A retrospective internet-based survey of French cat breeders about early-age neutering.

OBJECTIVES: The aim of this study was to analyse cat breeders' application of and opinions concerning early-age (ie, <16 weeks old) neutering in cats in France. METHODS: This study analysed a retrospective cohort. A web survey was designed for French cat breeders and was published in June 2017 on the Facebook page of Livre Officiel des Origines Félines, the official feline studbook for purebred cats born in France. The early-age cat neutering habits, opinions and expectations of breeders were collected. RESULTS: A total of 999 breeders returned the questionnaire. Almost half of the breeders (49%) reported consistently requesting neutering of kittens before selling them, 32% claimed that they never requested it and the remaining 19% reported that they inconsistently requested it. When performed, 83% of breeders had kittens neutered at 12 weeks of age; for a large majority of these breeders (94%), the neutering was undertaken on their own initiative. Various reasons for neutering were provided, including the prevention of uncontrolled breeding, short- and long-term welfare benefits for neutered cats, and practical and economic reasons. Reported incidents related to early-age neutering were scarce. Nearly half of breeders who did not apply early-age neutering to their kittens cited a veterinarian's unwillingness to perform the surgery as a cause. CONCLUSIONS AND RELEVANCE: A large majority of surveyed French cat breeders supported early-age neutering that would occur before kittens were sold, most of the time at the age of 3 months. These breeders reported high satisfaction with early-age neutered cats, with a low number of incidents and accidents reported.

Canine placenta: A promising potential source of highly proliferative and immunomodulatory mesenchymal stromal cells?

In veterinary medicine, therapeutic mesenchymal stromal cells (MSC) have been traditionally isolated from adult bone marrow or adipose tissue. Neonatal tissues, normally discarded at birth from all species have become an alternative source of cells for regenerative medicine in the human clinic. These cells have been described as being more primitive, proliferative and immunosuppressive than their adult counterparts. Our objective was to examine if this phenomena holds true in dogs. Little information exists regarding canine neonatal MSC characterisation. In this study, we were able to both isolate, phenotype and assess the differentiation and immunomodulatory properties of MSC from canine foetal adnexa allowing us to compare their characteristics to their more well-known bone marrow (BM) cousins. Neonatal tissues, including amnion (AM), placenta (PL), and umbilical cord matrix (UCM) were collected from 6 canine caesarean sections. Primary cells were expanded in vitro for 5 consecutive passages and their proliferation measured. BM-MSC were isolated from 5 control dogs euthanised from other studies and grown in vitro using an identical protocol. All MSC lines were systematically evaluated for their ability to differentiate into 3 mesodermal lineages (adipocyte, osteocyte and chondrocyte) and phenotyped by cytometry and qPCR. In addition, the enzymatic activity of the key immunomodulatory marker indoleamine 2,3-dioxygenase (IDO) was evaluated for each MSC line. MSC displaying a fibroblastic appearance were successfully grown from all neonatal tissues. PL-MSC exhibited significantly higher proliferation rates than AM- and UCM-MSC (p=0.05). Cytometric analysis showed that all MSC express CD90, CD29, and CD44, while no expression of CD45, CD34 and MHC2 was detected. Molecular profiling showed expression of CD105 and CD73 in all MSC. Low levels of SOX2 mRNA was observed in all MSC, while neither NANOG, nor OCT4 were detected. All MSC differentiate into 3 mesodermal lineages. Following inflammatory stimulation, the activity of the immunomodulatory enzyme IDO was significantly higher in neonatal MSC compared to BM-MSC (p=0.009). Our results show that canine foetal adnexa cells share very similar properties to their adult equivalents but upon stimulation show significantly higher IDO immunomodulatory activity. Further studies will be needed to confirm the potential therapeutic benefits of these cells.

A case report of an ectopic fetus in a cat.

An ectopic fetus was discovered in an 18-month-old uniparous queen that was admitted for an elective ovariectomy. Six months prior she had delivered three healthy kittens. During the preoperative examination, a mass similar in size to a full-term fetus was detected in the abdominal cavity. Ultrasound examination revealed the mass to be an ectopic fetus in the mid-abdominal region. A mummified fetus was removed by laparotomy. No rupture of the uterine wall was visible, but a small necrotic area was present on the left uterine horn, adjacent to the very proximal portion of the uterine horn. The fetus, which was fully developed and covered by a thin membrane, was carefully dissected. Histological examination did not enable us to definitively prove the extra-uterine development of the fetus; however, the ectopic development of the conceptus secondarily expelled into the peritoneal cavity could be assumed.

Structural, metabolic and developmental evaluation of ovulated rabbit oocytes before and after cryopreservation by vitrification and slow freezing.

The cryopreservation of oocytes is valuable for the preservation of women's fertility and might also be an interesting tool to preserve animal genetic biodiversity but it is not often used because of the very poor fertility recovered after thawing, especially in rabbit species. The objective of our study was to evaluate the effect of slow-freezing and vitrification on the structural integrity of ovulated rabbit oocytes, their ATP contents, and their developmental competence. Results show that, whatever the method is used, cryopreservation has a dramatic effect on the metabolic integrity, the structural integrity, and the developmental ability of the oocytes. Vitrification and slow freezing both impair the rabbit oocytes viability after thawing but the processes act differently. Further studies are needed to improve the cryopreservation techniques in rabbit species. Moreover, we underlined that morphology and maintenance of the structural integrity of the oocytes are not suitable enough to assess the potential for further development of cryopreserved M(II) oocytes. The assessment of ATP metabolism allows efficient evaluation of the viability of the frozen or vitrified oocytes. It should be used in addition to parthenogenesis to better assess the potential for further development.

Isolation, culture and characteristics of epididymal epithelial cells from adult cats.

A tissue-culture system in which cells retain defined ultrastructural and functional characteristics was established to provide a basis for functional investigations of the epididymal duct in the cat. A widely used culture protocol for rat epididymal epithelium was used as a starting point and subsequently modified. The cellular population of the cat's epididymal epithelium was isolated by successive collagenase and trypsin digestion. A high yield of isolated cells obtained with good viability, were cultured in DMEM/F12 medium supplemented with foetal bovine serum, in absence or in presence of additional dihydrotestosterone (1 nM). The plated primary cultures reached confluence within 5-8 days, producing a monolayer of cohesive cells. Samples taken after 6 days in culture were processed for transmission and scanning electron microscopies. Immunocytochemical staining was used to estimate the purity of the epithelial cell population in the monolayers. The cell cultures displayed several functional traits of in vivo epithelia, including [35S] hypotaurine and [35S] taurine production. These results demonstrate that primary cultures of epididymal epithelial cells isolated from sexually mature cats maintain several differentiated characteristics of the intact organ and therefore provide a valuable system for the study of epididymal epithelial cell functions, metabolic activities and their regulation in cats.