Effects of Surgical Sterilization on Canine and Feline Health and on Society

Antibody fragments targeting the extracellular domain of follicular stimulating hormone receptor for contraception in male dogs and cats

The increased LH levels resulting from the absence of negative feedback after castration has been linked to long-term health issues. A need exists for an alternative contraceptive agent that functions without interfering the LH pathways. This study aimed to develop antibody fragments against the follicular-stimulating hormone receptor (anti-FSHr) using phage-display technology and evaluate its effects on Sertoli cell functions. Phage clones against the extracellular domain of dog and cat FSHr selected from an antibody fragment phagemid library were analyzed for binding kinetics by surface plasmon resonance. Sertoli cells were isolated from testes of adult animals (five dogs and five cats). Efficacy test was performed by treating Sertoli cell cultures (SCCs) with anti-FSHr antibody fragments compared with untreated in triplicates. Expressions of androgen binding protein (ABP), inhibin subunit beta B (IHBB) and vascular endothelial growth factor A (VEGFA) mRNA in SCCs were quantified by RT-qPCR. The results demonstrated that the molecular weight of the purified dog and cat anti-FSHr antibody fragment was 25 kDa and 15 kDa, respectively. Based on protein molecular weight, the antibody fragment of dogs and cats was therefore, so-called single-chain variable fragments (scFv) and nanobody (nb), respectively. The binding affinity with dissociation constant (KD) was 2.32 × 10-7 M and 2.83 × 10-9 M for dog and cat anti-FSHr antibody fragments, respectively. The cross-binding kinetic interactions between the dog anti-FSHr scFv and the cat ECD of FSHr could not be fitted to the curves to determine the binding kinetics. However, the cross-binding affinity KD between the cat anti-FSHr nb and the dog ECD FSHr was 1.75 × 10-4 M. The mRNA expression of ABP, IHBB and VEGFA in SCCs was less (P < 0.05) in both dogs (12.26, 4.07 and 5.11 folds, respectively) and cats (39.53, 14.07 and 20.29 folds, respectively) treated with anti-FSHr antibody fragments, indicating the Sertoli cell functions were suppressed. In conclusion, this study demonstrated the establishment of species-specific antibody fragments against FSHr in SCCs for dogs and cats. The fragment proteins illustrate potential to be developed as non-surgical contraceptive agent targeting FSHr in companion animals.

Enhancing community health: Veterinary services for underserved areas in Costa Rica with a One Health Approach

In underserved areas of Costa Rica, community veterinary services aim to provide comprehensive care for companion animals, covering preventive, therapeutic, and surgical medicine. Emphasizing a One Health approach, our model focuses on animal welfare, health, and public well-being in vulnerable regions. The project's goal is to ensure the overall well-being of animals, people, and the environment by collaboratively addressing animal health issues and recognizing their interconnected impact on optimal health. Limited resources in underprivileged areas, including restricted access to veterinary care for pets, pose challenges to overall health. Despite its global health benefits, the absence of companion animal veterinary care in these regions has been largely overlooked. Our One Health approach not only addresses animal health but also has a significant impact on human and environmental health, economies, and social factors. This innovative strategy is a pioneering effort to tackle complex health issues in Costa Rica.

Canine Pyometra: A Short Review of Current Advances

Pyometra, characterized by the accumulation of purulent exudate in the uterus, is the most prevalent reproductive disease in canines. While the disease often begins with mild local symptoms, it can escalate into peritonitis, sepsis, and multi-organ dysfunction, thereby posing a significant threat to life. Despite the high incidence and recognized significance of canine pyometra, gaps persist in our understanding of its epidemiology, etiology, and pathogenesis. Recent studies have, however, broadened our comprehension of this disease, shedding light on potential new infection sources, etiologies, and the application of clinical predictive biomarkers and new therapeutic protocols. This study aimed to review the current understanding of canine pyometra, with particular emphasis on the latest research concerning its etiology and epidemiology. Furthermore, it addressed key research questions and proposed directions for future investigations into various facets of canine pyometra.

The effect of neuter status on longevity in the Rottweiler dog

Surgical sterilization or neutering of dogs is a commonly performed procedure in veterinary practices in many countries. In recent decades, concerns have been raised regarding possible side effects of neutering, including increased risk of certain neoplastic, musculoskeletal and endocrinological conditions. Considering that age serves as a significant confounding factor for some of these conditions, evaluating longevity statistics could provide valuable insights into the impact of neutering. The aim of this study was to compare longevity between neutered and sexually intact male and female Rottweilers, using electronic patient records collected by the VetCompass Australia database. Male and female Rottweilers neutered before 1 year of age (n = 207) demonstrated an expected lifespan 1.5 years and 1 year shorter, respectively, than their intact counterparts (n = 3085; p < 0.05). Broadening this analysis to include animals neutered before the age of 4.5 years (n = 357) produced similar results.

A biocompatible NIR-II light-responsive nanoknife for permanent male sterilization

Nanomaterial-mediated photothermal therapy (PTT) is a promising strategy for permanent male sterilization owing to its easy operation, rapid heating, minimal invasiveness, and high spatiotemporal controllability. However, the currently available PTT for male sterilization utilizes irradiation sources in the first near-infrared window (NIR-I), which may suffer from incomplete sterilization due to the insufficient penetration depth of NIR-I light. Herein, we developed a facile one-pot hydrothermal synthetic method of cysteine-coated copper sulfide (Cys-CuS) nanosheets for the second NIR window (NIR-II) PTT-mediated permanent male sterilization. In this method, Cys acted not only as a template but also as a sulfur resource in the formation of Cys-CuS nanosheets. The obtained Cys-CuS nanosheets possessed good photothermal properties and satisfied deep-tissue light response capacity under 1064 nm laser exposure. Given this, the permanent male sterilization in vivo was readily achieved by Cys-CuS nanosheets in a rapid manner (only 40 s). To the best of our knowledge, it is the first time that nanomaterial-mediated NIR-II PTT is applied for permanent male sterilization. We believe that the facilely prepared biocompatible Cys-CuS nanosheets can serve as a promising NIR-II light-responsive nanoknife to control the overpopulation of domestic pets and stray animals.

