Natural and artificial hyperimmune solutions: Impact on health in puppies

Topics on maternal, fetal and neonatal immunology of dogs and cats

Birth and the first few weeks of age are critical periods of developing the immune system of puppies and kittens and adapting to an environment containing a variety of infectious agents. The survival rate during these periods depends mainly on the newborn's immune capacity to prevent and combat infections. Although most components of innate and adaptive immunity are present at birth, responses are slow and immature compared to adults. Due to immunological immaturity and the endotheliochorial placental structure, circulating concentrations of immunoglobulins in dogs and cats at birth are quite low. Thus, newborns need a prompt and immediate immune response, which is essentially provided by defense cells and maternal antibodies via colostrum. Failure to ingest colostrum is correlated with high mortality rates in the neonatal period. Concurrently, factors related to pregnant, such as pregnancy physiological immunosuppression and nutritional and health states, can directly influence newborn immunity and health. Therefore, understanding the maternal and neonatal immunological aspects, importance of colostrum, risk factors for failure to transfer passive immunity and colostrum substitute strategies are essential to ensure the survival of the litter.

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.

Effect of an Enteroprotective Complementary Feed on Faecal Markers of Inflammation and Intestinal Microbiota Composition in Weaning Puppies

Weaning entails numerous modifications of the intestinal structure and microbiota composition, making puppies at high risk of sickness during this delicate life stage. The aim of this study was to investigate the effects of a four-week administration of a supplement composed of ultramicronised Palmitoylethanolamide, bovine colostrum and Bacillus subtilis (Normalia® Extra, Innovet Italia Srl, Saccolongo, Italy) on markers of gut health and microbiome of weaning puppies. Twenty-nine four-week-old Golden Retriever puppies were randomly assigned to control (CG, n = 13) and treated (TG, n = 16) groups. During the whole experimental time, there were no differences between the groups with regard to average daily gain and faecal score. In TG, faecal calprotectin and zonulin values were statistically significantly decreased compared to CG, especially at week 8 (zonulin: 42.8 ± 1.54 ng/mL and 55.3 ± 42.8 ng/mL, and calprotectin: 2.91 ± 0.38 µg/g and 5.71 ± 0.43 µg/g, in TG and CG, respectively; p < 0.0001 for both comparisons). Bacteria belonging to phylum Campylobacterota decreased (p = 0.04), while those referring to genera Coprococcus and Pseudomonas increased (p = 0.01 and p = 0.04, respectively). The supplementation of the tested complementary feed can promote the intestinal health of puppies and therefore facilitate weaning by lowering gut inflammation.

Two Types of Management for the Noninvasive Treatment of Pectus Excavatum in Neonatal Puppies-Case Reports

Pectus excavatum is a deformity of the thorax characterized by ventrodorsal narrowing of the sternum bone and costal cartilages, which can lead to compression and cardiopulmonary alterations in dogs, presenting a high prevalence in brachycephalic breeds. The aim of this report was to describe two types of management for the noninvasive treatment of pectus excavatum in newborn puppies of the breeds French Bulldog and American Bully. The puppies presented dyspnea, cyanosis and substernal retraction during inspiration. The diagnosis was performed by physical examination and confirmed by chest X-ray. Two types of splints were performed (a circular splint with plastic pipe and a paper box splint on the chest), aiming at thoracic lateral compression and frontal chest remodeling. The management was effective for the conservative treatment of mild-grade pectus excavatum, resulting in the repositioning of the thorax and improvement of the respiratory pattern.

Dead or Alive? A Review of Perinatal Factors That Determine Canine Neonatal Viability

Simple Summary

The article summarizes the current knowledge on factors related to pregnancy, parturition, and newborns that affect the health status of a puppy and determine its chances for survival and development. The detailed information is provided in terms of breed predispositions, objectives of pregnancy monitoring, potential sources of complications, and veterinary advances in care and treatment of perinatal conditions. Successful pregnancy outcomes still pose challenges in veterinary neonatology; thus, publications presenting the current state of knowledge in this field are in demand.

Abstract

The perinatal period has a critical impact on viability of the newborns. The variety of factors that can potentially affect the health of a litter during pregnancy, birth, and the first weeks of life requires proper attention from both the breeder and the veterinarian. The health status of puppies can be influenced by various maternal factors, including breed characteristics, anatomy, quality of nutrition, delivery assistance, neonatal care, and environmental or infectious agents encountered during pregnancy. Regular examinations and pregnancy monitoring are key tools for early detection of signals that can indicate disorders even before clinical signs occur. Early detection significantly increases the chances of puppies’ survival and proper development. The purpose of the review was to summarize and discuss the complex interactions between all elements that, throughout pregnancy and the first days of life, have a tangible impact on the subsequent fate of the offspring. Many of these components continue to pose challenges in veterinary neonatology; thus, publications presenting the current state of knowledge in this field are in demand.

