The pathological newborn in small animals: the neonate is not a small adult

The rate of perinatal death is variable but highest during parturition, immediately after birth and in the first days of life. Infectious diseases, above all bacterial, are the second most important cause of mortality after losses during parturition. A lot of factors are involved predisposing puppies and kittens to bacterial infections: respiratory distress, hypothermia, hypoglycaemia, dehydration, congenital abnormalities. E. coli, streptococci and staphylococci, Klebsiella sp., Pseudomonas sp., Enterobacter sp., Proteus sp. and anaerobes are regularly involved in bacterial infections in neonates. Postmortem findings especially document E. coli, Staphylococcus or Streptococcus species as causes of disease and death shortly after birth. The environment and mothers are suspected as sources of infection (vaginal discharge, milk, faeces, oropharynx, skin) for puppies and kittens. Genetic relatedness of bacterial strains in puppies and their mothers was found in staphylococci and E.coli. These results indicate that for repeated cases of bacterial infections in neonates diagnostic procedures of milk, vaginal and faecal swabs from bitches result in isolation of the responsible bacteria with a high probability and suggest that preterm treatment could help to control bacterial diseases and losses in pups.

     

Cause, occurrence, and clinical signs of mastitis and anorexia in cows in a Wisconsin study

Microbiologic culture revealed the following cause of mastitis and anorexia in 145 cows in Wisconsin to be Escherichia coli, 66 cows; Klebsiella spp, 3; Corynebacterium pyogenes, 27; streptococci, 21; staphylococci, 20; yeasts, 1; and no bacterial growth, 7. Mastitis was detected with approximately equal frequency throughout the year. Escherichia coli was isolated throughout the year, but was more common and was the predominant organism during the summer. Corynebacterium pyogenes was isolated most often in winter and spring; streptococci in fall, winter, and spring; and staphylococci throughout the year. Corynebacterium pyogenes caused most of the mastitis in nonlactating cows. Escherichia coli, C pyogenes, streptococci, and staphylococci were isolated with about equal frequency at parturition, whereas E coli was the predominant cause of mastitis in early and late lactation. Of cases of mastitis, 27% were seen 10 days before and after parturition. Local and systemic clinical signs of infection were similar for all causes, except that C pyogenes caused more (P less than 0.01) malodorous and purulent milk than did other organisms and was isolated more commonly from quarters with injured teats. Recovery was significantly (P less than 0.01) higher in cows with E coli infections, compared with recovery in cows with gram-positive organism infections. Cows with C pyogenes infections frequently had quarters that ultimately ceased lactation. A few cows were recumbent at initiation of antimicrobial therapy and a few were not eating 24 hours later; however, 50% of these cows recovered. Criteria such as season of year, stage of lactation, appearance of milk and udder, and appetite permitted the cause (gram-negative or gram-positive organisms) of the mastitis to be predicted with 77% accuracy.     

产后奶牛子宫内微生物菌群动态变化及其与子宫黏液性状关系的研究

本文旨在研究奶牛产后子宫内优势菌群随时间的动态变化及细菌种类与子宫黏液性状之间的关系,以便于临床的快速诊断及治疗。选取分娩日期临近、产后子宫黏液性状不同的荷斯坦奶牛42头,于分娩后10、20、30和40d采集子宫黏液,体外培养法进行细菌分离、鉴定。结果显示,产后奶牛子宫内分离率最高的细菌分别为大肠杆菌(85.7%)、变形杆菌(64.3%)和葡萄球菌(61.9%);除大肠杆菌在整个试验期分离率均较高外,产后10、20、30和40d优势细菌分别为葡萄球菌、产气荚膜梭菌、沙门氏菌和葡萄球菌。白色或灰白色脓性黏液,黄色或土黄色黏液中细菌平均分离株数(5.6±0.4,5.5±1.4)高于清亮透明黏液(3.5±1.6),其中沙门氏菌、变形杆菌、链球菌和化脓隐秘杆菌产后30和40d的分离株数高于清亮黏液,说明其可能与白色或黄色脓性黏液的出现相关;产后40d黄色或土黄色化脓性黏液可能与产气荚膜梭菌的出现相关;而粪肠球菌和嗜酸乳杆菌产后20、30、40d在脓性黏液中分离数高于清亮黏液,说明其作为有益菌可能在分泌不正常黏液的子宫内具有抵抗病原菌的作用。结果表明,产后奶牛子宫内优势菌群呈动态变化,子宫黏液性状与特异病原菌的出现有关。     

