Epidemiological analysis of reproductive performances and kitten mortality rates in 5,303 purebred queens of 45 different breeds and 28,065 kittens in France

Spay/neuter laws as a debated approach to stabilizing the populations of dogs and cats: An overview of the European legal framework and remarks

To reduce the (over) population of unwanted companion non human animals, namely dogs and cats. They are used to lower negative impacts on human societies and on the animals themselves, and opting for the neutering status is usually considered a demonstration of "responsible ownership." In Western countries, however, such provisions are not uniform and must increasingly be balanced with the recognition of animals as sentient beings with interests under the law. Furthermore, there is no consensus on whether routine neutering benefits both human and nonhuman parties, and the veterinary profession progressively claims the need for case-by-case management. Such premises make deciding how to manage companion animals' reproductive lives legally challenging. The current work examines the European legal framework for companion animal protection and animal legal status after providing a brief overview of the global problem of overpopulation. Subsequently, the author discusses the main legal approaches to controlling companion animal reproduction, in European countries. Remarks about the legally binding option and on alternative approaches are provided, while highlighting the persistent need for appropriate and coherent European legislation.

Observations about declining fertility in a feline breeding colony

Feline breeding colonies are important to the feline industry by preserving traits desirable for a particular breed or in research settings by maintaining medically valuable genetic traits. As breeding females age, their reproductive efficiency declines. The objective of this study was to determine the most common causes of infertility in breeding females that were producing fewer kittens. Knowing the cause and average age of infertility would allow management decisions to be made for the betterment of the colony. The medical records of 70 queens retired from breeding from a single research colony were examined for litter size and number, fertility over their lifespan, and age and reason for removal from breeding stock. Sections of uterus and ovaries were evaluated using gross and histopathological examination for a subset of these queens (46). The data suggests that mature, continuously breeding female cats may show signs of reduced fertility (infertile matings or reduced litter size) as early as 3 years of age and may be a result of undiagnosed Cystic Endometrial Hyperplasia (CEH), endometritis, pyometra and/or ovarian cysts. Evaluation of breeding queens should include periodic ultrasounds to monitor for ovarian cysts and evidence of CEH. Retiring animals from breeding once signs of infertility become apparent is recommended.

A Prospective Study of Growth Rate, Disease Incidence, and Mortality in Kittens Less than 9 Weeks of Age in Shelter and Foster Care

A prospective study was designed to (a) investigate the rate of daily weight gain among kittens less than 9 weeks old presented to an animal shelter, (b) identify factors (e.g., sex, clinical signs of disease, diet, and medical treatment) that affect daily weight gain, and (c) investigate the mortality of study kittens. The study of 203 kittens was conducted at a managed admission, no-kill animal shelter in upstate New York, USA, from April 2014 through October 2014. Body weight was measured daily from day of intake to adoption or 12 weeks of age. Fecal score, clinical signs of disease, food type, and medical treatments were recorded daily. Lethargy and being female were significantly associated with lower daily weight gain. Despite the challenges of shelter and foster care, the average daily weight gain for study kitten was higher than that reported in other settings such as catteries and laboratories. Five study kittens (2.5%) died or were euthanized. Daily monitoring systems provide opportunities for interventions, increased live outcomes, and improved welfare for kittens in shelter and foster care.

Scientific and technical assistance on welfare aspects related to housing and health of cats and dogs in commercial breeding establishments

This Scientific Report addresses a mandate from the European Commission according to Article 31 of Regulation (EC) No 178/2002 on the welfare of cats and dogs in commercial breeding establishments kept for sport, hunting and companion purposes. The aim was to scrutinise recent recommendations made by the EU Platform on Animal Welfare Voluntary Initiative on measures to assist the preparation of policy options for the legal framework of commercial breeding of cats and dogs. Specifically, the main question addressed was if there is scientific evidence to support the measures for protection of cats and dogs in commercial breeding related to housing, health considerations and painful procedures. Three judgements were carried out based on scientific literature reviews and, where possible a review of national regulations. The first judgement addressed housing and included: type of accommodation, outdoor access, exercise, social behaviour, housing temperature and light requirements. The second judgement addressed health and included: age at first and last breeding, and breeding frequency. Judgement 3 addressed painful procedures (mutilations or convenience surgeries) and included: ear cropping, tail docking and vocal cord resections in dogs and declawing in cats. For each of these judgements, considerations were provided indicating where scientific literature is available to support recommendations on providing or avoiding specific housing, health or painful surgical interventions. Areas where evidence is lacking are indicated.

