Pulmonary inflammatory effects of source-oriented particulate matter from California's San Joaquin Valley.

The EPA regulates ambient particulate matter (PM) because substantial associations have been established between PM and health impacts. Presently, regulatory compliance involves broad control of PM emission sources based on mass concentration rather than chemical composition, although PM toxicity is likely to vary depending upon PM physicochemical properties. The overall objective of this study was to help inform source-specific PM emission control regulations. For the first time, source-oriented PM was collected from the atmosphere in Fresno, CA, onto 38 source/size substrates. Mice were exposed via oropharyngeal aspiration to equivalent mass doses [50 µg] of two size fractions: ultrafine (Dp < 0.17µm) and submicron fine (0.17 < Dp < 1 µm) during summer and winter seasons. At 24 hours post-exposure, cellular and biochemical indicators of pulmonary inflammation were evaluated in the bronchoalveolar lavage fluid. Significant inflammatory responses were elicited by vehicle, regional background, and cooking PM sources that were dependent on season and particle size. This is the first study of source-oriented toxicity of atmospheric PM and supports source-specific emissions control strategies.

Assisting decision-making on age of neutering for German Short/Wirehaired Pointer, Mastiff, Newfoundland, Rhodesian Ridgeback, Siberian Husky: associated joint disorders, cancers, and urinary incontinence.

Spaying female and castrating male dogs, hereinafter referred to as neutering, is a US convention for the first year in the dog's life. Research on 35 breeds of dogs revealed that early neutering increases risks of joint disorders, such as hip dysplasia (HD), elbow dysplasia (ED), or cranial cruciate ligament (CCL) tear, or cancers, such as lymphosarcoma (LSA), mast cell tumor (MCT), hemangiosarcoma (has), or osteosarcoma (OSA), for some breeds. Joint disorder risks are heightened for some larger breeds and for mixed-breed dogs weighing more than 20 kg. Some breeds had elevated risks for cancers. Several other research teams have reported health complications associated with neutering. The study goal includes using the same methodology for data collection and analyses as in the study on 35 breeds for five additional dog breeds weighing at least 20 kg. The breeds were: German Short/Wirehaired Pointer, Mastiff, Newfoundland, Rhodesian Ridgeback, and Siberian Husky. Major differences among breeds appeared in vulnerability to joint disorders and cancers with early neutering: male and female Pointer breeds had elevated joint disorders and increased cancers; male Mastiff breeds had increased CCL and LSA and females had non-significant elevated CCL risks; female Newfoundland breeds had heightened risks for joint disorders and males had non-significant elevated risks; female Ridgeback breeds had heightened MCT with very early neutering; and Siberian Huskies showed no significant effects on joint disorders or cancers, but female breeds showed a non-significant but elevated CCL. Updated guidelines cover 40 dog breeds. These results further emphasize the importance of personalized decisions regarding the neutering of dogs, considering the dog's breed, sex, and context.

Large diurnal temperature fluctuations negatively influence Aedes aegypti (Diptera: Culicidae) life-history traits.

Seasonal variation in dengue virus transmission in northwestern Thailand is inversely related to the magnitude of diurnal temperature fluctuations, although mean temperature does not vary significantly across seasons. We tested the hypothesis that diurnal temperature fluctuations negatively influence epidemiologically important life-history traits of the primary dengue vector, Aedes aegypti (L.), compared with a constant 26 degrees C temperature. A large diurnal temperature range (DTR) (approximately equals 18 degrees C daily swing) extended immature development time (>1 d), lowered larval survival (approximately equals 6%), and reduced adult female reproductive output by 25% 14 d after blood feeding, relative to the constant 26 degreesC temperature. A small DTR (approximately equal 8 degrees C daily swing) led to a negligible or slightly positive effect on the life history traits tested. Our results indicate that there is a negative impact of large DTR on mosquito biology and are consistent with the hypothesis that, in at least some locations, large temperature fluctuations contribute to seasonal reduction in dengue virus transmission.

