# Uterine Infections in the Bitch: Diagnosis and Management ## Key Takeaways - Uterine infections in bitches range from postpartum metritis to life-threatening cystic endometrial hyperplasia-pyometra complex, with pathophysiology driven by hormonal priming (progesterone and estrogen) creating a permissive environment for bacterial colonization, primarily by *Escherichia coli*. - Diagnostic workup relies on signalment, history, clinicopathologic findings (CBC, biochemistry panel), and abdominal ultrasound, which is crucial for identifying fluid-filled uterine horns and assessing uterine wall integrity. - Medical management is reserved for stable, open-cervix pyometra cases in breeding stock without sepsis, utilizing prostaglandin F2α analogues and dopamine agonists, while surgical ovariohysterectomy is indicated for closed-cervix pyometra, sepsis, uterine rupture, or non-breeding animals. - Prognostic indicators for systemic involvement include white blood cell count, band neutrophil proportion, serum creatinine, and blood glucose, with serial monitoring of vital signs, laboratory parameters, and ultrasound findings essential for assessing treatment response. - Post-treatment monitoring for medical cases includes ultrasound rechecks at 2 and 4 weeks, with breeding considered at the next estrus, while surgical candidates require careful pre-anesthetic stabilization, particularly those with signs of sepsis or peritonitis. - Complications such as sepsis, uterine rupture, and persistent renal compromise necessitate prompt recognition through serial monitoring of perfusion parameters, lactate levels, and renal function, guiding escalation to emergency surgical intervention or specialized referral. --- Uterine infections in the bitch span a clinical spectrum from postpartum metritis to the life-threatening cystic endometrial hyperplasia-pyometra complex. This article provides a diagnostic and therapeutic framework for the practicing veterinarian, covering pathophysiology, patient assessment, medical stabilization, and the decision between medical and surgical management. The content assumes familiarity with canine reproductive physiology and routine surgical technique. The central clinical challenge is not identifying the infected uterus, but determining which patient can be managed medically, which requires ovariohysterectomy, and how to stabilize the surgical candidate before anesthesia. This article addresses those decisions directly, with attention to the evidence base where it exists and explicit acknowledgment where it does not. Companion articles on dystocia management and related reproductive conditions are referenced separately. ## At a Glance | Parameter | Clinical Consideration | |---|---| | Primary differentials | Pyometra (open or closed), postpartum metritis, mucometra, hydrometra, pregnancy | | Key diagnostic tests | Complete blood count, biochemistry panel, abdominal ultrasound, vaginal cytology, aerobic culture | | Ultrasound findings | Fluid-filled uterine horns, thickened or thin-walled uterus, ovarian remnants, fetal remnants | | Medical therapy candidates | Open-cervix pyometra, stable perfusion, no evidence of sepsis, breeding stock | | Surgical therapy candidates | Closed-cervix pyometra, septic peritonitis, uterine rupture, failed medical therapy, non-breeding animals | | Prognostic indicators | White blood cell count, band neutrophil proportion, serum creatinine, blood glucose, total protein | | Post-treatment monitoring | Clinical signs, ultrasound recheck at 2 and 4 weeks, breeding at next estrus | ## Pathophysiology of Canine Uterine Infection The canine uterus resists infection through multiple innate barriers, including the cervix, the endometrial epithelial surface, and local mucosal immunity. These defenses fail when hormonal priming creates a permissive environment. Progesterone promotes endometrial glandular secretion, reduces myometrial contractility, and suppresses local immune responses, while estrogen sensitizes the endometrium to progesterone's effects. The result is the cystic endometrial hyperplasia-pyometra complex, a disease of the luteal phase in intact bitches, typically recognized 2 to 8 weeks after estrus. Bacterial colonization follows the breakdown of mucosal defenses. The ascending route predominates, with organizms from the vaginal flora gaining access when the cervix relaxes during estrus or parturition. *Escherichia coli* is the most frequently isolated pathogen, followed by *Staphylococcus* spp., *Streptococcus* spp., and various anaerobes. The mechanisms by which bacteria establish endometrial infection and cause tissue damage have been studied most thoroughly in cattle, where *E. coli* and *Trueperella pyogenes* are the dominant pathogens. In