Veterinary World Vol.3(7): 340-342 REVIEW Canine Pyometra

Rubina kumari Baithalu*, Biswa Ranjan Maharana, Chinmoy Mishra, Laxminarayan Sarangi and Lipismita Samal

Indian Veterinary Research Institute, Izatnagar - 243 122, Dist. Bareilly, UP * Corresponding author email: [email protected]

Introduction effects of on the . The hormonal Canine Pyometra is a common reproductive therapies that include either progesterone for estrous disorder of intact, diestrual bitch which affects nearly suppression or for estrous induction or one fourth of all female before they reach ten pregnancy termination may explain the development of years of age . By definition it is the accumulation of pyometra in young bitches. Thus estrogen being an within the uterine lumen, typically occurring during or important factor in young animals and endogenous immediately following a period of progesterone progesterone being crucial in older animal. Evidence dominance. It can be classified as open or close suggests that there is increase risk for pyometra in 1-2 cervix pyometra. Closed cervix pyometra is particularly years old age group due to estrogen administration but dangerous, so it needs early recognition, diagnosis no significant association between progesterone and appropriate treatment to avoid any disastrous therapy and pyometra. consequences i.e death of patient due to septicemia Higher concentration of IGF-1 located in and toxaemia . Despite modern treatment the mortality surrounding epithelial cells of the in dogs with may play important role in the development of rate due to pyometra is about 4% . CEH-Pyometra complex. Etiological factors Breed: Breeds reported to be predisposed to pyometra Age : Pyometra occurs at any age after the first estrus, includes the Rottweiler, Saint Bernard, Chow Chow, typically a condition of the middle aged to older bitch. Golden Retriever, Miniature Schnaeger, Irish terrier, Reported mean age of 7.25 yrs as young as 4 months Spanish, Callie etc. Breeds with low risk for pyometra to as old as 16 years of age. Spontaneous disease includes Drevers, German Shepherd, Daschunds, occurs most frequently in bitches over 6 yrs of age. It Swedish hounds etc. also affects younger animals with a mean age of approximately 2 yrs. Pathophysiology Parity : Previously it was suggested that nulliparity, Pyometra in the bitch is a hormonally mediated abnormal and pseudopregnancy disease. Prolonged or repeated stimulation of increase the risk of pyometra. But recent literature has endometrium by progesterone produces CEH, if suggested that there is no association between bacterial infection occurs at that time leads to pyometra. pseudopregnancy and abnormal estrus cycle and After ovulation increase progesterone concentration (> pyometra. However there is a modest relationship 40 ng/ml) promotes endometrial (endometrial between nulliparity and pyometra. hyperplasia) growth and glandular secretion leads to Stages of estrous cycle: Most bitches present to accumulation of uterine glandular secretion which pyometra within 8 weeks of last estrous. However, it provides excellent media for bacterial growth. In the may occur at any stage of estrous cycle or during progesterone primed uterus leucocyte response to pregnancy. infection also inhibited. But recent research suggested Hormone: Progesterone has a role in initiating the that CEH and pyometra complex are not necessarily pathogenesis of cystic (CEH)- sequent events, but each may develop independently. Pyometra complex. Endometrial hyperplasia that In endometrial hyperplasia, endometrial gland resulted into CEH caused by progesterone is more secretion results in an accumulation of fluid within pronounced when it has been primed with estrogen. lumen of uterus lead to hydrometra or mucometra but Thus administration of estrogen when progesterone these conditions are sterile. levels high may predispose bitches to pyometra. Estrogen by itself doesn't produce CEH but it Estrogen keeps the cervix relaxed for longer period in enhance the stimulatory effects of progesterone on the the luteal phase and also enhancing the stimulatory uterus. Estrogen induces proliferation of the

