Walking the dog and moving the cat: rabies serology in the context of international pet travel schemes

Data of 13'469 blood samples from 10'999 dogs and 2'470 cats tested for rabies neutralizing antibodies within the framework of pet travel schemes were analysed for single and combined factors influencing antibody titres and failures. The time span between vaccination and drawing the blood sample was confirmed as a major source of failure in dogs with a proportion of 23 % at 4 months after primary vaccination (single dose). Failures in dogs and cats (titre < 0.5 IU) were significantly reduced after double primary vaccination (2 doses within 7 - 10 days), although failures reached comparable levels in dogs as early as 6 months after vaccination. In contrast, failure after vaccination was generally below 5 % in dogs and absent in cats after a booster applied at earliest 12 months after single primary vaccination. Statistically significant differences between the failures of the vaccine brands ?Rabisin? (1.5 %), ?Defensor? (6.7 %), ?Nobivac Rabies? (11.0 %) and ?Rabdomun? (18.2 %) were found in dogs but also between the titres induced in cats. Significant differences were found between different dog breeds with some small breeds showing a significantly higher responsiveness. Taken together, a new regimen for rabies vaccination consisting of double primary vaccination with a short interval of 7 - 10 days and a one-year booster appears to be highly recommended for dogs and cats.     

Serosurveillance of rabies antibodies in dogs in Mumbai region by using indirect ELISA

Rabies is a highly fatal viral infection of the central nervous system affecting all warm-blooded animals including humans. To implement the preventive and control measures, it is important to decide the status of anti-rabies antibodies in dogs. Out of 120 serum samples, 47 (39.2 %) serum samples, showed an antibody titre equal to or above the cut off value of 0.5 IU/ml. The maximum number of dogs showed anti-rabies antibody titres equal to or above the cut-off value of 0.5 IU/ml after <1 month pre-exposure to the rabies vaccine. In 15 serum samples of pet dogs, we observed 13 (86.66 %) dogs with protective anti-rabies antibody titre. Statistical analysis suggests that the age of the animal had no significant effect on anti-rabies antibody titre in vaccinated pet dogs. The overall low seroprevalence of anti-rabies antibody in stray dogs indicates their susceptibility to rabies infection and thus posing a risk of rabies to other animals and humans.     

Measurement of titres of naturally occurring alloantibodies against feline blood group antigens in the UK

Measurement of anti-A and anti-B haemagglutinating alloantibody titres was performed on serum samples from both pedigree (n = 61) and non-pedigree (n = 43) cats previously typed using a commercial blood typing kit. All 40 type B cats had anti-A antibody with titres ranging from 4 to 1600. Among the 61 type A sera tested, an anti-B agglutination titre of greater than 2 was recorded in 16.4 per cent. There was no significant association between serum alloantibody titre and cat breed or gender (P > 0.05).     

A latex cryptococcal antigen agglutination test for diagnosis and monitoring of therapy for cryptococcosis

SUMMARY: A latex cryptococcal antigen agglutination test (LCAT) was performed on sera obtained during the first 14 days of treatment from 58 animals (46 cats, 9 dogs, 2 koalas and 1 long billed corella) with cryptococcosis. The same commercial kit was used for all samples, and most serum samples were treated with pronase before testing. Sera from all 58 cases tested positive with the qualitative LCAT protocol (using undiluted sera), while sera from all 26 cats without cryptococcosis tested negative. Titres determined using the quantitative protocol ranged from 1 to 131 072 (median titre between 2048 and 4096), with 57 of 58 cases (including all 8 animals that presented for neurological signs) having titres 2 and thus considered positive according to the manufacturer's recommendations. The LCAT titre was positively correlated with disease severity (r = 0.4169; P = 0.0011), and patients with disseminated skin and/or lymph node involvement had significantly higher titres than those that did not (P = 0.0157). The presence of neurological signs, the species of the patient, concurrent viral disease (in cats) and the biotype of the isolate had no significant association with the LCAT titre. Cats that died of active cryptococcosis despite treatment did not have significantly higher titres (P = 0.3010) than those that responded to treatment. Sequential LCAT determinations obtained in 37 patients during treatment provided a useful quantitative indication of clinical progress, although the decline in titre lagged somewhat behind clinical improvement. Generally, the antigen titre declined by 2 to 4 fold per month during successful therapy. Although there are insufficent data to make unequivocal recommendations, we suggest that either antifungal therapy be continued until the LCAT titre declines to less than 1, or therapy be discontinued after a 32 fold or greater reduction in titre, with periodic monitoring of the serum antigen titre. Treatment of serum samples with pronase substantially increased the sensitivity of the LCAT.     