Gold nanoparticle intratesticular injections as a potential animal sterilization tool: Long-term reproductive and toxicological implications

This study aimed to evaluate the gold nanoparticles (AuNPs) animal sterilizing potential after intratesticular injections and long-term adverse reproductive and systemic effects. Adult male Wistar rats were divided into control and gold nanoparticle (AuNPs) groups. The rats received 200µL of saline or AuNPs solution (16µg/mL) on experimental days 1 and 7 (ED1 and ED7). After 150 days, the testicular blood flow was measured, and the rats were mated with females. After mating, male animals were euthanized for histological, cellular, and molecular evaluations. The female fertility indices and fetal development were also recorded. The results indicated increased blood flow in the testes of treated animals. Testes from treated rats had histological abnormalities, shorter seminiferous epithelia, and oxidative stress. Although the sperm concentration was lower in the AuNP-treated rats, there were no alterations in sperm morphology. Animals exposed to AuNPs had decreased male fertility indices, and their offspring had lighter and less efficient placentas. Additionally, the anogenital distance was longer in female fetuses. There were no changes in the histology of the kidney and liver, the lipid profile, and the serum levels of LH, testosterone, AST, ALT, ALP, albumin, and creatinine. The primary systemic effect was an increase in MDA levels in the liver and kidney, with only the liver experiencing an increase in CAT activity. In conclusion, AuNPs have a long-term impact on reproduction with very slight alterations in animal health. The development of reproductive biotechnologies that eliminate germ cells or treat local cancers can benefit from using AuNPs.

A prospective cohort study investigating the peri- and postoperative outcomes following ovariohysterectomy in bitches neutered prepubertally or post-pubertally

The aim of this prospective cohort study was to investigate perioperative and postoperative outcomes for bitches that were neutered at different times in relation to puberty (rather than age). Three hundred and six Labrador and Golden Retriever crossbreed bitches were neutered before (prepubertal neuter [PPN], n = 155) or after puberty (Control, n = 151) by experienced veterinarians at one of four veterinary practices (VP1-4). Data were gathered from veterinarians at the time of neutering and from bitch caregivers for the 14-day period after neutering using purpose-designed questionnaires. PPN bitches had shorter surgery durations than Control bitches (OR = 0.877, 91% CI = 0.800 to 0.961, P = 0.015). Longer surgery durations were reported for bitches that had intraoperative complications (OR = 1.620, 91% CI = 1.397 to 1.879, P < 0.001). Shorter surgery durations were reported for VP1 compared to all other veterinary practices (OR = 1.189 to 1.534, P < 0.001). There was no difference in the number of PPN or Control bitches that had perioperative complications (PPN: 3.9%, n = 6; Control: 7.7%, n = 11) and no bitch had more than one perioperative complication reported. For the 14-day postoperative period, fewer PPN (1.3%, n = 2) compared to Control bitches (8.9%, n = 13) had wound discharge (Chi-square = 11.151, D.F = 1, P = 0.001) or showed inappetence (PPN: 2.9%, n = 4; Control: 17.3%, n = 19, Chi-square = 14.884, D.F. = 1, P < 0.001). There was no difference in the number of PPN and Control bitches that had redness or swelling of the wound (52 PPN, 48 Control), showed attention to the wound (6 PPN, 6 Control), required veterinary attention (25 PPN, 23 Control), or that showed any other unusual behaviours: discomfort (27 PPN, 16 Control), uncharacteristic irritability (2 PPN, 4 Control), or uncharacteristic licking or chewing of parts of the body (15 PPN, 6 Control). Bitches neutered at VP2-4 were more likely to have wound redness or swelling reported than those neutered at VP1 (OR = 3.109 to 4.076, P = 0.003). Future studies should consider the impact of veterinary practice on results. These results for peri and postoperative complications could suggest that prepubertal ovariohysterectomy may be a suitable option for neutering bitches. However, it is recommended that they be interpreted together with evidence relating to the impacts on other factors including behaviour and longer-term health in order to make fully informed decisions.

Identification of Canine Pyometra-Associated Metabolites Using Untargeted Metabolomics

Canine pyometra frequently occurs in middle-aged to older intact bitches, which seriously affects the life of dogs and brings an economic loss to their owners. Hence, finding a key metabolite is very important for the diagnosis and development of a new safe and effective therapy for the disease. In this study, dogs with pyometra were identified by blood examinations, laboratory analyses and diagnostic imaging, and fifteen endometrium tissues of sick dogs with pyometra and fifteen controls were collected and their metabolites were identified utilizing a UHPLC-qTOF-MS-based untargeted metabolomics approach. The results indicated that the elevated inflammatory cells were observed in dogs with pyometra, suggesting that sick dogs suffered systemic inflammation. In the untargeted metabolic profile, 705 ion features in the positive polarity mode and 414 ion features in the negative polarity mode were obtained in endometrium tissues of sick dogs with pyometra, with a total of 275 differential metabolites (173 in positive and 102 in negative polarity modes). Moreover, the multivariate statistical analyses such as PCA and PLS-DA also showed that the metabolites were significantly different between the two groups. Then, these differential metabolites were subjected to pathway analysis using Metaboanalyst 4.0, and Galactose metabolism, cAMP signaling pathway and Glycerophospholipid metabolism were enriched, proving some insights into the metabolic changes during pyometra. Moreover, the receiver operating characteristic curves further confirmed kynurenic acid was expected to be a candidate biomarker of canine pyometra. In conclusion, this study provided a new idea for exploring early diagnosis methods and a safe and effective therapy for canine pyometra.

What Happens in Male Dogs after Treatment with a 4.7 mg Deslorelin Implant? I. Flare up and Downregulation

Simple Summary

Until now, information about the “flare up” and the time to downregulation in male dogs after treatment with a 4.7 mg deslorelin implant is strongly limited, regarding testosterone concentrations, testicular and prostatic volume and semen quality. The aim of this study was to provide detailed insights into these open questions. GnRH and hCG stimulation tests were performed to gain further insights into testicular endocrine function. Seven male beagle dogs were treated with a 4.7 mg deslorelin implant, and three animals were treated with saline, representing the controls. In deslorelin-treated dogs, first basal testosterone concentrations were observed earliest on D7 and latest on D28 after treatment. Infertility—based on the lack of semen or spermatozoa— was diagnosed earliest on D35 and latest on D77. After five months, the treatment was still effective in six dogs but was reversed in one deslorelin-treated dog.

Abstract

Although registered since 2007, knowledge about changes in testosterone concentrations (T), testicular and prostatic volumes (TV, PV) and semen quality, as well as the time point of infertility following treatment with a 4.7 mg deslorelin (DES) slow-release implant, is limited. Therefore, seven sexually mature male dogs were treated with DES (TG); three male dogs treated with saline served as controls (CG). The study assessed local tolerance, TV, PV, semen parameters and T subsequent to GnRH/hCG stimulation in regular intervals. Local tolerance was good. In TG, T was increased right after treatment, but decreased four hours afterwards. Subsequently, TV, PV, semen quality and T decreased over time in TG, but not CG. T was basal (≤0.1 ng/mL) from D28 onwards. Response to GnRH/hCG stimulation was variable, with two TG dogs having increased T post-stimulation on all study days independent of pre-treatment concentrations. A(zoo)spermia in TG was observed from D35–D77 in all seven dogs. Whereas treatment was still effective in six TG dogs five months after implant insertion, it was fully reversed in one dog in terms of T and spermatozoa on the last examination. These results indicate high variation in individual dogs, necessary to consider when advising dog owners.