www.veterinaryworld.org Veterinary World, Vol.3 No.7 July 2010 340 Canine Pyometra endometrial glands and progesterone does branching pyometra the degree of uterine distention is greater and coiling of the glands, responsible for onset of and may be associated with visible enlargement. secretion. Clinical pathology Exogenous or endogenous concentration of circulating steroid hormones particularly estrogen and Vaginal cytology examination is an initial tool in progesterone influence the distribution of steroid diagnosis of canine pyometra. Intracellular and receptors within the uterus of bitches. Regulation of extracellular bacteria may be seen on cytological estrogen and progesterone receptor expression in examination with pyometra. Common clinical findings endometrial glands may play an important role in is peripheral leukocytosis, often exceeding 30,000 pathogenesis of pyometra complex in the bitch. In cells/mm3, degenerative left shift with toxic neutrophils normal estrous cycle progesterone induces are oftenly seen. But the degree is much less marked in downregulation of estrogen receptors in endometrium cases of open cervix pyometra. A mild normocytic, so proliferative process halted but this mechanism normochromic nondegenerative anemic (PCV within failed in CEH. Due to increase expression of estrogen 30-35%) condition reflects chronic nature of disease receptor, the endometrium remain receptive to even and toxic suppression of bone marrow. low levels of circulating estrogen. So simultaneous In pyometra abnormal serum chemistry includes action of estrogen and progesterone could explain the hyperproteinemia and hyperglobinemia may result due CEH and pyometra complex pathway. Bacterial to and chronic antigenic stimulation of the infection plays an important role in pathogenesis of immune system. These changes reflect hepatocellular pyometra. Progesterone sensitized endometrium and damage due to toxaemia or diminished hepatic had an affinity for E. coli i.e commonly circulation and cellular hypoxia due to dehydration. isolated from uterine fluid as part of the normal vaginal Clinical blood chemistry includes-mild to and vulval microflora Endometrium develop E. coli moderate increase of Alanine aminotransferase (ALT) receptors during early metestrus. If infection results and Alkalinephosphatase (AP) concentration app. 50- during this time then there is colonization of bacteria in 75% cases. Toxaemic condition develop due to the uterus leads to pyometra. bacterial infection especially E. coli impair the collecting tubules reabsorbing ability, insensitive to the Clinical signs action of ADH resulting in further loss of urinary Onset of clinical signs in case of pyometra is concentrating ability. gradual and insidious. Clinical signs in case of Immune complex deposits in glomeruli causes a pyometra depends upon patency of cervix. In open mixed membrano glomerulo-nephropathy and leads to cervix pyometra, bitches are less systemically ill than proteinuria. This proteinuria gradually resolves with closed cervix pyometra. Common clinical signs includes correction of pyometra. mucopurullent discharge, lethargy, depression, Diagnostic imaging inappetence, polyurea, polydypsia, vomiting and diarrhoea. Bitches with closed cervix pyometra The diagnosis of pyometra is best made with the generally are very ill at presentation, death may occure aid of ultrasonography and radiology. Ultrasonographic due to toxaemia alone or may be associated with findings includes an enlarged uterus with convoluted, due to rupture of uterus. In some cases, tubular horns filled with anechoic to hypoechoic fluid. there may be intermittant opening of cervix, with The diagnosis of uterus may vary depending upon relative good health following discharge of pus and whether the cervix is open or closed. The uterine wall is malaise during intervening period. usually relatively hypoechoic and increase in thickness. Fever may or may not be present in case of open The luminal contents are usually homogenous and cervix pyometra, but in closed cervix pyometra is filled with anechoic flud, although small echogenic commonly associated with fever. Those bitches particles may be identified. Radiography may also be associated with toxaemia, may be hypothermic. used as an aid in diagnosis of pyometra in the bitch . In Character of vulval discharge may be variable in pyometra radiographically, a fluid dome, tubular consistency and light chocolate brown in colour and structure should be seen in the ventral and caudal malodorous. Sometimes yellow colour and often blood , displacing loops of intestine dorsally and tinged and watery to creamy consistency. is cranically. In open cervix pyometra with significant generally enlarged and there may be discolouration or drainage of uterine contents through , uterus scalding of perivulval tissues and perineum. may not visualize radiographically. So inability to radiographically visualize the uterus does not rule out Physical examination pyometra. It may be difficult to palplate uterine enlargement, Treatment especially in case of open-cervix pyometra and in case of large and obese bitch. In case of closed cervix Ovariohysterectomy is the choice of treatment for www.veterinaryworld.org Veterinary