Impact of Rabies Vaccination History on Attainment of an Adequate Antibody Titre Among Dogs Tested for International Travel Certification,Israel – 2010–2014

Rabies is endemic in wildlife or domestic carnivore populations globally. Infection of domestic dogs is of particular concern in many areas. In regions where domestic animals are at risk of exposure to rabies virus, dogs should be routinely vaccinated against rabies to protect both pet and human populations. Many countries require demonstration of an adequate level of serum rabies neutralizing antibodies to permit entry of dogs during international travel. We analysed rabies titres of dogs seeking travel certification in Israel to assess demographic and vaccine history factors associated with antibody titres below the acceptable threshold for travel certification. Having received only one previous rabies vaccination and a longer duration since the most recent vaccination was received were primary risk factors for not achieving an adequate rabies virus neutralizing antibody titre for travel certification. These risk factors had stronger effects in younger animals, but were consistent for dogs of all ages. In particular, these findings reiterate the importance of administering at least two rabies vaccinations (the primo vaccination and subsequent booster) to ensure population‐level protection against rabies in dogs globally.     

The ERA Strain of Rabies Vaccine

An antigenic extinction trial in cats showed that the ERA rabies vaccine had superior antigenic properties over Flury H.E.P. C.E.O. and killed tissue culture rabies vaccine.

Dogs and cats on a duration of immunity study of ERA rabies vaccine were challenged with fox salivary gland “street” rabies virus. The results of this challenge show a duration of immunity of five years in dogs and four years in cats.

Vaccination of dams in late pregnancy with ERA rabies vaccine resulted in transference of maternal antibody to the newborn, in both cattle and dogs. This maternally derived antibody interfered with the successful active immunization of the young calf. Calves free of antibodies for rabies could be successfully vaccinated as early as 17 days of age and were able to withstand a challenge with virulent “street” rabies virus two years later.

     

Dried solidified blood calculi in the urinary tract of cats

We have noted an increased number of calculi submitted to the Gerald V. Ling Urinary Stone Analysis Laboratory, University of California, Davis, that do not contain crystalline material but appear to be composed of dried solidified blood (DSB). Canine and feline laboratory records from 1986-2003 were reviewed for samples composed of >99% DSB. No calculi from dogs were found, but specimens from 49 cats were composed of >99% DSB, of which almost half (n = 22) had been submitted after 2001. The DSB calculi had been removed surgically or by postmortem examination from all areas of the upper and lower urinary tract. All samples were well formed and could be divided in half with Rongeur forceps. Detailed case information was available for 12 cats. Urinalyses were available for 9 of the 12 cats, and the mean specific gravity was 1.017 (range, 1.009-1.032). Red blood cells were reported in the sediment of all cats, with most containing >100 RBC/hpf. Ureteral obstructions but no radio-opaque calculi were visible by radiography, including radiographic contrast studies. Reports of ultrasound examinations were available for 10 cats, and discrete calculi were not recorded. In addition to polarized light microscopy, infrared spectroscopy and electron probe microanalysis were performed on a subset (n = 6, DSB calculi; n = 3, control calculi) of samples. Significantly more carbon, nitrogen, and sulfur (P = .012, P = .02, and P = .012, respectively) were present in the elemental analysis of the DSB calculi than in the control calculi, suggesting that the DSB calculi are primarily formed from organic material. At this time, we are uncertain why these DSB calculi become solidified, and we recommend that samples be submitted both in formalin and preservative free to further investigate their etiology.     

