**6. Diagnosis**

Diagnosis of aplasia of the uterine-vaginal segment in dog before puberty or in young nonbreeding dogs is seldom achieved, as clinical evidences are absent. Also, since the ovaries are present in congenital aplasia of the uterine-vaginal segment, normal cyclicity after puberty does not allow suspecting the existence of a defect.

Thus congenital aplasia of the uterine-vaginal is frequently asymptomatic and often missed during routine gynaecological examination, unless side effects associated to failure of genital patency develop in more severe or more prolonged situations. Further, due to unspecific and limited clinical symptoms described, congenital aplasia often requires more than one diagnostic approach to assure success.

Clinical signs or mild illness appears in older bitches, usually associated with fluid retention within the uterus or with other age-related diseases of the genital tract. The later is not taken into consideration herein when describing the diagnostic approach.

In *unilateral uterine aplasia*, few clinical signs develop even in older animals that may be related to the defect. The owner may complain on the female low prolificacy (Romagnoli & Schlafer, 2006; McIntyre et al., 2010) or on the tendency of recurrent abortion in the absence of microbiological or parasitic agents. Vaginoscopy or digital manipulation fails to evidence the primary defect. On ultrasound, the inability to find one uterine horn or the finding of a fibrous threadlike structure on its normal location are the expected findings. Both ovaries are found. Simple X-rays are not useful for diagnosis unless hysterosalpingography (a contrast X-ray) is performed. This would reveal that diffusion of the contrast is limited to one of the uterine horns, particular when using dorso-ventral projections.

A similar situation is found in the *segmental aplasia of the uterine horns*. Unless fluid accumulation in the uterine segment above the atresia becomes important and may be suspected during routine abdominal palpation or ultrasound, the defect remains undetectable in routine consultations. Complains on the female sub-fertility in the presence of regular estrous cycles may exist. The vaginoscopy and digital manipulation are not useful to evidence the primary defect. On ultrasound, segments of the uterus may show uterine distension, uterine walls of variable thickness and areas where the uterus is absent or reduced to a cord-like fibrous structure. However, often the image resembles that of a mucometra/pyometra, except that uterine distension may be limited to one portion of the uterus. On simple X-ray it may be observed dense, non-continuous masses in the normal location of the uterus, frequently in one side of the body, while the remainder parts of the genital tract are not visible. Comparison of these X-rays with those obtained by hysterosalpingography will allow to visualise the occlusion and the existence of a dense pouch cranially.

In the *segmental aplasia of the uterine body and cervix*, the most important symptom for diagnosis is the absence of the typical estrus vulvar discharge in a regularly cycling female (Oh et al., 2005; McIntyre et al., 2010). With time, also abdominal distension associated to uterine distension due to mucometra is found. During abdominal palpation, a uterus increased in size is detected. The vaginoscopy and digital manipulation fail to evidence the primary defect. On ultrasound, bilateral distension of the uterus, thin uterine walls and anechoic or hypoechoic uterine content are commonly found. The distension of the body of

Diagnosis of aplasia of the uterine-vaginal segment in dog before puberty or in young nonbreeding dogs is seldom achieved, as clinical evidences are absent. Also, since the ovaries are present in congenital aplasia of the uterine-vaginal segment, normal cyclicity after

Thus congenital aplasia of the uterine-vaginal is frequently asymptomatic and often missed during routine gynaecological examination, unless side effects associated to failure of genital patency develop in more severe or more prolonged situations. Further, due to unspecific and limited clinical symptoms described, congenital aplasia often requires more

Clinical signs or mild illness appears in older bitches, usually associated with fluid retention within the uterus or with other age-related diseases of the genital tract. The later is not taken