The Implications of Policies on the Welfare of Free-Roaming Cats in New Zealand

A lack of national legislation for cat management in New Zealand poses challenges for ensuring that practices are consistently humane and effective. In this paper, we review the current cat management policies in New Zealand and the implications they have on the welfare of free-roaming cats (from here on, referred to as 'cats'). Our review demonstrates that there are multiple policy mechanisms used to manage cats in New Zealand for a variety of reasons, including animal welfare, pest management, and nuisance, and that these different policies have both positive and negative implications for cat welfare. We provide context pertaining to New Zealanders' acceptance of current or future laws and regulations and compare the New Zealand policy landscape with other countries, with a particular emphasis on Australia, to identify potential directions and outcomes of increased regulation. We discuss the future of the regulatory environment in New Zealand, including the need to better understand the impact of policies on cats, people, and other animals in urban, rural, and wild spaces. We further discuss the need to better understand the cat-human relationship for future policy decisions and offer a solution based on national cat legislation.

Age of sexual maturity and factors associated with neutering dogs in the UK and the Republic of Ireland

BACKGROUND

Surgical neutering of dogs is common, however the average age that dogs reach sexual maturity, are neutered, and dog owners' attitudes to neutering in the UK and the Republic of Ireland have not been explored in a longitudinal study.

METHODS

Owner-reported data on the timing of the first oestrus, timing of neutering and the reasons given for neutering dogs by 12 and 15 months of age were summarised. Factors associated with neutering at 15 months and factors associated with intention to neuter were quantified using multivariable logistic regression.

RESULTS

At 15 months of age, 90.0% (n = 207/230) of unneutered females had had their first oestrus. By 7, 9, 12 and 15 months of age, 22.1% (n = 131/593), 32.2% (197/593), 45.4% (n = 269/593) and 59.9% (n = 352/593) of dogs were neutered, respectively. Breed purity, dog's source, owners' intentions to neuter and the number of dogs in the household were associated with neuter status at age 15 months. Dog's sex, Kennel Club registration, dog's source, dogs intended to be working dogs and previous dog ownership were associated with intentions to neuter. Preventing puppies was the most common reason for neutering.

CONCLUSION

Understanding factors that shape owners' intentions to neuter can inform owner-vet discussions regarding whether to neuter a dog and the optimal age for doing so.

Effects of short-term administration of melatonin before gonadectomy on oxidative stress, cortisol and sex hormones in male dogs

The aim of this study was to investigate gonadectomy stress, steroid hormones and serotonin in male dogs treated with melatonin before gonadectomy. Twenty-five mixed breed adult dogs were divided into five equal groups. The melatonin and melatonin + gonadectomized groups received melatonin treatment (3 mg/10 Kg, PO, TID) the day before gonadectomy; the gonadectomized and anaesthesia groups did not receive melatonin; and the control group just received the melatonin vehicle. Blood sampling was performed before melatonin administration (day -1) and on days 0 (gonadectomy), 1, 3 and 6 after gonadectomy. Superoxide dismutase and glutathione peroxidase concentrations decreased significantly in gonadectomized dogs compared with dogs treated with melatonin before gonadectomy and intact dogs. Gonadectomy led to a significant decrease in catalase concentration in gonadectomized dogs compared with other study groups. Malondialdehyde levels increased significantly in gonadectomized dogs compared with other groups. Melatonin administration before gonadectomy led to decreased malondialdehyde concentration in gonadectomized and intact dogs compared to the control group. Cortisol concentration increased significantly in gonadectomized dogs compared to the control dogs. Serotonin levels decreased in gonadectomized dogs, but melatonin treatment increased serotonin concentration in gonadectomized and intact dogs. Melatonin treatment before gonadectomy suppressed oxidative stress and the cortisol but increased serotonin level.

Laparoscopic Castration Using Bipolar Forceps vs. Orchiectomy in Dogs: A Comparison of Two Techniques

Simple Summary

Castration of dogs is one of the most often performed surgeries in veterinary medicine. Minimally invasive techniques used in human medicine are now being used in animals. We compared the feasibility and effects on pain and inflammation of a new laparoscopic technique with the classical castration technique. The animals in which the new technique was applied showed less pain and inflammation then the other group. Our results suggest that this is a feasible alternative to classical castration.

Abstract

This paper aimed to study the feasibility of a new laparoscopic castration technique in male dogs, evaluate the pain associated with it, and compare it with the classical orchiectomy. Surgical times, pain scores, blood and salivary cortisol, and CRP were recorded and compared between the two groups. The use of high-frequency bipolar forceps allowed quick and uneventful laparoscopic procedures. The laparoscopic group had significantly lower pain scores, cortisol, and PCR values than the orchiectomy group. No complications were seen in any group. Our results suggest that this laparoscopic castration is a safe and beneficial surgical alternative to traditional orchiectomy in dogs.

Long-term effect of neutering on plasma luteinising hormone concentration in cats

OBJECTIVES

The objectives of this study were to validate a commercially available luteinising hormone (LH) cat ELISA, to determine whether the increases in plasma LH concentration that occur after neutering are maintained throughout cats' lives and if other factors such as calendar seasons in both intact and neutered cats, and neutering age in neutered cats, influence plasma LH concentrations.

METHODS

Stored plasma samples from client-owned cats were used for the measurement of LH concentrations. Clinical data, including age, sex, age at neutering and medical history, were reviewed. Two populations were included in this study: (1) a senior and geriatric cat population (⩾9 years old), including 18 intact and 18 neutered cats matched for age, sex and month of sample collection; and (2) an adult cat population (2-8 years old), including 45 neutered cats. LH concentrations were measured using a commercially available feline ELISA.

RESULTS

Senior and geriatric neutered cats had higher plasma LH concentrations than age-matched intact cats (P <0.001). Calendar season did not influence plasma LH concentrations in the adult (P = 0.727) or senior/geriatric (P = 0.745) cats included in this study. No influence of age at neutering was observed on plasma LH concentrations (P = 0.296).

CONCLUSIONS AND RELEVANCE

Neutering causes a significant long-term increase in LH concentrations in cats and further studies are required to determine the consequences on feline health.