Litter Management Practices and House-Soiling in Italian Cats

There are about 10.1 million domestic cats in Italy, but information on cats' litter management and house-soiling prevalence is scant. This study described cats' and cat owners' profiles, litter management practices, and whether cats show house-soiling, also comparing between professionals (i.e., breeders) and amateurs (i.e., pet owners). A cross-sectional online survey sought respondents' housing, family, and cat details, as well as other pet details, litter details, and whether the cats showed house-soiling. Data for a total of 3106 cats were obtained. Italian cats lived mainly in apartments, along with other cats or dogs. Italians owned mostly adult European breed cats, to whom they provided covered litter boxes filled with clumping substrates, scooped daily, and completely replaced weekly. Litter cleaning was more frequent when cats were owned for financial purposes (i.e., breeders) rather than for companionship, but more space was provided for pets than for breeding cats. The recalled prevalence of elimination problems (16.7%) was lower compared to other studies, with cats mainly eliminating urine (54.6%) on objects in squatting posture (35.2%). Overall, this research increased our understanding of cat litter management in Italy. These findings could fill a gap in the knowledge regarding litter management and house-soiling incidences in Italy. Further studies to investigate possible risk factors for house-soiling are needed.

Cat: Empirical modelling of Felis catus population dynamics in the UK

Domestic cats are popular companion animals, however not all live in human homes and many cats live within shelters or as free-roaming, unowned- feral or stray cats. Cats can transition between these subpopulations, but the influence of this connectivity on overall population dynamics, and the effectiveness of management interventions, remain poorly understood. We developed a UK-focused multistate Matrix Population Model (MPM), combining multiple life history parameters into an integrated model of cat demography and population dynamics. The model characterises cats according to their age, subpopulation and reproductive status, resulting in a 28-state model. We account for density-dependence, seasonality and uncertainty in our modelled projections. Through simulations, we examine the model by testing the effect of different female owned-cat neutering scenarios over a 10-year projection timespan. We also use the model to identify the vital rates to which total population growth is most sensitive. The current model framework demonstrates that increased prevalence of neutering within the owned cat subpopulation influences the population dynamics of all subpopulations. Further simulations find that neutering owned cats younger is sufficient to reduce overall population growth rate, regardless of the overall neutering prevalence. Population growth rate is most influenced by owned cat survival and fecundity. Owned cats, which made up the majority of our modelled population, have the most influence on overall population dynamics, followed by stray, feral and then shelter cats. Due to the importance of owned-cat parameters within the current model framework, we find cat population dynamics are most sensitive to shifts in owned cat husbandry. Our results provide a first evaluation of the demography of the domestic cat population in the UK and provide the first structured population model of its kind, thus contributing to a wider understanding of the importance of modelling connectivity between subpopulations. Through example scenarios we highlight the importance of studying domestic cat populations in their entirety to better understand factors influencing their dynamics and to guide management planning. The model provides a theoretical framework for further development, tailoring to specific geographies and experimental investigation of management interventions.

Reproduction of Domestic Cats in Laboratories, Catteries, and Feral Colonies: A Review

Cat reproduction is important for research and commercial cat breeding operations, as well as the control of feral cat populations. This review describes studies examining reproductive performance in laboratory cats, privately-owned breeding cats, and feral cats, including sexual maturity, the estrous cycle (timing, behavior, and hormonal changes), seasonal effects, gestation length, parturition (litter size, litter weight, and parity effects), mortality, and stillbirth. Because the studies highlighted in this review vary in the location where they were conducted and the region's management practices, these factors should be considered depending on the goal of the reader when interpreting these data. Furthermore, standard practices were lacking in some earlier studies of cat reproduction, so they should be considered for historical context only and may not reflect the actual reproductive potential of cats as described in the new studies due to advancements in husbandry practices and nutrition. The objective of this manuscript is to review scientific studies examining reproductive performance in laboratory cats, privately-owned breeding cats, and feral cats. The data sources for this manuscript included original research publications and scientific reviews from the veterinary literature. All reviews or studies that augmented the knowledge of the reproduction of domestic cats in laboratories, catteries, and feral colonies were included. Most studies on laboratory cats have been conducted under the conditions of controlled light cycles, temperature, and diet. The environmental effects on reproductive behavior are subtler than those in feral cat studies, but the effects are still distinguishable. Cat breeding studies focus on genetic effects and rely heavily on surveys or questionnaires from cat breeders. However, the reliability of these data can be variable, in part because the methodology of record-keeping and other protocols are generally not reported. In addition, laboratory animal management standards, specific pathogen-free cat colonies, and nutritional requirements for cats were not fully established until the 1970s. Reproductive outcomes of earlier studies may not be a true representation of the modern cat due to more advanced, regulated husbandry practices, including improvements in nutrition, resulting in diets formulated to meet feline requirements for every life stage.

