bile
ducts are plugged with casts consisting of a nucleus of cholesterol crystals
surrounded by cellular detritus, similarly as is observed in lechuguilla
poisoning. Numerous clefts resulting from the dissolving out of cholesterol
during infiltration and staining furnish evidence of considerable deposi-
tion of this lipoid in the liver cells.

The kidneys show a pronounced albuminous degeneration and marked
fatty changes of both the tubular and glomerular epithelium. Many of
the tubules are filled with casts which may be hyaline and take a bright
eosin stain or are composed of loosely arranged, amorphous material
which takes very little stain. Above the casts the tubules are distended
with urine with the distention in some tubules extending into Bowman’s
capsule. Bowman’s capsule is frequently distended with casts similar to
those found in the tubules. Much of the tubular epithelium has a greenish-
brown appearance due to the deposits of bile salts within the epithelium.

The edematous reaction in the corium and underlying connective tissue
is due to an injury to the endothelium of the capillaries and smaller
veins. Both the nucleus and cytoplasm of the injured endothelium are
edematous and stain faintly with their respective stains. This injury is
accompanied by an escape of serum into the surrounding tissue and infil-
tration by various wandering cells. the predominant type being polymor-

phonuclear leucocytes. The presence of plasma cells is a conspicuous part

of the histological picture, and the distribution of this type of cell, which
in many instances is around an injured blood vessel, suggests that this
cellular response is reparative in nature, with a function of preventing
the escape of the serum to the surrounding tissue. Necrosis may be
superficial or extend well into the corium, and is associated with a
marked polymorphonuclear leucocytic infiltration along the margin of the
necrosed areas.

EXPERIMENTAL PROCEDURE

The experimental animals consisted of 9 Angora goats, 18 white sheep,
and 25 albino rats. The ages of the sheep and goats varied from about
8 months to several years. The most of the work was conducted during
the blooming seasons of 1932, and 1936 to 1939 inclusive. Since, under
range conditions, the fresh buds and blooms were evidently quite palatable
it was assumed that they would be readily eaten under experimental con-
ditions. In the first experiment, however, it was found that the greater
part of the alfalfa hay which was generally fed had to be withheld in
order to induce the animals to eat the desired amounts of sacahuiste
buds. In following experiments weighed amounts of the plant were force
fed, each daily dose being divided into two equal parts, one part being
fed in the morning, the second in the afternoon. All animals were allowed
cured alfalfa ad libitum, in addition some of the animals were fed two
to three pounds of fresh green grass daily. Six of the animals were

POISONING IN SHEEP AND GOATS BY SACAHUISTE 11

maintained in a shed with an open southern exposure, thus being exposed
to more or less direct sunlight for the duration of the experiment. The
remainder were housed in a closed shed and not exposed to direct sun-
light until the first appearance of icterus. Exposures were made twice
daily for three consecutive days from 11:00 a. m. to 12 m. and from 1:00
p. m. to 2:00 p. m., provided the affected animals were able to tolerate
the full hour in the afternoon. The rats were housed in a building and
exposed at various intervals, the exposures generally being completed be-
fore 10:00 a. 1n., and a second exposure being made for such time as the
animals were able to tolerate after 1:00 p. m.

Results of Experimental Feeding

The results of feeding the buds and blooms to sheep are summarized
in Tables 1 and 2. In these tables the sheep which are shown to have
become icteric but not photosensitive had been fed cured alfalfa in addi-
tion to the sacahuiste. The sheep which developed icterus and were photo-
sensitive had been fed fresh green grass in addition to cured alfalfa, four

Table 1. The toxicity of buds, blooms and ripe fruit of sacahuiste for sheep. Alfalfa hay fed
in addition to sacahuiste
NVeight _ Total Amount Percent
Animal of Feeding amount fed body Results
Number animal period d daily wei ht
fed aily
Lbs. Days Lbs. Lbs.