New Prospects in Neutering Male Animals Using Magnetic Nanoparticle Hyperthermia

Controlling populations of free-roaming dogs and cats poses a huge challenge worldwide. Non-surgical neutering strategies for male animals have been long pursued, but the implementation of the procedures developed has remained limited to date. As submitting the testes to high temperatures impairs spermatogenesis, the present study investigated localized application of magnetic nanoparticle hyperthermia (MNH) to the testicles as a potential non-surgical sterilization method for animals. An intratesticular injection of a magnetic fluid composed of manganese-ferrite nanoparticles functionalized with citrate was administered followed by testicle exposure to an alternate magnetic field to generate localized heat. Testicular MNH was highly effective, causing progressive seminiferous tubule degeneration followed by substitution of the parenchyma with stromal tissue and gonadal atrophy, suggesting an irreversible process with few side effects to general animal health.

11 years of regular access to subsidized veterinary services is associated with improved dog health and welfare in remote northern communities

Access to veterinary services can have positive impacts on animal health and welfare, and on human mental and physical health and well-being; however, many communities worldwide lack access to such services. At their request, the 5 communities of the Sahtu Settlement Area, Northwest Territories, Canada, have received annual access to preventive veterinary services through the University of Calgary's Northern Community Health Rotation since 2008. To determine the reach of the program, we conducted a dog census in 2017. We then conducted a chart review of 11 years of dog medical records from 2008 to 2018 to evaluate how the reach of the program, the uptake of veterinary services, and dog population demographics, health and welfare measures changed over the duration of the program. In the chart review, we used either multi-level logistic regression or generalized linear models, to determine how seven variables, including age, sex, breed, body condition, deworming, vaccination, and sterilization status upon clinic entry, changed over the course of program delivery. Our results suggest that program reach, veterinary service uptake, and dog demographic, health and welfare measures improved over time. We observed high rabies vaccination coverage in some communities (48 %-83 % of the dog population) and moderate overall sterilization status (25 %-56 % of the dog population) with female dog sterilization more common than male (75 % of dogs leaving the 2017 clinics, compared to 43 %). Several dog demographic, health, and welfare measures, including age, body condition, and vaccination, deworming, and sterilization status, were significantly better in later years of the program (all p < 0.001). Differences among communities, both in dog population numbers from the 2017 census (40-89 dogs) and in the uptake of veterinary services in 2017 (48 %-83 % of the dog population), were notable. Vaccination uptake was directly related to clinic attendance, but sterilization was impacted by additional factors, including community members' acceptance of the procedure. Some unintended consequences were noted, however, including the potential effect of sterilization on the availability of traditional dog breeds in the communities. Overall, our study findings demonstrate that subsidized veterinary services provided over a regular and extended period of time benefit animal population demographics, health and welfare, and could have positive impacts on human well-being. The framework of community collaboration and long-term commitment developed through this program serves as a model for achieving common health goals among communities in need and veterinary service providers.

Short Term Safety, Immunogenicity, and Reproductive Effects of Combined Vaccination With Anti-GnRH (Gonacon) and Rabies Vaccines in Female Feral Cats

Overpopulation of free-roaming cats is a major problem leading to negative impacts on animal health and welfare, public nuisance, transmission of zoonotic diseases, and well-documented harm to wildlife. Surgical sterilization had failed to provide a practical solution to free-roaming cats' overpopulation under field conditions; therefore, efficient and safe non-surgical immunocontraception methods are aspired. Rabies is a deadly virus that may infect people and animals. However, the safety and efficacy of combined vaccination with anti-GnRH and rabies vaccines in feral cats, which often suffer from disrupted health conditions and experienced high stress level, has never been studied. Therefore, our objective was to examine the short-term safety and efficacy of anti-GnRH vaccine (Gonacon), in combination with rabies vaccine in female feral cats. Mature feral female cats were captured and divided into the following groups: (I) GonaconX1-Rabies: queens vaccinated with both Gonacon and rabies (n = 5); (II) GonaconX2-Rabies: queens vaccinated twice with Gonacon (3 weeks apart) and with Rabies (n = 4); (III) OVx-Rabies: queens ovariohysterectomized and vaccinated with rabies (n = 4); (IV) Intact-Rabies: queens vaccinated against rabies and remained intact (n = 3). Comprehensive veterinary examinations and blood tests were performed every 2 weeks for 14 weeks. Data were analyzed by Repeated-Measures-ANOVA or Fisher-Exact-Test. There were neither systemic nor local adverse reactions at the vaccination sites. Blood count (PCV, TS, RBC, HGB, HCT, WBC) and chemistry (Total protein, Total globulin, Albumin, Urea, Creatinine, Creatine kinase, Bilirubin, GGT, ALT, AST) analyses revealed no differences among groups. There were no differences in serum rabies antibodies titers among groups, and queens kept a protective titer (>0.5 IU/mL) starting at 2–4 weeks after vaccination. Anti-GnRH antibodies were detected in all Gonacon-vaccinated queens, excluding one queen (GonaconX2-Rabies group). Anti-müllerian hormone serum concentrations reduced significantly after ovariohysterectomy, as well as gradually following vaccination with Gonacon, but it remained high in intact queens. Evaluation of vaginal cytology and ovarian histology suggested that reproductive cyclicity was suppressed in Gonacon-vaccinated queens. Our results support the conclusion that in the short term, the combined vaccination with Gonacon and rabies is safe and effective in female feral cats. However, further long-term studies are warranted to test this immunologic regimen in feral cats.

Influence of Gonadectomy on Canine Behavior

Due to the lack of unequivocal scientific evidence, gonadectomy's effects on dogs' behavior are still debated. Since veterinarians differ in their opinion, there may be considerable diversity in the advice received by owners. This study aimed to evaluate the effects of gonadectomy on dog behavior across time. Ninety-six dog owners (48 control dogs and 48 experimental dogs) were interviewed twice (T0 and T1, nine months later) to obtain information about their dog's behavior. No change was found in the eating behavior or weight of dogs of both groups. Compared to T0, at T1, experimental dogs were reported to show less mounting behavior, pull on the leash, and roaming behaviors. Marking behavior did not vary across time for both groups of dogs. A tendency to reduce owner-directed aggression was observed at T1 for experimental male dogs, while no change was observed for male controls. The literature reports conflicting information about the effect of gonadectomy on behavior, suggesting that further studies about this topic should be undertaken.