Association between Birth Weight and Mortality over the Two First Months after Birth in Feline Species: Definition of Breed-Specific Thresholds

In many species, low birth weight is identified as a major determinant for neonatal survival. The objectives of the present study were (i) to assess, in a large feline purebred population, the impact of birth weight on 0-2 months mortality in kittens, and (ii) if such mortality occurs, to define cut-off values for birth weight to identify at-risk kittens. Data from 5596 kittens from 15 breeds and provided by 194 French breeders were analysed. A logistic mixed model was used to identify low birth weight, being a male, and being born in a large litter as significant risk factors for kitten mortality during the first two months after birth. Classification and regression tree analysis was used to define the thresholds, first at the species level and, when possible, at the breed level. Two thresholds were defined to group kittens into three categories: low, moderate, or high risk of 0-2 months mortality (normal, low, and very low birth weight, respectively). In our population, 19.7% of the kittens were classified as low birth weight and 1.9% as very low birth weight. Critical thresholds may differ between breeds with similar birth weight distributions and equivalent mortality rates (e.g., Russian Blue/Nebelung vs. Egyptian Mau). These critical birth weight thresholds, established in 15 breeds, could be used to identify kittens requiring more intensive nursing to improve survival.

Uterine issues in infertile queens: nine cases

This prospective case series investigated potential uterine causes of infertility in queens. Purebred queens with infertility (failure to conceive, embryonic death, or failure to maintain pregnancy and produce viable kittens), but no other reproductive disorders were examined approximately 1-8 weeks before mating (Visit 1), 21 days after mating (Visit 2), and 45 days after mating (Visit 3) if pregnant at Visit 2. Investigations included vaginal cytology and bacteriology, urine bacteriology, and ultrasonography. At Visit 2 or 3, uterine biopsy or ovariohysterectomy was performed for histology. Of nine eligible queens, seven were non-pregnant by ultrasound at Visit 2 and two had lost pregnancies by Visit 3. Ovulation was confirmed by serum progesterone concentration in all queens. Ultrasonic appearance of the ovaries and uterus was compatible with a healthy status except for one queen with signs of cystic endometrial hyperplasia (CEH) and pyometra, a follicular cyst in another, and fetal resorptions in two queens. Six cats had histologic lesions of endometrial hyperplasia, including CEH (n=1). Only one cat had no histologic uterine lesions. Bacteria were cultured from vaginal samples in seven queens at Visit 1, (two were non-evaluable), and in five of seven queens sampled at Visit 2. Uterine cultures were negative except for the cat with pyometra. All urine cultures were negative. In summary, the most frequent pathology observed in these infertile queens was histologic endometrial hyperplasia, which can potentially inhibit embryo implantation and healthy placental development. This suggests that uterine disease might contribute substantially to infertility in purebred queens.

Biochemical factors affecting newborn survival in dogs and cats

The importance and implications of small animal neonatology were underestimated until recent times. Despite the recent increasing interest for this branch of veterinary medicine, however, perinatal mortality rates in canine and feline species remain high, representing an important challenge for the clinician. In this perspective, the prompt identification of newborns requiring additional and tailored assistance becomes a key to reduce the perinatal losses in small animals. To achieve this goal, clinical and laboratory findings must be carefully evaluated. This paper focuses on biochemical parameters and their reported influence on neonatal survival, guiding through the evaluation of canine and feline newborn laboratory analyses, with a thorough discussion about the use of different biological material in these subjects. Beside blood, other biological material, such as urines and fetal fluids proved to be interesting for the identification of possible prognostic markers, thanks also to their easy and safe collection. However, the correct reading-through the results must consider many variables such as type of delivery, anesthesia protocol in case of Caesarean section, age of the newborn at samples collection, and for blood analysis, also the type of blood, site of collection, modality of collection and storage must be considered. Notwithstanding the recent progress in literature, for most of the parameters more research is needed to define cut-off values with certainty.

Prevalence of lactational oestrus in cats and consequences for kittens

Objectives

Although lactation and suckling suppresses fertility in most mammals, some feline breeders have reported spontaneous oestrus during lactation, causing distress to kittens. This led the Official French Feline Pedigree Registry (Livre Officiel des Origines Félines – LOOF) to send a questionnaire to cat breeders requesting data on their last three litters. The aim of this study was to investigate the prevalence of lactational oestrus, its impact on litters and potential associations with litter size, age, parity, breed and seasonality.

