2022 AAHA Canine Vaccination Guidelines

The first evidence of Asian-like CPV-2b in Slovakia in a vaccinated dog with an acute fatal course of parvovirus infection: a case report

This study provides a comprehensive description of the clinical course of a fatal parvovirus infection in a vaccinated dachshund puppy, along with the first identification of a new CPV-2 variant in Slovakia, elucidated through molecular amino acid analysis of the VP2 gene. The dog exhibited clinical signs such as apathy, vomiting, and bloody diarrhea. After confirming CPV-2 infection with a commercial snap test, intensive therapy was initiated. The dog succumbed within 48 h of admission. A rectal swab sample was collected, CPV-2 was examined using the PCR method, and sequenced. The virus detected in the patient was related to strains of CPV-2c of Asian origin and unrelated to European CPV-2b strains. The sequence had genetic signatures typical of Asian strains (VP2: 5Gly, 267Tyr, 324Ile, 370Arg, and 440Thr). Phylogenetic analysis classified this strain as similar to Asian strains of CPV-2c. It is believed to be derived from an Asian strain similar to CPV-2c that acquired the 426Asp mutation. With this finding, we present the first evidence of an Asian-like CPV-2b strain in the territory of Slovakia.

Human Case of Leptospirosis During a Canine Disease Outbreak - Wyoming, 2023

Leptospirosis is a zoonotic bacterial disease spread through the urine of infected animals; the typical incubation period is 5-14 days. In approximately 90% of human cases, illness is asymptomatic or mild, characterized by fever, chills, myalgia, nausea, vomiting, diarrhea, headache, calf pain, and conjunctival suffusion, but severe illness can progress to multiorgan dysfunction and death. Although Wyoming is considered a low-risk area for leptospirosis because of its cold and semiarid climate, the Wyoming Department of Health was notified of a probable human case in August 2023, the first reported in the state since 1983. The patient had occupational exposure to dogs but did not report other risk factors. The same week that the human patient's illness began, public health authorities received notification of an increase in canine leptospirosis cases. Public health authorities investigated to determine potential sources of infection, identify additional cases, and recommend control measures. After public health outreach activities were implemented, canine vaccination practices changed substantially in the affected city: a survey conducted after the outbreak revealed that all responding veterinary clinics in the affected city were recommending the vaccine more frequently to dog owners and reporting higher levels of owner compliance with vaccination recommendations. Increased vaccination coverage offers protection from leptospirosis for both dogs and persons exposed to them. Leptospirosis should be considered in the differential diagnosis of persons with occupational exposure to animals and clinically compatible signs and symptoms, including fever, chills, myalgia, nausea, vomiting, diarrhea, headache, calf pain, and conjunctival suffusion, irrespective of geographic location.

Humoral Immune Response in Immunized Sheep with Bovine Coronavirus Glycoproteins Delivered via an Adenoviral Vector

Bovine coronavirus (BCoV) is distributed globally and mainly causes different clinical manifestations: enteric diarrhea in calves, winter dysentery in adults, and respiratory symptoms in cattle of all ages. Low mortality and high morbidity are the hallmarks of BCoV infection, usually associated with substantial economic losses for the livestock industry. Vaccination, combined with the implementation of biosecurity measures, is the key strategy for the prevention of infections. This pilot study evaluates the immunogenicity of a recombinant vaccine containing two BCoV antigens (S and M) in sheep, compared to vaccines containing only the M or S protein. Three groups of sheep were inoculated intramuscularly at day 0 and day 21 with recombinant adenoviruses expressing BCoV S protein (AdV-BCoV-S), BCoV M protein (AdV-BCoV-M), or both proteins (AdV-BCoV-S + M). Serum antibodies were evaluated using immunofluorescence (IF) and serum neutralization (SN) tests. Moderate seroconversion was observed by day 21, but serum antibodies detected via SN increased from 1:27.5 (day 21) to 1:90 (day 28) in sheep inoculated with the recombinant AdV expressing both the S- and M-BCoV proteins. Based on the SN results, a repeated-measures ANOVA test indicated a more significant difference in immune response between the three groups (F = 20.47; p < 0.001). The experimental investigation produced satisfactory results, highlighting that the S + M recombinant vaccine was immunogenic, stimulating a valid immune response. Despite some inherent limitations, including a small sample size and the absence of challenge tests, the study demonstrated the efficacy of the immune response induced via the recombinant vaccine containing both S and M proteins compared to that induced via the individual proteins S or M.