Companion Animals' Roles for AIDS Survivors, Mostly Aging Males, during HIV/AIDS and COVID-19 Pandemics.

Long-term HIV/AIDS survivors responded online concerning their experiences during the AIDS and COVID pandemics. Recruited from web-based organizations for AIDS survivors, 147 answered questions on: frequency of experiencing stigma, isolation, aloneness, or grief/sadness; pet ownership; and sources of human support during each pandemic. Conditional inference trees were run to identify relevant demographic factors. Post-hoc comparisons were conducted to compare dog owners and cat owners. AIDS survivors reported more frequent feelings of stigma, aloneness, and sadness/grief during the AIDS pandemic than during COVID. Cat owners' sadness/grief during AIDS was greater than non-owners. During COVID, older respondents unexpectedly were less often sad/grieving than younger ones; dog owners less often felt alone and isolated than non-dog owners. Support during the AIDS pandemic retrospectively was rated better for older respondents; young gays' support was greater than young straights. During COVID, support was better for men than women. Contrastingly, women with pets felt less support than those without; men with dogs felt more support than those without. Cat owners more often felt isolated and unsupported during COVID than dog owners. Few dog or cat owners received support from family members in either pandemic; during AIDS, family support was better for owners of dogs than cats.

Varying combinations of Lactobacillus species: impact on laying hens' performance, nitrogenous compounds in manure, serum profile, and uric acid in the liver.

This study was conducted to evaluate the effects of various combinations of Lactobacillus species (L. rhamnosus, L. paracasei, and L. plantarum) on closely associated variables of production of laying hens, nitrogenous compounds in manure, the serum concentration of specific chemicals, and liver uric acid (UA) concentrations at peak lay. White Leghorns W-36 (32-week-old) were randomly assigned to five treatments for 8 weeks. Treatments were T1, the Control, a commercial feed; T2, the Control + L. paracasei + L. plantarum; T3, the Control + L. paracasei + L. rhamnosus; T4, the Control + L. plantarum + L. rhamnosus and T5, the Control + L. paracasei + L. plantarum + L. rhamnosus. Each bacterial species was included at 3.33 × 1011cfu/kg feed for a total of 6.66 x 1011 cfu/kg feed for T2-T4 and a total of 1.0 × 1012 cfu/kg feed for T5. Major effects among combinations of probiotics on production were not noted. The interaction of Probiotics by Week (Probiotics*Time) affected feed intake (P = 0.0007) and feed conversion ratio (FCR, P = 0.0049) due to fluctuation by week. Significant effects of time were also recorded for a gradual increase in body weight (BW, P = 0.0007); lowest and greatest feed intake at weeks 2 and 7, respectively (P < 0.0001); an increase in egg production (P = 0.0007) and maximum FCR at week 7 (P < 0.0001). Ammonia (NH3) concentration, ammonium nitrogen (NH4-N), total Kjeldahl nitrogen (TKN), and total nitrogen remained unaffected at P < 0.05. Although there were fluctuations, a trend emerged for the reduction of TKN. Combinations of probiotics did not affect NH3, UA, total protein (TP), albumin (ALB), creatine kinase (CK), and UA in the liver. Temporal (Time as a fixed effect) effects were noted for all nitrogenous compounds present in manure. For ammonia, temporal effects were significant due to fluctuation over time. Week 0 had the lowest value followed by weeks 4 and 8. Week 6 had the greatest value. For ammonium nitrogen, week 8 had the lowest value followed by week 0 and 4 with the next highest value. Week 6 had the greatest value. For TKN, week 4 had the lowest value followed by weeks 6 and 8. Week 0 had the greatest value. For TN, weeks 4, 6, and 8 had similar and lowest values followed by week 0 having the greatest value. However, an overall reduction in NH4-N, TKN, and TN was noted. Fluctuations in NH3 (P = 0.0033) and CK (P = 0.0085) were noted for Time. There was also a trend (P = 0.0706) for the increase of UA in serum. Two or more species of probiotics with yeast should be investigated. If the combination is applicable for increasing production measurements and reducing nitrogenous and serum compounds, the most appropriate time to feed the probiotics from day 1 to the end of production should be investigated.