Indigenous community perspectives on dogs in Northern Canada after 10 years of veterinary services indicates improved animal and human welfare

Access to veterinary services in marginalized communities has important implications for people and animals around the world. Subsidized veterinary services are occasionally provided, however, they are seldom evaluated for their value to stakeholders and overall animal health. In 2017, we evaluated a decade-long veterinary program in four remote communities in the Sahtu Settlement Area of the Northwest Territories, Canada to understand if there were changes in dog husbandry and community perceptions of, and experiences with, dogs since an initial assessment at the beginning of the program in 2008. Using questionnaires and a dog census, we found a significant increase over time in dog health indicators, including the proportion of dogs that had received preventive veterinary care and had been sterilized. We documented significant changes in the described purpose of dogs, husbandry practices, experiences with dogs, and attitudes towards dogs and veterinary services. In 2017, respondents commonly described their dog(s) as companions and as part of their family. However, communities differed in the way dogs were housed and fed and in their attitudes towards dogs and dog-related issues. These inter-community differences are noteworthy as they impact service provision, uptake, and evaluation and must be taken into consideration in order to develop effective programs. Regular program evaluations are critical to check in with stakeholders, to ensure the program is meeting community needs, and to optimize effective use of resources.

Demographics, distribution, ownership and naming patterns of pets presented to a mobile clinic for sterilisation in Namibia

This study analysed the demographics, spatial distribution, ownership and naming patterns of dogs and cats presented to the University of Namibia’s veterinary mobile clinic for sterilisation from small underserved towns around Namibia. The proportional distribution of pets was determined based on species, sex, age, owner gender, town of origin and naming categories. Overall, 84.4% (n = 2909) of the animals presented for sterilisation were dogs and the remainder were cats (15.6%, n = 539). Of the dogs presented for sterilisation, 51.9% (n = 1509) were male and 48.1% (n = 1400) were female. In cats, 51.4% (n = 277) were male, whilst 48.6% (n = 262) were female. Overall, the majority of pets (68.2%) were presented for sterilisation from urban areas than rural areas (31.8%). About 49.8% of men and 24.2% of women that presented pets for sterilisation came from urban areas, whilst 20.1% of the women and 11.7% of the men that presented pets for sterilisation were from rural areas. Of all the pets presented for sterilisation, the majority were male-owned (64%, n = 2206). Pets were mainly presented for sterilisation at < 2 years (41.1%), 2 to < 4 years (32.4%) and 4 to < 6 years (15.4%). The naming of pets was mainly after people (42.4%), circumstances (20.6%) and appearance (15.5%). This community engagement exercise yielded valuable demographic data indicating that pet origin, sex and species and owner gender were important factors in determining the voluntary presentation of pets for sterilisation in the study area.

Neutering in dogs and cats: current scientific evidence and importance of adequate nutritional management

Neutering or spaying is a commonly recommended veterinary procedure. However, veterinarians are often confronted with conflicting findings and differences in concepts regarding practice and proper nutritional management after the procedure. The objective of the present review was to bring to light the most recent literature, summarise it and discuss the findings focusing on the risks and benefits of neutering in dogs and cats, and to determine the appropriate nutritional management for these animals.

Prostatic Neoplasia in the Intact and Castrated Dog: How Dangerous is Castration?

Elective gonadectomy in the dog is a topic of interest for clinicians, pet-owners, and society. Although canine prostatic neoplasia (CPN) has a low incidence (0.35%), reports of an increased risk for castrated dogs attract attention and cause concern in pet-owners. Our aim is to provide professionals and non-professionals with a detailed description of this possible side effect of gonadectomy in the dog. The mean age at diagnosis of CPN ranges from 8.5 to 11.2 years. Medium to large size breeds are more frequently affected. Symptoms and findings of non-invasive examinations are not pathognomonic, therefore, cytological or histological examinations are needed for diagnosis. Overall, the incidence of metastasis reaches up to 80%, yet lung metastasis reportedly has no negative impact on median survival time (MST). It has been reported that castrated males have a significantly higher MST than intact males. Differences in inclusion criteria for studied populations make a comparison of studies difficult. Citation of odds ratios without consideration of the context of the reference may result in premature conclusions. We conclude that elective gonadectomy of adult male dogs under six years of age cannot be excluded from the veterinary practice due to concern of causing CPN until clear and strong evidence is available.

Optimal Suture Bite Size for Closure of Feline Linea Alba-A Cadaveric Study

Objective: This study aimed to determine the most appropriate suture bite and stitch interval (SBSI) size for closing feline linea alba.

Study design: Randomized ex vivo mechanical testing.

Sample population: Ventral abdominal walls from 35 male feline cadavers were harvested and separated into 125 segments.

Methods: Segments were incised along midline then sutured back together using 3-0 polydioxanone using one of the following SBSI: 3, 5, 7.5, or 10 mm whereby the distance represents the distance both between the suture bites, and from the bite to incision line. The location of segments as well as the weight of the cadaver were recorded. A single linear distraction mechanical breaking test was performed. Statistical analyses (logistic and linear regression) were performed to determine which factors were associated with visual and mechanical failure, as well as load at failure or maximum displacement.

Results: SBSI was significantly associated with load at failure or maximum displacement (p < 0.001). In particular, 5 mm SBSI had the highest load at failure amongst all the bite sizes (LSmeans = 27.55N, 95% Confidence Interval (CI): 23.65–31.44); this was significantly higher than 7.5 mm (LSmeans = 19.15N, 95% CI: 15.26–23.05, p = 0.016) and 10 mm (LSmeans = 16.55N, 95%CI:12.39–20.70, p = 0.0012) but not significantly higher than 3 mm (LSmeans = 23.78N, 95% CI: 19.69–27.86, p = 0.2). Increased SBSI increased the odds of visual failure (p < 0.001) whereas increased weight of the cadaver reduced the odds of visual failure (OR = 0.52, 95%CI: 0.30–0.88, p = 0.016).

Conclusion: The 5 mm SBSI had the highest load at failure and was not significantly different from the 3 mm SBSI when apposing feline linea alba using 3-0 polydioxanone.

Clinical significance: Using 5 mm SBSI is the preferred bite size compared to 7.5 or 10 mm SBSI when apposing feline linea alba with 3-0 polydioxanone.

Neutering Effects on Social Behaviour of Urban Unowned Free-Roaming Domestic Cats

The "trap, spay/neuter, and release" programs to manage unowned free-roaming cat populations are diffused worldwide and they are largely advised even in countries where the suppression of unowned cats is enforced by law. Despite the massive neutering campaigns in the world, there is little information on the influence of neutering on individual cat behaviour, as well as on the social structure of cat colonies. The aim of this study is to verify such effects. Before neutering, the group consisted of 17 free-roaming domestic cats, who were totally unrestrained. After neutering it consisted of 16 individuals. Data on the outcomes of aggressive, submissive, affiliative, and territorial behaviour were collected, using classic ethological methods ("focal animal", "all occurrences", and "1/0" sampling methods) (735 h of observation before and 537 h after neutering). The dominance hierarchy did not change after neutering. On the other hand, the frequency of aggressive, territorial behaviour as well as proximity among individuals decreased significantly. Affiliative behaviour has been observed among neutered adult males that never performed it before neutering. The results of this study suggest that, after neutering: (i) The group of free-ranging cats was stable over time; (ii) the hierarchical structure of the cat social group did not change; (iii) the general level of activity, decreased; (iv) urine spraying marking behaviour almost disappeared; (v) the level of social proximity among group members decreased, although it tended to increase in some male-male dyads. The most obvious effect of neutering, detected on individual behaviour, was that cats were less active.

