Objective—To determine the frequency of viral detection in conjunctival samples from client-owned domestic dogs with naturally acquired idiopathic conjunctivitis and to identify signalment, historical, and clinical findings positively associated with viral detection.
Animals—30 dogs with naturally acquired idiopathic conjunctivitis and a control population of 30 dogs without ocular disease.
Procedures—Complete physical and ophthalmic examinations were performed for each dog. Conjunctival swab specimens were analyzed by use of virus isolation and PCR assays for the following viruses: canine adenovirus-2 (CAV-2), canine distemper virus, canine herpesvirus-1 (CHV-1), canine parainfuenza virus, canine respiratory coronavirus, infuenza A virus, and West Nile virus. Signalment, clinical, and historical information was recorded and compared between study groups.
Results—Viruses were detected by either virus isolation or PCR methods significantly more frequently in conjunctival samples from dogs with conjunctivitis (7/30 [23.3%]) than dogs without conjunctivitis (0/30 [0%]). Canine herpesvirus-1 was isolated from 2 conjunctival samples and detected by use of PCR assay in 5 conjunctival samples. Canine adenovirus-2 was isolated from 1 conjunctival sample and detected by use of PCR assay in 2 conjunctiva samples. Sexually intact dogs and frequent exposure to dogs outside the household were positively associated with viral detection in the conjunctivitis group
Conclusions and Clinical Relevance—Results suggested that CHV-1 and CAV-2 are common etiologic agents of conjunctivitis in domestic dogs. Risk factors for viral conjunctivitis in dogs reflected increased exposure to other dogs and opportunities for contact with infectious secretions.
Objective—To compare 2 assays for use in the identification of dogs with a protective antibody titer (PAT) against canine parvovirus (CPV) and canine distemper virus (CDV).
Design—Prospective cross-sectional study.
Animals—431 dogs admitted to a municipal animal shelter in north central Florida.
Procedures—Blood samples were collected from dogs on the day of admission to the shelter. Serum was obtained, criterion-referenced assays were used to identify dogs that had PATs against CPV (titers ≥ 80; hemagglutination inhibition assay) and CDV (titers ≥ 32; virus neutralization assay), and results were compared with results of a semiquantitative ELISA and an immunofluorescence assay (IFA).
Results—For correct identification of dogs that had PATs against viruses, the ELISA had significantly higher specificity for CPV (98%) and CDV (95%) than did the IFA (82% and 70%, respectively) and had significantly lower sensitivity for CDV (88%) than did the IFA (97%); the sensitivity for CPV was similar (ELISA, 98%; IFA, 97%). Overall diagnostic accuracy was significantly greater with the ELISA than with the IFA. Predictive value of a positive result for PATs was significantly higher with the ELISA for CPV (99%) and CDV (93%) than with the IFA (92% and 71 %, respectively).
Conclusions and Clinical Relevance—The ELISA had fewer false-positive results than did the IFA and could be performed on-site in shelters in < 1 hour. Accuracy and practicality of the ELISA may be useful for identifying the infection risk of dogs exposed during outbreaks attributable to CPV and CDV infections in shelters.
Objective—To determine the frequency and duration of feline panleukopenia virus (FPV) vaccine-induced interference with fecal parvovirus diagnostic testing in cats.
Design—Prospective controlled study.
Animals—Sixty-four 8- to 10-week-old specific-pathogen–free kittens.
Procedures—Kittens were inoculated once with 1 of 8 commercial multivalent vaccines containing modified-live virus (MLV) or inactivated FPV by the SC or intranasal routes. Feces were tested for parvovirus antigen immediately prior to vaccination, then daily for 14 days with 3 tests designed for detection of canine parvovirus. Serum anti-FPV antibody titers were determined by use of hemagglutination inhibition prior to vaccination and 14 days later.
