Recommendations on vaccination for Asian small animal practitioners: a report of the WSAVA Vaccination Guidelines Group

Zoonoses and pet owners: A survey on risk perception in Northern Italy

Veterinary and human medicine are focused on the issue of emerging and re-emerging diseases, which are especially represented by zoonosis that could be a threat for public health. Zoonotic risk may come from pets: some canine and/or feline viral, bacterial, parasitic, protozoal or mycotic diseases can be transmitted directly to humans. There are several strategies to prevent the transmission of such zoonosis, and among them vaccination plays an important role. Through a survey carried out in Northern Italy aimed to collect information regarding owners' knowledge and perception of the zoonotic risks associated with three zoonoses (rabies, leptospirosis, and dermatophytosis), it was demonstrated that dog owners tend to adhere more consistently to their pets' vaccination schedules and are more receptive to changes in vaccination scheduling compared to cat owners. This study also suggests that cat owners predominantly visit veterinarians for vaccination purposes, whereas dog owners seek veterinary services for a variety of reasons. The survey highlighted the ongoing need to enhance owners' understanding of zoonoses affecting their pets and also the protective role of vaccines. Veterinarians should undertake the responsibility of educating, reassuring, and informing pet owners about the significance of vaccines for their pets and for public health.

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.

Compatibility Between A Rabies Vaccine and Two Canine Combined Vaccines Against Canine Distemper, Adenovirosis, Parvovirosis, Parainfluenza Virus Disease and Leptospirosis, With or without Canine Coronavirus

In many countries, vaccination programs still require dogs to be vaccinated against rabies in addition to Canine distemper virus (CDV), adenovirus (CAV), parvovirus (CPV), parainfluenza virus (CPiV), Leptospira (L) or Canine coronavirus (CCV= Cv). Few vaccines containing all these antigens are commercially available and, unless compatibility between the vaccines was demonstrated, concurrent administration of a DAPPi-L(Cv) vaccine and a vaccine against rabies should not be recommended. This may be of concern for practitioners who wish to vaccinate dogs with all components on the same day. This study aimed at evaluating immunological compatibility between a monovalent rabies vaccine (Rabisin™) and two large combination vaccines against CDV, CAV, CPV, CPiV with 2 leptospira components +Cv (Recombitek® C6/Cv) or with 4 Leptospira components (Recombitek® C8), when injected concomitantly at two separate injection sites.

Fourteen days after administration of the rabies vaccine, with or without concomitant administration of combo vaccines, all dogs had seroconverted against rabies and maintained protective titers over the duration of the study. In addition, 100% of the puppies vaccinated with one or the other combo vaccines seroconverted against CDV, CAV, CPV, CPiV (CCV) and Leptospira, whatever the vaccination group. Lack of immunological interference between Rabisin™ and all components of the Recombitek® C6/Cv or Recombitek® C8 Combo vaccines was demonstrated by non-inferiority analysis, except for CDV in the Recombitek®C8+ Rabisin™ group. Based on these results, a concomitant administration of Rabisin™ with Recombitek® C6/Cv or Recombitek® C8 can be recommended in daily practice, which can be essential for facilitating vaccination compliance.

Prevalence of Neutralizing Antibodies to Canine Distemper Virus and Response to Vaccination in Client-Owned Adult Healthy Dogs

Re-vaccinations against canine distemper virus (CDV) are commonly performed in 3-year intervals. The study's aims were to determine anti-CDV antibodies in healthy adult dogs within 28 days of vaccination against CDV, and to evaluate factors associated with the presence of pre-vaccination antibodies and with the antibody response to vaccination. Ninety-seven dogs, not vaccinated within 1 year before enrollment, were vaccinated with a modified live CDV vaccine. A measurement of the antibodies was performed before vaccination (day 0), on day 7, and 28 after the vaccination by virus neutralization. A response to vaccination was defined as a ≥4-fold titer increase by day 28. Fisher's exact test was used to determine factors associated with a lack of antibodies and vaccination response. In total, 94.8% of the dogs (92/97; CI 95%: 88.2-98.1) had antibodies (≥10) prior to vaccination. A response to vaccination was not observed in any dog. Five dogs were considered humoral non-responders; these dogs neither had detectable antibodies before, nor developed antibodies after vaccination. Young age (<2 years) was significantly associated with a lack of pre-vaccination antibodies (p = 0.018; OR: 26.825; 95% CI: 1.216-1763.417). In conclusion, necessity of re-vaccination in adult healthy dogs should be debated and regular vaccinations should be replaced by antibody detection.