that species, endometrial cells recognize bacterial components through Toll-like receptors, particularly TLR4 for lipopolysaccharide, triggering cytokine and chemokine secretion that recruits neutrophils and macrophages. Bacterial toxins, including cholesterol-dependent cytolysins, cause direct endometrial cell death. These same innate immune pathways operate in the bitch, although the specific bacterial species and their virulence factors differ. The comparative literature on [bacterial mechanisms of endometrial disease and infertility](https://pubmed.ncbi.nlm.nih.gov/26952747/) provides a useful framework for understanding why some infections resolve and others progress to systemic illness. The transition from localized endometrial infection to systemic disease depends on bacterial load, virulence, and host immune competence. In closed-cervix pyometra, the uterus becomes a distended, pus-filled sac with compromised blood flow to the endometrium. Bacteria and their toxins translocate across the thinned uterine wall into the peritoneal cavity and bloodstream. The resulting systemic inflammatory response syndrome can progress to sepsis, endotoxemia, and multiple organ dysfunction. This progression explains the classic laboratory abnormalities: leukocytosis with a left shift, or leukopenia in severe cases, azotemia from prerenal and renal causes, and hyperglobulinemia from chronic antigenic stimulation. ## Distinguishing Pyometra from Metritis Pyometra and metritis share a common endpoint, uterine infection, but differ in timing, inciting cause, and clinical trajectory. Pyometra develops during the luteal phase in nonpregnant bitches, often weeks after a silent or unobserved estrus. Metritis occurs within days of parturition, after abortion, or following retained fetal membranes. The distinction matters for prognosis and management. Postpartum metritis often responds to medical therapy alone because the cervix is typically patent and the underlying hormonal milieu differs. Pyometra, particularly the closed-cervix form, frequently requires surgical intervention. The postpartum uterus is vulnerable for reasons that parallel the bovine model of [postpartum uterine infection](https://pubmed.ncbi.nlm.nih.gov/18280065/). The disrupted endometrial surface, retained lochia, and devitalized tissue provide a culture medium for bacteria introduced during parturition or from the lower reproductive tract. Involution normally clears these contaminants within weeks, but delayed involution, retained placentas, or obstetrical trauma can allow infection to establish. Metritis in the bitch is less commonly reported than in cattle, where uterine disease affects a large proportion of dairy animals after calving, but the clinical approach to the individual patient follows the same principles: identify the infection, assess systemic involvement, and support uterine clearance. ## Diagnostic Reasoning and Imaging The diagnostic workup begins with signalment and history. Pyometra should be suspected in any intact bitch presenting with polyuria, polydipsia, lethargy, vomiting, or inappetence, particularly if there is a vulvar discharge. The absence of discharge does not exclude the diagnosis, as closed-cervix pyometra may present with abdominal distension and no visible vulvar signs. Abdominal ultrasound is the imaging modality of choice. The normal canine uterus is difficult to identify sonographically, so the presence of fluid-filled, tubular structures dorsal to the bladder is highly suggestive of uterine disease. The character of the fluid, the thickness of the uterine wall, and the presence of ovarian remnants should be assessed. Ultrasound also permits evaluation of the kidneys, bladder, and other abdominal organs for concurrent disease. Clinicopathologic testing complements imaging. A complete blood count may reveal neutrophilia with a left shift, toxic neutrophils, or leukopenia. Serum biochemistry often shows azotemia, which in pyometra reflects both prerenal dehydration and renal injury from immune complex deposition. Hyperglobulinemia and hypoalbuminemia are common. Urinalysis may demonstrate bacteriuria, proteinuria, or isosthenuria. Blood culture is indicated in patients with suspected sepsis, although results are often negative due to prior antibiotic administration. Vaginal cytology can confirm the stage of the estrous cycle and may show degenerate neutrophils and bacteria, but it does not distinguish pyometra from vaginitis or metritis. Aerobic culture of the uterine contents is best obtained at surgery or during medical therapy via guarded transcervical catheterization, which requires specialized equipment and is not routinely available in general practice. The Society for Theriogenology