Characteristics of Plant Eating in Domestic Cats.

Plant eating by domestic cats is of interest to veterinarians and cat owners, especially with the current trend to keep cats totally indoors. Feline grass gardens are commonly provided to such cats as a reflection of cat owners believing in the need or desire of cats for eating plants. Two surveys with 1000 to 2000 returns from cat owners were launched over 10 years to test different hypotheses regarding plant eating. These hypotheses are that plant eating: (1) is a response to the cat feeling ill; (2) induces vomiting; (3) is a means of expelling hair balls from consumed hair. Additionally, a perspective acquired from observations of wild felids is that plant eating reflects an innate predisposition acquired from the ancestral cat. In this study, very few cats showed signs of illness before eating plants. However, 27 to 37 percent of cats, respectively in the two surveys, frequently vomited after eating plants, indicating that gastrointestinal disturbance may be related to vomiting in some cats. Young cats consumed plants more frequently than older cats and appeared ill and vomited less frequently in association with plant eating. Short-haired cats ate plants as frequently as long-haired cats, arguing against the hairball expelling hypothesis. Some guidelines for cat owners with indoor cats are provided.

Effects of the 2018 Camp Fire on birth outcomes in non-human primates: Case-control study.

The November 2018 Camp Fire, a devastating wildfire in Northern California, occurred during the peak of breeding season for field monkeys at the California National Primate Research Center (CNPRC). Effects of environmental stressors, such as wildfires, on birth outcomes in primates, and in humans, are poorly understood. Additionally, wildfires are of growing concern due to their increasing frequency and severity. The objective was to examine the impact of wildfire smoke on fertility, timing of birth, and pregnancy loss for field monkeys. A unique case-control study to investigate birth outcomes in rhesus macaques (Macaca mulatta) was conducted at the CNPRC. All females in the study were maintained in outdoor fields during a period of elevated ambient wildfire smoke from November 8-22, 2018. In addition to ambient air quality evaluations, the effects on fertility, timing to birth, and pregnancy loss were documented. Archival records of approximately 5,000 conceptions from the previous nine years served as control data. During the Camp Fire, ambient fine particulate (PM 2.5) levels exceeded the 24 -h National Ambient Air Quality Standard (35 µg/m 3) of the United States Environmental Protection Agency, reaching levels as high as 185 µg/m 3. A statistically significant association was observed between birth loss and the 2018-2019 CNPRC breeding season. As this wildfire event occurred during various stages of early pregnancy, an association can be inferred between early gestational exposure and increased risk of pregnancy loss.

Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence.

Neutering (including spaying) of male and female dogs in the first year after birth has become routine in the U.S. and much of Europe, but recent research reveals that for some dog breeds, neutering may be associated with increased risks of debilitating joint disorders and some cancers, complicating pet owners' decisions on neutering. The joint disorders include hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers include lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. In previous studies on the Golden Retriever, Labrador Retriever and German Shepherd Dog, neutering before a year of age was associated with increased risks of one or more joint disorders, 2-4 times that of intact dogs. The increase was particularly seen with dogs neutered by 6 months of age. In female Golden Retrievers, there was an increase in one or more of the cancers followed to about 2-4 times that of intact females with neutering at any age. The goal of the present study was to expand and use the same data collection and analyses to cover an additional 29 breeds, plus three varieties of Poodles. There were major breed differences in vulnerability to neutering, both with regard to joint disorders and cancers. In most cases, the caregiver can choose the age of neutering without increasing the risks of these joint disorders or cancers. Small-dog breeds seemed to have no increased risks of joint disorders associated with neutering, and in only two small breeds (Boston Terrier and Shih Tzu) was there a significant increase in cancers. To assist pet owners and veterinarians in deciding on the age of neutering a specific dog, guidelines that avoid increasing the risks of a dog acquiring these joint disorders or cancers are laid out for neutering ages on a breed-by-breed and sex basis.

