Objective—To identify the geographic distribution of
babesiosis among dogs in the United States and
determine, for dogs other than American Pit Bull
Terriers (APBTs), whether infection was associated
with a recent dog bite.
Procedure—Canine blood samples submitted to the
North Carolina State University Vector-Borne Disease
Diagnostic Laboratory between May 2000 and
October 2003 for which results of a Babesia-specific
polymerase chain reaction assay were positive were
identified, and breed and geographic origin of dogs
from which samples were obtained were recorded.
History and hematologic abnormalities for dogs that
were not APBTs were recorded, and possible associations
with a recent dog bite were examined.
Results—Dogs positive for Babesia DNA were located
in 29 states and 1 Canadian province (Ontario).
Babesia gibsoni was the most commonly detected
species, with B gibsoni DNA detected in blood samples
from 131 of 144 (91%) dogs. Of the 131 dogs
positive for B gibsoni DNA, 122 (93%) were APBTs.
Of the 10 dogs positive for Babesia canis vogeli DNA,
6 were Greyhounds. In dogs other than APBTs, there
was an association between having recently been bitten
by another dog, particularly an APBT, and infection
with B gibsoni.
Conclusions and Clinical Relevance—Results document
an expansion of the known geographic range for
babesiosis among dogs in the United States. Testing
for babesiosis should be pursued in dogs with clinicopathologic
abnormalities consistent with immunemediated
hemolytic anemia or thrombocytopenia,
particularly if there is a history of a recent dog bite.
(J Am Vet Med Assoc 2005;227:942–947)
Objective—To determine whether infection with
Tritrichomonas foetus causes diarrhea in specific pathogen-free or Cryptosporidium coinfected cats.
Animals—4 cats with subclinical cryptosporidiosis
(group 1) and 4 specific-pathogen-free cats (group 2).
Procedure—Cats were infected orogastrically with an
axenic culture of T foetus isolated from a kitten with
diarrhea. Direct microscopy and protozoal culture of
feces, fecal character, serial colonic mucosal biopsy
specimens, and response to treatment with nitazoxanide
(NTZ; group 1) or prednisolone (groups 1 and 2)
Results—Infection with T foetus persisted in all cats
for the entire 203-day study and resulted in diarrhea
that resolved after 7 weeks. Group-1 cats had an earlier
onset, more severe diarrhea, and increased number
of trichomonads on direct fecal examination, compared
with group-2 cats. Use of NTZ eliminated shedding
of T foetus and Cryptosporidium oocysts, but
diarrhea consisting of trichomonad-containing feces
recurred when treatment was discontinued.
Prednisolone did not have an effect on infection with
T foetus but resulted in reappearance of
Cryptosporidium oocysts in the feces of 2 of 4 cats.
During necropsy, T foetus was isolated from contents
of the ileum, cecum, and colon. Tritrichomonas foetus
organisms and antigen were detected on surface
epithelia and within superficial detritus of the cecal
and colonic mucosa.
Conclusions and Clinical Relevance—After experimental
inoculation in cats, T foetus organisms colonize
the ileum, cecum, and colon, reside in close contact
with the epithelium, and are associated with transient
diarrhea that is exacerbated by coexisting cryptosporidiosis
but not treatment with prednisolone.
(Am J Vet Res 2001;62:1690–1697)
Objective—To determine the efficacy of tinidazole for treatment of cats with experimentally induced Tritrichomonas foetus infection.
Animals—8 specific-pathogen-free kittens.
Procedures—Tinidazole was tested for activity against a feline isolate of T foetus in vitro. Kittens were infected orogastrically with the same isolate and treated or not with tinidazole (30 mg/kg, PO, q 24 h for 14 days). Amoxicillin was administered 28 weeks after completion of tinidazole administration to induce diarrhea. Feces were repeatedly tested for T foetus by use of PCR assay and microbial culture for 33 weeks.
Results—Tinidazole killed T foetus at concentrations ≥ 10 μg/mL in vitro. In experimentally induced infection, tinidazole administered at 30 mg/kg decreased T foetus below the limit of molecular detection in 2 of 4 cats. Recrudescent shedding of T foetus, as elicited by amoxicillin-induced diarrhea, was diminished in cats that received prior treatment with tinidazole.
Conclusions and Clinical Relevance—Although tinidazole decreased the detection of T foetus and treated cats were resistant to later efforts to incite the infection, inability of tinidazole to eradicate infection in many cats poses a serious impediment to the drug’s effectiveness in practice.
Objective—To determine the optimum reaction conditions and detection limits of PCR assay for identification of Pentatrichomonas hominis in DNA extracted from canine feces.
Sample Population—DNA extracted from feces of 4 dogs with diarrhea from which trichomonads were observed, 81 dogs that had feces submitted to a diagnostic laboratory, and 19 dogs residing in a laboratory animal facility.
Procedures—Optimum reaction conditions and absolute and practical detection limits of 2 P hominis 18S species-specific primer pairs were determined by use of an in vitro cultivated canine isolate of P hominis in the presence and absence of canine feces. The optimized PCR assay was applied to amplification of P hominis 18S rRNA genes from DNA extracted from the feces of dogs.
Results—Under optimized conditions, a primer pair was identified as able to detect as few as 1 P hominis organism/180-mg fecal sample. The PCR assay identified P hominis in diarrheic feces of 4 dogs in which trichomonads were seen by light microscopy. The P hominis genes were not amplified from other fecal samples examined.