Methods

Answers from 108 breeders were collected, providing data on 238 litters in 23 different breeds. Data were also collected on successive litters from multiparous queens (n = 20) and were analysed separately from the 195 independent births.

Results

Of the 195 independent births with complete data sets, 96 (49%) queens came into oestrus during lactation, 37 (38%) of which were associated with loss of maternal interest (n = 20), milk quality variation (n = 2), clotted milk (n = 3), reduced milk quantity (n = 13), which in kittens led to reduced weight (n = 6), diarrhoea (n = 9), vomiting (n = 4), nausea (n = 2) or death (n = 4), and bottle feeding (n = 2), early weaning (n = 4) or modified litter behaviour (n = 1). A significant association was found between small litter size (one or two kittens) and the onset of lactational oestrus ( P = 0.007) and between births occurring in February, March and April and lactational oestrus ( P = 0.005); there was no association with age or breed.

Conclusions and relevance

Breeders perceived a relationship in 38% of cases of lactational oestrus with maternal disinterest, clotted milk, reduced milk yield and in kittens, weight loss, vomiting, diarrhoea or even death. An association between small litter size and lactational oestrus was found, as well as with births occurring between February and April. Breeders presenting with at-risk females should be warned. Conservative and preventive measures such as contraceptive options are discussed as a possible therapy.

Neonatology: Topics on Puppies and Kittens Neonatal Management to Improve Neonatal Outcome

The productivity of kennels and catteries is directly linked to maternal prolificacy and neonatal survival. During the neonatal period, mortality is high, not only due to environmental factors after birth but also with regard to gestational fetal life, complications during delivery, and management errors. Neonatology is an area of veterinary medicine where having a strong knowledge base of applied physiology and common clinical presentations for newborns can often favor better outcomes and greater neonatal survival. The teaching of animal theriogenology topics, particularly neonatal medicine, in the veterinary curriculum has evolved significantly in recent years. It is essential that the veterinarian understands the maternal and neonatal particularities and the main aspects involved in the handling of puppies and kittens for the instruction of the correct handling to the breeders and better medical conduct. The breeder of dogs and cats, experienced or not, must count on the help of a veterinarian in their breeding. Proper management, constant monitoring of the litter, and prompt assistance are the keys to successful breeding.

Feline Fertility: Consequences of inbreeding and implications for reproductive fitness

PRACTICAL RELEVANCE

When compared with the number of individuals that make up a dog breed, the population within a given cat breed is very small. Therefore, to maintain a breed standard, a certain degree of inbreeding is necessary. However, when inbreeding reaches a certain threshold, it can lead to decreased fertility, which manifests as failure to conceive, smaller litter size, increased neonatal illness and neonatal mortality. Breeders should be encouraged to keep comprehensive records on breeding outcomes, including number of kittens born, neonatal vitality, daily kitten weights and kitten health at weaning. Commercially available DNA panels are available to inform and facilitate excellent breeding choices and can estimate the coefficient of inbreeding. Clinicians should include a review of the degree of inbreeding in the work-up for any cattery or cat colony experiencing decreased fertility.

AIM

The objective of this article is to provide clinicians, especially those working with cat breeders, with an easy-to-understand guide to genetics and to demonstrate how inbreeding influences fertility and neonatal survival.

EQUIPMENT AND TECHNICAL SKILLS

Medical records and the pedigree of the cats in question are required to investigate cases of infertility that may be related to inbreeding. A DNA analysis kit that measures genetic diversity and health parameters can also be helpful; those that have been developed by geneticists and veterinarians at universities are preferable, as they include access to highly skilled genetic counselors and researchers who are open to working up newly discovered genetic diseases.

EVIDENCE BASE

The material provided is based on current literature and the author's own studies examining outcomes in a closed cattery.

Reproductive Management in Catteries: Optimising health and wellbeing through veterinarian-breeder collaboration

PRACTICAL RELEVANCE

Many veterinarians - even those engaged in small animal reproduction - are uncomfortable with taking care of cat breeders or being in charge of catteries. Likely reasons for this are that feline reproduction is largely under-represented in undergraduate and graduate reproduction teaching, as well as in postgraduate education and science, whereas cat breeders themselves are often well informed and actively share knowledge with other cat breeders via the internet and social media.

CLINICAL CHALLENGES

A variety of problems can exist within a cattery, and collaboration between veterinarian and breeder to solve these is ultimately beneficial for the breeder, for the veterinarian, and for the health and wellbeing of the individual cats and of the cattery as a whole.