Assisting Decision-Making on Age of Neutering for Mixed Breed Dogs of Five Weight Categories: Associated Joint Disorders and Cancers.

The early neutering of male and female dogs and its relationship to an increased risk of joint disorders and some cancers has recently become a concern, raising questions about the standard practice in the U.S. and much of Europe of neutering by 6 months of age. A noteworthy recent finding from this center is that there are major breed differences with small-dog breeds generally showing little vulnerability to neutering compared with breeds of larger body size. These findings on purebreds raise questions for dog owners and veterinarians about mixed-breed dogs. The purpose of this study was to examine a sample of mixed breed dogs of five weight categories using the same veterinary hospital database and diagnostic criteria for joint disorders and cancers as used in the newly published paper on 35 breeds and previous papers on the Golden Retriever, Labrador Retriever, and German Shepherd Dog. The weight categories were <10 kg (739 cases), 10-19 kg (546 cases), 20-29 kg (992 cases), 30-39 kg (604 cases), and over 40 kg (258 cases). Males and females were analyzed separately, as were various ages at neutering. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers were lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. There was no significant increased occurrence of one or more cancers, compared with intact dogs, in any weight category. However, in the three categories of dogs weighing 20 kg or more, neutering before 1 year generally was significantly associated with risks of one or more joint disorders above that of dogs left intact, commonly to 3 times the level of intact dogs, with sex differences in the degrees of joint disorders associated with neutering. For the dogs in the two weight categories <20 kg, no increased risks were found for joint disorders. This information can be useful to dog caregivers in deciding on the age at which to neuter specific dogs, and for veterinarians offering guidance to pet owners.

How different types of natal experience affect habitat preference.

In many animals, exposure to cues in a natal habitat increases disperser preferences for those cues (natal habitat preference induction [NHPI]), but the proximate and ultimate bases for this phenomenon are obscure. We developed a Bayesian model to study how different types of experience in the natal habitat and survival to the age/stage of dispersal interact to affect a disperser's estimate of the quality of new natal-type habitats. The model predicts that the types of experience a disperser had before leaving its natal habitat will affect the attractiveness of cues from new natal-type habitats and that favorable experiences will increase the level of preference for natal-type habitats more than unfavorable experiences will decrease it. An experimental study of NHPI in Drosophila melanogaster provided with "good" and "bad" experiences in their natal habitats supports these predictions while also indicating that the effects of different types of natal experience on NHPI vary across genotypes. If habitat preferences are modulated by an individual's experience before dispersal as described in this study, then NHPI may have stronger effects on sympatric speciation, metapopulation dynamics, conservation biology, and pest management than previously supposed.

Geographic Availability of Assistance Dogs: Dogs Placed in 2013-2014 by ADI- or IGDF-Accredited or Candidate Facilities in the United States and Canada, and Non-accredited U.S. Facilities.