provides [professional resources on reproductive health management](https://www.therio.org/) that include updated guidance on diagnostic techniques and therapeutic protocols for canine uterine disease. Practitioners should consult these resources alongside standard references such as the [MSD Veterinary Manual](https://www.msdvetmanual.com/) for current recommendations on imaging criteria and treatment algorithms. ## Diagnostic Confirmation and Laboratory Assessment When imaging findings support a presumptive uterine infection, the next step is laboratory confirmation and severity staging. Complete blood count frequently reveals a mature neutrophilia with a left shift in pyometra, although the absence of leukocytosis does not exclude the diagnosis. Serum biochemistry should include creatinine, urea, glucose, and electrolytes, with particular attention to total protein and albumin. Azotemia in the bitch with pyometra is often prerenal from dehydration, but it can reflect renal compromise from pre-existing disease or immune complex deposition. Vaginal cytology is of limited value in diagnosing pyometra because the cervix is typically closed and vaginal discharge may be absent. When discharge is present, cytology shows degenerate neutrophils and mixed bacteria, but this finding does not distinguish metritis from vaginitis. Bacterial culture of the cranial vagina is poorly predictive of uterine pathogens and should not guide antimicrobial selection. Uterine culture is best obtained at ovariohysterectomy or by transcervical catheterization where this technique is available. The most commonly isolated organizm is *Escherichia coli*, followed by *Streptococcus* spp., *Staphylococcus* spp., and anaerobes. As in other species, the uterine disease microbiome is more complex than traditional culture suggests, and the causative role of individual isolates is not always straightforward [Mechanisms linking bacterial infections of the bovine endometrium to disease and infertility](https://pubmed.ncbi.nlm.nih.gov/26952747/). Antimicrobial susceptibility testing is warranted when culture is performed, but empirical therapy should not be delayed in the unstable patient. Ultrasonographic findings that support a diagnosis of pyometra include a distended, fluid-filled uterus with hyperechoic contents and a thickened wall. The distinction between pyometra and hydrometra or mucometra can be difficult on imaging alone, and the clinical context, particularly the presence of systemic illness, is the deciding factor. In the postpartum bitch with metritis, the uterus is enlarged and the uterine wall is thickened, with variable intraluminal fluid. The presence of fetal membranes or retained fetuses should be assessed carefully, as these require specific management. ## Medical versus Surgical Decision-Making The decision between ovariohysterectomy and medical management rests on several factors: the bitch's reproductive value, her cardiovascular stability, the presence of ovarian remnant or stump pyometra, and the owner's willingness to accept the risks of recurrence. Open-cervix pyometra with mild systemic signs can be managed medically in a breeding bitch, but closed-cervix pyometra with sepsis is a surgical emergency. Ovariohysterectomy is curative and eliminates the risk of recurrence. It is the treatment of choice for the non-breeding bitch, for any animal with evidence of septic peritonitis or uterine rupture, and for cases that fail to respond to medical therapy within 48 hours. The procedure is technically straightforward in most cases, but the surgeon must handle the friable, distended uterus gently to avoid rupture and peritoneal contamination. Medical management is appropriate for the reproductively valuable bitch with an open cervix, no evidence of sepsis, and normal or near-normal renal function. Prostaglandin F2 alpha analogues and dopamine agonists are the mainstays of medical therapy. The response to treatment is monitored by resolution of vaginal discharge, reduction in uterine diameter on ultrasound, and improvement in systemic parameters. Medical management carries a recurrence risk that is reported to be substantial, and the owner must understand that future estrous cycles may be accompanied by recurrent infection. The Society for Theriogenology provides professional resources on reproductive health management that include current guidance on medical protocols and case selection [Society for Theriogenology resources](https://www.therio.org/). Current formularies and label references must be consulted for dosing and contraindications, as protocols vary by jurisdiction and product availability. ## Treatment Algorithm for Pyometra | Patient Category | Recommended Approach | Rationale | |---|---|---| | Non-breeding