LUCRĂRI TIINłIFICE MEDICINĂ VETERINARĂ VOL. XLII (2), 2009, TIMI OARA
OESTRUS CONTROL WITH PROGESTINS AND CYSTIC ENDOMETRIAL HYPERPLAZIA PYOMETRA COMPLEX IN THE BITCH
C. IGNA, VIOLETA IGNA, LARISA SCHUSZLER, ROXANA DASCĂLU, A. SALA, M. SABĂU
Faculty of Veterinary Medicine Timisoara Calea Aradului No. 119, 300645, Timisoara, Romania E mail: [email protected]
Summary
Objective: to investigate dogs with cystic endometrial hyperplasia pyometra complex and the relationships between hormonal therapy (progestins) and this uterine pathology. Design : retrospective study of the 362 canines with cystic endometrial hyperplasia (CEH) or pyometra. Intervention: ovariohysterectomy Results: 362 bitches with CEH pyometra complex, representing 17.8% of the bitches included in this study were assessed. In 75.7 per cent of the cases, bitches were treated with progestins for suppression of ovarian cycles at variable time intervals. Conclusion: ovarian cycle suppression with progestins represents an important risk in the development of the CEH pyometra complex. Key words: cystic endometrial hyperplasia – pyometra complex, progestins, bitch
Pyometra is a hormonally mediated diestrual disorder characterized by cystic endometrial hyperplasia with secondary bacterial infection. In the common dogma, CEH associated degenerative changes within the uterine tissues (cystic distention of glands, fibrosis, etc.) are suggested to provide opportune conditions for establishment of uterine infections. The uterus is invaded by opportunistic pathogens (primarily Escherichia coli) from the vagina, which will proliferate and establish infection within the uterus. It is inferred that infection is established because of: excessive amounts of secretory fluids accumulated within the lumen, the presence of numerous crypts and cysts where bacteria can proliferate, and reduced local immunity, that are associated with local tissue degeneration. This association is reflected in the naming of the condition ‘‘Cystic Endometrial Hiperplasia Pyometra Complex’’ (4, 5, 10). Although the association between pyometra and diestrus has been well established, the precise mechanism is still not clear (2). Early reports suggested that excessive or prolonged exposure to progesterone was responsible for the susceptibility to pyometra (6). A review of the literature concerning the effect of oestrogens for treating mismating in bitches on the occurrence of pyometra indicated that low doses of 84 LUCRĂRI TIINłIFICE MEDICINĂ VETERINARĂ VOL. XLII (2), 2009, TIMI OARA oestradiol benzoate substantially increase the incidence of pyometra. (9, 11). The most widely used agents for cycle prevention in dogs are the progestins and include medroxyprogesterone acetate (MPA), megestrol acetate (MA), proligestone (PR), chlormadinone acetate (CMA), delmadinone acetate (DMA), norethisterone acetate (NTA) and melengesterol acetate (MGA). Other studies have not been able to substantiate that either higher concentrations or more prolonged periods of progesterone secretion in bitches resulted in development of pyometra (1, 3). In they study Niskanen M, Thrusfield MV. 1998 (8) reveal no significant risk enhancing effect of progestin treatment and conclude that, if present, such risk is probably low. In this retrospective study regarding clinical cases, we aim to investigate dogs with pyometra and the relationships between hormonal therapy and pyometra.
Materials and methods
Three hundred sixty two bitches with pyometra of eight different breeds, mean age 7.3 years (range 4–14 years), were clinically examined and diagnosed at the Department of Small Animal Surgery, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Banat, Timisoara Romania, from April 1999 to December 2008 – table 1. The presumptive clinical diagnosis was based on case history, clinical signs and ultrasonography, radiography, or both. The diagnosis was verified by gross examination of a pus filled uterus during and after the ovariohysterectomy. The bitches with pyometra had a moderately to severely depressed general condition, impaired circulation, fever, hypothermia or abnormal appearance of visible mucous membranes. In all cases, under general anesthesia (acepromazine 0.15 mg x kcorp 1, ketamine 5 mg x kcorp 1, thiopental sodic 4 8 mg x kcorp 1, and inhalation anesthesia halothane 4 – 2 %) ovariohysterectomy was applied. Postoperative pain was managed with buprenorphine or meloxicam. The medical therapy consisted of fluids (i.v.) and broad spectrum bactericidal antibiotics. Fluid, electrolyte, and acid base imbalances was corrected. The owners were contacted to complete a questionnaire about sexual activity and eventual treatment for oestrus suppression.
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Table 1 Cases with pyometra (1999 2008) Specification Total Race Puddle Pekinese Westy Coker Terrier Sheppard Doberman Mixed No. case 54 48 32 32 47 58 24 67 362 Age (year) 7.1 / 8.5 / 7.0 / 6.8 / 7.9 / 7.7 / 5.8 7.6 / 7.3 / X/range 5 12 7 14 5 10 4 9 5 12 6 9 5 7 5 14 4 14 Oestrus 45 37 26 24 42 30 16 54 274 suppression total 140/ MA/PR 23/22 21/16 17/9 13/11 22/20 12/18 5/11 28/26 134 Legend MA - Medroxprogesterone acetate ; PR – Proligestone
Results and discussions
A retrospective study of the clinical records of surgery cases performed within the Faculty of Veterinary Medicine in the past ten years found that the incidence of pyometra was 17.8 per cent from the total number of examined females, respectively 362 pyometra / 2034 female with reproduction problems accessed of our clinic service between 1999 and 2008. This incidence is similar to the data reports of the Fukuda S. – 2001 (7). The 306 pyometra patients were moderately to severely depressed, lethargic and anorectic, and had a purulent vulval discharge. Vomiting, dehydration, abnormal visible mucous membranes and polydipsia were also present, but more rarely described (34 dogs). The 32 bitches presented only uterine tissues degeneration (cystic distention of glands and fibrosis), typical for the cystic endometrial hyperplasia (CEH), that represent first stage of the CEH pyometra complex (10). Cases were reported in animals aged between 4 and 14, with a median age at diagnosis of 7.3 years. Eight breeds had an increased risk of developing the CEH pyometra complex. The analysis of the anamnesis data reveal that from 362 bitches diagnosed with CEH pyometra complex in 75.7 per cent (274 cases) were treated for oestrus suppression, at variable time intervals, with progestins (Medroxprogesterone acetate or Proligestone). This data records suggest that more than 75 per cent of pyometras occurred after of the iatrogenic treatment with progestins. Whereas in a Finnish study (8) low risk enhancing effect of progestin treatment was reported, our data concluded that progestins administration represent an important risk for the development of the CEH pyometra complex, appropriate values after oestradiol use report (9, 11).
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Conclusions
The present study confirms elevation of pyometra risk in the bitch treated with progestins. The efficacy and safety use of the progestins for ovarian cycle suppression in the bitch is suitable only under veterinary recommendation and supervision.
References
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