Results—All fecal parvovirus test results were negative prior to vaccination. After vaccination, 1 kitten had positive test results with test 1, 4 kittens had positive results with test 2, and 13 kittens had positive results with test 3. Only 1 kitten had positive results with all 3 tests, and only 2 of those tests were subjectively considered to have strongly positive results. At 14 days after vaccination, 31% of kittens receiving inactivated vaccines had protective FPV titers, whereas 85% of kittens receiving MLV vaccines had protective titers.
Conclusions and Clinical Relevance—Animal shelter veterinarians should select fecal tests for parvovirus detection that have high sensitivity for FPV and low frequency of vaccine-related test interference. Positive parvovirus test results should be interpreted in light of clinical signs, vaccination history, and results of confirmatory testing. Despite the possibility of test interference, the benefit provided by universal MLV FPV vaccination of cats in high-risk environments such as shelters outweighs the impact on diagnostic test accuracy.
Objective—To characterize clinical ocular disease, viral shedding, and serologic response associated with primary canine herpesvirus-1 (CHV-1) ocular infection in naïve adult dogs.
Animals—12 specific pathogen-free adult Beagles.
Procedures—Dogs were topically inoculated in the right eye with CHV-1 (infection group; n = 8) or virus-free medium (control group; 4). Dogs were inoculated with or without corneal microtrephination and subconjunctivally administered corticosteroids. Conjunctiva, buffy coat, and serum samples for real-time PCR assay, virus isolation, and serum neutralization (SN) antibody titers were collected until postinfection day (PID) 224, and general physical and ophthalmologic examinations were performed.
Results—Dogs in the infection group developed bilateral, mild to moderate conjunctivitis that reached maximal intensity on PIDs 7 to 10. Ocular viral shedding was detected in all dogs in the infection group between PIDs 3 and 10. Infected dogs developed CHV-1 SN antibody titers, beginning at PID 7 and peaking on PID 21. All buffy coat PCR assay results were negative. Corneal microtrephination and subconjunctival corticosteroid administration did not significantly affect clinical disease or viral shedding. Following recovery from primary infection, dogs remained clinically normal, did not shed virus, and had slowly decreasing SN antibody titers. Dogs in the control group did not develop conjunctivitis, shed virus, or develop CHV-1 SN antibody titers.
Conclusions and Clinical Relevance—Primary ocular infection of adult dogs with CHV-1 was associated with self-limiting conjunctivitis and ocular viral shedding, which was evident in the absence of clinically detectable keratitis or systemic disease. Features of this infection resembled herpes simplex virus primary ocular infection in humans.
Objective—To estimate the seroprevalence of antibodies against H3N8 canine influenza virus (CIV) in a population of US dogs with influenza-like illness (ILI) and to identify factors associated with seropositivity.
Animals—1,268 pet and shelter dogs with ILI in 42 states.
Procedures—Serum samples collected from dogs from 2005 through June 2009 were tested for H3N8 CIV antibodies with a hemagglutination inhibition assay. Intrinsic factors (age, breed, and sex), extrinsic factors (dogs housed in a shelter facility, boarding kennel, or other setting), and geographic region (southwest, west, Midwest, southeast, and northeast) were compared between seropositive and seronegative dogs to identify variables associated with seropositivity.
Results—Most (750/1,268 [59%]) dogs in the study were from Colorado, Florida, or New York. The overall seroprevalence of antibodies against H3N8 CIV was 49% (618/1,268 dogs; 95% confidence interval, 46% to 51%). The annual prevalence of H3N8 CIV seropositivity increased from 2005 (44%) to 2006 (53%) and 2007 (62%), then decreased in 2008 (38%) and 2009 (15%). The likelihood of H3N8 CIV seropositivity was associated with geographic region (southeast during 2005, west and northeast during 2006 and 2007, and northeast during 2008) and exposure setting (dogs housed in a shelter facility or boarding kennel during 2005 and 2006).
