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

Impact of compensatory growth on survival in newborn kittens

In the feline species, the mortality of live-born kittens over the first 2 months of life is around 10%. Although some losses are inevitable, progress in veterinary medicine and improved knowledge of feline neonatalogy should make it possible to reduce them to a lower level. The objectives of this study were: (i) to describe early growth in kittens, and (ii) to assess whether low birth weight kittens develop compensatory growth during the first week of life and if so, whether compensatory growth is associated with increased chances of survival. Using data collected from 5,504 kittens born in 193 different French catteries, five growth rates were calculated to reflect the growth of kittens during the first week after birth. Low birth weight kittens had higher growth rates than normal birth weight kittens. In addition, low birth weight kittens whose early growth was in the lowest 25% had a significantly higher 0-2 months mortality rate than all the other groups. Weight loss (or lack of weight gain) between birth and Day 2 was identified as a risk factor for 0-2 months mortality whatever the birth weight category. Finally, critical early growth thresholds were determined separately for low and normal birth weight kittens. These figures could help caregivers to validate the adequacy or inadequacy of kitten early growth. They will be able to quickly identify and provide appropriate care for the kittens whose growth is deemed insufficient in order to improve their chances of survival.

Canine Neonatal Health

This article provides a high-level overview of canine neonatal health for clinicians to use as a mental framework so that when presented with a canine neonate it is easier to construct a logical and systematic clinical approach that is less overwhelming. As early detection of the at-risk neonate results in earlier intervention, and improved health outcomes, there will be a focus on pro-active care. Where appropriate, other articles in this issue will be mentioned for a more in-depth discussion of specific areas. Key points will be highlighted throughout the text.

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.

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.

Relation between the Dam's Weight on Superficial Temperature of Her Puppies at Different Stages of the Post-Partum

The thermal stability of newborns is an essential parameter that can be recorded to evaluate neonatal care. Knowing the thermal windows to evaluate and maintain a constant temperature helps significantly reduce neonatal mortality. This study aimed to assess the superficial temperature alterations in the distinct thermal windows of puppies with mothers of diverse weights and their repercussions. We evaluated the superficial temperature using infrared thermography at eight thermal windows and seven different times: when wet due to the fetal fluid immediately after birth until 24 h of life in newborn puppies from bitches divided into four bodyweight groups. The results revealed a positive correlation between the dam's weight and the ability to achieve thermostability in the newborn puppies in all the evaluated thermal windows. The time effect showed the lowest temperatures when the puppies were still wet, a gradual increase, and the highest temperature at 24 h after birth. The thermal windows with the highest temperatures were abdominal, thoracic, nasal, and upper left palpebral, and those with the lowest were the thoracic limb brachial biceps, thoracic limb elbow, metacarpal, and femoral pelvic limb. A significant increase in the temperatures in the thermal windows of the abdominal, thoracic, and upper left palpebral immediately after ingesting colostrum was observed. The weight of the dams is an important factor that positively intervenes in the thermoregulatory capacity of the puppies, especially when newborns are dry and have been passed 24 h after birth.

Growth charts for small sample sizes using unsupervised clustering: Application to canine early growth

Breed-specific growth curves (GCs) are needed for neonatal puppies, but breed-specific data may be insufficient. We investigated an unsupervised clustering methodology for modeling GCs by augmenting breed-specific data with data from breeds having similar growth profiles. Puppy breeds were grouped by median growth profiles (bodyweights between birth and Day 20) using hierarchical clustering on principal components. Median bodyweights for breeds in a cluster were centered to that cluster’s median and used to model cluster GCs by Generalized Additive Models for Location, Shape and Scale. These were centered back to breed growth profiles to produce cluster-scale breed GCs. The accuracy of breed-scale GCs modeled with breed-specific data only and cluster-scale breed GCs were compared when modeled from diminishing sample sizes. A complete dataset of Labrador Retriever bodyweights (birth to Day 20) was split into training (410 puppies) and test (460 puppies) datasets. Cluster-scale breed and breed-scale GCs were modelled from defined sample sizes from the training dataset. Quality criteria were the percentages of observed data in the test dataset outside the target growth centiles of simulations. Accuracy of cluster-scale breed GCs remained consistently high down to sampling sizes of three. They slightly overestimated breed variability, but centile curves were smooth and consistent with breed-scale GCs modeled from the complete Labrador Retriever dataset. At sampling sizes ≤ 20, the quality of breed-scale GCs reduced notably. In conclusion, GCs for neonatal puppies generated using a breed-cluster hybrid methodology can be more satisfactory than GCs at purely the breed level when sample sizes are small.