Comparison of four commercially available point-of-care tests to detect antibodies against canine distemper virus in dogs

Pre-vaccination antibody testing to determine dogs' immunity against canine distemper virus (CDV) is increasingly used. Four point-of-care tests (POC A-D) are available in Europe, but their diagnostic accuracy has not been compared. The study evaluated the diagnostic accuracy and usability of these tests. Sera of client-owned dogs (n = 198; healthy n = 22; unhealthy dogs n = 176) and specific pathogen-free (SPF) dogs (n = 40) were included. Virus neutralisation (VN) was performed as the reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy (OA) were determined. McNemar's test was used to determine significant differences between specificity and sensitivity of the tests and Cohen's kappa was used to assess agreement. The prevalence of anti-CDV antibodies by VN was 80% in client-owned dogs overall, with 100% prevalence in healthy dogs, and 0% in SPF dogs. POC-C and POC-D were considered easiest to perform. Specificity of all tests was high using sera from SPF dogs (88-100%). In healthy dogs, sensitivity was variable (45-98%). Specificity was low in all four POC tests when using sera from acutely ill dogs (6-53%) and clinically healthy dogs with chronic disease (5-77%). In client-owned dogs, including healthy and unhealthy dogs, agreement was poor between tests. All POC tests had a low specificity when investigating sera from ill client-owned dogs and usefullness of these tests especially in dogs that are acutely ill or have chronic disease is not supported by this study.

Evaluation of a Point-of-Care Test for Pre-Vaccination Testing to Detect Antibodies against Canine Adenoviruses in Dogs

(1) Background: Antibody testing is commonly used to assess a dog's immune status. For detection of antibodies against canine adenoviruses (CAVs), one point-of-care (POC) test is available. This study assessed the POC test´s performance. (2) Methods: Sera of 198 privately owned dogs and 40 specific pathogen-free (SPF) dogs were included. The reference standard for detection of anti-CAV antibodies was virus neutralization (VN) using CAV-1 and CAV-2 antigens. Specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy (OA) of the POC test were assessed. Specificity was considered most important. (3) Results: Prevalence of CAV-1 neutralizing antibodies (≥10) was 76% (182/238) in all dogs, 92% (182/198) in the subgroup of privately owned dogs, and 0% (0/40) in SPF dogs. Prevalence of CAV-2 neutralizing antibodies (≥10) was 76% (181/238) in all dogs, 91% (181/198) in privately owned dogs, and 0% (0/40) in SPF dogs. Specificity for detection of CAV-1 antibodies was lower (overall dogs, 88%; privately owned dogs, 56%; SPF dogs, 100%) compared with specificity for detection of CAV-2 antibodies (overall dogs, 90%; privately owned dogs, 65%; SPF dogs, 100%). (4) Conclusions: Since false positive results will lead to potentially unprotected dogs not being vaccinated, specificity should be improved to reliably detect anti-CAV antibodies that prevent infectious canine hepatitis in dogs.

Comparison of Four Commercially Available Point-of-Care Tests to Detect Antibodies against Canine Parvovirus in Dogs

Measuring antibodies to evaluate dogs' immunity against canine parvovirus (CPV) is useful to avoid unnecessary re-vaccinations. The study aimed to evaluate the quality and practicability of four point-of-care (POC) tests for detection of anti-CPV antibodies. The sera of 198 client-owned and 43 specific pathogen-free (SPF) dogs were included; virus neutralization was the reference method. Specificity, sensitivity, positive and negative predictive value (PPV and NPV), and overall accuracy (OA) were calculated. Specificity was considered to be the most important indicator for POC test performance. Differences between specificity and sensitivity of POC tests in the sera of all dogs were determined by McNemar, agreement by Cohen's kappa. Prevalence of anti-CPV antibodies in all dogs was 80% (192/241); in the subgroup of client-owned dogs, it was 97% (192/198); and in the subgroup of SPF dogs, it was 0% (0/43). FASTest^® and CanTiCheck^® were easiest to perform. Specificity was highest in the CanTiCheck^® (overall dogs, 98%; client-owned dogs, 83%; SPF dogs, 100%) and the TiterCHEK^® (overall dogs, 96%; client-owned dogs, 67%; SPF dogs, 100%); no significant differences in specificity were observed between the ImmunoComb^®, the TiterCHEK^®, and the CanTiCheck^®. Sensitivity was highest in the FASTest^® (overall dogs, 95%; client-owned dogs, 95%) and the CanTiCheck^® (overall dogs, 80%; client-owned dogs, 80%); sensitivity of the FASTest^® was significantly higher compared to the one of the other three tests (McNemars p-value in each comparison: <0.001). CanTiCheck^® would be the POC test of choice when considering specificity and practicability. However, differences in the number of false positive results between CanTiCheck^®, TiterCHEK^®, and ImmunoComb^® were minimal.

