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Abortion, Spontaneous (Dog) 3

○ Histologic examination of fetal organs, ○ Trimethoprim/sulfadiazine (15 mg/kg PO subsequent pregnancies (exceptions: B. canis
liver, spleen, thymus, kidneys, adrenals, q 12h) may be teratogenic. and occasionally recrudescent herpesvirus
VetBooks.ir • Serum progesterone level of dam must be > Chronic Treatment PEARLS & CONSIDERATIONS Diseases and Disorders
intestines, stomach, heart, lung, thymus,
infections).
and brain
• Hormone replacement with confirmed cases
2 ng/mL (6 nmol/L) to sustain pregnancy.
at least 2 days before expected term (i.e.,
○ Concentrations below this threshold for of hypoluteoidism should be discontinued Comments
more than 48 hours are diagnostic of 62-63 days after the luteinizing hormone • Abortion is uncommon in the bitch;
hypoluteoidism. surge) to allow for normal parturition. embryonic death with fetal resorption or
○ Low progesterone level may also occur Hormone replacement options include mummification is more common.
secondary to fetal death. Other causes of ○ Progesterone in oil 2 mg/kg IM q 48h • Most cases of canine abortion go unnoticed
fetal death (e.g., genetic) should be ruled ○ Altrenogest 0.09 mg/kg PO q 24h by the owner as the bitch may consume the
out. ○ Micronized progesterone (Prometrium aborted tissues.
• Thyroid hormone analyses: Subclinical 10 mg/kg PO q 24h; or Utrogestan • Infectious agents, notably viruses (CHV-1)
hypothyroidism may be aggravated to a 5 mg/kg PO q 8h) or specific bacteria (B. canis), are the most
clinically significant disease during periods • If antibiotics are used in B. canis–infected common causes of canine abortion.
of stress (e.g., pregnancy) (p. 525). dogs, antibiotic treatment should be con- • The diagnosis of abortion should prompt a
• Routine laboratory testing: CBC and serum tinued for at least 4 weeks, based on culture search for an underlying cause.
biochemistry profile and sensitivity results and clinical state.
○ Normal hematocrit values in pregnant Prevention
bitches are lower (30%-35%) than in Nutrition/Diet • A CHV-1 vaccine (i.e., Eurican Herpes 205)
nonpregnant bitches in diestrus (45%- A good-quality maintenance diet is recom- is available in Europe. Vaccination should
55%) because of an increase in plasma mended for bitches with lost pregnancies (p. be given 1 month before anticipated estrus,
volume. 816). Puppy food should be continued for followed by vaccination within 8 days after
○ Mild, mature neutrophilia is normal bitches undergoing treatment with remaining mating. If titers are below 1 : 128 at mid-
in pregnant bitches, but pronounced live fetuses. pregnancy, a third vaccination may be given
neutrophilia, immature neutrophils, or 10 days before parturition.
monocytosis is abnormal. Behavior/Exercise • Isolate pregnant bitches from showing or
Controlled physical activity is recommended performing dogs during pregnancy, especially
Advanced or Confirmatory Testing during pregnancy. Avoid exposure to new dogs, if herpesvirus or brucellosis is endemic in
• Ultrasonography may reveal fetal death extensive travel, or abrupt changes in the dam’s the area.
(absence of a fetal heartbeat or movement) environment. • Maintain an adequate vaccination and
before onset of abortion. deworming program.
• Contact diagnostic laboratories for further Drug Interactions • Bitches with hypoluteoidism may experience
recommendations for specific pathogens. Glucocorticoids are unpredictably abortifacient recurrent abortion, and mating of these
• Toxicology of organs and/or blood is needed drugs in dogs. increases risk.
when a specific toxin or drug is suspected. • Breeding dogs should be screened for B. canis
Possible Complications and, if positive, should not be bred.
TREATMENT For hypoluteoidism, hormone replacement
therapy is recommended only if the whelping Technician Tips
Treatment Overview date is known, as failure to discontinue supple- An understanding of normal pregnancy, pre-
• Acute supportive care of the bitch (e.g., mentation at the appropriate time may cause ventative measures for breeding animals, and
intensive treatment of an infection) is the prolonged gestation, fetal death, and lactation pregnancy emergencies that require veterinary
main aim of treatment since the prognosis failure. In addition, supplementation with attention is essential. Ability to recognize
for saving the current pregnancy is poor. progesterone analogs (i.e., altrenogest) before abnormal vaginal discharge, signs of discomfort
• B. canis infection sexual differentiation of the fetus (before day in pregnant females, and high-risk pregnancies
• With hypoluteoidism, progesterone supple- 45) is not recommended because of potential is also important.
mentation may be attempted to prevent masculinization of female fetuses.
abortion of remaining fetuses. This preemp- Client Education
tive approach has been effective in bitches Recommended Monitoring • Pregnancy diagnosis should be made in
that have aborted from hypoluteoidism in • If suspicious of impending abortion, serum bitches at day 25-30 after breeding using
previous pregnancies. progesterone concentrations should be abdominal ultrasonography or a serum
monitored weekly. Frequent monitoring of relaxin test (pp. 816 and 1378).
Acute General Treatment fetal viability with abdominal ultrasonogra- • Regular medical evaluation of breeding dogs
• Supportive: intravenous fluids (e.g., lactated phy can be valuable. with appropriate vaccinations and regular
Ringer’s solution) if fever is present • If abnormal vaginal discharge is observed deworming
• Broad-spectrum antibiotics safe for use during gestation, abdominal ultrasonography • Genetic counseling to avoid inbreeding
during pregnancy: empirical pending culture should be used to assess fetal viability, and • Screen breeding pair for brucellosis.
and sensitivity results (if clinically feasible). supportive therapy should be initiated.
For specific antimicrobial treatment of SUGGESTED READING
brucellosis, see web chapter. PROGNOSIS & OUTCOME Lamm CG, et al: Clinical approach to abortion,
○ Amoxicillin (22 mg/kg PO q 8h) stillborn, and neonatal death in dogs and cats. Vet
○ Pivampicillin (30 mg/kg PO q 12h) • Prognosis is poor for maintaining pregnancy Clin North Am Small Anim Pract 42:501-513,
○ Cephalexin or cefadroxil (20 mg PO q once signs of impending abortion occur. 2012.
8-12h) • Bitches with hypoluteoidism may experience AUTHOR: Wenche K. Farstad, DVM, Dr. scient., PhD,
○ Enrofloxacin (5 mg/kg SQ, IM, or PO q recurrent abortion. DECAR
24h) recommended for B. canis but may • For causes of abortion other than hypolu- EDITOR: Michelle A. Kutzler, DVM, PhD, DACT
be teratogenic. teoidism usually there are no problems in

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