Immune response to Japanese rabies vaccine in domestic dogs

To evaluate the immune response induced by Japanese rabies vaccine for veterinary use as international units (IU), we measured levels of rabies antibody in serum samples from dogs by the rapid fluorescent focus inhibition test (RFFIT). In dogs immunized with a reference vaccine (potency level of 3.1 IU/ml), prepared by the same method as that used to produce commercial vaccine, and its dilutions (1 : 2 or 1 : 4), neutralizing-antibody levels increased to 1.0-2.0 IU/ml over a period of 1 month and then decreased to 0.2-1.5 IU/ml over a period of 1 year after the first vaccination and showed a remarkable increase to 12-47 IU/ml after the second vaccination. Sixty-five (74.7%) of the 87 serum samples from domestic dogs that were tested were seropositive (> or =0.1 IU/ml). However, the seropositive rate in dogs less than 1-year old at the time of vaccination was low (57.1%), and the antibody levels in these dogs were not sufficiently high for the rabies antibody titre in serum to be maintained for 1-year. Levels of rabies antibody in all serum samples were also measured by the virus neutralizing test (VNT), and a strong correlation (r > 0.95) was found between the results of the RFFIT and those of the VNT.     

北京地区犬猫弓形虫病流行病学调查

为初步调查北京地区犬猫弓形虫感染的流病学特征,用酶联免疫吸附试验(ELISA)方法检测2010年5月至2011年4月采集的家养犬猫、流浪猫血清样本.其中,家养犬血清样本1876份,家养猫血清样本561份,检测发现,家养犬动物弓形虫IgG抗体阳性率24.9％;家养猫弓形虫IgG阳性率21.2％;同时检测流浪猫样本201份,阳性率30.3％.家养犬弓形虫血清抗体阳性率不同季节间差异显著(P＜0.05),夏季最高,为30.0％,家养猫弓形虫血清抗体阳性率不同季节间无显著差异(P＞0.05).不同性别犬猫弓形虫血清抗体阳性率无显著差异(P＞0.05).随着年龄增长,犬猫弓形虫抗体阳性率均有明显增长.对25例弓形虫抗体阳性家养犬病例和37例弓形虫抗体阳性家养猫病例进行了回访调查,结果发现,该62例动物主人的弓形虫检测结果均为阴性.     

Attitudes of the public towards dogs and cats as companion animals

A questionnaire was used to collect information on attitudes toward dogs and cats as companion animals. Thirty-nine attitudinal questions on dogs were grouped using principal component analysis (PCA) into six independent major factors; whereas, 38 items on cats were grouped using principal component analysis (PCA) into four independent major factors. In addition, 18 items which did not fit the PCA model but that were related to the respondents' attitudes towards dogs and cats as companion animals were analysed separately. The hypotheses tested, using analysis of variance (ANOVA) were that there was no significant relationship between the factors and five variables, i.e., pet ownership, age or sex of the respondents and their like or dislike of either dogs or cats. The respondents' like or dislike of dogs or cats influenced their attitudes towards ownership of companion animals. Furthermore, nonowners stated they derive minimal value from a dog or cat as a pet and viewed the negative characteristics of the animal itself per se as a more important factor in determining ownership. Female respondents were more emotionally involved and younger owners derived more of a feeling of importance-vanity from dog or cat ownership.     

High Porcine Parvovirus Antibodies in Sow Herds: Prevalence and Associated Factors

Porcine parvovirus (PPV) is widespread among swine. Our objective was to determine the prevalence of loosely housed sow herds in Finland with at least one animal with high (infection level) PPV antibodies and to gather basic knowledge about vaccination practices. In addition, selected factors associated with high antibody levels found in sows were examined. Altogether, 247 animals were sampled in 21 randomly chosen loosely housed sow herds. Samples were analysed with the haemagglutination inhibition (HI) test. PPV proved to be common; in 17 farms (81%) at least one animal had a high titre (>1 : 512), and 44% of all animals sampled had a high titre. The vaccination programmes had many shortcomings. In the generalised estimation equations (GEE) population-averaged model developed, the factors found to have a significant (p < or = 0.05) effect on HI titres were herd size, parity of two or greater and storage of the vaccine vial after use. Non-returning rate, re-breeding interval and litter size did not differ between herds with no high HI titres (n = 4) and those with at least one high HI titre (n = 17).     

