Hypoluteoidism in a dog associated with recurrent mammary fibroadenoma stimulated by progestin therapy

Abstract

BackgroundHypoluteoidism in the bitch is characterized by insufficient production and secretion of progesterone by the corpora lutea. It is a rare pathologic condition and during pregnancy, it leads to embryonic resorption or fetal abortion. Supplementary therapy with progestins is indicated during pregnancy to obtain delivery of vital puppies but unwarranted side effects of such treatment are poorly documented.Case presentationA 4-year-old, nulliparous, female Istrian Shorthaired Hound dog had been mated repeatedly in six heats with different dogs of proven fertility but signs of pregnancy did not develop. Estrous cycles, mating and pregnancies were monitored as hypoluteoidism or genital disease was suspected. During the first monitored estrus, the bitch was mated and on day 18 [day 0, day of estimated peak of luteinizing hormone (LH)], ultrasound examination showed three amniotic vesicles that were however found to be resorbed between day 20 and 23. Progesterone concentrations, measured by ELISA, were >8 ng/mL until day 12 and 1–2.5 ng/mL on days 20, 23 and 26. Primary hypoluteoidism was therefore suspected. In the second monitored estrus, the bitch was mated and during pregnancy, progesterone concentrations were >8 ng/mL until day 17 and 1–2.5 ng/mL on day 19. On days 20 and 22, two out of three embryonic vesicles had been resorbed. The bitch was treated with progesterone in oil from day 19 to day 58. Increase in the size of 2nd left thoracic mammary gland (T2-L) was observed and on day 46, ultrasound evaluation and biopsy were performed revealing a low-cellularity fibroadenoma. Parturition started spontaneously at day 65 but due to dystocia caused by fetal macrosomia, a Caesarean section was performed. During the next (third) monitored estrus, the bitch was bred again and during pregnancy, early decrease in progesterone concentration confirmed the diagnosis of primary hypoluteoidism. The bitch was treated with synthetic progestin (altrenogest) from day 8 to day 57. Five amniotic vesicles were detected by ultrasonography. Recurrence of swelling of T2-L was observed. On day 60, the bitch whelped five pups, two males and three females. As reported later by the owner, the latter did not show any sign of heat over the past 3 years. In one of them, clitoral hypertrophy and a blind ending vagina were diagnosed.ConclusionsThis is the first description of early hypoluteoidism in a pregnant bitch developing a mammary fibroadenoma under progestin treatment.

Mammary Fibroadenoma in Cats: A Matter of Classification

“…Data regarding ER and PR expression in fibroadenoma in dogs and cats are, unfortunately, lacking. In dogs, only one report has described the development of a recurrent mammary fibroadenoma in association with the administration of progestogens which, however, underwent spontaneous regression after caesarean section [48]. No ER and PR expression was assessed.…”

Dead or Alive? A Review of Perinatal Factors That Determine Canine Neonatal Viability

“…Recently, the first documented case of mammary gland fibroadenoma in dogs, so far reported only in cats, has also been described. An Istrian Shorthaired Hound bitch was diagnosed with primary corpus luteum insufficiency in three consecutive pregnancies [ 51 ]. Based on the diagnosis established during the first pregnancy, in the second one with repeated suspicion of corpus luteum insufficiency, the bitch was treated with 1.65 mg/kg of progesterone in oil intramuscularly (PROGEST-E ® , Fort Dodge Animal Health S.p.A., Bologna, Italy) daily, from day 19 to day 22, and every 48 h from day 23 to day 58.…”

“…During the third pregnancy, based on previous experience, the bitch also received 0.075 mg/kg alternogest (Regumate ® , Intervet Italia S.r.l., Peschiera Borromeo, MI, Italy) from day 8 and then every 24 h until day 52 of pregnancy. The dose was reduced to 0.058 mg/kg PO from day 53 to day 57 [ 51 ]. Both times, an increase in the size of the mammary glands was observed.…”

Corante Azul Patente Como Identificador De Linfonodo Sentinela Em Cadelas Com Neoplasia De Mama

“…Ainda, segundo Zedda et al (2017) não existe nenhum efeito protetor da OH realizada após os quatro anos de idade, já que os maiores efeitos dos hormônios ovarianos na glândula mamária ocorrem na fase de desenvolvimento mamário. Entretanto, a exposição a doses farmacológicas de hormônios exógenos, independentemente da idade do animal, é capaz de elevar o risco de aparecimento de neoplasias mamárias em cães, em até 2,3 vezes (FELICIANO et al, 2012).…”

“…Outro fator que parece apresentar influência no desenvolvimento mamário é acúmulo corpóreo de tecido adiposo. A obesidade em cães de até 1 ano de idade atua como fator de predisposição ao desenvolvimento de tumores em menor proporção, pois os lipídios são precursores de andrógenos que por sua vez, são convertidos em estrógenos (ZEDDA et al, 2017).…”