Antibody Response to Canine Adenovirus-2 Virus Vaccination in Healthy Adult Dogs

BACKGROUND

Re-vaccination against canine adenovirus (CAV) is performed in ≤3-year-intervals but their necessity is unknown. The study determined anti-CAV antibodies within 28 days of re-vaccination and factors associated with the absence of antibodies and vaccination response.

METHODS

Ninety-seven healthy adult dogs (last vaccination ≥12 months) were re-vaccinated with a modified live CAV-2 vaccine. Anti-CAV antibodies were measured before vaccination (day 0), and after re-vaccination (day 7, 28) by virus neutralization. A ≥4-fold titer increase was defined as vaccination response. Fisher's exact test and multivariate regression analysis were performed to determine factors associated with the absence of antibodies and vaccination response.

RESULTS

Totally, 87% of dogs (90/97; 95% CI: 85.61-96.70) had anti-CAV antibodies (≥10) before re-vaccination. Vaccination response was observed in 6% of dogs (6/97; 95% CI: 2.60-13.11). Time since last vaccination (>3-5 years, OR = 9.375, p = 0.020; >5 years, OR= 25.000, p = 0.006) was associated with a lack of antibodies. Dogs from urban areas were more likely to respond to vaccination (p = 0.037).

CONCLUSION

Many dogs had anti-CAV pre-vaccination antibodies, even those with an incomplete vaccination series. Most dogs did not respond to re-vaccination. Based on this study, dogs should be re-vaccinated every 3 years or antibodies should be determined.

Antibody response to feline herpesvirus-1 vaccination in healthy adult cats

OBJECTIVES

Vaccination against feline herpesvirus-1 (FHV-1) is recommended for all cats. However, it is unknown how adult healthy cats with different pre-vaccination antibodies respond to FHV-1 vaccination in the field. The aim of the study was to determine the prevalence of neutralising antibodies against FHV-1 in healthy adult cats and the response to FHV-1 vaccination within 28 days of vaccination.

METHODS

One hundred and ten cats (⩾1 year of age) that had not received a vaccination within the past 12 months were vaccinated with a combined FHV-1 vaccine. Antibodies against FHV-1 were determined before vaccination (day 0), on day 7 and day 28 by serum neutralisation test. Uni- and multivariate statistical analyses were used to determine factors associated with the presence of pre-vaccination antibodies and response to vaccination.

RESULTS

Pre-vaccination neutralising antibody titres (⩾10) were present in 40.9% of cats (45/110; 95% confidence interval [CI] 32.2-50.3); titres were generally low (range 10-640). Antibody response to vaccination (⩾four-fold titre increase) was observed in 8.3% (9/109; 95% CI 4.2-15.1). Cats ⩾2 years of age were more likely to have pre-vaccination neutralising antibodies than cats aged between 1 and 2 years (odds ratio [OR] 24.619; P = 0.005). Cats from breeders were more likely to have pre-vaccination neutralising antibodies than privately owned cats (OR 7.070; P = 0.007). Domestic shorthair cats were more likely to have an at least four-fold titre increase vs purebred cats (OR 11.22; P = 0.027).

CONCLUSIONS AND RELEVANCE

Many cats have no detectable neutralising antibodies against FHV-1 despite previous vaccinations and fail to develop a ⩾four-fold titre increase after vaccination. This is likely because older cats and cats with a higher FHV-1 exposure risk are more likely to get infected with FHV-1 and thus to have FHV-1 neutralizing antibodies. Purebred cats more often fail to develop a ⩾four-fold titre increase after vaccination.

Recommendations on vaccination for Latin American small animal practitioners: a report of the WSAVA Vaccination Guidelines Group

The World Small Animal Veterinary Association Vaccination Guidelines Group has produced global guidelines for small companion animal practitioners on best practice in canine and feline vaccination. Recognising that there are unique aspects of veterinary practice in certain geographical regions of the world, the Vaccination Guidelines Group undertook a regional project in Latin America between 2016 and 2019, culminating in the present document. The Vaccination Guidelines Group gathered scientific and demographic data during visits to Argentina, Brazil and Mexico, by discussion with national key opinion leaders, visiting veterinary practices and review of the scientific literature. A questionnaire survey was completed by 1390 veterinarians in five Latin American countries and the Vaccination Guidelines Group delivered continuing education at seven events attended by over 3500 veterinarians.

