Page 344 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Reproductive Toxicity and Endocrine Disruption Chapter | 17 311

VetBooks.ir TABLE 17.2 (Continued) Recommendation Comments

Drug
Cortisone C Corticosteroids have been associated with increased incidence of cleft palate
and other congenital malformations, and they may induce premature labor and
abortion in dogs (see text).
Dexamethasone C Corticosteroids have been associated with increased incidence of cleft palate
and other congenital malformations, and they may induce premature labor
(see text). Dexamethasone has caused abortion and fetal death in dogs.
Diethylstilberstrol (DES) D Malformation of male and female genitourinary systems.
Estradiolcypionate (ECP) D Malformation of male and female genital tracts and bone marrow depression.
Flumethasone C Corticosteroids have been associated with increased incidence of cleft palate
and other congenital malformations, and they may induce premature labor and
abortion in dogs (see text).
Mitotane (o,p-DDD) D Adrenocortical necrosis.
Prednisolone C Although prednisolone has been administered to pregnant women without
adverse effects, caution is advised (see dexamethasone). Prednisolone may be
used in serious diseases in absence of a suitable alternative.
Stanozolol D Manufacturer states that it should not be administered to pregnant dogs and
cats.
Testosterone D Causes masculinization of female fetus.
Thyroxine B Does not cross placenta easily and has not been associated with any problems.
Miscellaneous drugs
Ammonium chloride B May cause fetal acidosis; discontinue use during pregnancy.
Aspartame (Nutra Sweet) A No risk.
Dimethylsulfoxide (DMSO) C Teratogenic in laboratory animals; manufacturers state that it should not be
applied to breeding animals.
A: Probably safe. Although specific studies may not have proved the safety of all drugs in dogs and cats, ther are no reports of adverse effects in laboratory
animals or in women.
B: Safe for use if used cautiously. Studies in laboratory animals may have uncovered some risk, but these drugs appear to be safe in dogs and cats or these
drugs are safe if they are not administered when the animal is near term.
C: These drugs may have potential risks. Studies in people or laboratory animals have uncovered risks, and these drugs should be used cautiously, as a last
resort when the benefit of therapy clearly outweighs the risks.
D: Contraindicated. These drugs have been shown to cause congenital malformations or embryotoxicity.

been extensively reviewed in this chapter. Teratogenesis cessation of placental function or disruption of the gesta-
can be associated with each of the following mechanisms tional source of progestagens can also induce abortion in
of action: (1) excessive cell death; (2) interference with animals.
apoptosis; (3) reduced cellular proliferation rate; (4) failed
interactions between cells; (5) impaired morphogenetic
movements; (6) reduced synthesis of components essen- Heavy Metals
tial for growth and development; (7) mechanical disrup- Several heavy metals have been identified as teratogens
tion; (8) and alterations in pH (Hood et al., 2002; Hood, and possible abortifacients in humans and animals. The
2006). Some teratogens are capable of more than one adverse effects of in utero lead exposure, on the develop-
mechanism of action. Premature parturition or abortion ing nervous systems of both humans and laboratory ani-
can be induced by any xenobiotics which cause fetal or, mal species, have been well documented (Evans et al.,
potentially, maternal stress and initiate the cascade of 2003; Rogers and Kavlock, 2008). Prenatal exposure to
endocrine and neural signaling events which would nor- organotins has been associated with pregnancy loss and
mally lead to parturition. Any intoxication in a pregnant impaired ossification in rodents (Ema and Hirose, 2006),
animal has the potential to threaten fetal survival. and organic mercury is a known developmental neuro-
Toxicants which cause sudden fetal death or complete toxicant (Golub, 2006b). Other heavy metals, including