15 65 25 11.5 0.46 0.7 No ill effects
30 90 12 8.0 0.66 0.73 No ill effects
1A 100 12 9.6 0.8 0.8 No ill effects
13 65 28 18.0 0.65 1.0 No ill effects
56 70 11 7.7 0.7 1.0 No ill effects
14 60 28 18.0 0.65 1.08 No ill effects
30 65 6 4.2 0.7 1 .08 No ill effects
3A 67 6 6.0 1.0 1.5 No ill effects
63 40 9 5 .0* 0.55 1 .3 Icteric 9th day; not photosensitive
71 90 12 12 .0 1.0 1.1 Icteric 12th day; not photosensitive
56 70 11 1 .0 1 .0 1 .28 Icteric 8th day; not photosensitive
70 70 12 12.0 1.0 1.4 Icteric 12th day; not photosensitive
12 60 13 12 .2 0.93 1.5 Icteric 8th day". not photosensitive
68 75 7 10.0 1 .4 1 .8 Icteric 7th day; not photosensitive
37 80 5 11 .25 2 .25 2 . 8 Icteric 5th day; not photosensitive

*Fed ground ripe fruit.

of them having been fed rescue grass (Bromus catharticus), the other two
green Johnson grass (Sorghum halepense). In addition to the grass they
were allowed alfalfa hay ad libitum. From these tables it will be noticed
that daily doses of buds and blooms ranging from 0.7 to 1.08 per cent of the
body weight had no ill effects when fed in conjunction with cured alfalfa.
As no ill effects were noted in the case of sheep 14, which received 28
doses of buds, each representing 1.08 per cent of the body weight it
appears that there was no cumulative effect of the poison. With one
exception (Sheep 3A, fed but 6 doses), doses of 1.1 per cent of the body
weight eventually produced toxic effects. Therefore, in the presence of dry
feed 1.1 per cent of the body weight is very close to the minimum toxic

12 BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

Table 2. The toxicity of buds and blooms of sacahuiste for sheep. Alfalfa hay plus two to
three pounds fresh green grass fed in addition to sacahuiste

Percent
WVeiQht Total Amount body
Animal of Feeding amount fed weight Results
Number animal period fed daily fed
daily
Lbs. Days Lbs. Lbs.
68 85 12 9.6 0.8 0.94 Icteric 12th day; photosensitive
2A 97 6 6.0 1.0 1.0 Icteric 6th day; photosensitive
72 57 6 4.2 0. 7 1.2 Icteric 5th day; photosensitive
65 55 12 8.0 0.66 1.2 Icteric 8th day; photosensitive
73 90 5 11.25 2.25 2.5 Icteric 5th day; photosensitive
64 70 5 11.25 2.25 6.2 Icteric 5th day; photosensitive

Sheep 73 and 64 were fed dry blooms; weight of dry material being expressed as its original
weight cf green plant material.

Sheep 68, 2A, 72 and 65 were fed fresh green buds and blooms.
dose. Since 12 days were required to produce toxic effects at this level
of feeding and but 5 days when the daily dose was increased to 2.2 per
cent of the body weight it is probably safe to conclude that the larger
the dose the quicker toxic effects will occur.

The addition of fresh green grass to the daily ration of sacahuiste pro-
duced two interesting results. First, less sacahuiste was required to
produce icterus (sheep 68 and 2A); second, the six animals which were
fed green grass all became photosensitive. This condition was not observed
in the controls which received no green grass. The dried blooms were
found to retain their toxicity for as long as eight months as sheep 73
and sheep 64 were fed the material after drying for this length of time.
The ground ripe fruit of the plant was also found to be toxic. However,
the toxic content of the fruit is evidently much less than that of the
buds and blooms as, in the case- of sheep 63, doses representing 1.3 per
cent of the body weight were required to produce intoxication. Sheep
63 is one of the three animals which recovered, thus indicating a milder
case.