AIM

This review presents a comprehensive overview of aspects of cattery management that might negatively impact reproduction, including sanitation, hygiene and infectious disease control. It also discusses monitoring of reproductive performance, breeding recommendations, and the diagnostic and therapeutic approach to some common and specific problems.

EQUIPMENT AND TECHNICAL SKILLS

Reproductive management in the cattery requires no specialised equipment, as such. What it does need is an open mind, in terms of seeing how things are done, an open ear, for listening to the breeder, and the veterinarian's clinical skills in palpation, auscultation and, where required, further examination of the animals. Keeping abreast of the latest information on infectious diseases, disinfection and genetics ensures proper advice is provided.

EVIDENCE BASE

Current knowledge of reproductive management in catteries is summarised in order to apply an evidence-based approach, whenever possible. Notwithstanding, much of the information remains empirical.

Infertility In Queens: Clinical approach, experiences and challenges

CLINICAL CHALLENGES

It is not easy for a veterinarian to determine the cause of infertility in a queen. The simplest method is to start by investigating the most common causes and then progress by successive elimination to the less common causes. For example, mating problems are commonly responsible for reproductive failure, and owners should be particularly vigilant in checking that the mating is progressing satisfactorily. Frequently, a veterinarian may have to determine, among other things, if there is a uterine or hormonal disorder or if an infectious pathology may be involved. In the case of a queen that is not cycling, it is important to differentiate a lack of onset of puberty in a young queen from a lack of cyclicity in an adult queen.

AIM

This review sets out a practical, step-by-step approach that veterinarians can follow, starting with the most common causes of infertility in queens and moving towards more rare or specific causes.

EQUIPMENT AND TECHNICAL SKILLS

Simple techniques such as vaginal smears are essential to determine if a queen that is ready to be mated is in full oestrus, if a queen is cycling or not and to diagnose inflammation of the genital tract. Veterinarians should be familiar with the peculiarities of the swabbing technique in cats, as well as the interpretation of feline vaginal cytology. Progesterone assays are useful on many occasions in the diagnosis pathway. A laboratory capable of performing karyotypes should ideally be available. Finally, it is important to be able to perform an ultrasound examination of the ovaries and uterus in a queen.

EVIDENCE BASE

Although it appears that infertility is a problem among purebred queens, there is a lack of knowledge in this area and too few published studies. Some causes of feline infertility remain poorly investigated.

Birth weight in the feline species: Description and factors of variation in a large population of purebred kittens

Birth weight is one of the earliest health parameters with short (neonatal period) and long term (adulthood) implications for an individual. The present work was conducted on the domestic cat, with the objective of determining factors affecting kitten birth weight. Data voluntarily shared by 139 French breeders allowed building a large dataset of purebred kittens (n = 3,547) from 15 breeds. A linear mixed model with queen and cattery as random terms was used to investigate variation factors of kitten birth weight such as breed, litter size, season of birth, age of the queen, presence of stillborn in the litter, sex of the kitten. The most important factor was breed which explained 25% of the variation in birth weight observed in the study population. The five other parameters were also significant but explained only a small additional part of the variance (less than 3% each). Analyses showed that kitten birth weight increased with the age of the queen, was higher in males than females and in litters without stillbirth than in litters with at least one stillborn. In addition, lower birth weights were recorded in summer and autumn compared to other seasons, and birth weight values decreased as the number of kittens in the litter increased. In order to group feline breeds according to their average birth weights and litter sizes, a K-means algorithm was used to identify three clusters among the 15 breeds represented (Group 1: small litter sizes/low birth weights; Group 2: large litter sizes/intermediate birth weights; Group 3: large litter sizes/high birth weights). This study, based on a large dataset established at the national scale, provides reference values of feline birth weights for breeders and veterinarians. The next step could be to explore the relationship between birth weight and neonatal mortality to help identify neonates requiring specific care.

Topics in the routine assessment of newborn kitten vitality: Apgar score, reflexes and complementary assessments

OBJECTIVES

The aim of this study was to perform neonatal clinical assessments at birth to identify newborn kittens at risk according to type of delivery, thus allowing immediate intervention and increasing their chances of survival.

METHODS

This study compared Apgar scores, reflexes and clinical parameters (temperature, weight, blood glucose and peripheral oxygen saturation [SpO2]) between eutocic neonates and those delivered by emergency cesarean section. The animals were evaluated at birth and after 10 and 60 mins.