In *unilateral uterine aplasia*, few clinical signs develop even in older animals that may be related to the defect. The owner may complain on the female low prolificacy (Romagnoli & Schlafer, 2006; McIntyre et al., 2010) or on the tendency of recurrent abortion in the absence of microbiological or parasitic agents. Vaginoscopy or digital manipulation fails to evidence the primary defect. On ultrasound, the inability to find one uterine horn or the finding of a fibrous threadlike structure on its normal location are the expected findings. Both ovaries are found. Simple X-rays are not useful for diagnosis unless hysterosalpingography (a contrast X-ray) is performed. This would reveal that diffusion of the contrast is limited to

A similar situation is found in the *segmental aplasia of the uterine horns*. Unless fluid accumulation in the uterine segment above the atresia becomes important and may be suspected during routine abdominal palpation or ultrasound, the defect remains undetectable in routine consultations. Complains on the female sub-fertility in the presence of regular estrous cycles may exist. The vaginoscopy and digital manipulation are not useful to evidence the primary defect. On ultrasound, segments of the uterus may show uterine distension, uterine walls of variable thickness and areas where the uterus is absent or reduced to a cord-like fibrous structure. However, often the image resembles that of a mucometra/pyometra, except that uterine distension may be limited to one portion of the uterus. On simple X-ray it may be observed dense, non-continuous masses in the normal location of the uterus, frequently in one side of the body, while the remainder parts of the genital tract are not visible. Comparison of these X-rays with those obtained by hysterosalpingography will allow to visualise the occlusion and the existence of a dense

In the *segmental aplasia of the uterine body and cervix*, the most important symptom for diagnosis is the absence of the typical estrus vulvar discharge in a regularly cycling female (Oh et al., 2005; McIntyre et al., 2010). With time, also abdominal distension associated to uterine distension due to mucometra is found. During abdominal palpation, a uterus increased in size is detected. The vaginoscopy and digital manipulation fail to evidence the primary defect. On ultrasound, bilateral distension of the uterus, thin uterine walls and anechoic or hypoechoic uterine content are commonly found. The distension of the body of

puberty does not allow suspecting the existence of a defect.

into consideration herein when describing the diagnostic approach.

one of the uterine horns, particular when using dorso-ventral projections.

than one diagnostic approach to assure success.

**6. Diagnosis** 

pouch cranially.

the uterus may be found when cervical agenesis exists. The thickness of the uterine walls is equivalent in the uterine horns and body. Radiographic signs are similar to those of mucometra or pyometra. Hysterosalpingography allows to identify the local of occlusion.

In case of *segmental stenosis of the vagina*, the major symptom is also the absence of the estrus vulvar discharge in a regularly cycling female. However, a large number of females also present clinical history of intermittent, chronic vaginitis or of recurrent, chronic lower urinary tract infection (Kyles et al, 1996; McIntyre et al., 2010), which have not being reported in the aplasia of the uterine body or cervix. Abdominal palpation shows increased size of the uterus that prolongs caudally into the pelvic brim (cranial segment of the vagina). As the vagina dilates more than the uterine body, it can appear as being more ballooned. Also transrectal digital palpation shows the distension of the vagina, that appears as a balloon at the entrance of the pelvic vault. Digital manipulation of the vagina or vaginoscopy usually allows detecting the defect (Kyles et al., 1996; Viehoff & Sjollema, 2003). On the ultrasound bilateral distension of the uterus is observed, as in the segmental aplasia of the uterine body or cervix, which is prolonged beneath the urinary bladder into the pelvic brim. The bladder may be dislocated from its normal position. Ultrasound scans allow to distinguish between the uterine and the vaginal segment, the latter having thinner walls and usually increased dilatation. On simple X-rays cranioventral displacement of the bladder and increased dimensions of the uterus, extending into the vaginal position, are observed. Hysterosalpingography allows the localization of the occlusion.

For the defects originating in the cervix or the vagina, endoscopic visualization of the vaginal cavity and of the cervical morphology may be useful in diagnosis. Furthermore, three-dimension ultrasonography and the magnetic resonance imaging may give useful information on the development of the genital structures even when secondary diseases are absent. However, these techniques are not easy to develop in the current veterinary clinics.

On table 2 we condensed the most relevant information to reach diagnosis.