Conclusions and Clinical Relevance—Results of this study suggested there is a need for continued surveillance for H3N8 CIV infection in dogs in the United States and that personnel in communal dog-housing facilities should formulate, implement, and evaluate biosecurity protocols to reduce the risk of CIV transmission among dogs.
Objective—To determine the frequency of spontaneous canine herpesvirus-1 (CHV-1) reactivation and ocular viral shedding in latently infected dogs and the effect of topical ocular administration of cyclosporine.
Animals—8 mature Beagles with experimentally induced latent CHV-1 infection.
Procedures—Following induction of primary ocular CHV-1 infection, the presence of reactivatable CHV-1 latency was confirmed by systemically administering prednisolone to the dogs. Dogs were then monitored for 36 weeks via clinical examination and conjunctival sample CHV-1 PCR assay performed at 4-day intervals and CHV-1 virus neutralization antibody assay performed at 2-week intervals. During weeks 16 to 32, dogs were administered 0.2% cyclosporine ointment in both eyes twice daily and blood cyclosporine concentrations were monitored. During weeks 33 to 36, the presence of reactivatable CHV-1 latency was reconfirmed via systemic administration of prednisolone.
Results—Reactivation of latent CHV-1 was not detected via clinical examination or viral shedding during the initial 32 weeks, including before and during topical ocular administration of cyclosporine, and there were no significant differences in CHV-1 virus neutralization titer increases between the study periods. Blood cyclosporine concentrations were less than assay detection limits in all dogs on the sampling days. Systemic administration of corticosteroids repeatedly resulted in ocular disease and viral shedding.
Conclusions and Clinical Relevance—Spontaneous CHV-1 reactivation did not occur frequently in latently infected mature dogs, and this was not altered by topical ocular administration of cyclosporine. This characteristic may be a factor contributing to the lower frequency of recurrent herpetic ocular disease in dogs relative to other host species and their associated alphaherpesviruses.
Objective—To determine the proportion of dogs entering an animal shelter with protective antibody titers (PATs) for canine distemper virus (CDV) and canine parvovirus (CPV) and identify factors associated with having a PAT.
Animals—431 dogs admitted to an open-admission municipal animal shelter in north central Florida with a history of infectious disease outbreaks.
Procedures—Blood was collected from dogs on the day of admission to the shelter. Antibody titers for CDV and CPV were measured by virus neutralization and hemagglutination inhibition, respectively. Age, sex, neuter status, address of origin, source (stray or previously owned), health status (healthy or not healthy), and outcome (adoption, euthanasia, or reclaimed by owner) data were also collected.
Results—Overall, 64.5% (278/431) of dogs had insufficient titers for antibodies against CDV, CPV, or both. A total of 153 (35.5%) dogs had PATs for both CDV and CPV, 33 (7.7%) had PATs for CDV but not CPV, 136 (31.5%) had PATs for CPV but not CDV, and 109 (25.3%) did not have PATs for either virus. Older dogs were more likely to have PATs for CDV and CPV. Neutered dogs were more likely to have PATs for CDV. Factors not associated with having a PAT included source, health status, and type of community from which the dog originated.
Conclusions and Clinical Relevance—Most dogs had insufficient antibody titers for CDV, CPV, or both at the time of admission to the animal shelter. Findings support current guidelines recommending vaccination of all dogs immediately upon admission to shelters, regardless of source or physical condition.
Objective—To determine the effects of anesthesia and surgery on serologic responses to vaccination in kittens.
Design—Prospective controlled trial.
Animals—32 specific-pathogen–free kittens.
Procedures—Kittens were assigned to 1 of 4 treatment groups: neutering at 7, 8, or 9 weeks of age or no neutering. All kittens were inoculated with modified-live virus vaccines against feline panleukopenia virus (FPV), feline herpesvirus (FHV), and feline calicivirus (FCV) at 8, 11, and 14 weeks of age and inactivated rabies virus (RV) at 14 weeks of age. Serum antibody titers against FPV, FHV, and FCV were determined at 8, 9, 11, 14, and 17 weeks of age; RV titers were determined at 14 and 17 weeks of age.