Six goats were fed the same material as was employed in feeding of
the sheep and the results of this experiment are summarized in Table 3.
These animals were all fed dry alfalfa, none being fed green grass. As

Table 3. The toxicity of buds and blooms of sacahuiste for goats. Alfalfa hay fed in addition
to sacahuiste

Percent
Weight Total Amount body
Animal of Feeding amount fed weight - Results
Number animal period fed daily fed
dailv
Lbs. Days Lbs. Lbs.
3O 125 27 21.6 0.8 0.64 Icteric 30th day; not photosensitive
10 105 27 21 6 0.8 0.76 Icteric 30th day; not photosensitive
3 8 16 15 0 0.93 1.16 Icteric 16th day; not photosensitive
18 115 26 38 0 1.4 1.2 Icteric 30th day; not photosensitive
7 95 13 18 0 1.4 1 4 Icteric 12th day; not photosensitive
46 50 12 8 4* 0.7 1 4 Icteric llth day: not photosensitive

*Dry material expressed as green plant (66.6 per cent moisture).

POISONING IN SHEEP AND GOATS BY SACAHUISTE 13
is indicated in the table all the goats developed icterus but none became
photosensitive. Since 27 doses, each representing 0.64 per cent of the body
weight of goat 30, were sufficient to produce icterus and later a fatal
termination, it is concluded that goats are more susceptible to the toxic
principle than are sheep. As was the case with sheep when allowance
is made for individual susceptibility, the larger the dose the quicker
icterus was produced.

Intermittent Feeding
The effect of intermittent feeding was tested on three goats and the

results are presented in Table 4. The animals in this experiment were
all of the same age and weight and were fed the same amount of the

Table 4. Intermittent feeding of the dry buds and blooms of sacahuiste to goats. Alfalfa
hay fed ad libitum

Animal Numbcr** Animal Number
Dale Date —~i—————
37 44 41 44——continued
Grams fed Grams fed
December, 1932 February, 1933 '

12 100 12 150
100 13 150

100 14 150

100 15 150

100 16 150

100- 17 150

icteric 18 150

. . . . . . . . . . 19 150

2O 150

21 150

22 150

Died N0 ill effects

 

*Fee_ding of goat 37 discontinued on account 0f lack 0f sufficient blooms. _
**\Vc|ght of goats, 55 pounds each. Per cent 0f body weight of dry plant fed on the basis
of green plant as follows:

100gm. = 1.2 %
125 gm. = 1.5 %
150 gm. = 1.81%

plant. Between December 12 and December 20 each animal was fed five
times, each feeding consisting of 100 grams of the dry blooms, equivalent
to 0.66 pound of the green plant and 1.2 per cent of the body weight. The
feedings were omitted from December 21 to 23, and on December 24
goat 41 was found to be icteric but was given one more feeding on that
day. It died on January 3, 1933.

From December 24, 1932, to January 19, 1933, the other two goats
received seven doses, each representing the same body weight as in pre-
vious feedings. On January 20 the amount was increased to 1.5 per cent

14 BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

of the body Weight and on January 21 to 24 they were fed 1.81 per cent
of the body Weight. By January 24 the supply of buds and blooms was
not sufficient to continue the two animals for which reason the feeding
of this plant material to goat 3'7 was discontinued. From February 12
to 22, inclusive, goat 44 was fed 1.81 per cent of the body weight daily,
or a total of 11 feeds. The appetite remained good and no ill effects
were noted. It is evident that there is considerable variation in the sus-
ceptibility of different animals of the same species; however, there is
some question in the case of goat 44 as to whether or not the resistance
encountered in this animal was entirely due to individual resistance or
to a possible acquired resistance which was brought about by the earlier
intermittent feeding of small doses. It hardly seems possible that this
animal could have tolerated 11 consecutive doses, each representing 1.81
per cent of the body weight at the beginning of the experiment.

Symptoms and Pathology 0f Experimental Cases

From a study of the experimental cases there is little to be added to the
discussion of symptoms which has been previously presented in this paper.
Loss of appetite is unquestionably the first evidence of intoxication and
appears from one to three days before recognizable icterus. The pruritis
which is part of the photodynamic reaction is quite intense during the
first sunlight exposure, especially of the ears and about the nostrils. The
pruritis is less noticeable upon exposure the following day and by the
third day light exposures caused little or no distress. In recently shorn
sheep a peculiar crouching condition was manifested shortly after pruritis
appeared. The affected animal would gradually flex the hock joint, thus
lowering the hind quarters until extreme fiexion was reached at the joint,

.1 i}

Fig. 4. Sheep 73 showing the peculiar crouching attitude assumed during
the first exposure to light.