Canine Amniotic Fluid at Birth Holds Information about Neonatal Antibody Titres against Core Vaccine Viruses

There is a growing interest in the composition of amniotic fluid (AF) in both humans and animals. In addition to its nutritional and protective functions for the foetus, current knowledge demonstrates that AF also serves advanced diagnostic, prognostic, and therapeutic roles. Newborn dogs have an underdeveloped immune system, making them highly susceptible to dangerous pathogens such as canine parvovirus (CPV-2), canine infectious hepatitis virus (CAdV-1), and canine distemper virus (CDV), thus exposing them to a high risk of mortality in the first weeks of life. Immunoglobulins G (IgGs) represent the only antibody isotype capable of crossing the placenta in a small amount and have been detected also in canine AF. The primary aim of this study was to investigate the reliability of AF collected at birth as a marker of passive immunity in canine species. For this purpose, total and specific IgGs against CPV-2, CAdV-1, and CDV were investigated and quantified in both maternal plasma and AF collected at the time of caesarean section. The vaccination status of the bitches was also taken into consideration. Since the immune system can be influenced by gestational age, with preterm infants having immature innate and adaptive immunity, IgG concentrations were correlated with amniotic lecithin, sphingomyelin, cortisol, surfactant protein A, and pentraxin 3 levels. In a previous study from our group on foetal maturity these molecules were measured in the same samples. Finally, correlations between their amniotic content and neonatal outcomes were investigated. This study demonstrates that AF analysis at birth can provide valuable insights into neonatal immunity in puppies, offering a non-invasive method to detect potential early health risks, for improved puppy care and management.

Molecular epidemiology of canine parvovirus type 2 in Sicily, southern Italy: A geographical island, an epidemiological continuum

Since it emerged as a major dog pathogen, canine parvovirus type 2 (CPV-2) has featured a remarkable genetic and phenotypic heterogeneity, whose biological, epidemiological, and clinical impact is still debated. The continuous monitoring of this pathogen is thus of pivotal importance. In the present study, the molecular epidemiology of CPV-2 in Sicily, southern Italy, has been updated by analysing 215 nearly complete sequences of the capsid protein VP2, obtained from rectal swabs/faeces or tissue samples collected between 2019 and 2022 from 346 dogs with suspected infectious gastrointestinal disease. The presence of the original CPV-2 type (4%) and CPV-2a (9%), CPV-2b (18%), or CPV-2c (69%) variants was documented. Over the years, we observed a decrease in the frequency of CPV-2a/-2b and a rapid increase of CPV-2c frequency, with a progressive replacement of the European lineage of CPV-2c by the Asian lineage. The observed scenario, besides confirming epidemiological relevance of CPV-2, highlights the occurrence of antigenic variant shifts over time, with a trend toward the replacement of CPV-2a, CPV-2b, and the European lineage of CPV-2c by the emerging Asian CPV-2c lineage. The comparison with other Italian and international sequences suggests the occurrence of viral exchange with other Italian regions and different countries, although the directionality of such viral flows could not be often established with confidence. In several instances, potential CPV-2 introductions led to epidemiological dead ends. However, major, long-lasting clades were also identified, supporting successful infection establishment, local spreading, and evolution. These results, besides demonstrating the need for implementing more effective control measures to prevent viral introductions and minimize circulation, stress the relevance of routine monitoring activities as the only tool to effectively understand CPV-2 epidemiology and evolution, and develop adequate countermeasures.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Cats

Feline core vaccines strongly recommended for all cats are against Feline panleukopenia virus (FPV), Felid herpesvirus type 1 (FeHV-1), and Feline calicivirus (FCV), but cats can be classified as low- and high-risk based on their lifestyle. The aim of this study was to determine the actual seroprotection against FPV, FeHV-1, and FCV in a large cohort of Italian cats by using the VacciCheck test. A total of 740 cats (567 owned and 173 stray cats; 435 vaccinated and 305 unvaccinated) were analyzed for Protective Antibody Titers (PATs). Differences related to origin, sex, age, breed, FIV/FeLV status, health status, and time elapsed since last vaccination were evaluated. Less than half of the entire cohort (36.4%) had PATs for all three diseases simultaneously, increasing to 48.6% if weak positive values were also considered and 50.3% when considering only the 435 vaccinated cats. Particularly, antibodies were detected against FCV, FPV, and FeHV-1 at protective titers (PATs) in 78.6%, 68.1, and 49.1% of the cats, respectively. In general, owned, neutered, and adult FIV- and/or FeLV-negative cats were the most protected categories, even if not always for the three viruses. Most cats maintained high PATs for 3 years or longer after vaccination against FPV and FCV but not FeHV-1. Long-lasting protective immunity persisted for many years after the last vaccination (more than 18 years in the oldest cats). Nevertheless, since not all cats were protected after so many years and for all pathogens, checking protection via antibody titration could be the best choice to prevent immunity breakdowns. The discussion also focuses on the reliability of antibody titration for the two URTD (upper respiratory tract disease) viruses which, unlike for FPV, is not widely accepted as a valid index of protection.