RESULTS

Thirty-two neonates were evaluated, with 19 animals in the eutocic group (EG) and 13 animals in the cesarean group (CG). When comparing groups, CG neonates had significantly lower Apgar scores (P <0.0001), lower SpO2 (P = 0.0535), higher blood glucose (P = 0.0009), reduced reflexes (P <0.0001) and lower respiratory rates (P <0.0001) at birth and after 10 and 60 mins than EG neonates. Apgar scores positively correlated with parameters such as heart rate, reflex score, SpO2 and weight. The mortality rate in evaluated newborns was 15.6% (5/32). The early mortality rate (0-2 days old) was 80% (4/5) and the late mortality rate (3-30 days old) was 20% (1/5).

CONCLUSIONS AND RELEVANCE

This study showed lower vitality in cats delivered by emergency cesarean section than in those delivered through eutocic birth. In general, neonates delivered by cesarean section have greater depression and low vitality at birth and may require advanced resuscitation procedures. The evaluations carried out in this study identified newborns with low vitality and those requiring advanced resuscitation, thus allowing immediate intervention. Apgar and reflex scores for feline neonates were suggested. Newborn-specific clinical assessment with these feline vitality scores allows the identification of at-risk neonates. Care immediately after birth increases the chance of survival among these patients.

Feline neonatology: From birth to commencement of weaning - what to know for successful management

PRACTICAL RELEVANCE

Despite considerable interest in the field of companion animal reproduction, feline neonatology remains largely unstudied. This contrasts with the need for a more professional veterinary approach to newborn kittens and feline husbandry, across the pet, breeding cattery and rescue shelter settings, to reduce kitten mortality.

GLOBAL IMPORTANCE

Feline neonatology has relevance for veterinarians around the world as cats are continuing to become established as popular companion animals.

CLINICAL CHALLENGES

Perinatal mortality in cats is remarkably high. Therefore, adequate neonatal evaluation and assistance at birth, careful monitoring of kittens in the vulnerable period until weaning begins, assessment of maternal factors and well-informed management of orphans are crucial in helping to reduce kitten losses.

AIM

This review aims to deepen the basic knowledge of the veterinary clinical team regarding the characteristics of feline newborns under normal conditions at birth through to the commencement of weaning. Much of the information is also relevant to breeders and rescue/shelter caregivers.

EVIDENCE BASE

In compiling the present review, the authors have drawn on specific feline research data, where available, complemented by data extrapolated from scientific publications on newborn dogs, and also their own and their colleagues' professional clinical experience.

Fading kitten syndrome: Factors predisposing to 'faders' and treatment options

PRACTICAL RELEVANCE

Fading kitten syndrome is a condition where one or more kittens of a litter are born apparently healthy but gradually become inactive, sick and die; typically faders are considered those that die during the first 2 weeks of life. Fading has many potential aetiologies, including a wide variety of infectious, toxic, traumatic, metabolic and genetic diseases. Regardless of the underlying cause, the approach to a sick neonate is similar, and initiating supportive care is the first priority, followed by a detailed physical examination. Where possible, the cause of disease should be determined, and this may inform adjustments to the treatment protocol.

CLINICAL CHALLENGES

Most perinatal and neonatal diseases present similarly and a specific cause cannot usually be determined from clinical signs alone, which can make diagnosis challenging. When examining a kitten, it is important to remember that there are distinct physiological differences between adults and neonates. In addition, some procedures can be more difficult to perform than in adults, such as blood collection, and some diagnostic tests are harder to interpret, such as radiography. When treating kittens, differences compared with adults again need to be considered.

AIM

The aim of this review is to provide guidance to veterinarians who are presented with a fading kitten. As well as reviewing the potential causes of fading kitten syndrome, the diagnostic approach and treatment options are discussed. Algorithms summarising possible pathways to neonatal mortality in kittens, and diagnostic and therapeutic options in fading kittens, are also provided.

EVIDENCE BASE

Information provided in this review is based on the published feline literature and papers discussing puppies and/or a range of species including cats, as well as the author's own clinical experience.

Management of Low Birth Weight in Canine and Feline Species: Breeder Profiling

Simple Summary

Mortality rate in puppies and kittens over the first two months of age is high, estimated at around 20%. Low birth weight has been identified as a major risk factor for neonatal mortality in these species. Using an online questionnaire, we explored perceptions and management practices of breeders regarding newborns at low birth weight. Three different profiles were identified among 649 breeders. The first one included mainly dog and cat breeders who weighed newborns and monitored their suckling by the dam (controlled suckling) but did not warm them. The second group consisted of breeders of both species who did not weigh puppies or kittens to identify low birth weight or to monitor their weight afterwards. The third and final group included mostly cat breeders who routinely weighed neonates as in the first group, but who used artificial feeding rather than controlled suckling. This better knowledge of the management of puppies and kittens at high risk of neonatal mortality in the field provides the basis to establish guidelines to increase their chances of survival.