bitch, any cervical status | Ovariohysterectomy after stabilization | Curative, eliminates recurrence risk | | Breeding bitch, open cervix, stable | Medical management with prostaglandin and dopamine agonist | Preserves fertility, requires owner compliance | | Breeding bitch, closed cervix, stable | Medical management with intensive monitoring, or surgery if no response in 48 hours | Closed cervix carries higher risk of uterine rupture and sepsis | | Any bitch with sepsis, rupture, or peritonitis | Emergency ovariohysterectomy after fluid resuscitation | Source control is life-saving | | Stump pyometra or ovarian remnant | Surgical exploration and removal of remnant tissue | Medical therapy is rarely curative | ## Metritis Management in the Postpartum Bitch Metritis in the postpartum bitch is managed differently from pyometra because the cervix is typically patent and the primary goal is to eliminate infection while preserving the dam's ability to nurse. Broad-spectrum antimicrobial therapy is the foundation of treatment. The choice of agent should cover Gram-negative and anaerobic organizms, and the route of administration depends on the severity of systemic signs. Fluid therapy and nutritional support are critical in the anorexic, febrile bitch. The puppies should be removed from the dam if she is systemically ill, and hand-rearing or cross-fostering should be arranged. The decision to return the puppies depends on the dam's clinical response and her willingness to accept them. Uterine evacuation can be facilitated by the administration of oxytocin or prostaglandins, but this is not without risk. The uterine wall in metritis is friable and atonic, and vigorous contraction could predispose to rupture. The use of ecbolic agents should be reserved for cases with confirmed retained fetal membranes or fetuses, and the response should be monitored ultrasonographically. ## Monitoring Parameters and Documentation Serial assessment is essential in both medical and surgical cases. The following parameters should be tracked at defined intervals: | Parameter | Frequency | What It Detects | |---|---|---| | Rectal temperature | Every 6 to 8 hours | Persistent fever indicates inadequate source control or antimicrobial failure | | Mucous membrane color and capillary refill time | Every 6 to 8 hours | Perfusion status and progression to shock | | Vaginal discharge volume and character | Every 12 hours | Resolution or worsening of infection | | Uterine diameter on ultrasound | Every 24 to 48 hours in medical cases | Response to medical therapy | | Creatinine and urea | Every 24 hours until normalized | Renal recovery in azotemic patients | | Packed cell volume and total protein | Every 24 hours | Hemoconcentration, blood loss, or protein loss | | White blood cell count | Every 24 to 48 hours | Resolution of leukocytosis or development of leukopenia | Documentation should include the initial diagnostic findings, the rationale for the chosen treatment path, and the response to therapy at each reassessment. In medical cases, the owner should be given a written plan that includes the expected timeline for response, the signs that warrant immediate re-evaluation, and the long-term risk of recurrence. In surgical cases, the operative findings, including the presence of uterine rupture, peritonitis, or ovarian remnants, should be recorded in the medical record. The evidence base for canine uterine infection management draws heavily on comparative reproductive immunology. The mechanisms of endometrial inflammation, the role of Toll-like receptor signaling, and the impact of infection on ovarian function are well characterized in cattle and are broadly applicable to the bitch [Defining postpartum uterine disease and the mechanisms of infection and immunity in the female reproductive tract in cattle](https://pubmed.ncbi.nlm.nih.gov/19439727/). However, the clinician should recognize that species differences in anatomy, hormonal control, and pathogen prevalence mean that direct extrapolation is not always valid. ## Complications and Failure Modes Uterine infection in the bitch can progress through several recognized complications, each with distinct early warning signs. Sepsis and systemic inflammatory response syndrome represent the most immediate threats in pyometra, particularly with closed-cervix disease. Serial assessment of perfusion parameters, including mucous membrane color, capillary refill time, heart rate, and blood pressure, identifies deterioration before overt shock develops. Serial lactate measurement provides a quantitative trend that is more informative than a single value. Uterine rupture with secondary peritonitis occurs most commonly in closed pyometra when the distended uterine