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in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To raise veterinary awareness of a newly recognized parasitic threat to canine and human health, highlight the increasing availability of molecular parasitological diagnostics and the need to implement best practices of cestocidal use in high-risk dogs.

ANIMAL

A young Boxer dog with vomiting and bloody diarrhea, suspected diagnosis of inflammatory bowel disease.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

Bloodwork revealed inflammation, dehydration, and protein loss, addressed with supportive therapy. Fecal culture revealed only Escherichia coli. On centrifugal flotation, tapeworm eggs (which could be Taenia or Echinococcus spp) and, unusually, adult cestodes of Echinococcus were observed. The referring veterinarian was contacted to initiate immediate treatment with a cestocide due to zoonotic potential. Diagnosis was confirmed with a coproPCR which has higher sensitivity for Echinococcus spp than fecal flotation alone. DNA was identical to an introduced European strain of E multilocularis currently emerging in dogs, people, and wildlife. Since dogs can also self-infect and develop hepatic alveolar echinococcosis (severe and often fatal), this was ruled out using serology and abdominal ultrasound.

TREATMENT AND OUTCOME

Following cestocidal treatment, fecal flotation and coproPCR were negative for eggs and DNA of E multilocularis; however, coccidia were detected and diarrhea resolved following treatment with sulfa-based antibiotics.

CLINICAL RELEVANCE

This dog was serendipitously diagnosed with E multilocularis, acquired through ingestion of a rodent intermediate host likely infected from foxes and coyotes. Therefore, as a dog at high risk of reexposure from eating rodents, regular (ideally monthly) treatment with a labeled cestocide is indicated going forward.

Open access
in Journal of the American Veterinary Medical Association

Abstract

OBJECTIVE

To describe the novel PCR diagnosis and outcome of intestinal Echinococcus multilocularis in a dog.

ANIMAL

A 13-month-old female intact dog with naturally occurring intestinal E multilocularis.

CLINICAL PRESENTATION, PROGRESSION, AND PROCEDURES

The 13-month-old dog initially presented with a reduced appetite and weight loss and then developed hematochezia. The clinical history included a lack of endoparasite preventive care (fecal testing, deworming), exposure to coyotes, fox, sheep, and rodents and the dog had intermittently been fed a raw food diet. Physical examination revealed a thin dog, with a 2/9 body condition score, that was otherwise clinically unremarkable. A fecal sample was submitted for screening for gastrointestinal parasites as part of an infectious disease assessment. The fecal PCR test reported detection of E multilocularis. This result was sequenced as the European haplotype E3/E4. Centrifugal flotation (same sample) did not detect taeniid eggs.

TREATMENT AND OUTCOME

The dog was treated with metronidazole, maropitant, and milbemycin oxime/praziquantel. Clinical improvement was noted within 48 hours. No DNA of E multilocularis was detected in a fecal sample collected approximately 10 days after treatment. The dog’s owner was advised to provide monthly deworming (praziquantel) for all dogs on the property and to contact their human health-care provider due to potential zoonotic exposure risk.

CLINICAL RELEVANCE

Increasing detection of E multilocularis is occurring in dogs in Canada and the US. Alveolar echinococcosis can cause severe disease in dogs and humans. Fecal PCR detection and surveillance may alert practitioners to canine intestinal cases and allow dogs to serve as sentinels for human exposure risk.

Open access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association

SUMMARY

Recombinant human interleukin-2 (rhil-2) was evaluated for its influence on total and differential wbc counts, lymphocyte blastogenic responsiveness to mitogens, and several measurements of neutrophil function in clinically normal and in dexamethasone-treated cattle. A single dose of rhil-2 (2.5 × 107 U) given sc had no influence on the total or differential wbc count; however, it did cause an inhibition of neutrophil random migration. The other measurements of neutrophil function (Staphylococcus aureus ingestion, cytochrome C reduction, iodination, and antibody-dependent and antibody-independent cell-mediated cytotoxicity) evaluated were not significantly altered. The rhil-2 treatment was associated with a significant (P < 0.01) decrease in uptake of [3H]thymidine in unstimulated lymphocytes and a tendency toward enhanced blastogenesis of lymphocytes stimulated with phytohemagglutinin. This enhancement was significant (P < 0.05) only when the results were expressed as a stimulation index. Lymphocyte responsiveness to concanavalin A and pokeweed mitogen was not significantly influenced by rhil-2 administration. Dexamethasone (0.04 mg/kg) administered every 24 hours for 3 consecutive days altered the wbc count and several measurements of lymphocyte and neutrophil function. The administration of a single dose of rhil-2 (2.5 × 107 U) 8 hours after the first dose of dexamethasone did not alter the influence of dexamethasone on any of the measurements. These results indicated that rhil-2 has some biologic activity in cattle, but when used as administered here, did not overcome the influence of dexamethasone on the in vitro measurements of lymphocyte and neutrophil function that were evaluated.