POISONING IN SHEEP AND GOATS BY SACAHUISTE 15

the hock would then be extended and the rear quarters elevated to their
normal level. This lowering and raising of the hind quarters was con-
tinuous during light exposure and paralleled other evidence of photo-
sensitization. Stamping of the feet was about as constant as rubbing of
the ears and was started and discontinued about the same time, thus sug-
gesting that this symptom as well as the purplish band which appeared
at the top of the hoof was part of the photodynamic reaction.

Under the heading of pathology the results of blood studies of affected
animals remains to be presented. The blood studies consisted of total and
differential leucocytic counts, red blood corpuscles and non-protein nitrogen
determinations. The figures obtained from the studies of two representa-
tive animals are presented in Table 5. The first studies were made on the

Table 5. Changes in the blood picture as observed in two goats after symptoms of sacahuiste
poisoning appeared; normal also listed for comparison

Red Blood Differential leucocyte count
Corpuscles, Leucocytes, I Non-protein
Animal Millions Thousands Poly. g Lymph. Mono. Eosin. nitrogen
Number per cubic per cubic Per- l Per- Per- Per- mg. per
millimeter millimeter cent  cent cent cent 100 c.c.
l
1N* 22.0 10.0 29 l 60 3 2 30
41** 20.0 7.6 65  28 4 3 65
41*** 8.0 19.0 as  9 3 0 144
3** 19.0 12.0 I 57  3s 5 0 Not determined
I
3*** 1 19.5 16.0 8O  l8 2 O Not determined
| .

*The approximate normal as determined on healthy goats in the region of Alpine, Texas.

**First determination at the time icterus was first detected.
***Sec0nd determination one week after icterus was first detected.

day icterus was first detected, the second one week later or as happened
in both cases one day before death. The constant blood changes noted
were an increase in the total number of leucocytes per cubic millimeter
of blood and a corresponding increase in the percentage of polymor-
phonuclears. The non-protein nitrogen content of the blood was noticeably
increased by the time icterus was detectable and reached very high levels
shortly before death. In view of the kidney destruction the high non-
protein nitrogen level is not surprising. There was generally a slight
decrease in the total number of red blood corpuscles per cubic millimeter
and in two cases there was an actual anemia such as is recorded in goat 41.
For two days preceding death the urine of this animal was port wine in
color and it was assumed that the color was due to hemoglobin, no red
cells being present. Albuminuria is also a constant factor appearing
about the same time as icterus.

The mortality rate was very high, for out of 19 animals in which icterus
was produced only three recovered and one of these was sheep 63 which
was fed the ripe fruit and from all indications was the mildest case pro-
duced. The figures on the mortality are slightly misleading as five of the

16 BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

animals were killed for pathological studies. At the time of slaughter
four of these were in such a condition that recovery was exceedingly
doubtful. The fifth animal was killed at the height of the photodynamic
reaction at which time no prognosis was possible; however, the other five
animals in which photosensitization was produced died. Excluding the
five animals upon which controversy can arise there was a recovery of
three out of 14 animals, a somewhat higher percentage of recovery than is
generally observed under range conditions.

TOXIC PRINCIPLE OF SACAHUISTE

Efiorts to obtain hepato-nephro-toxin from the dried buds and blooms
have thus far been unsuccessful. The ground material has been extracted
with 70 and 96 per cent ethyl alcohol, water, and methyl alcohol. The
feeding of the extracts to rats with the exception of the one obtained with
96 per cent ethyl alcohol, at the rate of 1 to 1.8 grams per day for as
much as a week has produced no ill effects other than a constant diarrhea.
The feeding of the dried 96 per cent ethyl alcohol extract at the rate
of one- gram per day for six consecutive days resulted in the death of
rats, but it is probable that death in these cases was due to the per-
sistent purgation rather than a specific hepato-nephro-toxin. The micro-
scopic changes in these rats failed to indicate the presence of such a
toxin. Fractional separation of the 96 per cent alcoholic extract resulted
in no concentration of the toxic principle; ether extracts were non-toxic
and all other efforts at concentration resulted in a non-toxic soluble fraction
and an insoluble resinous fraction which could not be fed to rats by the
use of the stomach tube.