World, Vol.3 No.7 July 2010 341 Canine Pyometra older bitches, closed cervix pyometra or in cases where slower evacuation of the uterine contents. owner has no strong desire to breed bitches presented In bitch, prolactin is important luteotropic at early course of the disease surgical risk is low and hormone. So Dopamine agonists or prolactin inhibitors success rates upto 92%. In toxaemic cases, lower such as bromocriptine (20 mcg/kg) or cabergoline (@ 5 success rate may be obtained. Before surgery bitches mcg/kg) are used in combination with natural or should be stabilized with fluid therapy and broad synthetic Prostagalndin to treat pyometra. These spectrum . Surgical removal of the uterus will combinations potentiates the luteolysis effects of each resolve the septic state of the bitch. 7 days after drug and results in rapid luteolysis. hysterectomy altered haematological parameters Progesterone receptor blocker like Aglepristone returned to normal levels. The main advantage of competitively prevents progesterone from binding to its Ovariohysterectomy is the exclusion of any risk of receptor. There is controversy of its use, to induce reccurrence. However, surgical treatment has its limits uterine contractions if used alone. The combination of when the risk of anaesthesia and surgery are life aglepristone with cloprostenol more effective in threatening medical treatment of open and closed cervix pyometra Medical treatment: If condition is not life threatening than aglepristone alone. and the animal is particularly valuable, in such cases, Antimicrobial treatment involves broad spectrum restoration of fertility may be done with medical antibiotics necessary to combate from infectious treatment. agents. Before starting treatment sensitivity Principles of treatment test should be done for selection of antibiotics. Induction of luteolysis or prevention of Antibiotics like amoxicillin, amoxicillin plus clauvanic progesterone binding to its receptors for prevention of acid and cephalosporins or potentiated sulfonamides progesterone effects. Now-a-days PGF2alpha used are choice for initial treatment. either alone or in combination with other drugs like To avoid recurrence of the pyometra, it is prolactin inhibitor or progesterone receptor blocker for necessary to facilitate uterine regeneration during the this effect. Expulsion of the uterine contents by allowing post treatment anestrus. This prolongation of anestrus cervical relaxation in closed pyometra either by the use allows apoptosis and regeneration of endometrium, of Prostaglandins or progesterone receptor blocker. this can be done by administration of androgen Induction of uterine contraction and emptying receptor agonist, postponing the estrus for 2-3 month. either by the use of Prostaglandins or progesterone References receptor blocker. Use of broad-spectrum antibiotics for inhibition of bacterial growth and development. 1. Bartoskova A, Vitasek R, Leva L, Faldyna M. Facilitating uterine regeneration by prolonging (2007) : J. Small Anim. Pract;48: 564-8. anestrus. 2. De Bosschere H, Ducatille R, Tshamala M. PGF2alpha treatment is a practical treatment for (2002): Reprod. Dom. Anim.;3: 152-157. pyometra when reproduction is desired. PGF2alpha 3. Dow C. (1957):Vet Rec;69:1409-15. brings lysis of CL, cervical relaxation which permits 4. Egenvall A, et.al.(2001): J Vet Int.Med.; 15:530-538. drainage of exudate and promotes myometrial 5. England G.(2001): In:Arthur’s Veterinary contraction. These action are depending on the Reproduction and , 8th Edn. Pp.650-654. dosage, route and frequency of administration. PG 6. Ettinger SJ, Feldman, Edward, C. (1995): therapy is not approved for use in , so clients Textbook of Veterinary Internal Medicine. 4th consent must be taken before its use. PGF2alpha edn., W.B. Saunders Company. should be used with caution in case of closed cervix 7. Gandotra VK, Singla VK, Kochhar HPS, Chauhan pyometra because of the chance of uterine rupture. FS, Dwivedi PN.(1994): Indian Vet J;71:816-8. PGF2alpha have been used successfully for 8. Meyers-Wallen VN, Goldschmidt MH, Flickinger GL. treatment of pyometra. Natural prostaglandin @ 10-50 (1986): Prostaglandin F2a treatment of canine mg, 3-5 times daily for 3-7 days have been used. One pyometra;189:1557-61. should start with lower dosage to avoid side effects and 9. Niskanen M, Thrusfield M.V. (1998): Vet.Rec; then slowly increase the dosage to reach higher 143: 493-498. dosage. One should careful for side effects of PG 10. "Pyometra"-The Merck Veterinary Manual treatment. Initially, the bitch may be restless, may begin (2006): Retrieved on 2006-12-14. pacing, hypersalivation, panting, vomition and 11. Smith F.O, (2006): Canine pyometra. defaecation may occur. These reactions subsided Theriogenology;66: 610-612. within 20-60 minutes of treatment. This drug is not 12. Stone EA, et.al.(1988): Journal of American Vet ideal for severely ill animals. Use of synthetic PG such Med Assoc; 193:457-64. as cloprosterol instead natural PG associated with 13. Tsumagari S, et al.(2005): Anim Reprod Sci; 87: 301-8. reduced side effects and prolonged activity resulting in 14. Verstegen.J,et.al.(2008):Theriogenol.;70:364-374.

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