A 3-year-old 44.7-kg spayed female Boxer was referred for evaluation because of acute hind limb weakness, difficulty walking, and hyporexia. The owners reported initially noticing that the dog appeared uncomfortable when getting up from lying down and that the dog seemed unsteady on its hind limbs when standing. The referring veterinarian had initiated treatment with deracoxib (1.7 mg/kg, PO, q 24 h) for signs of pain and cephalexin (11.2 mg/kg, PO, q 12 h) for a concurrent dermatologic infection. The dog had progressive weakness and 3 days later was referred for further evaluation.
A 1-year-old externally sexually intact female Great Dane was referred for further evaluation of abnormal and underdeveloped internal reproductive organs.
Physical examination findings included a cranioventrally displaced vulva and a grade 2/6 left apical systolic heart murmur. No uterus or ovaries were identified during abdominal ultrasonography. Computed tomography with retrograde vaginourethrography revealed an underdeveloped uterus and possible left intra-abdominal gonad. Karyotyping revealed mixed sex chromosomes (70% XY and 30% XX). Analysis of a serum sample yielded positive results for anti-Müllerian hormone; other findings included mid range estradiol concentration (48.2 pg/mL [within reference intervals for sexually intact and neutered males and females]), low progesterone concentration (< 0.2 ng/mL [within reference intervals for anestrous females]), and low testosterone concentration (< 20 ng/dL [similar to the expected concentration in neutered males]). Overall, the results of the sex hormone analyses were consistent with findings for either a sexually intact female or a neutered male dog. The dog's cardiac structure and function were echocardiographically normal.
TREATMENT AND OUTCOME
The dog was anesthetized and underwent laparoscopic gonadectomy. The gonads, although abnormal and underdeveloped, were readily identified intraoperatively and successfully removed. On the basis of histologic findings, the removed gonads were confirmed to be rudimentary testicles. The dog recovered from anesthesia and surgery without complications.
Laparoscopic surgery was effective for visualization of abnormal and hypoplastic reproductive organs when abdominal ultrasonography and CT were of limited diagnostic usefulness, and laparoscopic surgery allowed straightforward gonadectomy in a 78,XX/78,XY chimeric dog.