A Survey on Vaccination and Disease Occurrence in Municipal and Non-Profit Animal Shelters in Portugal

Few studies are available describing animal shelters in Portugal. The aim was to characterize prophylactic measures and disease occurrence in shelters with a questionnaire. The response rates of 67 shelters (42 municipal shelters, 25 associations) were compared by the Fisher's exact test. More veterinarians answered for municipal shelters (98%) than for associations (40%; p < 0.001). Over 80% of the respondents indicated using individual medical records and routine prophylaxis. Excessive length of stay for dogs was reported by 54% of associations and 33% of municipal shelters. Management tools should be promoted to improve the situation. Puppy vaccinations were similar and a final vaccination at 16 weeks was indicated by >33% of shelters. Annual revaccination of dogs was reported more frequently by associations (88%) than municipal shelters (55%; p = 0.02). The three most reported diseases were parvovirus and mange in dogs, upper respiratory disease and panleukopenia in cats, and dermatophytosis in both species. Similar response rates for diagnostic options were obtained by both shelter types, except for distemper. Testing for feline retroviruses was indicated by most shelters (>69%), but only a few (<24%) confirmed positive test results. Clinical diagnoses should be complemented by testing. Additional information on disease occurrence should be obtained by objective monitoring.

Influence of age and vaccination interval on canine parvovirus, distemper virus, and adenovirus serum antibody titers

Canine core vaccine titer screenings are becoming increasingly popular in veterinary practice as a tool to guide vaccination decisions, despite a lack of supportive, peer-reviewed evidence-based literature. Additionally, it has been suggested that the canine core vaccine duration of host protective immunity can persist past the currently recommended vaccination interval. Thus, this study evaluated serum antibody titers against three core antigens in dogs with known vaccination histories and lifestyles, analyzing the effect of life stage, exposure risk, and time since last vaccination (TSLV). Clinically healthy dogs (n = 188) presenting to the primary care services of three colleges of veterinary medicine were selected to represent a variety of ages, breeds, and vaccination history. Serum antibody titers for canine parvovirus (CPV), canine distemper virus (CDV), and canine adenovirus-2 (CAV2) were measured via virus neutralization and hemagglutination inhibition. CAV2 and CPV titers decreased, while CDV titers had a decreasing trend with increasing time since last vaccination or vaccination interval. When assessing circulating antibody levels historially associated with protective immunity across various vaccination intervals, 62% (95%CI 36-82%; 8/13) of dogs had positive titers for CDV 5 years post last vaccination, while 92% (95%CI 67-99%; 12/13) of dogs were positive for CAV2 and CPV. Both advanced age and life stage were associated with lower titers and thus, identify a canine population cohort likely at higher disease risk. The results of this study revealed that patient duration of core vaccine-mediated immunity changes with a number of variables, with animal aging and time since vaccination influencing host humoral immunity. This provides further support for the performance of canine core antibody titers to assess whether a vaccine booster and/or specific type of booster is warranted.

Effect of Aging on the Immune Response to Core Vaccines in Senior and Geriatric Dogs

Elderly dogs are steadily increasing worldwide as well as veterinarians' and owners' interest in their health and wellness. Aging is not a disease, but a combination of changes negatively affecting the organism in general and the immune system in particular, resulting in a decline in protection over time. The aim of this study was to measure the specific serum antibody titers against the main dangerous and widespread viral diseases preventable by core vaccinations in senior and geriatric dogs using the in-practice test VacciCheck. A cohort of three hundred fifty elderly dogs was analyzed for Protective Antibody Titers (PATs) against CPV-2, CDV and CAdV-1. The age ranged from 5 to 19 years, with two hundred fifty-eight seniors (73.7%) and ninety-two geriatrics (26.3%), and 97.4% of them were vaccinated at least once in their lives. More than half of the entire study population (52.9%) had PATs simultaneously for all three diseases, with 80.5% seniors and 19.5% geriatrics. Specific PATs were found in 88.6% of aging dogs for CPV-2, 82.3% for CadV-1 and 66.0% for CDV, demonstrating that unprotected aging dogs represent a minority. Unexpectedly, the larger elderly dogs resulted as more protected than smaller ones for CPV-2. Protection then decreases over time, with geriatric dogs less protected than senior ones. Veterinary practitioners should therefore always consider whether to maintain core vaccinations in aging dogs as in adults on a three-year basis or opt instead for closer boosters (every 1 or 2 years). PATs for core vaccines could then represent a good biomarker of protection and their titration could become a standard of care, especially in such a sensitive period of the dogs' life.