Assistance dogs' roles have diversified to support people with various disabilities, especially in the U.S. Data presented here are from the U.S. and Canada non-profit facilities (including both accredited and candidate members that fulfilled partial requirements: all here termed "accredited") of Assistance Dogs International (ADI) and the International Guide Dog Federation (IGDF), and from non-accredited U.S. assistance dog training facilities, on the numbers and types of dogs they placed in 2013 and 2014 with persons who have disabilities. ADI categories of assistance dogs are for guide, hearing, and service (including for assistance with mobility, autism, psychiatric, diabetes, seizure disabilities). Accredited facilities in 28 states and 3 provinces responded; accredited non-responding facilities were in 22 states and 1 province (some in states/provinces with responding accredited facilities). Non-accredited facilities in 16 states responded. U.S./Canada responding accredited facilities (55 of 96: 57%) placed 2,374 dogs; non-accredited U.S. facilities (22 of 133: 16.5%) placed 797 dogs. Accredited facilities placed similar numbers of dogs for guiding (n = 918) or mobility (n = 943), but many more facilities placed mobility service dogs than guide dogs. Autism service dogs were third most for accredited (n = 205 placements) and U.S. non-accredited (n = 72) facilities. Psychiatric service dogs were fourth most common in accredited placements (n = 119) and accounted for most placements (n = 526) in non-accredited facilities. Other accredited placements were for: hearing (n = 109); diabetic alert (n = 69), and seizure response (n = 11). Responding non-accredited facilities placed 17 hearing dogs, 30 diabetic alert dogs, and 18 seizure response dogs. Non-accredited facilities placed many dogs for psychiatric assistance, often for veterans, but ADI accreditation is required for veterans to have financial reimbursement. Twenty states and several provinces had no responding facilities; 17 of these states had no accredited facilities. In regions lacking facilities, some people with disabilities may find it inconvenient living far from any supportive facility, even if travel costs are provided. Despite accelerated U.S./Canada placements, access to well-trained assistance dogs continues to be limited and inconvenient for many people with disabilities, and the numerous sources of expensive, poorly trained dogs add confusion for potential handlers.

Job-Related Stress in Forensic Interviewers of Children with Use of Therapy Dogs Compared with Facility Dogs or No Dogs.

Sexually abused children providing essential testimony regarding crimes in forensic interviews now sometimes are provided facility dogs or therapy dogs for comfort. Facility dogs are extensively trained to work with forensic interviewers; when using therapy dogs in interviews, volunteers are the dog handlers. Interviews can impact child welfare workers' mental health causing secondary traumatic stress (STS). To investigate this stress, first data were gathered on stress retrospectively for when interviewers initially started the job prior to working with a dog, and then currently, from forensic interviewers using a facility dog, a therapy or pet dog, or no dog. These retrospective and secondary traumatic stress scale (STSS) data compared job stress among interviewers of children using: a certified, workplace facility dog (n = 16), a volunteer's trained therapy dog or the interviewer's pet dog (n = 13/3), or no dog (n = 198). Retrospective scores of therapy dog and no dog interviewers' stress were highest for the first interviewing year 1 and then declined. Extremely or very stressful retrospective scores differed among the three groups in year 1 (p < 0.038), and were significantly elevated for the therapy dog group as compared with the facility dog group (p < 0.035). All interviewing groups had elevated STSS scores; when compared with other healthcare groups that have been studied, sub-scores were especially high for Avoidance: a psychological coping mechanism to avoid dealing with a stressor. STSS scores differed among groups (p < 0.016), primarily due to Avoidance sub-scores (p < 0.009), reflecting higher Avoidance scores for therapy dog users than no dog users (p < 0.009). Facility dog users more consistently used dogs during interviews and conducted more interviews than therapy/pet dog users; both groups favored using dogs. Interviewers currently working with therapy dogs accompanied by their volunteers reported they had experienced heightened stress when they began their jobs; their high stress levels still persisted, indicating lower inherent coping skills and perhaps greater empathy among interviewers who later self-selected to work with therapy dogs. Results reveal extreme avoidant stress for interviewers witnessing children who are suffering and their differing coping approaches.

Compatibility of Cats With Children in the Family.