Behavioural risks in female dogs with minimal lifetime exposure to gonadal hormones

Spaying of female dogs is a widespread practice, performed primarily for population control. While the consequences of early spaying for health are still being debated, the consequences for behaviour are believed to be negligible. The current study focused on the reported behaviour of 8981 female dogs spayed before 520 weeks (ten years) of life for reasons other than behavioural management, and calculated their percentage lifetime exposure to gonadal hormones (PLGH) as a proportion of their age at the time of being reported to the online Canine Behavioral Assessment and Research Questionnaire (C-BARQ). We found that 23 behaviours differed between entire and spayed dogs, of which 12 were associated with PLGH and 5 with age-at-spay (AAS). Two behaviours, chewing and howling, were significantly more likely in dogs with longer PLGH. In contrast, longer PLGH was associated with significantly reduced reporting of 10 (mostly unwelcome) behaviours. Of these, one related to fearfulness and three to aggression. The current data suggest that dogs' tendency to show numerous behaviours can be influenced by the timing of spaying. They indicate how female dog behaviour matures when gonadal hormones are allowed to have their effect. The differences reported here between undesirable behaviours of spayed and entire dogs were in the range of 5.33% and 7.22%, suggesting that, for some dogs, partial or complete denial of maturation may reduce howling and chewing and improve retrieval and recall, but have other undesirable consequences. Veterinarians may take these data into account to discuss the risks and benefits of spaying with clients, and the timing of the procedure.

Desexing Dogs: A Review of the Current Literature

Background: Desexing dogs is promoted for population control, preventative healthcare, and behavior modification. Common methods are orchiectomy and ovariectomy/ovariohysterectomy. GnRH superagonist implants are available in some areas. Alternative methods like vasectomy and salpingectomy/hysterectomy are uncommon. The terminology used to describe desexing is inconsistent and contradictory, showing a need for the adaption of standardized terminology. Population Control: Surprisingly, empirical studies show no effects of desexing on population control in companion and shelter dogs despite desexing being consistently recommended in the literature. There is evidence for a population control effect in free-roaming dogs, where desexing also has benefits on zoonotic disease and bite risk. Population control in free-roaming dogs is mostly correlated with female, not male desexing. Health and Lifespan: Desexing affects numerous disease risks, but studies commonly neglect age at diagnosis and overall lifespan, age being by far the most important risk factor for most diseases. We argue that lifespan is a more important outcome than ultimate cause of death. A beneficial effect of desexing on lifespan is consistently demonstrated in females, while evidence for a beneficial effect in males is inconsistent. Studies are likely biased in desexing being a proxy for better care and desexed dogs having already lived to the age of desexing. Desexing reduces or eliminates common life-limiting diseases of the female reproductive system such as pyometra and mammary tumors, while no analogous effect exists in males. Disease risks increases across sexes and breeds include cruciate ligament rupture, various cancers, and obesity. Urinary incontinence risk is increased in females only. Various other disease risk changes show considerable variability between breeds and sexes. Behavioral Effects: Desexed males show reduced libido, roaming, conspecific mounting, and urinary marking frequency, as well as reduced male dog-directed aggression in a majority of males desexed for behavioral reasons. There is a detrimental effect on the risk and progression of age-related cognitive dysfunction. Desexed dogs may be less likely to cause bite injuries across sexes. The evidence for other effects such as human-directed aggression, human or object mounting, resource guarding, or shyness and anxiety is inconsistent and contradictory. There are few studies specific to females or individual breeds. Conclusions: The evidence for a beneficial effect of desexing is stronger in female than in male dogs; however, there is significant variation between breeds and sexes, and more research is needed to further elucidate these differences and to arrive at individualized evidence-based recommendations for clinical practice.

Do prevalence rates and severity of acquired urinary incontinence differ between dogs spayed by laparoscopy or laparotomy? Comparing apples with apples with a matched-pair cohort study

OBJECTIVE

To compare the prevalence rates and severity of acquired urinary incontinence (AUI) between dogs spayed with laparoscopic and open laparotomy approaches.

STUDY DESIGN

Retrospective matched-pair cohort study.

ANIMALS

In total, 1285 privately owned dogs spayed >5 years previously were included in the study.

METHODS

Laparoscopically spayed dogs were matched with dogs spayed by traditional laparotomy. Matching variables were breed, bodyweight, age at spaying, time of spaying in relation to the onset of puberty, time interval since spaying, and age. In 400 matched-paired dogs, the outcome of AUI was assessed by using an owner questionnaire. A conditional logistic regression for matched pairs was performed on the data of 308 dogs.

RESULTS

Among 308 dogs, 30 and 29 dogs spayed by laparotomy and laparoscopy, respectively, were affected by AUI. The identified risk factors for AUI were age and time interval since spaying. The surgical approach (laparoscopy or laparotomy) was neither revealed as a risk factor nor did it influence the severity of AUI.

CONCLUSION

The risk of AUI after spaying is not influenced by the surgical approach, (laparoscopy or laparotomy). Nearly every fifth dog spayed by laparotomy or by laparoscopy was affected by AUI. A relatively longer time interval since spaying and increased age of the dog increased the risk for AUI.

CLINICAL SIGNIFICANCE

Owners of dogs with a predisposition for AUI must be counseled about this risk when they present their dogs for spaying, regardless of surgical approach chosen.

Changes in thyroid hormones, leptin, ghrelin and, galanin following oral melatonin administration in intact and castrated dogs: a preliminary study

Background

Melatonin regulates metabolism and metabolism related hormones in mammalians. Castration has some adverse effects on the metabolic hormones of dog. This study was conducted to determine the effects of oral melatonin administration on metabolic hormones, as well as to compare changes of these hormones after administration of melatonin in castrated and intact dogs. Twenty healthy mixed breed mature male dogs were divided randomly into four groups (n = 5): melatonin (3 mg/10 kg(, castrated, castrated and melatonin treated, and negative control. Blood sample was collected from jugular vein weekly for 1 month.

