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Summary

The safety and efficacy of a commercially available Borrelia burgdorferi bacterin were examined under field conditions in 1,969 dogs that received a total of 4,033 doses of bacterin during a 20-month period. For comparison, 4,498 dogs that were not vaccinated also were evaluated. All dogs were examined at 1 of 3 veterinary practices in borreliosis-endemic areas. Owners of all dogs were educated about the benefits of and methods for avoiding infected ticks.

Vaccination was found to be safe regardless of previous exposure to B burgdorferi or history of borreliosis. Thirty-eight (1.9%) of the 1,969 dogs had minor reactions; 1 of these dogs had a reaction after the first and second doses of B burgdorferi bacterin. Reactions resolved without complications immediately or within 72 hours after vaccination. Cumulative incidence of borreliosis was 1.0% (20/1,969) in vaccinated dogs and 4.7% (211/4,498) in nonvaccinated dogs. Preventable fraction, a measure of the reduction of incidence of disease in vaccinated dogs vs nonvaccinated dogs, was 78%. Preventable fraction in dogs that were seropositive prior to vaccination (ie, previously exposed to B burgdorferi) was 58% and in dogs that were seronegative prior to vaccination (ie, without evidence of prior exposure to B burgdorferi) was 86%. This suggested that, in borreliosis-endemic areas, dogs may be most effectively protected by vaccinating them when they are young and before they are exposed to infected ticks, and that in areas where borreliosis is not endemic, it may be useful to initiate vaccination programs so that dogs will be protected prior to exposure to infected ticks.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To evaluate equine IgG as a treatment for kittens with failure of passive transfer of immunity (FPT).

Animals—13 specific pathogen-free queens and their 77 kittens.

Procedure—Kittens were randomized at birth into 9 treatment groups. One group contained colostrumfed (nursing) kittens; the other groups contained colostrum-deprived kittens that were administered supplemental feline or equine IgG PO or SC during the first 12 hours after birth. Blood samples were collected at serial time points from birth to 56 days of age for determination of serum IgG concentrations. The capacity of equine IgG to opsonize bacteria for phagocytosis by feline neutrophils was determined via flow cytometry.

Results—Kittens that received feline or equine IgG SC had significantly higher serum IgG concentrations than those of kittens that received the supplements PO. In kittens that were administered supplemental IgG SC, serum IgG concentrations were considered adequate for protection against infection. The half-life of IgG in kittens treated with equine IgG was shorter than that in kittens treated with feline IgG. Feline IgG significantly enhanced the phagocytosis of bacteria by feline neutrophils, but equine IgG did not.

Conclusions and Clinical Relevance—Serum concentrations of equine IgG that are considered protective against infection are easily attained in kittens, but the failure of these antibodies to promote bacterial phagocytosis in vitro suggests that equine IgG may be an inappropriate treatment for FPT in kittens. (Am J Vet Res 2003;64:969–975)

Full access
in American Journal of Veterinary Research

Abstract

OBJECTIVE To characterize the clients served by and the cats and dogs admitted to nonprofit spay-neuter clinics.

DESIGN Cross-sectional survey.

SAMPLE 2,154 dogs and 1,902 cats that were owned by 3,768 survey respondents and admitted to 22 nonprofit spay-neuter clinics across the United States between April 29, 2013, and January 24, 2014.

PROCEDURES Participating clinics distributed surveys to clients during each of 4 quarterly study weeks. The survey collected descriptive information about clients' pets and households as well as their decision-making regarding sterilization of their pets. For each of the study weeks, clinics reported the total number of surgeries, including those involving shelter animals, feral cats, and other owned animals.

RESULTS Respondents indicated that 49% of dogs and 77% of cats had not been examined previously by a veterinarian, except during vaccine clinics. Among animals ≥ 4 months of age, 1,144 of 1,416 (81%) cats and 572 of 1,794 (32%) dogs had not received a rabies vaccination. Previous litters were reported for 204 of 716 (28%) queens and 153 of 904 (17%) bitches. Most clients' (53%) household income was < $30,000 annually. Common reasons for clinic choice included cost; friend, neighbor, or family recommendation; and good reputation.

CONCLUSIONS AND CLINICAL RELEVANCE Nonprofit spay-neuter clinics predominantly served low-income clients and animals lacking regular veterinary care, in addition to animals from shelters and community cats. These clinics increase access to services needed for animal population control and public health.

Full access
in Journal of the American Veterinary Medical Association

SUMMARY

The vascular permeability of the ocular fundus, alterations in the coagulation system, and plasma concentrations of thromboxane B2 (txb 2) and 6-keto-prostaglandin F, (6-keto-pgf ) were studied in dogs following intradermal inoculation with 5 × 105 tcid 50 of Rickettsia rickettsii. Twenty-four to 48 hours after the onset of fever and rickettsemia, multifocal areas of retinal vasculitis were evident, which corresponded to areas of altered vascular permeability demonstrated by fluorescein angiography. The number and intensity of retinal vessels with sodium fluorescein leakage peaked during the second week after inoculation, and retinal vascular permeability remained altered during the third week of infection, well past the phase of clinical and clinicopathologic recovery.