Although studies involving pet dogs and cats, and human adults and children, have been reported, the specific interactions between cats and children have not. This study sought information from parents about the cat's role in families that have at least one child 3-12 years of age and at least one cat. Demographic data on cat source, breed, gender/neuter status, was sought as well as information on adults and children in the families and on affectionate, aggressive, fearful, and playful responses of the cats to children. A convenience sample was recruited via listservs for pet owners and parents. Using a pilot tested web survey, descriptive statistics were based on 865 respondents. Multi-variate statistical analyses were conducted on data from 665 respondents with complete responses for all items, including respondents' locations and whether cats were adopted as kittens. Multi-variate analyses included consideration of demographic data, geographic region of respondents, behavioral characteristics of the cats, and responses of the children to the cats. From descriptive statistics, cats' affection was more typical with adults than young children. Neuter status or gender was unrelated to cats' aggression or affection. Being the family's only cat was associated with heightened aggression and reduced affection. Younger cats were more likely to be affectionate. Multivariate analysis revealed three primary factors accounting for children's compatibility with the specified cat: positive interactions of the cat, aggression/fearfulness of cat, and the cat's playfulness and children's reaction to the cats. Positive child-cat relationships were more typical with two or more adults and multiple cats in the home. Old cats were the least satisfactory. A breeder or shelter was a better source than as a feral, from a newspaper ad, or another source. European respondents rated their cats' interactions with children more favorably than in U.S./Canada. This difference may reflect the European adoptions more frequently being of kittens, often purebred, assuring more early handling within the family. A noteworthy finding was that all family participants, humans, and pets alike, affect the cat-child relationship, and these results reveal that many variables can play a role in achieving a desirable relationship for a cat and child.

Affectionate Interactions of Cats with Children Having Autism Spectrum Disorder.

Mental and physical benefits of dogs have been reported for adults and children with special needs, but less is known about benefits of cats for children. A cat that can be held by a child could provide important therapeutic companionship for children with severe or less severe autism spectrum disorder (ASD) who otherwise may lack prosocial behaviors. Because relatively little is known about the behavior of cats around children, we conducted this study. Phase 1 gathered web-survey data from families having an adult cat and a child with ASD (n = 64). In Phase 2, there were direct telephone interviews of parents having a child with severe ASD (n = 16) or less severe ASD (n = 11), or typical development (n = 17). From the Phase 1 web survey of families with ASD children (full range of severities), affectionate interactions of the cats with children were common. Most parents with ASD children volunteered positive comments regarding the cat, such as calming the child, being a soothing protector or a guardian. In the interviews in Phase 2, for all three groups, most parents characterized cats as at least moderately affectionate toward the child. However, cats living with severe ASD children were reported to exhibit less affection than those living with typically developing children or children with less severe ASD. A minority of cats in each group showed some aggression to the specified child; this was not elevated with ASD children. Responses suggested that the cats adopted as kittens were more affectionate and less aggressive to all categories of children than those adopted as adults. Overall, participants reported that ASD children's behaviors indicated that they valued the relationship with the cat, similar to typically developing children, pointing to the importance and potential usefulness of selecting affectionate and compatible cats for ASD children.

Assistance Dogs: Historic Patterns and Roles of Dogs Placed by ADI or IGDF Accredited Facilities and by Non-Accredited U.S. Facilities.

Dogs' roles to support people with disabilities are increasing. Existing U.S. laws and regulations pertaining to the use of dogs for people with disabilities are only minimally enforced. Pushback legislation against some aspects of uses of assistance dogs currently is being passed or proposed in several states. Further, the U.S. Department of the Army and the Veterans' Administration support only dogs trained by an Assistance Dogs International (ADI) or International Guide Dog Federation (IGDF) accredited facility. Lacking a mandatory national process for screening the selection, training, and placement of assistance dogs with persons who have disabilities, the U.S. offers a creative but confusing opportunity for people to train their own dogs for any disability. While no U.S. surveillance system monitors assistance dogs, other countries generally have a legislated or regulatory process for approving assistance dogs or a cultural convention for obtaining dogs from accredited facilities. We conducted an online survey investigating current demographics of assistance dogs placed in 2013 and 2014 with persons who have disabilities, by facilities worldwide that are associated with ADI or IGDF and by some non-accredited U.S. facilities. Placement data from ADI and IGDF facilities revealed that in most countries aside from the U.S., guide dogs were by far the main type of assistance dog placed. In the U.S., there were about equal numbers of mobility and guide dogs placed, including many placed by large older facilities, along with smaller numbers of other types of assistance dogs. In non-accredited U.S. facilities, psychiatric dogs accounted for most placements. Dogs for families with an autistic child were increasing in all regions around the world. Of dog breeds placed, accredited facilities usually mentioned Labrador Retrievers and Golden Retrievers, and sometimes, German Shepherd Dogs. The facilities bred their dogs in-house, or acquired them from certain breeders. Non-accredited facilities more often used dogs from shelters or assisted people in training their own dogs. Facilities in Europe and the U.S. place dogs in all roles; other parts of the world primarily focus on guide dogs. Expansion of assistance dogs in many roles is continuing, with numbers of dogs placed accelerating internationally.