Results

T3 and T4 hormones had a significant decrease within 1 month following administration of melatonin. No significant change was observed in concentration of FT3 and FT4 hormones. Leptin and ghrelin hormones also had a significant decrease in this period. Leptin and ghrelin had a more significant decrease in “non-castrated and melatonin treated” group compared to “castrated and melatonin treated” group. Galanin had a significant decrease but this neurotransmitter had no significant change in “non-castrated and melatonin treated” group in comparison to “castrated and melatonin treated” group.

Conclusions

It seems that daily administration of melatonin capsule in all dogs can probably decrease concentration of T3 and T4 hormones and balance other metabolic hormones following castration.

Methods

The dogs underwent castration, melatonin treatment and blood sampling.

Length of time domestic dogs (Canis familiaris) spend smelling urine of gonadectomised and intact conspecifics

Domestic dogs (Canis familiaris) use urine to communicate among themselves, however, it is unknown whether the gonadectomy (neutering or spaying) of a dog affects this communication in anyway. Urine samples from 10 intact and 10 gonadectomised, unfamiliar dogs were presented to 12 tester dogs to sniff under controlled conditions in a pilot study. The amount of time the tester dogs spent sniffing each sample was recorded. Overall, tester dogs were recorded smelling the urine of gonadectomised individuals for a longer time. In addition to the type of urine sample, the result is likely to have been influenced by the sex and status (gonadectomised or intact) of the tester dogs. The observed increase in the length of time spent sniffing urine from gonadectomised individuals could be explained by the tester dogs experiencing more difficulty in gaining information from the urine or facing more confusion while analysing the urine compared to the intact urine they have evolved to smell.

The Role of Dog Population Management in Rabies Elimination-A Review of Current Approaches and Future Opportunities

Free-roaming dogs and rabies transmission are integrally linked across many low-income countries, and large unmanaged dog populations can be daunting to rabies control program planners. Dog population management (DPM) is a multifaceted concept that aims to improve the health and well-being of free-roaming dogs, reduce problems they may cause, and may also aim to reduce dog population size. In theory, DPM can facilitate more effective rabies control. Community engagement focused on promoting responsible dog ownership and better veterinary care could improve the health of individual animals and dog vaccination coverage, thus reducing rabies transmission. Humane DPM tools, such as sterilization, could theoretically reduce dog population turnover and size, allowing rabies vaccination coverage to be maintained more easily. However, it is important to understand local dog populations and community attitudes toward them in order to determine whether and how DPM might contribute to rabies control and which DPM tools would be most successful. In practice, there is very limited evidence of DPM tools achieving reductions in the size or turnover of dog populations in canine rabies-endemic areas. Different DPM tools are frequently used together and combined with rabies vaccinations, but full impact assessments of DPM programs are not usually available, and therefore, evaluation of tools is difficult. Surgical sterilization is the most frequently documented tool and has successfully reduced dog population size and turnover in a few low-income settings. However, DPM programs are mostly conducted in urban settings and are usually not government funded, raising concerns about their applicability in rural settings and sustainability over time. Technical demands, costs, and the time necessary to achieve population-level impacts are major barriers. Given their potential value, we urgently need more evidence of the effectiveness of DPM tools in the context of canine rabies control. Cheaper, less labor-intensive tools for dog sterilization will be extremely valuable in realizing the potential benefits of reduced population turnover and size. No one DPM tool will fit all situations, but if DPM objectives are achieved dog populations may be stabilized or even reduced, facilitating higher dog vaccination coverages that will benefit rabies elimination efforts.

Correlation of neuter status and expression of heritable disorders

BACKGROUND

Gonadectomy, or neutering, is a very common surgery for dogs having many positive effects on behavior, health, and longevity. There are also certain risks associated with neutering including the development of orthopedic conditions, cognitive decline, and a predisposition to some neoplasias. This study was designed specifically to identify if a correlation exists between neuter status and inherited conditions in a large aggregate cohort of dogs representing many different breeds.

RESULTS

Neutered dogs were at less risk for early and congenital conditions (aortic stenosis, early onset cataracts, mitral valve disease, patent ductus arteriosus, portosystemic shunt, and ventricular septal defect) than intact dogs. Neutering was also associated with reduced risk of dilated cardiomyopathy and gastric dilatation volvulus in males. Neutering was significantly associated with an increased risk for males and females for cancers (hemangiosarcoma, hyperadrenocorticism, lymphoma, mast cell tumor, and osteosarcoma), ruptured anterior cruciate ligament and epilepsy. Intervertebral disk disease was associated with increased risk in females only. For elbow dysplasia, hip dysplasia, lens luxation, and patellar luxation neutering had no significant effect on the risk for those conditions. Neutering was associated with a reduced risk of vehicular injury, a condition chosen as a control.

CONCLUSIONS

In this retrospective study, several conditions showed an increased risk associated with neutering whereas other conditions were less likely to be expressed in neutered dogs. The complexity of the interactions between neutering and inherited conditions underscores the need for reflective consultation between the client and the clinician when considering neutering. The convenience and advantages of neutering dogs that will not be included in a breeding program must be weighed against possible risk associated with neutering.

Gonadectomy effects on the risk of immune disorders in the dog: a retrospective study

BACKGROUND

Gonadectomy is one of the most common procedures performed on dogs in the United States. Neutering has been shown to reduce the risk for some diseases although recent reports suggest increased prevalence for structural disorders and some neoplasias. The relation between neuter status and autoimmune diseases has not been explored. This study evaluated the prevalence and risk of atopic dermatitis (ATOP), autoimmune hemolytic anemia (AIHA), canine myasthenia gravis (CMG), colitis (COL), hypoadrenocorticism (ADD), hypothyroidism (HYPO), immune-mediated polyarthritis (IMPA), immune-mediated thrombocytopenia (ITP), inflammatory bowel disease (IBD), lupus erythematosus (LUP), and pemphigus complex (PEMC), for intact females, intact males, neutered females, and neutered males. Pyometra (PYO) was evaluated as a control condition.

RESULTS

Patient records (90,090) from the William R. Pritchard Veterinary Medical Teaching Hospital at the University of California, Davis from 1995 to 2010 were analyzed in order to determine the risk of immune-mediated disease relative to neuter status in dogs. Neutered dogs had a significantly greater risk of ATOP, AIHA, ADD, HYPO, ITP, and IBD than intact dogs with neutered females being at greater risk than neutered males for all but AIHA and ADD. Neutered females, but not males, had a significantly greater risk of LUP than intact females. Pyometra was a greater risk for intact females.