Free access
in American Journal of Veterinary Research

SUMMARY

The efficacy, safety, and compatibility of fenbendazole (fbz) and clorsulon (cln) were tested after oral administration of label recommended and of higher (5 ×) dosage rates to calves naturally infected with gastrointestinal nematodes and Fasciola hepatica. Results for 42 calves allotted to 4 treatment groups indicated a similar efficacy against mature F hepatica by fbz (5 mg/kg of body weight) and cln (7 mg/kg) in a combined oral suspension, compared with cln (7 mg/kg) alone (100 vs 99% reduction). A lesser efficacy was observed against immature flukes (88.6 and 84.9% reduction, respectively). Calves given 25 mg of fbz/kg and 35 mg of cln/kg had nearly complete reduction of both mature (99.6%) and immature flukes (99.1%). Fasciola egg counts were reduced by > 99.5% in all treated groups. Against Ostertagia ostertagi, the percentage ofe fficacy of the combined fbz (5 mg/kg) and cln (7 mg/kg) treatment was 94.3% against adults and 81.3% against inhibited larvae. Efficacy against all other nematodes was 100%, except against Cooperia spp adults (98.3%) and immature Oesaphagostomum radiatum (88.0%). At 5 × dosage rates for fbz and cln, percentage of removal of adults and inhibited larvae of O ostertagi was 99.3 and 99.0%, respectively, and 99 to 100% for other nematodes. Results indicate that fbz and cln are compatible when mixed together and administered as an oral suspension to cattle and that the efficacy is similar to that of the drugs individually. On the basis of further results, we suggest that summer treatment may be superior in preventive value for gastrointestinal nematodes and F hepatica, compared with spring treatment, because of seasonal infection dynamics of the major cattle parasites in Louisiana.

Free access
in American Journal of Veterinary Research

SUMMARY

The cytotoxic effect of Moraxella bovis 118F on bovine neutrophils was evaluated and characterized by use of a 51Cr release assay. Neutrophils harvested from healthy adult cattle were labeled with 51Cr. The leukocidic activity produced by M bovis 118F, a hemolytic strain of M bovis, was heat-labile. A live culture of strain 118F, at a ratio of 100 bacteria/neutrophil, released 97.7% of the 51Cr from labeled neutrophils. Neither a heat-killed preparation of M bovis 118F nor a live or heat-killed preparation of M bovis IBH63 (a nonhemolytic and nonpathogenic strain) induced significant (P > 0.05) release of 51Cr.

Moraxella bovis 118F broth culture filtrates prepared for evaluation of leukocidic activity also were evaluated for hemolytic activity. These 2 toxic activities had several characteristics in common. Both were filterable, heat-labile, produced by a hemolytic strain, and were released during early logarithmic phase growth from broth cultures. Leukocidic and hemolytic activities were protected from degradation by phenylmethyl sulfonyl fluoride, a serine protease inhibitor. Leukocidic and hemolytic activities were dependent on calcium ions. Filtrate resulted in 54.1% 51Cr release from labeled neutrophils and contained 646.7 hemolytic U/ml, respectively, when saline (0.85% NaCl) + 10 mM CaCl2 solution was used as diluent. Neither saline solution nor saline + 10 mM MgCl2 solution supported leukocidic or hemolytic activity. Serum, obtained from several calves 10 to 38 days after M bovis inoculation, substantially neutralized leukocidic and hemolytic activities, compared with paired preinoculation serum samples. In addition, no significant difference (P > 0.05) was detected when the ability of each calf's postinfection serum to neutralize leukocidic activity was compared with the ability of the serum to neutralize hemolytic activity.

