Pyometra in a Bitch Possibly Caused by Simultaneous Administration of Levonorgestrel and Estradiol Cypionate

Abstract

Background: Toxicological events in animals may be accidental or intentional and could occur in the home environment. These events could involve different agents such as pesticides, rodenticides, medicines, foods, and plants. Indiscriminate use of medication in pets by their owners is common. Self-medication of animals with drugs for human use can cause irreversible damage to their health. The emergency contraceptive pill (morning-after pill), comprising concentrated hormonal compounds, is sold freely in Brazil. The objective of this article was to report a case of pyometra in a bitch possibly caused by simultaneous administration of human emergency contraceptive pill along with a veterinary contraceptive medication.              Case: A 6-year-old bitch was referred to a Veterinary Medical Teaching Hospital for abdominal enlargement. According to the guardian, during estrus (30 days before the consultation) the female dog was covered. After intercourse, the owner administered a human emergency contraceptive pill (morning-after pill) and a veterinary contraceptive. Physical examination revealed severe dehydration (10%) and high temperature, besides the abdominal enlargement. The hemogram revealed leukocytosis with a left shift, characteristic of infection. After clinical examination, closed pyometra was suspected, and later confirmed by ultrasonography. Due to the poor clinical condition, fluid therapy was performed, and a systemic antibiotic was administered. After stabilization, the patient underwent ovariohysterectomy. In the postoperative period, the fluid therapy was continued, and antibiotic and anti-inflammatory drugs were administered. Two days after surgery, the patient was discharged for home recovery.  Discussion: Most cases of drug poisoning in animals involve female dogs, similar to the patient in this report. There is no theory elucidating the same, but the rate of incidence in female dogs has been reported to be higher than that in male dogs in the veterinary clinical routine. The administration of medicines at the guardian’s discretion, as seen in this case, is common in Brazil. The drugs involved may be of veterinary or human use. Drug intoxication is linked to the culture of self-medication. If the animal presents a symptom similar to that of a human, the guardian dispenses the same medicine used for him to their pet animal. Thus, it can be inferred that the guardian of the bitch in this report had the habit of self-medication and adopted the same conduct with the pet. The emergency contraceptive pill used here consisted of levonorgestrel, a progestin-type of hormone. No reports of levonorgestrel use have been reported in dogs; therefore, the mode of action of the drug in the canine species is unknown. The administration of progestogens in bitches is one of the main causes of reproductive diseases in the species. One of the diseases related to the use of contraceptives in bitches is pyometra. Despite the evidence, the human contraceptive cannot be determined as the cause of pyometra, because a veterinary contraceptive was also administered. Pyometra probably occurred due to the combined effect of both drugs. Thus, this case was diagnosed as drug intoxication. Veterinarians should be alert on this subject and invest in awareness and prevention of self-medication in animals by their guardians.