Immunoglobulin concentrations in feline colostrum and milk, and the requirement of colostrum for passive transfer of immunity to neonatal kittens

The purpose of this study was to clarify whether cats have a colostral and milk phase of lactation differentiated by concentrations of immunoglobulins, and whether colostrum ingestion by newborn kittens is essential for optimal transfer of passive immunity. Milk from specific pathogen-free queens was analyzed for IgG and IgA concentrations from parturition through 6 weeks of lactation. Serum IgG and IgA concentrations from birth through 8 weeks of age were determined for colostrum-fed kittens, colostrum-deprived kittens that were fed a milk replacer, and colostrum-deprived kittens that were fostered onto queens in the milk phase of lactation. The total IgG and IgA concentrations in milk were significantly higher on the day of parturition than on day 7 of lactation, indicating cats do have a colostral phase of lactation. The predominant immunoglobulin in both colostrum and milk was IgG. The serum IgG concentrations in colostrum-deprived kittens fostered on queens in the milk phase of lactation were similar to colostrum-deprived kittens fed a milk replacer, and the concentrations were significantly lower than in colostrum-fed kittens for the first 4 weeks of life. The serum IgA concentrations in both colostrum-deprived groups were significantly lower than colostrum-fed kittens on day 2 after parturition, but were similar thereafter. Colostrum-deprived kittens fostered onto queens in the milk phase of lactation had failure of passive transfer of maternal antibodies. Protective concentrations of immunoglobulins can be restored in kittens with failure of passive transfer of immunity by parenteral administration of adult cat serum, but not by fostering on queens in mid-lactation.     

Milk substitutes and the hand rearing of orphan puppies and kittens

Growth in puppies and kittens during the suckling period is briefly reviewed. The nutrients required for this are discussed, as is their provision in bitch and queen milk. The use of milk substitutes in the rearing of orphan puppies and kittens is considered. The composition of a variety of milk substitute diets is determined, and the nutritive value of each product assessed.     

Bacteriological status of canine milk and septicaemia in neonatal puppies--a retrospective study

Results of the bacteriological examination of milk samples from 46 bitches were evaluated retrospectively, and correlated with findings of the bacteriological examination of organs from dead, septicaemic puppies in their litters (n = 33). The aim of this study was to investigate, in how many cases of clinical and subclinical mastitis of the bitches, the same bacteria can be detected in their septicaemic neonates. One group of lactating bitches was clinically healthy (group I, n = 38), whereas in eight bitches different puerperal disorders were found (group II). Twenty-five septicaemic puppies were from group I, eight from group II. Out of a broad spectrum of bacteria isolated from the milk of clinically healthy and diseased bitches, only Escherichia coli, Klebsiella pneumoniae and/or ss-haemolytic (haem.) Streptococcus sp. could be isolated from organs of their septicaemic puppies. This was the case in three bitches with mastitis and in one clinically healthy bitch only. Staphylococcus intermedius, although frequently isolated from canine milk, does not seem to be a cause of septicaemia in neonates. It is assumed that in most cases of neonate septicaemia, bacteria from the bitches' milk are not the primary cause.     

