Transcervical artificial insemination in dogs and cats: review of the technique and practical aspects.

The technique of transcervical catheterization for artificial insemination has gained practical importance over the last 3 and 1 decades in bitches and queens, respectively. The vagina of both species has a thickening of the dorsal aspect called dorsal medial fold, which restricts the lumen of the paracervix, making catheterization of the cervix difficult both with manual and endoscopic techniques. Manual catheters have been used initially in the bitch and are now gradually being replaced by rigid endoscopy through the adaptation of human cystoscopes and ureteroscopes. Cystoscopes provide excellent imaging of the vagina, but cervical catheterization is more difficult due to the oblique 30° viewing angle of its telescope and may not be long enough to catheterize large size bitches. Ureteroscopes allow an acceptable view of the vaginal mucosa and offer advantages such as the possibility to catheterize the cervix of bitches of all body sizes, manipulate the cervical tubercle when the external cervical os is not visible, offer a better visualization of the cervix using the shunt (a large Foley catheter which allows insufflation and distention of the vagina). Feline cervical catheterization has been achieved with three different types of catheters; the last one, developed following careful anatomical studies of how the feline vaginal lumen changes during estrus, allows cervical catheterization thanks to digital manipulation of the cervix through the rectum.

Benign placental mass with fetal growth retardation in a bull mastiff.

A 4-year-old bull mastiff presented due to premature labour. The referring veterinarian elected to perform a caesarian delivery and at the time of surgery a 4×4×2 cm round, smooth, red to tan, lobulated soft mass was identified attached to the allantoic surface of the zonary placenta of one pup. Microscopically, this mass was composed of loosely arranged confluent undulating cords of polygonal to columnar epithelioid cells separated by a fine fibrovascular stroma resembling the placental labyrinth. The labyrinthine structure and epithelioid nature of the cells suggested that the mass was of trophoblastic origin. Due to the non-invasive nature of the mass and relatively low mitotic activity, this proliferative trophoblastic mass was considered to be benign. The absence of morphological features supporting malignant behaviour and the recapitulation of the normal labyrinthine architecture led to the diagnosis of a trophoblastic hamartoma. To the authors' knowledge this is the first report of a placental hamartoma in the dog.

Histopathologic and gross effects of testicular biopsy in the dog.

Eighty-one mixed breed intact male dogs were divided into three groups: Group 1 = left testicle biopsied by Trucut needle method (n=36); Group 2 = left testicle biopsied by Incisional method (n = 39); Group 3 = not biopsied (n = 6). The dogs were castrated 1 to 36 d following biopsy. The biopsy specimens and both testicles were examined for gross and histologic lesions. There was no effect of biopsy on testicle circumference. There was a positive correlation (r(2) = 0.93) between testicular circumference and occurrence of lesions. Incisional biopsies induced more gross lesions (67 vs 33%), and more histologic lesions (135 vs 43). The histologic lesions included hypospermatogenesis, coagulation necrosis, tubular degeneration, interstitial fibrosis and inflammation. In addition, the lesions observed in Incisional biopsy specimens were of greater severity and incidence than Trucut biopsy specimens (87 vs 35%). It was concluded that Incisional biopsy induced an increase in frequency and severity of lesions compared with Trucut biopsy of the canine testicle.