CONCLUSIONS

The data underscore the importance of sex steroids on immune function emphasizing a role of these hormones on tissue self-recognition. Neutering is critically important for population control, reduction of reproductive disorders, and offers convenience for owners. Despite these advantages, the analyses of the present study suggest that neutering is associated with increased risk for certain autoimmune disorders and underscore the need for owners to consult with their veterinary practitioner prior to neutering to evaluate possible benefits and risks associated with such a procedure.

LAPAROSCOPIC SALPINGECTOMY IN TWO CAPTIVE LEOPARDS (PANTHERA PARDUS) USING A SINGLE PORTAL ACCESS SYSTEM

Laparoscopic salpingectomy was performed in two adult leopards (Panthera pardus) using a single portal access system, with a multicannulated single-incision laparoscopic surgery port, without any complications. The poorly developed ovarian bursa provided easy access to the uterine tube for salpingectomy. Laparoscopic salpingectomy can be safely performed in the leopard using a single portal access system.

Using Plasmonic Copper Sulfide Nanocrystals as Smart Light-Driven Sterilants

As an efficient route to control pet overpopulation and develop neutered experimental animals, male sterilization via surgical techniques, chemical injections, and antifertility vaccines has brought particular attention recently. However, these traditional ways usually induce long-term adverse reactions, immune suppression, and serious infection and pain. To overcome the above limitations, we developed a platform in the present study by using plasmonic copper sulfide nanocrystals (Cu2-xS NCs) as intelligent light-driven sterilants with ideal outcomes. Upon NIR laser irradiation, these well-prepared Cu2-xS NCs can possess NIR-induced hyperthermia and generate high levels of reactive oxygen species (ROS). Due to the cooperation of photothermal and photodynamic effects, these nanocrystals exhibited NIR-mediated toxicity toward Sertoli cells both in vitro and in vivo in a mild manner. We attribute the potential mechanism of cellular injury to the apoptosis-related death and denaturation of protein in the testicles. Furthermore, the possible metabolism route and long-term toxicity of these nanocrystals after testicular injection indicate their high biocompatibility. Taking together, our study on the NIR-induced toxicity of Cu2-xS NCs provides keen insights for the usage of plasmonic nanomaterials in biomedicine.

Is Wildlife Fertility Control Always Humane?

Investigation of fertility control techniques to reduce reproductive rates in wildlife populations has been the source of much research. Techniques targeting wildlife fertility have been diverse. Most research into fertility control methods has focused upon efficacy, with few studies rigorously assessing animal welfare beyond opportunistic anecdote. However, fertility control techniques represent several very different mechanisms of action (modalities), each with their own different animal welfare risks. We provide a review of the mechanisms of action for fertility control methods, and consider the role of manipulation of reproductive hormones ("endocrine suppression") for the long-term ability of animals to behave normally. We consider the potential welfare costs of animal manipulation techniques that are required to administer fertility treatments, including capture, restraint, surgery and drug delivery, and the requirement for repeated administration within the lifetime of an animal. We challenge the assumption that fertility control modalities generate similar and desirable animal welfare outcomes, and we argue that knowledge of reproductive physiology and behaviour should be more adeptly applied to wild animal management decisions. We encourage wildlife managers to carefully assess long-term behavioural risks, associated animal handling techniques, and the importance of positive welfare states when selecting fertility control methods as a means of population control.

Prevalence of desexed cats in relation to age in a convenience sample of Western Australian cats

BACKGROUND

Desexing percentages for pet cats in Australia are nearly 95%, but the high numbers of unwanted kittens surrendered to animal shelters suggest that many pet cats breed before the owners consider desexing, or that the mothers of many of these kittens are stray or feral.

METHODS AND RESULTS

A convenience sample of Western Australian pet cats of known age presented for microchipping (584 in 2012 and 316 in 2013) found that younger cats were less likely to be desexed. In 2012, 93.2% of cats aged ≥2 years were desexed compared with 49.4% of cats <2 years old, with the data for 2013 being 97.4% and 28%, respectively.

CONCLUSION

If these results are reflected nationally, desexing of prepubescent cats up to 4 months old could significantly reduce the numbers of unwanted kittens born to pet cats.

Single-layer tungsten oxide as intelligent photo-responsive nanoagents for permanent male sterilization

Permanent male sterilization has been recognized as useful tools for the development of neuter experimental animals and fattening livestock, as well as efficient control of pet overpopulation. Traditional routes such as surgical ways, chemical injections, and anti-fertility vaccines have addressed these crucial problems with idea outcomes. However, these routes usually bring out serious pain and infection towards animals, as well as induce long-term adverse reaction and immune suppression. Thus, a convenient, but non-surgical strategy for male sterilization under a mild manner is highly desirable. Here, for the first time, we demonstrate a novel platform for male sterilization by using single-layer WO2.72 nanosheets as smart photo-responsive sterilants. Upon a 980 nm irradiation, these nanoagents can possess intrinsic NIR-induced hyperthermia and sensitize the formation of singlet oxygen due to the cooperation of photothermal and photodynamic effects. Mechanism of cellular injury can be attributed to the denaturation of protein and apoptosis-related death. Moreover, long-term toxicity and possible metabolism route after testicular injection are discussed, indicating the neglectable systemic toxicity and high bio-compatibility of our nanoagents. Overall, our strategy can extremely overcome the shortcomings in various routine routes and suggest the new biological application of nanomaterials.

Effects of ovariohysterectomy on oxidative stress markers in female dogs

Numerous studies reported an increase of oxidative stress increases in both women and female laboratory animals after ovariectomy. However, there is little information about the evaluation of antioxidative/oxidative status in ovariectomized dogs. The purpose of this study was to examine the changes in oxidative stress markers after ovariohysterectomy (OHE) in female dogs. The study included eighteen healthy mongrel female dogs. Blood samples were collected immediately before surgery and 14 and 30 days after surgery. Following parameters of oxidative stress intensity were determined: the erythrocyte activity of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) as well as the plasma concentrations of thiobarbituric acid reactive substances (TBARS), radical cations of N,N, diethylpara-phenylene diamine (RC-DEPPD), sulfhydryl groups (SH groups), bityrosine and formylkynurenine. The activity of GSH-Px increased markedly, although not significantly, 14 days after OHE and then significantly decreased at 30 days after OHE. A significant increase in plasma TBARS, bityrosine and formylkynurenine concentrations and a decrease in SH group content were concurrently noted at 30 days after surgery. Acquired results suggested that a loss of control over ROS production occurred in female dogs after OHE, which could lead to oxidative stress in the late post-operative period. In conclusion, our findings indicated that OHE is related with the risk of oxidative stress in the late period after operations. Given that oxidative stress contributes to the pathogenesis of various diseases, this may suggest an increased risk of disorders in ovariectomized female dogs; however, further studies are necessary to confirm this hypothesis.