Neutering of German Shepherd Dogs: associated joint disorders, cancers and urinary incontinence.

German Shepherd Dogs are important in police and military work, and are a popular family pet. The debilitating joint disorders of hip dysplasia, cranial cruciate ligament tear (CCL) and elbow dysplasia can shorten a dog's useful working life and impact its role as a family member. For this study, veterinary hospital records were examined over a 14.5-year period on 1170 intact and neutered (including spaying) German Shepherd Dogs for joint disorders and cancers previously associated with neutering. The diseases were followed through 8 years of age, with the exception of mammary cancer (MC) in females that was followed through 11 years. The cancers followed, apart from mammary, were osteosarcoma, lymphoma, hemangiosarcoma and mast cell tumour. In intact males, 7% were diagnosed with one or more joint disorders, while in males neutered prior to a year of age, a significantly higher 21% were diagnosed with one or more joint disorders. In intact females, 5% were diagnosed with one or more joint disorders, while in females neutered prior to a year of age, this measure was significantly increased to 16%. The increased joint disorder incidence mostly associated with early neutering was CCL. MC was diagnosed in 4% of intact females compared with less than 1% in females neutered before 1 year. The occurrence of the other cancers followed through 8 years of age was not higher in the neutered than in the intact dogs. Urinary incontinence, not diagnosed in intact females, was diagnosed in 7% of females neutered before 1 year, a significant difference. These findings, profiling the increase in joint disorders associated with early neutering, should help guide the timing of neutering for this breed.

The effect of methadone dose regimen on neonatal abstinence syndrome.

OBJECTIVES: To evaluate the effects of a multiple daily dose methadone regimen in pregnancy on neonatal outcomes. METHODS: Although methadone maintenance has been the standard for the treatment of opioid dependence in pregnancy, there is no consensus on proper dosing. Single daily dosing is the most common strategy. Because of accelerated metabolism of methadone in pregnancy, this regimen may expose mother and fetus to daily episodes of withdrawal and possibly contribute to more severe Neonatal Abstinence Syndrome (NAS). This study reports on a protocol that increased both methadone dose and dose frequency in response to maternal reports of withdrawal. RESULTS: Treatment of NAS was needed in 29% of neonates, compared to a published rate of 60% to 80%. The mean methadone dose was 152 mg at delivery, divided into 2 to 6 doses per day. Ninety-two percent of mothers were free of illicit drug use at delivery. There was no relationship between methadone dose and treatment of NAS. Female babies had a treatment rate of 16% versus 38% for male babies. Beyond abstinence symptoms, cohort outcomes in terms of gestational age, birth weight, prematurity, Caesarian sections, and breastfeeding equaled or approximated US population norms. CONCLUSIONS: The protocol was associated with low rates of treatment of NAS and high rates of maternal recovery. High rates of treatment for NAS reported in methadone-exposed neonates might relate in part to iatrogenic factors and be reduced through the use of divided daily doses and protocols that minimize maternal withdrawal.

Evaluation of jitter by stimulated single-fiber electromyography in normal dogs.