Development of retinal vasculitic foci was associated with thrombocytopenia, increased concentrations of circulating fibrinogen, and slight prolongation of activated partial thromboplastin time. Increased concentrations of fibrin/fibrinogen degradation products were detected in 4 of 9 dogs. Despite the degree of vascular endothelial damage evident on fluorescein angiographic and histologic studies in these dogs, plasma txb 2 and 6-keto-pgf concentrations were not increased.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To determine the pharmacokinetics of enrofloxacin in neonatal kittens and compare the pharmacokinetics of enrofloxacin in young and adult cats.

Animals—7 adult cats and 111 kittens (2 to 8 weeks old).

Procedure—A single dose of 5 mg of enrofloxacin/kg was administered to adults (IV) and kittens (IV, SC, or PO). Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined.

Results—The half-life of enrofloxacin administered IV in 2-, 6-, and 8-week-old kittens was significantly shorter and its elimination rate significantly greater than that detected in adults. The apparent volumes of distribution were lower at 2 to 4 weeks and greater at 6 to 8 weeks. This resulted in lower peak plasma concentration (Cmax) at 6 to 8 weeks; however, initial plasma concentration was within the therapeutic range after IV administration at all ages. Compared with IV administration, SC injection of enrofloxacin in 2-weekold kittens resulted in similar Cmax, half-life, clearance, and area under the curve values. Enrofloxacin administered via SC injection was well absorbed in 6- and 8- week-old kittens, but greater clearance and apparent volume of distribution resulted in lower plasma concentrations. Oral administration of enrofloxacin resulted in poor bioavailability.

Conclusions and Clinical Relevance—In neonatal kittens, IV and SC administration of enrofloxacin provided an effective route of administration. Oral administration of enrofloxacin in kittens did not result in therapeutic drug concentrations. Doses may need to be increased to achieve therapeutic drug concentrations in 6- to 8-week-old kittens. ( Am J Vet Res 2004;65:350–356)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To describe the demographic and clinical characteristics of feline cytauxzoonosis in the midAtlantic states and compare the Cytauxzoon felis 18S rRNA gene sequences from affected cats with sequences reported from affected cats in other regions.

Design—Retrospective case series.

Animals—34 cats with C felis infection.

Procedure—Medical records of cats in which C felis infection was diagnosed from May 1998 through June 2004 were reviewed; data collected included signalment, month of diagnosis, geographic location, clinicopathologic abnormalities, medical treatments, outcome, and necropsy findings when applicable. Cytauxzoon felis DNA was amplified, cloned, and sequenced from 4 of these cats and compared with previously reported C felis DNA sequences.

Results—Of 34 C felis–infected cats, 28 resided in North Carolina, 3 resided in South Carolina, and 3 resided in Virginia; in 32 cats, a diagnosis of C felis infection was made in April through September. Pancytopenia and icterus were the most common clinicopathologic abnormalities. Thirty-two cats either died or were euthanatized, and 2 cats survived. At 5 veterinary hospitals, multiple cases were identified, and 4 multicat households had > 1 cat infected with C felis. The 18S rRNA gene sequences characterized in organisms obtained from 4 cats were nearly identical to C felis DNA sequences reported from other US regions.

Conclusions and Clinical Relevance—Data indicate that veterinarians in the mid-Atlantic region of the United States should consider C felis infection in cats that become ill with fever, icterus, and pancytopenia or bicytopenia, especially in the spring and summer months.

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the long-term outcome of cats infected with Tritrichomonas foetus and identify treatment and management strategies influencing resolution of infection or associated diarrhea.

Design—Prospective study.

Sample Population—26 cats with T foetus-associated diarrhea at least 22 months prior to the study.

Procedure—A standardized survey regarding clinical course and management was administered to owners of cats with T foetus infection and associated diarrhea. Fecal samples were obtained from each cat; the presence of T foetus was assessed via microscopic examination of smears, culture in commercial media, and polymerase chain reaction amplification of T foetus rDNA involving species-specific primers.

Results—Survey responses were obtained from owners of all 26 cats. Twenty-three cats had complete resolution of diarrhea a median of 9 months after onset. Analysis of fecal samples obtained from 22 cats revealed persistent T foetus infection in 12, with a median of 39 months after resolution of diarrhea. History of implementation of a dietary change, treatment with paromomycin, or higher numbers of cats in the household was associated with significantly longer duration of time to resolution of diarrhea.

Conclusions and Clinical Relevance—Results suggested chronic T foetus-associated diarrhea in most cats is likely to resolve spontaneously within 2 years of onset. Chronic infection with T foetus(without clinical signs) after resolution of diarrhea appears to be common. Although often temporarily effective in decreasing severity of diarrhea, attempts to treat cats with T foetus infection may result in prolongation of time to resolution of diarrhea. (J Am Vet Med Assoc 2004;225:888–892)

Full access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine whether passive transfer of IgG in neonatal kittens affects plasma opsonic capacity and neutrophil phagocytic and oxidative burst responses to bacteria in vitro.