The toll-like receptor-4 (TLR-4) pathway and its possible role in the pathogenesis of Escherichia coli mastitis in dairy cattle

Mastitis is one of the most costly production diseases in the dairy industry that is caused by a wide array of microorganisms. In this review, we focus on the Gram-negative Escherichia coli infections that often occur at periods when the innate immune defence mechanisms are impaired (i.e., parturition through the first 60 days of lactation). There is substantial evidence demonstrating that at these periods, the expected influx of polymorphonuclear neutrophil leukocytes (PMN) into the mammary gland is delayed during inflammation after intramammary infection with E. coli. Here, we provide some hypotheses on the potential mechanisms of action on how the disease may develop under circumstances of immunosuppression, and describe the potential involvement of the toll-like receptor-4 signal transduction pathway in the pathogenesis of E. coli mastitis. In addition, some ideas are proposed to help prevent E. coli mastitis and potentially other diseases caused by Gram-negative infections in general.     

Growth characteristics of Staphylococcus aureus and Escherichia coli in whey from sequentially infected milk

The growth of Staphylococcus aureus and Escherichia coli was followed in bovine whey samples which had been prepared from milk previously incubated with cultures of S. aureus or E. coli. Staphylococcal strains were divided into 2 groups according to their ability to form compact or diffuse colonies on serum soft agar, which is related to the absence or presence of capsule respectively. The growth of compact staphylococci was dependent on the bulk tank milk used whereas diffuse colony forming staphylococci grew equally well in all bulk milk, also in all inoculated milk. The growth of E. coli was markedly enhanced in whey samples prepared from milk preincubated with staphylococci. However, clear growth inhibition was seen with E. coli and S. aureus strains when grown in whey prepared from milk preincubated with E. coli. Results indicate that the growth promotion of pathogens due to compositional changes in milk are of importance during the course of infection because the growth pattern on staphylococci is dependent on these compositional changes. The growth-inhibitory effects caused by E. coli may explain difficulties in isolating this organism.     

Dimensions and histologic characteristics of the small intestine of dogs during postnatal development

OBJECTIVE: To quantify dimensions of the small intestine of dogs and describe changes in histologic characteristics of the mucosa during postnatal development. SAMPLE POPULATION: Gastrointestinal tract tissues obtained from 110 Beagles (15 adult females and 95 puppies of both sexes). PROCEDURE: Several variables (length, total weight, mucosal weight, and nominal surface area) of the small intestine were measured in puppies at birth but before suckling; 1 day after birth and subsequent suckling, 21, 42, and 63 days after birth, and in the adult dams of the puppies. Tissue structure was examined and quantified at each time point by use of routine histologic examination and ocular micrometry of formalin-fixed specimens stained with H&E. RESULTS: Small intestinal dimensions increased throughout development with the greatest proportional changes during the first day after birth and onset of suckling. Villus height decreased during suckling but had consistent values from 42 days after birth to maturity, whereas crypt depth increased from birth to maturity. Vacuolated enterocytes were evident from birth to 21 days but not thereafter. CONCLUSIONS AND CLINICAL RELEVANCE: Increases in intestinal dimensions provide growing dogs with a greater capacity for digestion and absorption. Changes in mucosal architecture and cell populations coincided with shifts in dietary inputs. These findings may assist in the diagnosis of small intestinal diseases and nutritional responses during growth and development of dogs.     

PREWEANING MORTALITY IN THE PIG

The relative importance of the various causes of preweaning mortality in the pig was determined from the results of autopsy and laboratory examinations on 718 animals. Conditions associated with parturition accounted for 25.1% of the losses, while physical factors (33.0%), starvation (12.8%) and septicaemia (10.9%) were the most common causes of death in piglets which were born alive. In contrast enteric diseases, viral infections, genetic conditions and various miscellaneous diseases played a relatively minor part. Some biological factors affected the prevalence of the various causes of death. Most losses from physical factors, starvation and septicaemia occurred during the first 4 days of life, while other infectious conditions were more common in older piglets. Large litters at birth had significantly more deaths associated with parturition and due to physical factors and starvation. Increased losses from physical factors occurred in the litters of gilts and sows of parity 5. The size of the enterprise and the use of farrowing crates combined to influence the extent of losses due to physical factors. A significantly higher mortality occurred in the large piggery in which crates were not used. The large units also had fewer deaths resulting from starvation.     