Canine parvovirus-2: An Emerging Threat to Young Pets

Canine parvovirus-2 (CPV-2) is a highly contagious and key enteropathogen affecting the canine population around the globe by causing canine parvoviral enteritis (CPVE) and vomition. CPVE is one of the the leading causes of morbidity and mortality in puppies and young dogs. Over the years, five distinct antigenic variants of CPV-2, namely CPV-2a, CPV-2b, new CPV-2a, new CPV-2b, and CPV-2c, have emerged throughout the world. CPV-2 infects a diverse range of wild animals, and the newer variants of CPV-2 have expanded their host range to include felines. Despite the availability of highly specific diagnostics and efficacious vaccines, CPV-2 outbreaks have been reported globally due to the emergence of newer antigenic variants, expansion of the viral host range, and vaccination failures. The present chapter describes the latest information pertaining to virus properties and replication, disease manifestations in animals, and an additional recent updates on diagnostic, prevention and control strategies of CPV-2.

Neonatal sepsis in dogs: Incidence, clinical aspects and mortality

The neonatal period in dogs remains associated with high mortality rates. Sepsis is the main cause of neonatal losses during the first three weeks of life. Additionally, failure in the clinical assessment and early diagnosis of sick newborns is still common, leading to inadequate care, which contributes to a high mortality rate. Thus, the objective of this study was to describe the incidence of sepsis in canine newborns, the clinical aspects involved, the main isolated bacterial agents and mortality rates to facilitate clinicians' early recognition of this condition. Of the 152 litters and 762 neonates evaluated, 14.8% (113/762) had sepsis or septic shock, and the mortality rate among affected puppies was 25.6% (29/113). Among the puppies with sepsis that died, early mortality (0-2 days of age) occurred in 69% (20/29) of affected neonates, and late mortality (3-30 days of age) occurred in 31% (9/29) of affected neonates. Significant differences (p < 0.0001) in clinical parameters (heart and respiratory rates, blood glucose, body temperature, peripheral oxygen saturation and reflexes) were noted among healthy neonates and neonates with sepsis and septic shock. The main and most relevant clinical signs were apathy, a reduced sucking reflex, diarrhea, the neonatal triad, failure to gain weight, bradycardia, dyspnea, cyanotic mucous membranes, body erythema, reduced peripheral oxygen saturation, cyanosis and tissue necrosis in the extremities. The mother may have been the main source of infection for 87.6% (99/113) of neonates with sepsis. Most infections were transmitted during pregnancy (68%, 77/113) in cases of neonatal sepsis. The major source of infection for neonates was the uterus, followed by breast milk and maternal oropharyngeal secretions. The most frequently isolated bacterial agent was Escherichia coli, accounting for 25.6% (29/113) of sepsis cases. The morbidity and mortality of neonatal sepsis in dogs is high. The clinical evaluation and diagnosis of sepsis in neonates differ from those in adult animals. Thus, knowledge of the neonatal particularities of sepsis is essential for proper clinical management and greater survival of these patients.

Nutritional and Functional Properties of Colostrum in Puppies and Kittens

Simple Summary

The post-natal period is a crucial time for all animal species. During the course of their first two weeks of life, puppies and kittens face several risks to their health due to their scarce energy storage and weak immune system. Colostrum is the first production of the mammary glands that plays a pivotal role for puppies and kittens. Colostrum is an important source of immunoglobulins and key nutrients such as lipids and carbohydrates, which are fundamental for the health of newborns. Puppies and kittens must ingest a sufficient amount of colostrum within a few hours of birth to ensure their survival. On the other hand, there are some particular compounds that are not strictly essential, but their presence may play an important role in nutrition and health. As there are no recent studies on companion animals, we have reported published articles describing animal studies in different species to review the nutrition of newborn mammals, with particular emphasis on companion animals.