wall becomes ischemic and necrotic. Early detection depends on recognizing progressive abdominal pain, worsening systemic signs despite fluid therapy, and imaging findings of free peritoneal fluid with a fluid-filled uterus that appears decompressed. Abdominocentesis with cytology and bacterial culture confirms the diagnosis. Peritoneal fluid with degenerate neutrophils and intracellular bacteria mandates immediate surgical exploration. Renal compromise secondary to immune complex deposition and glomerulonephritis can persist after successful treatment. Serial creatinine and urine protein to creatinine ratio assessment at two to four weeks post-treatment identifies persistent renal injury. Azotaemia present at initial presentation that fails to improve within 48 to 72 hours of fluid therapy warrants further investigation. | Observation | Likely cause | Discriminating check | |---|---|---| | Worsening lethargy despite antibiotics | Sepsis, uterine rupture, or resistant organizm | Serial lactate, abdominocentesis, blood culture | | Persistent vaginal discharge after surgery | Stump pyometra, retained ovarian tissue, or infection | Ultrasonography of the uterine stump, progesterone assay | | Recurrent pyometra within months | Stump pyometra or retained ovarian tissue | Ultrasonography, progesterone or oestradiol assay | | Post-treatment infertility | Endometritis, adhesions, or ovarian pathology | Vaginal cytology, uterine culture, ultrasonography | | Polyuria and polydipsia after recovery | Renal compromise | Serial creatinine, urine specific gravity, proteinuria | ## Common Clinical Errors The most frequent error in managing open-cervix pyometra is delaying surgery while attempting medical therapy in a bitch that is systemically unwell. Patient selection for medical management requires strict criteria: open cervix, no systemic illness, normal renal function, and a breeding purpose that justifies the risk. A bitch with tachycardia, poor perfusion, or azotaemia requires surgery regardless of cervical patency. Failure to distinguish pyometra from hydrometra or mucometra leads to inappropriate antibiotic use and false reassurance. Ultrasonographic findings overlap considerably. The discriminating features are systemic signs, neutrophilia with left shift, and vaginal discharge. When imaging is equivocal, cytology of vaginal or uterine fluid showing degenerate neutrophils and bacteria supports infection. In metritis cases, a common error is attributing postpartum illness to metritis without ruling out other sources of sepsis. Retained fetal membranes, mastitis, and uterine rupture can coexist. A complete physical examination including mammary assessment and abdominal palpation, combined with imaging, prevents a narrowed diagnostic focus. Another recurring error is discontinuing antibiotics based on clinical improvement instead of documented resolution. Clinical signs improve before bacterial clearance is complete. Repeat imaging and, where indicated, culture should guide the duration of therapy. ## Evidence Limitations and Expert Divergence The evidence base for canine uterine infection draws heavily on extrapolation from bovine studies. Mechanisms of endometrial inflammation, Toll-like receptor signaling, and the role of bacterial lipopolysaccharide in ovarian dysfunction are well characterized in cattle [Mechanisms linking bacterial infections of the bovine endometrium to disease and infertility](https://pubmed.ncbi.nlm.nih.gov/26952747/) [Defining postpartum uterine disease and the mechanisms of infection and immunity in the female reproductive tract in cattle](https://pubmed.ncbi.nlm.nih.gov/19439727/). Whether these mechanisms translate directly to the bitch remains uncertain, particularly regarding the timing of ovarian recovery after infection. Expert opinion diverges on several practical points. The role of ovariohysterectomy versus medical management for open-cervix pyometra in breeding bitches remains contested. Published protocols vary in antibiotic selection, duration, and the use of prostaglandins or dopamine agonists. No large prospective trials compare outcomes. The optimal timing for breeding after medical management is likewise unresolved, with recommendations ranging from the next oestrus to skipping one cycle. The significance of subclinical endometritis in the bitch is poorly defined. In cattle, persistence of neutrophils in the uterine lumen is associated with infertility [Postpartum uterine infection in cattle](https://pubmed.ncbi.nlm.nih.gov/18280065/). The analogous condition in the bitch, and its impact on conception, lacks validated diagnostic criteria. Uterine culture results must be interpreted cautiously, as contamination from the vagina and cervix is common. ## Referral