Transmission of feline leukaemia virus in the milk of a non-viraemic cat

The possibility of the transmission of feline leukaemia virus (FeLV) from latently infected cats was studied. Five female cats with latent infections were examined for evidence of transmission of the virus to their kittens. One of the cats infected members of four consecutive litters of kittens which subsequently became persistently viraemic and transmitted the virus to other susceptible kittens by contact. Shortly after birth its kittens were apparently FeLV-free since neither viral antigen nor infectious virus was detected in their blood and no virus was found in cell cultures made from aspirates of bone marrow. The kittens became viraemic from 45 days of age onwards at a time when their passively acquired colostral FeLV neutralising antibodies were no longer detectable. Transmission of the virus occurred via the milk since both FeLV antigen and infectious virus were found in milk samples taken six weeks after kittening and the virus was transmitted to a fostered kitten. Eleven weeks after the birth of the fourth litter the cat became viraemic. The intermittent presence of FeLV antigens detected by the Leukassay F test, but not infectious virus, in the plasma of this cat over the previous months and a low level of serum neutralising antibodies distinguished it from four other latently infected queens which did not transmit infection to their kittens. These factors may indicate a risk of milk transmission and reactivation of latent virus.     

Orphan rearing of puppies and kittens

The following are some of the key elements to successful rearing of the orphaned puppies and kittens: Do not overfeed, especially during the first several days, to allow for adaptation to the milk replacer. Use a milk replacer with a composition similar to the natural milk. Cleanliness during feeding is essential. Weigh the animals periodically to monitor performance and establish feeding levels. Maintain a warm, draft-free environment with adequate humidity. Keep the animals clean and aid their bowel movements and urination if necessary. Feeding frequency should allow for stomach emptying before feeding. Control diarrhea as soon as possible by the suggested methods. If it becomes necessary to re-establish desirable bacterial populations in the gastrointestinal tract, a suitable live culture such as Bene-Bac may be used. Other supportive therapy may be necessary. Make all formula or ration changes slowly. Start the animals on some solid food as soon as possible and certainly by age 3 to 5 weeks, depending on the species. These 10 guidelines will allow for successful rearing of orphaned puppies and kittens. To follow them requires patience and attention to detail. The goal is the preservation of life and a sound program of nutrition and management throughout the nursing period.     

Objective evaluation of the immunogenic effectiveness of polyvalent vaccines against enteral infections of newborn calves under enzootic conditions

For evaluating the protective effect of polyvalent vaccine against diarrhoea in new born calves caused by rotaviruses, coronaviruses and enterotoxigenic E. coli the method was selected of mathematical and statistical analysis of the set of data characterizing the most important clinical symptoms of the disease during the first three weeks after birth. In two large-scale breeds with a mass occurrence of diarrhoea of the known etiology the state of health of calves before the vaccine application was compared with the state of health of calves born in the period after the vaccination. The following traits were selected for evaluating the severity of the disease: the age of calf at the beginning of the disease, character and intensity of diarrhoea, length of disease and results of treatment. In all the selected indicators, statistically significant differences were determined pointing to the fact that the vaccine used for increasing the immunity against enteropathogenic viruses and bacteria, applied in high pregnant cows and heifers before parturition, protected the sucking calves and calves fed the milk of their mothers against the disease in the first week after birth. The diarrhoea, occurring in the calves of the vaccinated cows and heifers mostly during the second week of age was easy to treat therapeutically and ended in most cases after a short period of a tea diet. After the vaccination, the death loss in both localities decreased more than eight times.     