Abstract

The present review aims toward a better understanding of the nutrition of newborn puppies and kittens. The post-natal period is very sensitive in dogs and cats, as in other animal species. During the first two weeks of life, puppies and kittens are at high risk of dehydration, hypothermia, and hypoglycemia, as well as infectious diseases as they start to acquire the physiological functions of the adult. Neonatal hepatic glycogen storage is low, and newborns depend on colostrum intake to survive. Colostrum provides immunoglobulins and other important substances such as lipids and carbohydrates. Immunoglobulins are central to the immunological link that occurs when the mother transfers passive immunity. The mechanism of transfer varies among mammalian species, but in this review, we focused our attention on dogs and cats. Furthermore, there are components of colostrum which, although their presence is not absolutely necessary, play an important role in nutrition. These components have received considerable interest because of their presumed safety and potential nutritional and therapeutic effects both in humans and animals; however, unfortunately, there are few recent studies in companion animals. Here, we have gathered the published articles that describe studies involving different species of animals, emphasizing companion animals. In particular, the purpose of this narrative of the nutritional and functional proprieties of queens’ and bitches’ colostrum.

[Prevention of canine parvovirosis - Part 1: Humoral and cellular immunity]

Canine parvovirosis remains a common and highly infectious disease. Thus, adequate protection is essential for all dogs at any time. In this, humoral immunity plays an essential role. The presence of antibodies in adult dogs suggests immunity against the disease, and nearly all adult dogs possess antibodies (either due to previous vaccination or infection). Meanwhile, worldwide vaccination guidelines recommend measurement of pre-vaccination antibodies instead of regular triennial re-vaccinations in adult dogs. Studies have demonstrated a long lasting duration of immunity against canine parvovirus. Re-vaccination therefore possesses no beneficial effect when dogs already have pre-vaccination antibodies. Thus, when antibodies are present, unnecessary re-vaccinations that potentially cause vaccine-associated adverse events should be avoided. Hemagglutination inhibition and virus neutralization can be performed in specialized laboratories for quantitative antibody titer measurement. Semiquantitative point-of-care (POC) tests for detection of CPV antibodies are available. Since the presence of CPV antibodies in adult dogs that have been vaccinated or previously infected suggests adequate immunity against disease, these POC tests can be a useful tool in practice. They identify dogs that might potentially be unprotected and require re-vaccination during preventive health care appointments. Concerning the POC tests' quality assessment, a high specificity (low number of false positive test results) is considered the most important feature.

Canine colostrum exosomes: characterization and influence on the canine mesenchymal stem cell secretory profile and fibroblast anti-oxidative capacity

Background

Canine colostrum milk (CCM) is a specific secretion of the mammary gland that is fundamental for the survival of the newborn. CCM has many described components (immunoglobulins, proteins or fat), but its small vesicles, named exosomes, are largely unknown.

Results

A characterization of CCM exosomes was performed. Exosomes were abundant in CCM and appeared with the characteristic cup-shaped morphology and well-defined round vesicles. The size distribution of exosomes was between 37 and 140 nm, and western blot analysis showed positive expression of specific exosomal markers. Proteomic analysis revealed a total of 826 proteins in exosome cargo. We also found that exosomes modified the proliferation and secretory profiles in canine mesenchymal stem cells derived from bone marrow (cBM-MSCs) and adipose tissue (cAd-MSCs). Additionally, CCM exosomes demonstrated a potent antioxidant effect on canine fibroblasts in culture.

Conclusions

Our findings highlight, for the first time, the abundant presence of exosomes in CCM and their ability to interact with mesenchymal stem cells (MSCs). The addition of exosomes to two types of MSCs in culture resulted in specific secretory profiles with functions related to angiogenesis, migration and chemotaxis of immune cells. In particular, the cAd-MSCs secretory profile showed higher potential in adipose tissue development and neurogenesis, while cBM-MSC production was associated with immunity, cell mobilization and haematopoiesis. Finally, exosomes also presented antioxidant capacity on fibroblasts against reactive oxygen species activity within the cell, demonstrating their fundamental role in the development and maturation of dogs in the early stages of their life.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12917-020-02623-w.

Passive immune transfer in puppies

The puppy, born without immunoglobulins G (IgG), acquires a passive systemic immunity thanks to colostrum intake during the two first days of life. The quality of passive immune transfer (i.e. blood IgG concentration at two days of age), highly variable between litters and between puppies within litters, depends mainly on the time elapsed between birth and ingestion of colostrum, with limited influence of colostrum IgG concentration. Deficit in passive immune transfer, impacting puppy's health and neonatal mortality rate, can be indirectly diagnosed through blood gammaglutamyltransferases assay and evaluation of growth rate over the two first days of life. In the absence of maternal colostrum, few homo- and heterospecific immune sources are available and canine colostrum banking remains the optimal solution. Whereas passive immune transfer is crucial for survival during the neonatal period, it later interferes with response to vaccination. In addition to systemic passive immune transfer, maternal antibodies (mainly IgA) would provide local (digestive) immunity, ensuring mid-term protection of the puppies' gut together with probably long term training of the digestive immune system.