Page 1217 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

1148 SECTION | XVIII Prevention and Treatment

VetBooks.ir hydrophilic mucilloid (e.g., Metamucil). Psyllium is found effects include diarrhea and aspiration of the oil leading
to lipid pneumonitis. Ensuring proper placement of the
in the ripe seed coatings of Plantago species. It absorbs
stomach tube and slow administration lessen the risk of
water and swells in the intestine increasing bulk to induce
peristalsis and decrease gastrointestinal transit time. The aspiration (Plumb, 2015).
dose in dogs is 0.32 4.9 g/kg/day, and the dose in cats is As mentioned earlier, hypernatremia attributed to
one to four teaspoons per meal (Plumb, 2015). Psyllium sorbitol administration has been reported in humans.
can also be used in birds by mixing one-half teaspoon Because all cathartics alter the water balance in the GIT,
with 60 mL of baby food to form a gruel, then administer- electrolyte abnormalities, especially hypernatremia, are a
ing by a dosing syringe or eyedropper (Richardson et al., potential risk to their use. A patient’s hydration status
2001). should be monitored frequently and fluids administered,
Another bulking cathartic that can be used in dogs and intravenously or via an enema, as needed.
cats is unspiced canned pumpkin. Dilute peanut butter,
fruit, or vegetables can also be used as bulking cathartic Enemas
agents in birds and reptiles. Timothy hay can be utilized
Enemas are also appropriate when elimination of toxi-
in rabbits. Bulking cathartics are also used to assist the
cants from the lower GIT is desired (Beasley and
passage of physical agents through the GIT (Beasley and
Dorman, 1990). Many extended-release or controlled-
Dorman, 1990). Examples include small pieces of plastic,
release medications are absorbed from the entire GIT,
coins, button batteries, and sand in horses.
including significant absorption from the colon (Buckley
Osmotic cathartics have limited absorption from the
et al., 1995). Enemas can be used to move those medica-
GIT so they are able to pull electrolyte-free water into the
tions quickly through the colon and lessen additional sys-
GIT, thereby increasing the fluid volume and stimulating
temic effects. The general technique is to use plain warm
motility to hasten expulsion in the feces. There are saline
water or warm soapy water. Commercial phosphate
and saccharide osmotic cathartics. Sorbitol is the most
enema solutions should be avoided due to the risk of elec-
commonly used saccharide osmotic cathartic; it is the
trolyte and acid base disturbances (Beasley and Dorman,
cathartic of choice and is frequently combined with
1990). Enemas are not recommended for birds since they
activated charcoal in commercially prepared charcoal pro-
already have a rapid gastrointestinal transit time. In rep-
ducts. The dose is 1 2 mL/kg of a 70% solution
tiles, enemas may be useful since ingested materials often
(Peterson, 2006). Sorbitol can be utilized in mammals,
lag for prolonged periods in the colon.
birds, and reptiles.
The saline cathartics include sodium sulfate
(Glauber’s salts) and magnesium sulfate (Epsom salts). Endoscopy/Gastrostomy
The recommended dose is 250 mg/kg. The use of magne- In some cases, endoscopy or gastrostomy may be indi-
sium sulfate has led to hypermagnesemia in some cases, cated to prevent further clinical effects. Endoscopy can be
which presents as depression of the central nervous and used to remove small objects, such as pennies, lead paint
cardiovascular systems (Rosendale, 2002). Saline cathar- chips and small batteries. These objects can also be
tics should not be used in patients with renal insufficiency removed via gastrostomy if endoscopy is not available.
or in birds or reptiles. Gastrostomy is also used to prevent obstruction from
Of the lubricant cathartics, mineral oil is the most expanding foreign objects. Expandable isocyanate-
often used. Heavy mineral oil is preferred to light mineral containing glues (i.e., Gorilla Glue) can swell once
oil since it is thought to carry less of a chance of systemic ingested to fill the entire volume of the stomach. A gas-
absorption and aspiration following oral administration. trostomy is needed in these cases to remove the mass
Mineral oil lubricates fecal material and the intestinal (Horstman et al., 2003).
mucosa easing elimination and reduces absorption of
water from the GIT, increasing fecal bulk and cutting ANTIDOTAL THERAPIES
transit time (Plumb, 2015). Mineral oil is not recom-
mended as a cathartic following activated charcoal admin- If an antidote to the toxicant a patient has been exposed
istration, as the mineral oil may render the charcoal less to exists, the appropriate time to administer it will depend
adsorptive (Buck and Bratich, 1986; Galey, 1992). on the situation. In some instances, the antidote will be
Mineral oil has been recommended to bind lipid-soluble crucial in stabilizing the patient. For example, atropine
toxicants including metaldehyde, nitrate, and cantharidin should be used immediately in cases of organophosphate
(Stair and Plumlee, 2004; Plumb, 2015), and it is used to (OP) toxicosis in which the patient has life-threatening
treat impaction in horses (Buck and Bratich, 1986). The bradycardia and bronchial secretions (Gwaltney-Brant and
recommended dose in horses is 2 4 L per 500 kg body Rumbeiha, 2002). On the other hand, in some cases,
weight (Brown and Bertone, 2001). Possible adverse administration of the antidote is best done later. This is