Investigations into the prevention of prenatal and lactogenic Toxocara canis infections in puppies by application of moxidectin to the pregnant dog

Aim of the investigation was to examine whether two administrations of moxidectin to pregnant dogs could prevent pre-natal and lactogenic infections of puppies with reactivated Toxocara canis larvae. Four pregnant beagles, infected experimentally with 20 000 embryonated eggs of T. canis, were treated subcutaneously with 1 mg moxidectin per kg body weight on days 40 and 55 of pregnancy (5-13 days before parturition). One further dam and its puppies served as untreated control. Two applications of moxidectin completely prevented pre-natal and lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae were found in the dams or their corresponding puppies. All puppies and dams of the treatment group remained coproscopically negative until 42 days after parturition. The administration of moxidectin did not show any side effects in the dams. None of the puppies of the treated dams showed any pathological abnormalities. In the untreated dam one adult and 26 somatic larvae of T. canis were detected at necropsy. All puppies of the untreated dam showed a patent T. canis infection from day 28 post-natum (p.n.); 296 pre-adult and adult stages of T. canis were spontaneously eliminated and 51 intestinal stages and five somatic larvae of T. canis were recovered at necropsy. In contrast to the puppies of the treated dams all negative control puppies showed blood eosinophilia after parturition and elevated liver enzyme levels.     

Feline calicivirus infection in kittens borne by cats persistently infected with the virus

On the basis of repeated isolation of feline calicivirus (FCV) from oropharyngeal swabs four to eight months after exposure to FCV strain 255, four carrier queen cats were identified. These cats gave birth to 16 kittens. Litters were individually housed with their mothers until nine weeks of age and were monitored virologically and serologically from birth until 15 weeks old. All kittens became infected between three and nine weeks old and shed FCV consistently for periods of three to 11 weeks. Clinical signs of FCV were observed in 11 kittens but none developed severe respiratory disease. At the time of initial infection maternal antibody titres in the kittens ranged from 1:4 to 1:24. Within one to three weeks of infection titres began to rise. The results indicated that kittens of queen cats persistently infected with FCV frequently experience mild or subclinical immunising infections.     

Prevalence and associations between bacterial isolates from dry mammary glands of dairy cows

To assess the prevalence and patterns of bacterial isolates, cultures were made from the dry mammary glands of dairy cows in six commercial dairy herds in the UK. Milk samples were taken from all four quarters of 480 cows at drying off and at weekly intervals from 14 days before to seven days after calving. A major mastitis pathogen was isolated from at least one quarter of 220 (45.8 per cent) of the cows and from more than one quarter of 90 (18.8 per cent) of them. During the late dry to calving period, of the 957 quarters with three culture results, a major mastitis pathogen was cultured from 236 (24.7 per cent) quarters of 186 (38.8 [corrected] per cent) cows. The most commonly isolated major pathogen was Escherichia coli, followed by Streptococcus uberis and coagulase-positive staphylococci. There were significant differences between the patterns of isolates from different farms and in different calving months, suggesting that the rate of infection was partially dependent on external conditions. The isolation of E. coli, S. uberis or coagulase-positive staphylococci from a cow during the late dry/periparturient period was associated with an increased risk of that cow being culled in the next lactation. Bayesian general linear mixed models were used to assess the associations between the different bacterial species. The probability of isolating either E. coli or S. uberis was significantly greater when the other organism was cultured in a milk sample; this was also true of coagulase-positive staphylococci and S. uberis. When Corynebacterium species were isolated from a milk sample, the probability of isolating coagulase-positive staphylococci or S. uberis decreased significantly, and when coagulase-negative staphylococci were isolated the probability of isolating coagulase-positive staphylococci was reduced.     