Free access
in American Journal of Veterinary Research

SUMMARY

Previous work indicated that adult Ancylostoma caninum can be removed from experimentally infected dogs, using a formulation of milbemycin oxime at dosage of 0.5 mg/kg of body weight. To determine the efficacy of this treatment in dogs naturally infected with adult hookworms, 24 mixed-breed dogs with patent hookworm infections were purchased from an out-of-state vendor, and 6 male and 6 female dogs were assigned to either a control group or a group that would be treated. Dogs were treated 10 days after their arrival and were euthanatized 1 week after treatment. Beginning 3 days before treatment, fecal samples were collected daily from all dogs, and the number of Ancylostoma eggs per gram of dry weight of feces was determined from each sample. By 1 week after treatment, the mean number of eggs being passed by the treated dogs had dropped from 12,700 to 10 eggs/g of dried feces; there was no apparent change in fecal egg counts for dogs of the control group. At necropsy, the mean number of adult A caninum in dogs of the treated and control groups was 1.3 and 56, respectively; in these naturally infected dogs, efficacy of treatment was calculated to be 97.8%. The mean number of adult Trichuris vulpis recovered in dogs of the control and treated groups at necropsy was 24 and 0, respectively, which yielded treatment efficacy of 100%. Although Uncinaria stenocephala and Toxocara canis appeared also to be removed by use of this dosage, too few dogs were in the study to calculate meaningful efficacies. The milbemycin oxime formulation appeared to have no effect on the cestodes (Taenia pisiformis and Dipylidium caninum) and spirurids (Physaloptera rara) that were present in some dogs.

Free access
in American Journal of Veterinary Research

Summary

Newborn pups from 4 large litters were allotted to 6 groups to determine effect of time and route of administration on absorption of an alternate source of immunoglobulin. Selective absorption of specific classes of immunoglobulins was also investigated. The alternate source of immunoglobulin consisted of pooled serum that was administered either po or sc. Control groups were either left with the dam (group C1) or fed milk replacer (group C2). Blood samples were collected from pups at birth and 24 hours. Immunoglobulin (IgA, IgG, IgM) concentrations were determined by use of radial immunodiffusion on samples of pooled serum, colostrum, and pups’ serum (birth and 24 hours).

Serum IgA concentration was less than the sensitivity of the procedure and was not included in the statistical analysis. Pups fed 8 ml of pooled serum at birth and 12 hours later (group T1) absorbed more (P< 0.05) IgG and IgM than did group-C2 pups, but less (P < 0.05) than did group-C1 pups. Pups fed 8 ml of pooled serum at 12 hours only had significant (P < 0.05) increase of IgG concentration, but no absorption of IgM (P > 0.05) at 24 hours, compared with control pups (group C2). Pups administered 8 ml of pooled serum SC at birth (group SC1) had similar (P > 0.05) absorption of IgG and higher (P < 0.05) absorption of IgM than did pups of group T1. Pups administered 16 ml of pooled serum sc at birth had the highest increase of IgG and IgM concentrations of all treatment groups, but immunoglobulin concentrations were lower (P < 0.05) than those for group-C1 pups. Absorption of IgG was favored, compared with IgM, when pooled serum was fed.

Results indicate clearly that intestinal absorption of immunoglobulins is minimal after 12 hours and thus, another route of administration should be used. Pups in groups SC1 and T1 had similar absorption of IgG, despite lower IgM absorption in pups of group T1. This lower IgM concentration in group-T1 pups may have been the result of selective intestinal absorption or the consequence of low number of pups per group. Subcutaneous administration of 16 ml of pooled serum was the most successful alternative to colostrum, with minimal pain to pups if serum was administered slowly. Serum IgG concentration in Cl pups was higher than expected and probably was attributable to the amount of colostrum available to the pups.

Free access
in American Journal of Veterinary Research

SUMMARY

Praziquantel was used successfully for treatment of a small number of dogs and 1 cat infected with Paragonimus kellicotti. To further evaluate the usefulness of this drug in treating such infections, 7 cats and 7 dogs were inoculated orally with metacercariae (12 and 20 to 22, respectively) obtained from crayfish, then were treated after the infections became patent; 2 cats and 2 dogs served as noninfected controls. Beginning 1 week before infection, and continuing weekly thereafter, physical, hematologic, and fecal examinations were performed on each animal; thoracic radiography was performed every other week. By postinoculation week 6, all dogs given metacercariae had patent infection diagnosed on the basis of positive results of fecal examination. By postinoculation week 7, 5 cats had confirmed patent infection, but 2 cats given metacercariae never had patent infection or had signs of infection. Clinical signs of infection were minor and included increased respiratory tract noise, slight inducible cough, or mild dyspnea. Transient eosinophilia was detected in dogs around postinoculation week 3. Pretreatment radiography revealed cavitated lesions in cats only; pleural lines and patchy infiltrates in cats and dogs; or pneumothorax in dogs only. The treatment regimen consisted of 23 mg of praziquantel/kg of body weight given every 8 hours for 3 days; 1 infected cat and dog were not treated. By 11 days after treatment, eggs had disappeared from the feces of infected animals, and marked resolution of lung lesions was evident radiographically. The 2 untreated animals and 1 treated dog were euthanatized and necropsied to verify lesions and their resolution. All treated animals were considered cured of infection by use of this treatment regimen.

Free access
in American Journal of Veterinary Research