Rabies Antibodies in Vaccinated Dogs

Forty-seven healthy, owned dogs were vaccinated with Madivak and 85 with Rabisin. Geometric mean titres of 17.40 and 1.03 IU/ml were measured by the rapid immunofluorescent focus inhibition test 30–40 and 350–370 days, respectively, after a single injection. Four out of 130 (3.1%) and 18 out of 106 (17% ) dogs had a titre of less than 0.5 IU/ml in serum 30–40 and 350–370 days after vaccination. Twenty-one dogs (19.8%) had a titre of 0.5 IU/ml 350–370 days after vaccinaton. There was no significant difference in antibody levels between animals vaccinated with Rabisin or Madivak. Our results indicate that a booster is always necessary after a single injection to ensure that all dogs have a lasting antibody titre.     

Factors associated with the success of rabies vaccination of dogs in Sweden

Background

United Kingdom, Ireland, Malta and Sweden maintain their national provisions for a transitional period regarding rules concerning rabies vaccination and individual serological test for rabies neutralizing antibodies. The purpose of vaccinating dogs against rabies is to establish pre-exposure immunity and protect individual animals from contracting rabies.The aim of the study was to investigate factors associated with reaching the internationally accepted threshold antibody titre of 0.5 IU/mL after rabies vaccination of dogs.

Methods

The study was a prospective single cohort study including 6,789 samples from Swedish dogs vaccinated with commercially available vaccines in Sweden, and the dog''s antibody responses were determined by the OIE approved FAVN test. Information on potential risk factors; breed, age, gender, date of vaccination, vaccine label and the number of vaccinations, was collected for each dog. Associations between the dependent variable, serological response ≥ 0.5 IU/mL or < 0.5 IU/mL and each of the potential risk factors were investigated using logistic regression analysis.

Results

Of 6,789 vaccinated dogs, 6,241 (91.9%) had an approved test result of ≥ 0.5 IU/mL. The results of the multivariable logistic regression analysis showed that vaccinating with vaccine B reduced the risk of having antibody titres of < 0.5 IU/mL by 0.2 times compared with vaccination using vaccine A. Breed size was found significant as an interaction with number of vaccinations and age at vaccination as an interaction with day of antibody testing after last vaccination. In summary, larger breeds were at higher risk of having antibody titres of < 0.5 IU/mL but if vaccinated twice this risk was reduced. Moreover, there were a increased risk for dogs < 6 months of age and > 5 years of age to have antibody titres of < 0.5 IU/mL, but this was affected by number of days from vaccination till testing.

Conclusions

The probability of success of rabies vaccinations of dogs depends on type of vaccine used, number of rabies vaccinations, the breed size of the dog, age at vaccination, and number of days after vaccination when the antibody titres are tested. The need for a booster vaccination regimen is recommended for larger breeds of dog.     

Use of radiographic measurements in distinguishing myasthenia gravis from other causes of canine megaoesophagus

OBJECTIVES: To evaluate whether dogs with megaoesophagus due to myasthenia gravis display less oesophageal dilatation radiographically than dogs with other causes of megaoesophagus. METHODS: Thoracic radiographs of 66 dogs with megaoesophagus in which concurrent acetylcholine receptor antibody titre was known were analysed retrospectively. Maximum oesophageal diameter was transformed to a "relative oesophageal diameter" using a ratio with thoracic inlet diameter. Dogs were divided into two groups according to "MG" or "non-MG" antibody status and median relative oesophageal diameter values were compared between groups and with age, weight and sex. A receiver operating characteristic plot was used to evaluate a suitable relative oesophageal diameter cut-off. RESULTS: Twenty dogs were diagnosed with myasthenia gravis and 46 with other causes of megaoesophagus. Thoracic inlet size correlated significantly with bodyweight and surface area (r(2)=0.627 and 0.669, respectively). Median values of relative oesophageal diameter for the MG group and non-MG group were 0.58 and 0.66, respectively, and these showed a small, but significant, difference (P=0.029), although there was complete overlap in the range of relative oesophageal diameter values between groups. There was no significant association between relative oesophageal diameter and sex, age or weight or significant difference in age, sex or weight between the two groups. An increased odds ratio for myasthenia gravis existed in golden retrievers and German shepherd dogs. CLINICAL SIGNIFICANCE: Relative oesophageal diameter appears to be of limited diagnostic utility in distinguishing dogs with megaoesophagus due to myasthenia gravis from those with megaoesophagus due to other causes.     