Conclusions and Clinical Relevance—Molecular identification of P hominis in feces of 4 dogs with trichomonosis and diarrhea reported here validates the identity of this species in such infections. Sensitive and specific PCR amplification of P hominis 18S rRNA genes from DNA extracted from feces will directly facilitate studies examining pathogenicity of this trichomonad and enable differentiation of P hominis from other known or novel species of trichomonads that may infect the gastrointestinal tract of dogs.
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.
OBJECTIVE To determine the seroprevalence of heartworm infection, risk factors for seropositivity, and frequency of prescribing heartworm preventives for cats.
DESIGN Prospective cross-sectional study.
ANIMALS 34,975 cats from 1,353 veterinary clinics (n = 26,707) and 125 animal shelters (8,268) in the United States and Canada.
PROCEDURES Blood samples were collected from all cats and tested with a point-of-care ELISA for Dirofilaria immitis antigen, FeLV antigen, and FIV antibody. Results were compared among geographic regions and various cat groupings.
RESULTS Seropositivity for heartworm antigen in cats was identified in 35 states but not in Canada; overall seroprevalence in the United States was 0.4%. Seroprevalence of heartworm infection was highest in the southern United States. A 3-fold increase in the proportion of seropositive cats was identified for those with (vs without) outdoor access, and a 2.5-fold increase was identified for cats that were unhealthy (vs healthy) when tested. Seroprevalence was 0.3% in healthy cats, 0.7% in cats with oral disease, 0.9% in cats with abscesses or bite wounds, and 1.0% in cats with respiratory disease. Coinfection with a retrovirus increased the risk of heartworm infection. Heartworm preventives were prescribed for only 12.6% of cats at testing, and prescribing was more common in regions with a higher seroprevalence.
CONCLUSIONS AND CLINICAL RELEVANCE At an estimated prevalence of 0.4%, hundreds of thousands of cats in the United States are likely infected with heartworms. Given the difficulty in diagnosing infection at all clinically relevant parasite stages and lack of curative treatment options, efforts should be increased to ensure all cats receive heartworm preventives.
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.
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
Objective—To evaluate the efficacy of and optimize a
commercially available culture system for sensitive
and specific in-clinic culture of Tritrichomonas foetus
from cat feces.
Sample Population—Samples of freshly voided
feces from 117 purebred cats and pure cultures of
T foetus obtained from a cat with chronic diarrhea.
Procedure—Optimal conditions for use of the culture
system, such as quantity of fecal inoculum (0.025 to
0.2 g) and cultivation temperature (25 or 37°C [98.6 or
77.0°F]), were determined. Specificity of the system
was examined by attempted culture of Giardia lamblia
and Pentatrichomonas hominis. Sensitivity of the system
to detect T foetus was determined by inoculation
of culture system pouches with serially diluted T foetus suspensions
with and without feces.
Results—Detection limit of the culture system was 1
and 1,000 T foetus organisms without and with feces
from cats, respectively. Optimal fecal inoculum was
< 0.1 g of feces. At 37°C, cultures yielded positive results
in 24 hours; organisms remained viable for 1 to 6 days,
and bacterial overgrowth was common. At 25°C, cultures
yielded positive results in 1 to 11 days; organisms were
long-lived, and bacterial overgrowth was uncommon.
Neither G lamblia or P hominis survived in the culture system.
Conclusions and Clinical Relevance—The culture
system was sensitive and specific for culture of
T foetus in feces of cats. Performance was optimal
when test kits were inoculated with ≤ 0.1 g of freshly
voided feces and cultured at 25°C. (J Am Vet Med Assoc
OBJECTIVE To estimate seroprevalences for FeLV antigen and anti-FIV antibody and risk factors for seropositivity among cats in the United States and Canada.
DESIGN Cross-sectional study.
ANIMALS 62,301 cats tested at 1,396 veterinary clinics (n = 45,406) and 127 animal shelters (16,895).
PROCEDURES Blood samples were tested with a point-of-care ELISA for FeLV antigen and anti-FIV antibody. Seroprevalence was estimated, and risk factors for seropositivity were evaluated with bivariate and multivariable mixed-model logistic regression analyses adjusted for within-clinic or within-shelter dependencies.
RESULTS Overall, seroprevalence was 3.1% for FeLV antigen and 3.6% for anti-FIV antibody. Adult age, outdoor access, clinical disease, and being a sexually intact male were risk factors for seropositivity for each virus. Odds of seropositivity for each virus were greater for cats tested in clinics than for those tested in shelters. Of 1,611 cats with oral disease, 76 (4.7%) and 157 (9.7%) were seropositive for FeLV and FIV, respectively. Of 4,835 cats with respiratory disease, 385 (8.0%) were seropositive for FeLV and 308 (6.4%) were seropositive for FIV. Of 1,983 cats with abscesses or bite wounds, 110 (5.5%) and 247 (12.5%) were seropositive for FeLV and FIV, respectively. Overall, 2,368 of 17,041 (13.9%) unhealthy cats were seropositive for either or both viruses, compared with 1,621 of 45,260 (3.6%) healthy cats.
CONCLUSIONS AND CLINICAL RELEVANCE Seroprevalences for FeLV antigen and anti-FIV antibody were similar to those reported in previous studies over the past decade. Taken together, these results indicated a need to improve compliance with existing guidelines for management of feline retroviruses.