The Vaccination Guidelines Group recognised numerous challenges in Latin America, for example: (1) lack of national oversight of the veterinary profession, (2) extraordinary growth in private veterinary schools of undetermined quality, (3) socioeconomic constraints on client engagement with preventive health care, (4) high regional prevalence of some key infectious diseases (e.g. feline leukaemia virus infection, canine visceral leishmaniosis), (5) almost complete lack of minimal antigen vaccine products as available in other markets, (6) relative lack of vaccine products with extended duration of immunity as available in other markets, (7) availability of vaccine products withdrawn from other markets (e.g. Giardia vaccine) or unique to Latin America (e.g. some Leishmania vaccines), (8) accessibility of vaccines directly by pet owners or breeders such that vaccination is not delivered under veterinary supervision, (9) limited availability of continuing education in veterinary vaccinology and lack of compulsion for continuing professional development and (10) limited peer‐reviewed published scientific data on small companion animal infectious diseases (with the exception of leishmaniosis) and lack of support for such academic research.

In this document, the Vaccination Guidelines Group summarises the findings of this project and assesses in evidence‐based fashion the scientific literature pertaining to companion animal vaccine‐preventable diseases in Latin America. The Vaccination Guidelines Group makes some recommendations on undergraduate and postgraduate education and academic research. Recognising that current product availability in Latin America does not permit veterinarians in these countries to vaccinate according to the global World Small Animal Veterinary Association guidelines, the Vaccination Guidelines Group makes a series of “pragmatic” recommendations as to what might be currently achievable, and a series of “aspirational” recommendations as to what might be desirable for the future. The concept of “vaccine husbandry” is addressed via some simple guidelines for the management of vaccine products in the practice. Finally, the Vaccination Guidelines Group emphasises the global trend towards delivery of vaccination as one part of an “annual health check” or “health care plan” that reviews holistically the preventive health care needs of the individual pet animal. Latin American practitioners should transition towards these important new practices that are now well embedded in more developed veterinary markets.

The document also includes 70 frequently asked questions and their answers; these were posed to the Vaccination Guidelines Group during our continuing education events and small group discussions and should address many of the issues surrounding delivery of vaccination in the Latin American countries. Spanish and Portuguese translations of this document will be made freely available from the on‐line resource pages of the Vaccination Guidelines Group.

Antibody Response to Feline Calicivirus Vaccination in Healthy Adult Cats

This study evaluated the prevalence of feline calicivirus (FCV) antibodies and response to vaccination in healthy adult cats. Cats >1 year (n = 111) that had not been vaccinated within 12 months of enrollment in the study received a vaccine containing inactivated FCV antigen strains 431 and G1. Antibodies were determined on Days 0, 7, and 28 by virus neutralization (VN) using FCV isolate KS20, and by broad spectrum blocking FCV enzyme-linked immunosorbent assay (ELISA). Factors associated with the presence of antibodies and vaccine response were determined by uni- and multivariate analysis. Pre-vaccination antibodies were detected in 62.2% of cats (CI_95%: 52.9-70.1) by VN and in 77.2% (CI_95%: 67.5-84.6) by ELISA. A ≥4-fold titer increase after vaccination was observed in 13.6% (CI_95%: 8.3-21.4) of cats with VN and 33.7% (CI_95%: 24.5-44.5) with ELISA. Factors associated with the presence of pre-vaccination VN antibodies were age (≥2 years; OR: 7.091; p = 0.022) and lack of previous vaccination (OR: 3.472; p = 0.014). The presence of pre-vaccination ELISA antibodies was associated with time since last vaccination (OR: 5.672; p = 0.043). Outdoor cats were more likely to have a ≥4-fold ELISA titer increase (OR: 5.556; p = 0.005). Many cats had pre-vaccination FCV antibodies, and their presence depended on previous vaccinations and increases with age. A ≥4-fold titer increase was rarely observed and was influenced by the lifestyle of the cat.

Toward the formation of a Companion Animal Parasite Council for the Tropics (CAPCT)

This letter advises the imminent formation of the Companion Animal Parasites Council for the Tropics (CAPCT). The CAPCT consists of region-specific (e.g., Asia-Pacific, Latin America and Caribbean, Africa) experts comprising academics, veterinarians, parasitologists, physicians and allied industry partners that will work together to inform, guide and develop best-practice recommendations for the optimal diagnosis, treatment and control of companion animal parasites in the tropics, with the aim of protecting the health of pets and that of the public.