Antibody Testing Against Canine Coronavirus by Immunoperoxidase Plaque Staining

The application of the immunoperoxidase (IP) plaque staining procedure (IP test) to the diagnosis of canine coronavirus (CCV) infection was investigated. The IP test did not react with sera from either 15 specific pathogen-free (SPF) dogs or 7 SPF dogs immunized with a multivalent vaccine, including canine parvovirus type 2, canine distemper virus, canine adenovirus type 2, and canine parainfluenza virus. To compare the IP test with the neutralizing test (NT), sera from 240 healthy dogs and from 3 experimentally CCV-infected dogs were examined. All 60 sera positive for NT antibody were positive for IP antibody, and all 180 sera negative for NT antibody were negative for IP antibody in the healthy dogs. The IP titres showed similar changes with time after CCV inoculation to those of the NT titres in the experimentally infected dogs. These findings indicate that the IP test specifically detected anti-CCV antibodies. When the IP test and NT were compared in dogs with diarrhoeic signs. 2.1% of 48 sera and 20.3% of 74 sera, which were all negative for NT antibody, were positive for IP antibody in the dogs of under one year of age and at least one year of age, respectively. The difference between the IP and NT titres (log₁₀ [reciprocal of IP titre] – log₁₀ [reciprocal of NT titre]) for the diarrhoeic dogs of under one year of age (2.350±0.931) was significantly larger than that for the healthy dogs (0.982±0.447) (p<0.0001), the NT titre being negative or very low, despite a high IP titre in many diarrhoeic dogs. Hence, the IP test is more able to detect anti-CCV antibodies, especially in dogs showing clinical signs. The IP-positivity rate was significantly higher in the diarrhoeic dogs of under one year of age (48.7%) than in the healthy dogs (25.0%) (² = 19.844, p<0.0001), suggesting that CCV may contribute to diarrhoea in many juvenile dogs.     

Clinical use of serum parvovirus and distemper virus antibody titers for determining revaccination strategies in healthy dogs

OBJECTIVE: To assess whether serum canine parvovirus (CPV) and canine distemper virus (CDV) antibody titers can be used to determine revaccination protocols in healthy dogs. DESIGN: Case series. ANIMALS: 1,441 dogs between 6 weeks and 17 years old. PROCEDURE: CPV and CDV antibody titers in serum samples submitted to a commercial diagnostic laboratory were measured by use of indirect fluorescent antibody (IFA) tests. On the basis of parallel measurements of CPV and CDV serum antibody titers in 61 paired serum samples determined by use of hemagglutination inhibition and serum neutralization methods, respectively, we considered titers > or = 1:5 (IFA test) indicative of an adequate antibody response. RESULTS: Age, breed, and sex were not significantly associated with adequate CPV- or CDV-specific antibody responses. Of 1,441 dogs, 1,370 (95.1%) had adequate and 71 (4.9%) had inadequate antibody responses to CPV, whereas 1,346 of 1,379 (97.6%) dogs had adequate and 33 (2.4%) had inadequate responses to CDV. Vaccination histories were available for 468 dogs (468 for CPV, 457 for CDV). Interval between last vaccination and antibody measurement was 1 to 2 years for the majority (281/468; 60.0%) of dogs and 2 to 7 years for 142 of 468 (30.3%) dogs. Interval was < 1 year in only 45 of 468 (9.6%) dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The high prevalence of adequate antibody responses (CPV, 95.1%; CDV, 97.6%) in this large population of dogs suggests that annual revaccination against CPV and CDV may not be necessary.     

Seroprevalence study of feline coronavirus in owned and feral cats in Sydney, Australia