Abstract

Low birth weight (LBW) has been identified as a major risk factor for neonatal mortality in many species. The aim of this survey was to determine the profiles of canine and feline breeders concerning their perceptions of, and management practices relating to, LBW individuals. An anonymous online survey was addressed to French cat and dog breeders in September 2019 via social networks. Multiple correspondence analysis and hierarchical clustering were used to explore breeders’ profiles. Three clusters were identified among the 649 breeders included in this analysis. Cluster 1 (49%) included dog and cat breeders who weighed newborns (and thus identified LBW) and controlled nursing by the dam (controlled suckling) but did not warm them up. Cluster 2 breeders (21%) of both species did not weigh puppies or kittens to identify LBW or to monitor the evolution of their weight afterwards. Cluster 3 (30%) including mostly cat breeders who weighed neonates routinely as in Cluster 1, but they practiced artificial feeding rather than controlled suckling. This survey provides a basis for better understanding of perceptions and practices regarding LBW puppies and kittens. It will be useful to provide guidelines for neonatal management to increase their chances of survival.

Retrospective evaluation of feline dystocia: clinicopathologic findings and neonatal outcomes in 35 cases (2009-2020)

OBJECTIVES

The aim of this study was to describe the characteristics of cases of feline dystocia presenting to a university emergency service.

METHODS

The medical records of queens presenting for dystocia between January 2009 and September 2020 were reviewed. Data collected included queen signalment, presenting complaints, treatments, and maternal and neonatal outcomes. Clinicopathologic data included serum ionized calcium concentration, blood glucose level, packed cell volume and total solids. Owing to the small sample size, descriptive statistics were used and data presented as median (range).

RESULTS

Thirty-five cases were reviewed. Dystocia was attributed to maternal factors in 69% (n = 24) and fetal factors in 31% (n = 11). Venous blood gas data from 19 queens in stage 2 labor revealed that no queens were hypocalcemic (median ionized calcium 5.4 mg/dl [range 4.9-5.8]) or hypoglycemic (median glucose 143 mg/dl [range 78-183]). Medical management was attempted in 21/35 queens. Successful medical management was achieved in 29% (n = 6/21). Thirteen queens underwent surgical management, six of these after failing medical management. Seven queens received no treatment. Fifteen queens were discharged and one queen was euthanized while still in labor. The remaining 19 queens delivered all fetuses with medical (n = 6) or surgical management (n = 13). Maternal survival was 94% (n = 33/35). A total of 136 kittens were born to all queens, with 58% (n = 79/136) born prior to initiation of treatment, 16% (n = 22/136) after medical management and 26% (n = 35/136) after surgical management. Overall neonatal survival to discharge was 66% (n = 90/136).

CONCLUSIONS AND RELEVANCE

Feline dystocia is an emergent condition that can result in up to 34% neonatal mortality for kittens delivered via both medical and surgical means. Hypoglycemia and hypocalcemia were not precipitating causes of feline dystocia in this population.

Pre-mortem risk factors for mortality in kittens less than 8 weeks old at a dedicated kitten nursery

OBJECTIVES

Kittens have unique requirements for care in a shelter setting given their higher susceptibility to infectious disease and socialization needs. Significant time and resources are necessary to care for this vulnerable population and dedicated kitten nurseries are one way to meet the requirements of kittens too young for neutering and rehoming. However, young kittens remain at a higher risk of dying relative to adult cats, even in specialized settings. Efforts to investigate kitten mortality have focused on post-mortem findings and little is known about pre-mortem clinical signs that may be associated with death. The purpose of this study was to elucidate predictors of mortality in underage kittens.

METHODS

The medical records of kittens aged <8 weeks reared in a kitten nursery in New York City during 2017 were examined. The data collected included signalment (estimated age and weight at intake, sex), physical findings (body condition score [BCS]), clinical signs (weight loss, anorexia, diarrhea, upper respiratory tract infection [URI]), diagnoses (panleukopenia, trauma), how early in the feline breeding season the kitten entered (April-November), and whether the kitten had died or was euthanized. The data were analyzed using Cox proportional hazard modeling with 1353 kittens to identify factors associated with any death or euthanasia.