Investigations into the prevention of neonatal Ancylostoma caninum infections in puppies by application of imidacloprid 10% plus moxidectin 2.5% topical solution to the pregnant dog

The aim of the investigation was to examine whether a single topical administration of a combination of imidacloprid and moxidectin to pregnant dogs could prevent neonatal infections with reactivated Ancylostoma caninum larvae. Three pregnant beagles, infected with A. caninum, were treated topically with the combination on day 56 of pregnancy. Three further dogs served as untreated controls. Treatment appeared to prevent neonatal infections in the puppies completely. Neither intestinal stages nor somatic larvae were found in two examined puppies per litter. All puppies and dams of the treatment group remained coproscopically negative. No side-effects in dams or puppies were observed. Two of three untreated dams showed a patent infection after parturition. Necropsy of two puppies of each negative control litter revealed seven intestinal and five somatic A. caninum stages in total. One litter of the untreated dams showed a patent infection 33 days after parturition. In the other two litters, no representative sample sizes could be collected.     

Investigations into the prevention of neonatal Ancylostoma caninum infections in puppies by application of moxidectin to the bitch.

The aim of this investigation was to examine whether reactivated Ancylostoma caninum larvae can be eliminated by the administration of moxidectin to pregnant bitches. Four pregnant bitches infected experimentally with 20,000 third-stage larvae of A. caninum were treated subcutaneously with 1 mg moxidectin/kg body weight on day 55 of the pregnancy (5-8 days before parturition). Another four experimentally infected pregnant bitches served as controls. The single moxidectin treatment completely prevented lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae could be found. The administration of moxidectin caused no local or systemic side-effects in the bitches. All 22 puppies of the treated bitches were born healthy and remained so during the whole trial period. Beginning during the third week after birth, all 20 puppies of the untreated bitches developed a severe microcytic, hypochromic anaemia and they revealed a total of 8649 intestinal stages of A. caninum after autopsy.     

Assessment of the aerobic faecal microflora in mink (Mustela vison Schreiber) with emphasis on Escherichia coli and Staphylococcus intermedius

The present study was undertaken to investigate the culturable aerobic faecal microflora of mink from newborn until adulthood with emphasis on the potential pathogens Escherichia coli and beta-haemolytic coagulase positive staphylococci. Rectal swabs were taken from 10 healthy dams and their offspring on seven mink farms throughout the production season and a semi-quantitative enumeration of total E. coli and haemolytic E. coli, beta-haemolytic streptococci, beta-haemolytic coagulase positive staphylococci, total lactic acid bacteria, and enterococci was carried out in all samples using selective and non-selective media.Aerobic bacteria were cultured from close to 100% of the samples throughout the survey. Prevalence of E. coli isolates varied between 70 and 90% of the samples throughout the survey with a small decline at the end of the study period. The highest bacterial counts were found among recently weaned kits or kits in the early growth period (P<0.0012). Lactic acid bacteria and enterococci were isolated from more than 90% of all samples, while beta-haemolytic staphylococci were isolated from 20 to 70% of the samples. While beta-haemolytic staphylococci were dominant from birth and during the nursing period, counts of staphylococci gradually decreased during the nursing period and were outnumbered by E. coli during the growth season.     

Proteinuria and immunoglobulinuria in neonatal dogs

Samples of urine and serum from 45 newborn rottweiler puppies from six litters, and milk from their mothers, were taken 24, 48 and 72 hours and seven and 14 days after birth. Urine total protein and creatinine concentrations were determined and the ratios calculated. The immunoglobulin (Ig) concentrations of IgG, IgM and IgA in urine, serum and milk were determined with a commercially available elisa kit. The concentration of total protein in urine decreased from 1.64 to 0.29 mg/ml, and it and the ratio of total protein to creatinine in the urine of the neonatal puppies exceeded the normal values for adult dogs, but all the puppies developed normally. The average concentration of IgG in urine decreased from 0.0035 to 0.0003 mg/ml, that of IgA from 0.0035 to 0.0002 mg/ml and that of IgM from 0.0006 mg/ml to undetectable levels after two weeks. After two weeks, 47 per cent of the puppies had measurable levels of IgA and 70.6 per cent had measurable levels of IgG, but none of them had measurable levels of IgM.