and Escalation Referral to a specialist in theriogenology or small animal internal medicine is appropriate when medical management of pyometra is contemplated in a valuable breeding animal, when the diagnosis remains uncertain after imaging and laboratory assessment, or when the bitch fails to respond to initial therapy within 48 hours. Specialist ultrasonography may identify ovarian remnants or uterine stump pathology that general practice imaging has missed. Laboratory involvement extends beyond routine hematology and biochemistry. Aerobic and anaerobic culture with susceptibility testing of uterine contents, obtained at surgery or by guarded swab, guides antibiotic selection when initial therapy fails. Histopathology of excised uterine tissue confirms the diagnosis and identifies concurrent pathology such as cystic endometrial hyperplasia or neoplasia. Regulatory reporting obligations vary by jurisdiction. The [WOAH terrestrial animal health standards](https://www.woah.org/en/what-we-do/standards/codes-and-manuals/terrestrial-code-online-access/) address notifiable reproductive diseases, although canine pyometra and metritis are not typically reportable. Brucellosis, which can cause abortion and infertility in dogs, is reportable in some regions. The [American Veterinary Medical Association practice resources](https://www.avma.org/resources-tools) provide guidance on zoonotic disease considerations and professional obligations. Clinicians should confirm local requirements through their regional veterinary authority. The [Society for Theriogenology resources](https://www.therio.org/) offer specialist guidance on reproductive case management and referral networks. The [MSD Veterinary Manual](https://www.msdvetmanual.com/) provides a general reference for drug selection and supportive care protocols. ## Frequently Asked Questions ### How Should I Manage a Suspected Uterine Infection When Advanced Imaging Is Unavailable? When ultrasonography is not accessible, base the diagnosis on signalment, history, and physical examination. A reproductively intact bitch with polyuria, polydipsia, lethargy, and a palpable tubular abdominal mass has pyometra until proven otherwise. Vaginal cytology can support the diagnosis: degenerative neutrophils and mixed bacteria suggest suppurative inflammation, while the absence of neutrophils in a bitch with systemic signs does not exclude a closed pyometra. Survey radiography may identify a fluid-filled uterus, though it is less sensitive than ultrasound. If imaging is unavailable and the clinical picture is consistent with pyometra, proceed with surgical management after appropriate stabilization instead of delaying treatment for confirmatory testing. ### What Are the Realistic Cost Considerations When Discussing Treatment Options with Owners? Ovariohysterectomy for pyometra is an emergency procedure that typically costs two to three times a routine elective spay because of after-hours care, intensive fluid therapy, and extended hospitalization. Medical management with aglepristone or prostaglandins requires multiple visits, serial ultrasonography, and a subsequent breeding plan, and it carries a recurrence risk that owners must understand before committing to the expense. When cost is a limiting factor, discuss staged options: stabilization with intravenous fluids and antibiotics while the owner arranges financing, or referral to a low-cost surgical program if one exists locally. Be explicit that delaying surgery in a septic bitch increases morbidity and total cost. ### How Does the Diagnostic Approach Differ in a Bitch with Vaginal Discharge but No Systemic Signs? The differential diagnosis expands to include vaginal foreign bodies, vaginitis, urine pooling, and neoplasia. A vaginal speculum examination and digital palpation can localize the source of discharge to the vestibule or vagina instead of the cervix. Cytology of the discharge helps distinguish inflammation from estrus smears. Ultrasonography remains the most useful test: measure endometrial thickness, assess for intraluminal fluid, and evaluate ovarian structures. A bitch with a normal uterus on ultrasound and purulent vaginal discharge is more likely to have vaginitis or a vaginal anomaly than endometritis. If the uterus appears normal but discharge persists, consider vaginoscopy and bacterial culture of the cranial vagina under aseptic technique. ### What Should I Document in the Medical Record for a Pyometra Case? Record the reproductive history, including last estrus date, parity, and any prior progesterone exposure. Document the physical examination findings systematically, including temperature, heart rate, respiratory rate, mucous membrane color, and abdominal palpation findings. Record