RESULTS

Elevated risk of dying was found for kittens in the lightest weight group (13 times greater), diagnosed with panleukopenia (13 times greater), exhibiting weight loss (>9 times greater), diagnosed with URI (almost four times greater), exhibiting anorexia (three times greater), identified with a low BCS at intake (two times greater) and experiencing diarrhea (almost two times greater).

CONCLUSIONS AND RELEVANCE

These findings identify clinical signs and diagnoses that can serve as prognostic indicators for underage kitten survival in a shelter/rescue setting and can aid in enhancing protocols for monitoring, intervention and euthanasia decision-making.

Infertility in purebred cats - A review of the potential causes

Although purebred cat breeding is growing in popularity in European countries, most research and publications concern dog reproduction. Infertility in queens has been poorly studied. It may not come as a surprise as common domestic shorthair cats are well known for their excellent fertility. However, even in the latter, the infertility rate is around 20%. Only recently, published articles have analyzed the reproductive performances in different breeds, for example in UK, Sweden, France and Italy, and found similar figures. In cats, infertility may arise from many factors such as mismating, prolonged anestrus or silent heats, hormonal, nutritional, genetical or chromosomal causes. Also, infectious diseases, probably frequent in breeding facilities, include pathological agents that are well recognized as having a negative effect on pregnancy or other pathogens for which the involvement in fertility problems is unclear. However, analyzing the literature, it appears that the most prevalent causes of infertility in pedigree cats may well be, in females, uterine pathology (sub-clinical endometritis, cystic endometrial hyperplasia, or mucometra), and in males, teratospermia, which may be "permanent" and linked to reduced heterozygosity or "transient" in tomcats that present normal quantitative spermatogenic parameters. The influence of the breed is unknown. There is an urgent need to study the origin of infertility in purebred cats in order to improve the diagnosis and to develop treatments that may restore normal fertility in subfertile or infertile animals.

Subsidised by junk foods: factors influencing body condition in stray cats (Felis catus)

Domestic cats (Felis catus) are one of the most widely distributed and successful carnivores globally. While cats are popular pets, many unowned, ‘stray’ cats live freely in anthropogenic environments at high densities where they make use of anthropogenic resources. These stray cats present a management challenge due to concerns about wildlife predation, pathogen transmission, public nuisance and threats to cat welfare (e.g. vehicle collisions). In Australia, there are few studies of strays compared with pet cats or feral cats (free-roaming cats in rural areas that are independent of resources provided by humans). To contribute original data about stray cat biology, the carcasses of 188 euthanised stray cats were collected from Perth, Western Australia. Cats were assessed for general health, age, reproduction, diet and gastrointestinal parasite biomass. The influence of cat demographics, collection location, season, parasite biomass, diet and history of supplemental feeding by people were tested against body condition. Overall, strays were physically healthy and reproductive, with few life-threatening injuries or macroscopic evidence of disease; however, helminths were extremely common (95% of cats) and pose a threat. Nearly 40% of strays consumed wildlife, including two species of endemic marsupial. Alarmingly, 57.5% of strays were scavenging vast amounts of refuse, including life-threatening items in volumes that blocked their gastrointestinal tracts. These findings illustrate that strays need to be removed from anthropogenic environments for their own health and welfare and to prevent continued breeding. Targeted control programmes should prioritise removal of cats from areas where refuse is common and where valued native fauna exist.

Ethics in animal breeding

Ethical breeding involves the use of healthy animals true to their species in behaviour and physical appearance, and when applicable, showing a sustainable performance. The concerns for the species/breed are essential parts of the breeding goals, including preservation of genetic resources within the species/breed, and the health and welfare of the individual animal. Ethical and welfare considerations were often not prioritized in developing new breeds of production or companion animals. As a result, animal breeding practices are increasingly becoming part of the debate on animal welfare. In companion animals, breeding for curiosity or "cuteness" may be a goal in itself, although dogs are also bred for utility. In production animals, breeding focus is on performance, i.e., quantitative entities and financial income, rather than physical appearance. For instance, dairy cows are bred to be larger and to have higher milk yields, sows and ewes to produce more offspring, and horses are designed for riding, racing, and companionship. Overbreeding in relation to current demand of horses, cats, and dogs raises welfare issues due to abandonment or killing of horses and millions of cats and dogs every year. There is variable regulation of health requirements for breeding animals in different countries of the world. In many countries, consumers are becoming increasingly aware of animal welfare issues such as negative effects of certain production traits in farm animals, leading to decreased demand for their meat at a time where increased food production is becoming crucial. Amidst these dilemmas are the veterinarians. This paper deals with issues connected to traditional breeding as well as some of the breeding technologies, and includes food safety, ethics, and animal welfare.