OBJECTIVES: i) To establish the seroprevalence of Feline Coronavirus (FCoV) infection in two defined groups of cats in Sydney: owned and feral cats; ii) to identify factors associated with an increased risk of infection with FCoV; and iii) to establish the seroprevalence and FCoV antibody titres of owned cats with immunohistochemically confirmed feline infectious peritonitis (FIP). DESIGN: Prospective multi-institutional cross sectional study. Procedure Serum samples from owned cats presented to three inner city veterinary clinics in Sydney and feral cats from a colony in South Western Sydney over an 11-month period were tested for FCoV antibodies using the Immunocomb test kit. The relationship between serological score and six major factors (breed, age, gender, number of cats per household, living environment and health status) in the owned cat sample population was analysed and compared to cats with FIR RESULTS: The seroprevalence of FCoV infection in the sample population of owned and feral cats was 34% and 0%, respectively. The median Immunocomb scores of DSH, Persian, Siamese and Devon Rex cats were significantly lower than that of Burmese, BSH, Abyssinian, Birman, Ragdoll and Russian Blue. The median lmmunocomb score of pedigree cats less than 2 years-of-age was significantly higher than for pedigree cats greater than 2 years-of-age. This distinction was not evident in DSH cats in these age groups. The number of cats per household at the time of blood collection had a strong positive association with Immunocomb score. The median Immunocomb score of cats with immunohistochemically confirmed FIP was significantly higher than cats in the sample population of owned cats but there was sufficient overlap between these two groups to make definitive diagnosis of FIP by serology impossible. CONCLUSION: This represents the first seroprevalence study of FCoV in Australia. The major determinants of antibody score of owned cats identified in this study were breed, age and the number of cats per household. The significant relationship between the breed of the cat and the FCoV antibody titre further supports the notion, proposed previously by the authors, that breed related differences exist in the immunological response to FCoV infection.     

Histological examination of the intestine from dogs and cats with intussusception

Objectives : To review the histological findings in the intestine from dogs and cats with intussusception. Methods : Medical records and histopathology reports of dogs and cats with intussusception were reviewed retrospectively. Results : Fourty‐nine animals (31 dogs and 18 cats) were identified for inclusion. Tissues examined com‐prised the intussusception alone in 29 animals (16 dogs and 13 cats), and the intussusception with additional intestinal biopsies in 20 animals (15 dogs and 5 cats). Twenty‐eight of 49 (57·1%) animals, comprising 19 of 31 (61·3%) dogs and 9 of 18 cats (50%) had abnormalities detected on histological examination of tissue. Eleven of 29 (46·9%) cases where only the intussusception was submitted achieved a histological diagnosis, compared to 17 of 20 (85%) where additional biopsies were submitted (P=0·003). Cats (median age 36 months, range 2 to 174) were significantly older than dogs (median age 7·5 months, range 1 to 125 months, P=0·010) and were significantly more likely to have underlying neoplasia (5 of 9; 55·6%) compared to dogs who were more likely to have inflammatory causes (17 of 19; 89·5%, P=0·020). There was no association between histological diagnosis and location of the intussusception (P=1·000). Clinical Significance : Histological abnormalities were detected in more than half of the animals. Diagnosis of intestinal disease in animals with intussusception may be improved by submission of additional biopsy samples. Cats with intussusception are more likely to be older and have underlying neoplasia than dogs which are more likely to have inflammatory disease.     

Epizootiologic association between feline immunodeficiency virus infection and feline leukemia virus seropositivity

Five hundred twenty-one feline serum samples submitted to the Texas Veterinary Medical Diagnostic Laboratory between Nov 1, 1988, and Jan 31, 1989 were tested for antibody to feline immunodeficiency virus (FIV) by use of an ELISA. The prevalence of FIV infection in this population was 11.3% (95% confidence interval: 8.6 to 14.0%). Serologic test results for FeLV were available for 156 of the 521 cats. A significant (P = 0.008) association between FIV infection and FeLV seropositivity was observed; FeLV-positive cats were nearly 4 times more likely to be seropositive for FIV than were FeLV-negative cats. The association remained statistically significant (P = 0.021) after adjusting for age and gender, using multiple-logistic regression analysis.     

Rabies antibody titres in vaccinated dogs

In a field study, rabies virus neutralizing antibody titres were determined by the microtest modification of the rapid fluorescent focus inhibition test before and after primary vaccination in 30 puppies, and before and after booster vaccination in 59 previously vaccinated dogs. A commercial modified live virus vaccine was used. Three weeks after primary vaccination the mean antibody titre was 102 ± 90, but only 24 dogs presented for booster vaccination had detectable antibody levels (mean titre 12 ± 16). The antibody responses three weeks after booster vaccination (mean 380 ± 216) were significantly greater than the responses to primary vaccination. It was concluded that previously vaccinated dogs could have an anamnestic response to booster vaccination, even when antibodies were not detected in their sera before revaccination.