Rats were fed various amounts of the 96 per cent ethyl alcohol extract
for three days and exposed to direct sunlight. Fifteen rats thus treated
were not rendered photosensitive. Emulsions of fresh green bermuda
grass were mixed with the alcoholic extract and fed to eight additional
rats. Upon exposure to sunlight these animals were found to be photo-
sensitive. The photosensitization in these cases is evidently due to phyllo-
erythrin, a matter which receives further consideration under the discus-
sion. Six pounds of the dried blooms were extracted twice with 96 per
cent ethyl alcohol, the alcohol evaporated off and the residue (145 grams)
was fed to a 40-pound lamb in three equal doses. No ill effects were noted.

The Leaf of the Plant

No experimental evidence concerning the toxic or non-toxic properties
of the leaf is available. This information was desired but sheep could
not be induced to eat the leaf and due to its fibrous nature it could not
be ground in an ordinary meat chopper, which is our method of preparing
plant material for force feeding. Judging from field observations this
part of the plant appears to be non-toxic for cattle. In a sacahuiste
region during the winter months it is a common sight to see cattle with
a bright green discoloration of the face and jaws extending up to about a

POISONING IN SHEEP AND GOATS BY SACAHUISTE 17

level of the eyes. This discoloration is acquired while grazing the leaves
of the plant which are extensively grazed during the winter months, and
over a period of years eventually tends to extermination of the plant.
From these observations it is evident that the leaf is quite palatable to
cattle during the Winter months. N0 ill effects have been (observed as a
result of the grazing and in all probability some food value is derived
therefrom. Sheep and goats rarely eat the leaves and when they do, it
is to such a limited extent that no ill effects could result even if they
were as toxic as the blooms or buds, which they are evidently not.

CONTROL

The control of this disease is a problem in ranch management and due
to the short duration of the blooming season it may be accomplished with-
out a great deal of expense or labor. Rarely is the distribution of the
plant the same in all pastures, and on many ranches some of the pastures
are relatively free of the plant. With such favorable conditions at hand
the lightly infested pastures should be lightly stocked until the blooming
season, at which time the sheep and goats can all be held in this pasture
until the blooms in the remainder of the pastures become Woody and
unpalatable. Lacking such favorable conditions a pasture may be selected
which contains the least number of plants and a suflicient number of them
grubbed out so that from the remainder it will be impossible for any
particular animal to obtain suflicient of the blooms or buds to produce
toxic effects. As the average length of the blooming season is about three
weeks the length of time which will be required to hold the flock in one
pasture is short and no serious results from overgrazing should follow
such a short period. Burning of the plants has been recommended, but a
single burning during the fall or winter months is not satisfactory as
the burnt-off stump will produce the usual crop of blooms and the removal
of the leaf of the plant has merely assisted the animals in harvesting the
blooms. It is reasonable to assume that repeated burning should eventually
kill the plant as the damage by fire is certainly as great if not greater
than that resulting from constant grazing by cattle, which in many cases
is exterminating the plant. From the standpoint of cattle feed the de-
struction of the plant is not a desirable practice since the leaves provide
considerable grazing during the winter. Cutting or pulling the blooms
and buds may be too laborious a task to be practical as a control measure.

DISCUSSION

It is to be noted that the basic or constant lesions of sacahuiste and
lechuguilla poisoning are practically identical, but in the photodynamic aspect
of the two diseases important differences are to be noted. In the case of
lechuguilla poisoning the photosensitization was produced in animals when
alfalfa hay was fed in addition to the plant; green grass was not required
to produce this part of the disease. Lechuguilla was shown to contain
two toxic principles (3). In the case of sacahuiste poisoning fresh green
feed is required in order to render the animals sensitive to sunlight. It is