Single-fiber electromyography (SFEMG), a technique used to investigate neuromuscular transmission, has been described previously in the pelvic limb of dogs. Because preferential involvement of isolated muscle groups can occur in disorders of neuromuscular transmission, SFEMG was done in the peroneus longus (PL), extensor carpi radialis (ECR), and orbicularis oculi (OO) muscles of 10 adult, clinically normal dogs. Jitter was calculated as the mean absolute value of the consecutive differences in latency of 50 single muscle fiber action potentials after stimulation of intramuscular nerve bundles at the level of the motor point in at least 20 muscle fibers per muscle. Bilateral recordings were performed in 3 dogs. Mean jitter values were determined for each muscle, and differences among muscle groups and among dogs were compared. The upper limits of mean consecutive difference (mean plus 3 standard deviations) for the PL, ECR, and OO muscles were 21.94, 22.53, and 23.39 micros, respectively, and the upper limit of mean consecutive difference for individual muscle fibers in the respective fiber pools was 28.62, 36.39, and 35.68 micros. Jitter values for the ECR and OO were significantly higher than the jitter value for the PL muscle (P < .05). Significant differences among muscles or dogs or between sides were not observed for the ECR. Significant differences among dogs were observed for OO jitter values and were attributed to extremely low jitter values in 1 dog. Significant differences were demonstrated between sides for the PL and were attributed to small sample size. Results of this study provide normative data that can be used in the application of the stimulated SFEMG technique to dogs with suspected disorders of neuromuscular transmission.

Effects of a mechanical response-contingent surrogate on the development of behaviors in nursery-reared rhesus macaques (Macaca mulatta).

Nursery-reared infants have several behavioral and physiologic differences from their mother-reared counterparts. We investigated whether a response-contingent surrogate mitigated some of those differences by decreasing fearfulness and partner-clinging and increasing environmental exploration in nursery-reared infants continuously paired with a peer. Six nursery-reared infant rhesus macaques (in pairs) were given a mechanical responsive surrogate (RS), and 6 (in pairs) were given an identical but nonresponsive surrogate (NRS). The 2 treatment groups were compared and then combined into a single group of all 12 of surrogate-exposed animals (CS) that was compared with a nonsurrogate control group (NS) of 10 nursery-reared infants. Results showed significant differences between CS and NS infants but no significant differences between the RS and NRS infants. As compared with NS infants, CS infants showed less partner-clinging, less affiliation directed toward only partner, and more foraging and tactile-oral exploration of the environment. These advantageous effects support additional research to develop improved surrogate and the implementation of surrogate programs for nursery-reared infants.

Long-term health effects of neutering dogs: comparison of Labrador Retrievers with Golden Retrievers.

Our recent study on the effects of neutering (including spaying) in Golden Retrievers in markedly increasing the incidence of two joint disorders and three cancers prompted this study and a comparison of Golden and Labrador Retrievers. Veterinary hospital records were examined over a 13-year period for the effects of neutering during specified age ranges: before 6 mo., and during 6-11 mo., year 1 or years 2 through 8. The joint disorders examined were hip dysplasia, cranial cruciate ligament tear and elbow dysplasia. The cancers examined were lymphosarcoma, hemangiosarcoma, mast cell tumor, and mammary cancer. The results for the Golden Retriever were similar to the previous study, but there were notable differences between breeds. In Labrador Retrievers, where about 5 percent of gonadally intact males and females had one or more joint disorders, neutering at <6 mo. doubled the incidence of one or more joint disorders in both sexes. In male and female Golden Retrievers, with the same 5 percent rate of joint disorders in intact dogs, neutering at <6 mo. increased the incidence of a joint disorder to 4-5 times that of intact dogs. The incidence of one or more cancers in female Labrador Retrievers increased slightly above the 3 percent level of intact females with neutering. In contrast, in female Golden Retrievers, with the same 3 percent rate of one or more cancers in intact females, neutering at all periods through 8 years of age increased the rate of at least one of the cancers by 3-4 times. In male Golden and Labrador Retrievers neutering had relatively minor effects in increasing the occurrence of cancers. Comparisons of cancers in the two breeds suggest that the occurrence of cancers in female Golden Retrievers is a reflection of particular vulnerability to gonadal hormone removal.