Results—Serologic responses of kittens neutered at the time of first vaccination (8 weeks) were not different from those of kittens neutered 1 week before (7 weeks) or 1 week after (9 weeks) first vaccination or from those of kittens that were not neutered. In total, 31%, 0%, 69%, and 9% of kittens failed to develop adequate titers against FPV, FCV, FHV, and RV, respectively, by 17 weeks of age.
Conclusions and Clinical Relevance—Neutering at or near the time of first vaccination with a modified-live virus vaccine did not impair antibody responses in kittens. Many kittens that were last vaccinated at 14 weeks of age had inadequate antibody titers at 17 weeks of age. Kittens may be vaccinated in the perioperative period when necessary, and the primary vaccination series should be extended through at least 16 weeks of age.
Objective—To determine whether administration of inactivated virus or modified-live virus (MLV) vaccines to feral cats at the time of neutering induces protective serum antiviral antibody titers.
Animals—61 feral cats included in a trap-neuter-return program in Florida.
Procedures—Each cat received vaccines against feline panleukopenia virus (FPV), feline herpes virus (FHV), feline calicivirus (FCV), FeLV, and rabies virus (RV). Immediately on completion of surgery, vaccines that contained inactivated RV and FeLV antigens and either MLV or inactivated FPV, FHV, and FCV antigens were administered. Titers of antiviral antibodies (except those against FeLV) were assessed in serum samples obtained immediately prior to surgery and approximately 10 weeks later.
Results—Prior to vaccination, some of the cats had protective serum antibody titers against FPV (33%), FHV (21%), FCV (64%), and RV (3%). Following vaccination, the overall proportion of cats with protective serum antiviral antibody titers increased (FPV [90%], FHV [56%], FCV [93%], and RV [98%]). With the exception of the FHV vaccine, there were no differences in the proportions of cats protected with inactivated virus versus MLV vaccines.
Conclusions and Clinical Relevance—Results suggest that exposure to FPV, FHV, and FCV is common among feral cats and that a high proportion of cats are susceptible to RV infection. Feral cats appeared to have an excellent immune response following vaccination at the time of neutering. Incorporation of vaccination into trap-neuter-return programs is likely to protect the health of individual cats and possibly reduce the disease burden in the community.
Objective—To determine the proportion of cats entering a Florida animal shelter with serum antibody titers against feline panleukopenia virus (FPV), feline herpesvirus 1 (FHV1), and feline calicivirus (FCV) and to identify factors associated with seropositivity.
Animals—347 cats admitted to a Florida animal shelter.
Procedures—Within 24 hours after admission to the animal shelter, blood samples were collected from all cats ≥ 8 weeks of age. Serum antibody titers against FPV were determined via a hemagglutination inhibition assay, and those against FHV1 and FCV were determined via virus neutralization assays. Age, sex, environment (urban or rural), source (stray or previously owned), evidence of previous caregiving, health status (healthy or not healthy), and outcome (adoption, transfer, return to owner, or euthanasia) were evaluated as potential factors associated with antibody seropositivity.
Results—Of 347 cats, 138 (39.8%), 38 (11.0%), and 127 (36.6%) had antibody titers ≥ 40, ≥ 8, and ≥ 32 (ie, seropositive) against FPV, FHV1, and FCV, respectively. Factors associated with seropositivity included being neutered, age ≥ 6 months, and being relinquished by an owner. On multivariable analysis, health status at shelter admission, environment, vaccination at shelter admission, and outcome were not associated with seropositivity.
Conclusions and Clinical Relevance—Most cats were seronegative for antibodies against FPV, FHV1, and FCV at the time of admission to an animal shelter. These findings supported current guidelines that recommend vaccination of all cats immediately after admission to animal shelters, regardless of the source or physical condition.