Can Chemotherapy Negatively Affect the Specific Antibody Response toward Core Vaccines in Canine Cancer Patients?

The life expectancy of our pets has been getting longer in recent years due to new therapeutic opportunities, better nutrition, and better diagnostic approaches. This positive effect, however, has been accompanied by a concomitant increase in neoplasms, particularly in canine patients. Therefore, veterinarians inevitably face new issues related to these diseases, poorly or never investigated in the past, such as the possible side effects resulting from chemotherapy. The aim of this study was to investigate whether and how chemotherapy influences the antibody response against CPV-2, CDV, and CAdV-1 in dogs vaccinated before starting chemotherapy. Twenty-one canine patients with different types of malignancies were sampled before, during, and after different chemotherapy protocols to determine their actual levels of seroprotection against CPV-2, CDV, and CadV-1 by using the in-practice test VacciCheck. Differences related to sex, breed size, type of tumor, and chemotherapy protocol were evaluated. No statistically significant changes in antibody protection emerged for any of the chemotherapy protocol used, suggesting that, contrary to expectation, chemotherapy does not have a marked immunosuppressive effect on the post-vaccine antibody response. These results, although preliminary, may be useful in improving the clinical approach to the canine cancer patient, helping veterinarians fully manage their patients, and enabling owners to feel more confident about their pets' quality of life.

Prevalence of Serum Antibody Titers against Core Vaccine Antigens in Italian Dogs

Canine vaccination is the main tool for preventing dangerous and widespread diseases. The strongly recommended (core) dog vaccines are against Canine Parvovirus type 2 (CPV-2), Canine Distemper Virus (CDV), and Canine Adenovirus (CAdV-1), but vaccination protocols should be tailored to dog lifestyles. Vaccination guidelines suggest vaccinating adult dogs no more frequently than every 3 years using modified live (attenuated) vaccines (MLV), thus obtaining a long-lasting (sometimes throughout life) specific protection in many but not all animals. The aim of this study was to determine the actual levels of seroprotection against CPV-2, CDV and CAdV-1 in a cohort of Italian dogs by using the in-practice test VacciCheck. A total of 1,027 dogs (951 vaccinated and 76 unvaccinated) were analyzed for Protective Antibody Titers (PATs) against CPV-2, CDV, and CAdV-1. Differences related to sex, age, breed size, health status, and time elapsed since last vaccination were evaluated. Half of the entire canine cohort (50.6%) had PATs for all three viruses (68.5% considering only vaccinated dogs). In particular, 90.8% of dogs were protected against CPV-2, 68.6% against CDV, and 79.8% against CAdV-1. Most dogs remained protected for 3 years after vaccination or longer. Revaccination on a 3-year basis can then be recommended for core MLV vaccines without altering individual's seroprotection or even herd immunity.

Potential Drivers for the Re-Emergence of Canine Leptospirosis in the United States and Canada

Canine leptospirosis is an important zoonotic disease in many countries. This review examines potential drivers for increased diagnoses of canine leptospirosis in the United States and Canada, using the epidemiologic triad of agent-environment-host as a template. Leptospira spp. are classified into more than 250 serovars, but in many laboratories only 6 are routinely tested for in serologic agglutination tests of canine sera. Leptospiral infections in dogs may potentially go undetected with unemployed or currently employed diagnostic methods. Disease transmission from infected reservoir hosts usually occurs via urine-contaminated environmental sources such as water. Direct contact between infected and susceptible individuals, environmental factors such as climate changes in temperature and/or rainfall, and increasing number and urbanization of reservoir hosts may greatly increase dog exposure risks. A dog's lifestyle may influence exposure risk to leptospirosis, but vaccination based on proper identification of circulating serogroups dramatically reduces post-exposure infections. Regrettably, resistance to vaccination by veterinarians and dog owners leaves a large number of dogs at risk for this zoonotic disease.