18 BULLETIN NO. 585, TEXAS AGRICULTURAL EXPERIMENT STATION

evident from these results that sacahuiste contains but one toxic principle,
namely, a hepato-nephro-toxin. The complete clinical picture of sacahuiste
poisoning is therefore similar to the condition produced by Quin (4) in
which a photosensitization was produced in sheep and goats by feeding
fresh green feed after ligation of the bile duct. The green feed in these
experiments had no photodynamic action when fed to normal animals. In
this strictly experimental condition the outstanding fact is the presence
of photosensitization associated with an obstructive jaundice. Quin, Rim-
ington, and Roets (5) showed that the photosensitization in these animals
was due to the presence of phylloerythrin in the blood stream, a prophyrin
produced in the digestive tract by infusorial action on chlorophyl, and
which gains access to the blood stream by virtue of a liver disfunction.
The toxic principle in sacahuiste produces a degeneration of the liver
which results in an obstructive jaundice and a liver disfunction; in the
absence of green feed this is the complete picture, but when green grass
is added the animals become sensitive to sunlight. Since this part of the
clinical picture was not obtained when the animals were fed dry alfalfa
it is evident that the digestive action on dry and green chlorophyl is not
the same.

No definite information concerning the chemical nature of the toxic prin-
ciple in sacahuiste was obtained, but from the results obtained in animal
feeding experiments on this phase of the problem, it is evident that it is
not the same hepato-nephro-toxin which is found in lechuguilla. In the
experimental feeding no great difference was noted in the toxicity of the
two plants for either sheep or goats, and the toxic principle was found
to withstand drying in both cases. The toxic saponin in lechuguilla was
readily extracted with alcohol and one gram of the crude extract was
found to be the minimum lethal dose for white rats. Furthermore, this
toxic principle in the alcoholic extract was easily obtained in a more
purified state and the purified product found to have much greater toxicity
for rats. Although rats were killed by feeding the crude alcoholic extract
of sacahuiste, the fatal results were due to purgation and not to a specific
hepato-nephro-toxin such as was extracted from lechuguilla. In addition
the methods employed in concentrating or purifying the toxic principle
in extracts of lechuguilla were unsuccessful when applied to similar ex-
tracts of sacahuiste.

Due to the fact that the ripe fruit of the plant is small and exceedingly
hard it was surprising that sheep could pick up from the ground sufficient
of this material to produce toxic effects. It is hardly probable that this
material will ever constitute a serious problem, but on one occasion a
light loss was observed as a result of lambs eating the ripe fruit after
it had shattered out of the dry bloom stock onto the ground.

SUMMARY

The grazing of buds and blooms of sacahuiste under range conditions
has been observed to cause serious losses among sheep and goats, and
to a lesser extent among cattle. The disease thus produced is described.

POISONING IN SHEEP AND GOATS BY SACAHUISTE 19

The feeding of the buds, blooms and ripe fruit to goats and sheep under

experimental conditions produced the same disease manifestations as were
observed on the ranges.

Icterus and liver and kidney destruction was produced when the toxic

material was fed in conjunction with alfalfa hay. The addition of fresh
green grass to the ration rendered the affected animals sensitive to
sunlight.

The minimum toxic dose of the fresh buds and blooms for sheep was

found to be about 1.1 per cent of the body weight.

The toxic principle which has a destructive action on the liver and

kidneys could not be extracted with either ethyl or methyl alcohol.

l0

CO

5. Quin, J. I., Rimington, C., and Roets, G. C. S.

The leaf of the plant is not considered to be toxic to cattle.
Methods for the control of sacahuiste poisoning are suggested.

LITERATURE CITED

Tunnicliif, E. A. 1929.
Station, page 139.
Mathews, F. P. 1937. Photosensitization and Photodynamic Diseases of Man and the

Lower Animals. Archives of Pathology, 23, 339.
Mathews, F. P. 1937. Lechuguilla (Agave lecheguilla) Poisoning
and Laboratory Animals. Texas Agricultural Experiment Station Bulletin No. 554.
Quin, J. I. 1933. The Effect of Surgical Obstruction of the Normal Bile Flow.
Onderstepoort Journal of Veterinary Science and Animal Industry, I, 505.
1935. The Biological Formation of
Phylloerythrin in the Digestive Tract of Various Domesticated Animals. Ondersbe-
poort Journal of Veterinary Science and Animal Industry, 4, 463.

Forty-second Annual Report, Texas Agricultural Experiment

in Sheep, Goats