the diagnostic plan and results: complete blood count, biochemistry panel, urinalysis, and imaging findings with measurements. For surgical cases, document the gross appearance of the uterus, ovarian status, and whether the cervix was patent. Note the antibiotic chosen, the rationale, and the planned duration. Finally, record the client communication, including the prognosis, recurrence risk if the uterus was preserved, and financial estimates provided. ### How Should I Counsel an Owner Who Wants to Breed the Bitch After Medical Management? Explain that medical management preserves breeding potential but carries a substantial recurrence risk, with some studies reporting recurrence in up to a quarter of bitches in subsequent estrous cycles. Recommend breeding at the first post-treatment estrus if the bitch is otherwise a good breeding candidate, because the risk of recurrence increases with each cycle. Advise a complete breeding soundness evaluation before mating, including vaginal cytology and progesterone monitoring to time breeding accurately. Discuss the option of surgical management after the desired litters are produced. Refer the owner to a theriogenologist for advanced reproductive planning, including the possibility of transcervical insemination or surgical embryo transfer if uterine disease compromises fertility. ### When Should I Refer a Pyometra Case to a Specialist or Emergency Facility? Refer when the bitch is hemodynamically unstable despite initial fluid resuscitation, when severe comorbidities such as cardiac disease or renal failure complicate anesthetic management, or when the clinician lacks experience with the surgical approach. Refer also when the diagnosis is uncertain and advanced imaging or endoscopy is needed to rule out other causes of abdominal effusion or vaginal discharge. A specialist in theriogenology or a board-certified surgeon can manage complex cases, including uterine stump pyometra or concurrent ovarian pathology. If the bitch is a valuable breeding animal and medical management is being considered, referral to a theriogenologist is appropriate before committing to a treatment plan. The [Society for Theriogenology](https://www.therio.org/) maintains a directory of diplomates for client referral. ## Related Clinical & Scientific Guides * [Diagnostic Approach to Canine Infertility in the Bitch](/knowledge/veterinary-medicine/theriogenology/diagnostic-approach-to-canine-infertility-in-the-bitch) * [Canine Neonatal Resuscitation: Protocol and Monitoring](/knowledge/veterinary-medicine/theriogenology/canine-neonatal-resuscitation-protocol-monitoring) * [Equine Breeding Soundness Examination of the Stallion](/knowledge/veterinary-medicine/theriogenology/equine-breeding-soundness-examination-of-the-stallion) ## References and Further Reading - [Mechanisms linking bacterial infections of the bovine endometrium to disease and infertility.](https://pubmed.ncbi.nlm.nih.gov/26952747/). 2016. - [Human parasitic protozoan infection to infertility: a systematic review.](https://pubmed.ncbi.nlm.nih.gov/26573517/). 2016. - [Defining postpartum uterine disease and the mechanisms of infection and immunity in the female reproductive tract in cattle.](https://pubmed.ncbi.nlm.nih.gov/19439727/). 2009. - [Postpartum uterine infection in cattle.](https://pubmed.ncbi.nlm.nih.gov/18280065/). 2008. - [Infectious causes of reproductive loss in camelids.](https://pubmed.ncbi.nlm.nih.gov/16697037/). 2006. - [Targeting regulatory T cells to improve vaccine immunogenicity in early life.](https://pubmed.ncbi.nlm.nih.gov/25309517/). 2014. - [Society for Theriogenology Resources](https://www.therio.org/). Society for Theriogenology. - [MSD Veterinary Manual, Professional Edition](https://www.msdvetmanual.com/). MSD Veterinary Manual. - [American Veterinary Medical Association Practice Resources](https://www.avma.org/resources-tools). American Veterinary Medical Association. ## Related Articles - [Dystocia Management in the Bitch: Decision-Making and Intervention](/knowledge/veterinary-medicine/theriogenology/dystocia-management-in-the-bitch-decision-making-and-intervention) - [Caprine Brucellosis: Diagnosis and Management](/knowledge/veterinary-medicine/theriogenology/caprine-brucellosis-diagnosis-and-management) - [Equine Brucellosis: Diagnosis and Management](/knowledge/veterinary-medicine/theriogenology/equine-brucellosis-diagnosis-and-management) - [Feline Dystocia: Diagnosis and Management](/knowledge/veterinary-medicine/theriogenology/feline-dystocia-diagnosis-and-management) - [Ovine Brucellosis: Diagnosis and Management](/knowledge/veterinary-medicine/theriogenology/ovine-brucellosis-diagnosis-and-management) > This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.