The Application of Nurse Stratified Management in Nursing Management

Objective

To explore the application value of nurse stratified management in nursing management.

Methods

One hundred nurses who worked in our hospital from June 2019 to September 2021 were recruited and assigned via the random number table method to an observation group (n = 50) and the control group (n = 50). The control group received routine nursing management, and the experimental group received stratified nursing management. The nursing quality, practice happiness, error rate, patient complaint, and patient satisfaction were compared between the two groups.

Results

The experimental group showed a significantly higher nursing quality than the control group (P < 0.05). The experimental group had significantly higher practice happiness among nurses than the control group (P < 0.05). Stratified nursing management mode resulted in a significantly lower error rate and patient complaint versus routine nursing management mode (P < 0.05). Patients were more satisfied with stratified nursing management than with the routine nursing management (P < 0.05).

Conclusion

The nurse stratified management method effectively improves the nursing quality and practice happiness of nurses, reduces the error rate of nursing and patient complaint, and increases nursing satisfaction.

Growth Curves and Body Condition of Young Cats and Their Relation to Maternal Body Condition

The aim of the present study was to assess factors like litter, individual and maternal effects on kitten overweight at 8 months of age, defined as body condition score (BCS) ≥ 6, in an intact cat family. To minimize confounding, a homogenized cat population was used. After categorization of the life weight data according to the kittens’ sex, BCS and maternal non-pregnant phenotype (overweight (OM), lean (LM), variable (VM)), analyses including Pearson’s correlation coefficients, two-way ANOVA, linear, linear broken-line regression and repeated measures mixed model analyses were performed. Overweight and OM kittens gained weight most quickly, and females reached their peak weight earlier than males (6.2 ± 0.6 vs. 7.4 ± 0.2 months). In females but not in males the age to reach peak weight differed markedly according to category. Male (5.82 ± 0.09, p < 0.01) and OM kittens’ (5.80 ± 0.11, p = 0.07) BCS at 8 months was higher and they were heavier than their counterparts, from 3 and 5 months onwards, respectively. Litter size negatively correlated with overweight (r = −0.30, p < 0.01) and birthweight showed a positive correlation to live weight (R2 = 0.05, p = 0.05) and monthly weight gain (R2 = 0.18, p < 0.01) over time. This study supports routine monitoring of birthweight, growth rate and maternal phenotype prior to pregnancy to identify kittens at risk for becoming overweight.

Strategies for Hypothermia Compensation in Altricial and Precocial Newborn Mammals and Their Monitoring by Infrared Thermography

Thermoregulation in newborn mammals is an essential species-specific mechanism of the nervous system that contributes to their survival during the first hours and days of their life. When exposed to cold weather, which is a risk factor associated with mortality in neonates, pathways such as the hypothalamic–pituitary–adrenal axis (HPA) are activated to achieve temperature control, increasing the circulating levels of catecholamine and cortisol. Consequently, alterations in blood circulation and mechanisms to produce or to retain heat (e.g., vasoconstriction, piloerection, shivering, brown adipocyte tissue activation, and huddling) begin to prevent hypothermia. This study aimed to discuss the mechanisms of thermoregulation in newborn domestic mammals, highlighting the differences between altricial and precocial species. The processes that employ brown adipocyte tissue, shivering, thermoregulatory behaviors, and dermal vasomotor control will be analyzed to understand the physiology and the importance of implementing techniques to promote thermoregulation and survival in the critical post-birth period of mammals. Also, infrared thermography as a helpful method to perform thermal measurements without animal interactions does not affect these parameters.