Animals—22 kittens from 6 specific pathogen-free queens.

Procedure—Kittens were randomized at birth into the following treatment groups: colostrum-fed, colostrum-deprived, or colostrum-deprived supplemented with feline or equine IgG. Blood samples were collected at intervals from birth to 56 days of age. Plasma IgG concentrations were determined by radial immunodiffusion assay. Neutrophil function was assessed by a flow cytometry assay providing simultaneous measurement of bacteria-induced phagocytosis and oxidative burst. The opsonic capacity of kitten plasma was determined in an opsonophagocytosis assay with bacteria incubated in untreated or heat-inactivated plasma.

Results—Among treatment groups, there were no significant differences in neutrophil phagocytic and oxidative burst responses to bacteria or opsonic capacity of plasma. In all samples of plasma, inactivation of complement and other heat-labile opsonins significantly reduced the opsonic capacity. Plasma IgG concentrations in kittens did not correlate with neutrophil function or plasma opsonic capacity before or after inactivation of complement.

Conclusions and Clinical Relevance—The plasma opsonic capacity and neutrophil phagocytic and oxidative burst responses in vitro of kittens receiving passive transfer of IgG via colostrum intake or IgG supplementation and those deprived of colostrum were similar. The alternate complement pathway or other heat-labile opsonins may be more important than IgG in bacterial opsonization and phagocytosis. ( Am J Vet Res 2003;64:538–543)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To determine the prevalence and severity of pulmonary arterial lesions in cats seropositive for heartworms (Dirofilaria immitis) but lacking adult heartworms in the heart and lungs during necropsy.

Animals—630 adult cats from an animal control shelter in Florida.

Procedure—Cats were tested for adult heartworms in the heart and pulmonary arteries and antibody against heartworms in the serum. Histologic examination was conducted on the right caudal lung lobe of 24 heartworm- and antibody-positive cats; 24 heartworm-negative and antibody-positive cats; and 24 heartworm-, antibody-, and antigen-negative cats. Wall areas of 10 small to medium-sized pulmonary arteries of each cat were measured and expressed as a proportion of total cross-sectional area.

Results—Heartworm infection or seropositive status was significantly and strongly associated with severity of medial hypertrophy of pulmonary arterial walls. Heartworm- and antibody-positive cats and heartworm-negative and antibody-positive cats had a significant increase in wall thickness, compared with wall thickness for heartworm- and antibody-negative cats. Heartworm- and antibody-positive cats had the most severe hypertrophy. The proportion with occlusive medial hypertrophy was significantly higher in heartworm- and antibody-positive cats (19/24 [79%]) and heartworm-negative and antibody-positive cats (12/24 [50%]), compared with heartworm- and antibody-negative cats (3/24 [13%]).

Conclusions and Clinical Relevance—Cats with serologic evidence of exposure to heartworms, including those without adult heartworms in the lungs and heart, have a greater prevalence of pulmonary arterial lesions than heartworm-negative cats without serologic evidence of exposure. Additional studies are needed to define the pathogenesis, specificity, and clinical importance of these lesions. (Am J Vet Res 2005;66:1544–1549)

Full access
in American Journal of Veterinary Research

Abstract

Objective—To assess the transmission of bovine viral diarrhea virus (BVDV) from experimentally infected white-tailed deer fawns to colostrum-deprived calves by use of a BVDV strain isolated from hunter-harvested white-tailed deer.

Animals—5 white-tailed deer (Odocoileus virginianus) fawns and 6 colostrum-deprived calves.

Procedures—Fawns were inoculated intranasally with a noncytopathic BVDV-1a isolate (2 mL containing 106.7 TCID50/mL), and 2 days after inoculation, animals were commingled until the end of the study. Blood and serum samples were obtained on days −6, 0, 7, 14, and 21 after inoculation for reverse transcriptase PCR assay, virus neutralization, and BVDV-specific antibody ELISA. Nasal, oral, and rectal swab specimens were collected on days 0, 3, 7, 14, 17, and 21 for reverse transcriptase PCR testing. By 21 days after inoculation, all animals were euthanized and necropsied and tissues were collected for histologic evaluation, immunohistochemical analysis, and virus isolation.

Results—All fawns became infected and shed the virus for up to 18 days as determined on the basis of reverse transcriptase PCR testing and virus isolation results. Evidence of BVDV infection as a result of cohabitation with acutely infected fawns was detected in 4 of the 6 calves by means of reverse transcriptase PCR testing and virus isolation.

Conclusions and Clinical Relevance—On the basis of these findings, BVDV transmission from acutely infected fawns to colostrum-deprived calves appeared possible.

Full access
in American Journal of Veterinary Research