Dermatitis associated with microfilariae (Filarioidea) in 10 dogs

Dermatitis associated with microfilariae of a nematode of the superfamily Filarioidea was diagnosed in 10 dogs from the western United States. Clinically, lesions were single or multiple papules and plaques with alopecia, scarring, erythema, ulceration, or crusting. Eight dogs had lesional pruritus. Microscopically, there was perivascular, periglandular, to interstitial inflammation, with many eosinophils and/or plasma cells, and scarring affecting the dermis and subcutis. Microgranulomas containing microfilaria were seen in six dogs. Microfilariae were noted in microgranulomas or free in the dermis or subcutis, but not in vessels. In one case, an adult female nematode emerged from a biopsy sample that was placed in physiologic saline. Study of this nematode revealed that it was a filarioid of the family Onchocercidae; it was identified as Acanthocheilonema sp. (syn: Dipetalonema ). Antigen tests of five dogs were negative for Dirofilaria immitis . The Knott tests and/or filter tests of nine dogs were negative for microfilariae. An indirect fluorescence antibody test of one dog was also negative for D. immitis . One dog was not evaluated for microfilariae.     

Genetic screening of the canine zinc finger protein multitype 2 (cZFPM2) gene in dogs with tetralogy of Fallot (TOF)

A recent genetic study in humans where the ZFPM2 gene was screened for mutations revealed a heterozygous mutation that was found to contribute to several sporadic cases of tetralogy of Fallot (TOF). We hypothesized that this would also hold true for a study group of dogs with TOF. We isolated the full-length cDNA of the canine ZFPM2 and aligned the deduced amino acid sequence against sequences from other species. Our analysis indicated that the canine ZFPM2 was phylogenetically much closer to the human ZFPM2 compared with the mouse or rat sequences. Further gene expression analysis also failed to identify differential gene expression between affected and unaffected dogs. We screened the cZFPM2 for mutations in a group of dogs with TOF but found no significant base changes in either the splice sites or the coding regions.     

Seroprevalence of canine influenza virus (H3N8) in Iditarod racing sled dogs

We conducted a cross-sectional convenience sampling study of dogs racing in the 2010 Iditarod to determine the seroprevalence of canine influenza virus (CIV) in the sled dog population. Questionnaires were completed detailing medical and CIV vaccination history, kennel size and location, travel history, and social interactions for each team. A total of 399 dogs were tested for CIV antibodies by hemagglutination inhibition assay. None of these, including 39 samples from dogs reported as CIV vaccinated, were seropositive for CIV antibodies. All of the vaccinated dogs were also negative on virus microneutralization assay. Risk factors for CIV seropositivity could not be determined due to a lack of positive samples. This is the first published study investigating the prevalence of CIV in sled dogs and additional studies are warranted to assess CIV infection among racing sled dogs and to evaluate the ecology of CIV and the vaccine efficacy in this population of dogs.     

Efficacy of a combination of imidacloprid 10%/permethrin 50% versus fipronil 10%/(S)-methoprene 12%, against ticks in naturally infected dogs

Preventing tick bites is a fundamental step towards reducing the impact of tick-borne protozoal, bacterial and viral diseases (TBDs) in humans and animals. The aim of this study was to evaluate the efficacy of a combination of imidacloprid 10%/permethrin 50% and of fipronil 10%/S-methoprene 12% against ticks in naturally infected dogs and to assess methodological parameters to calculate drug efficacy on tick immature stages.

From July to August 2004, 45 privately owned dogs of various sexes, ages, breeds, coat length and habits were enrolled in a trial carried out in an area (radius approximately 50 km) in Southern Italy. Three homogeneous groups (both for dog population and tick population) were formed: 15 dogs treated with imidacloprid 10% and permethrin 50% spot-on (group A), 15 dogs treated with fipronil 10% and methoprene 12% spot-on (group B) and 15 untreated dogs (group C). The dogs in each group were then sub-grouped according to their age and weight. Two different treatments were administered (time 0 and +28 days) to groups A and B, and the dogs were checked weekly for tick infestation until day +56 post-treatment (p.t.). Twenty-four areas distributed on the whole body surface were examined for ticks at each follow-up, while only at time 0 and at day +56 p.t., ticks were collected from the dogs and identified.

For the immature stages a semi-quantitative method was adopted and the load of immature stages was evaluated and grouped into four classes up to day +56 p.t. when the mean number of immature ticks (MIT) for each infection class was evaluated.

All the adult ticks collected were identified as brown dog ticks (Rhipicephalus sanguineus). Immature stages were first compared at day +28 p.t.. The efficacy of both products used in groups A and B on adult ticks was high and generally very similar. Conversely, the efficacy of imidacloprid 10% and permethrin 50% against immatures was higher than that of fipronil 10% and methoprene 12% throughout the observation period with statistically significant differences (p < 0.05) at day +28 p.t. (i.e. group A = 98.52%, group B = 72.40%).

On the whole, in analysing the efficacy of both products against adult plus immature ticks, it was found that the combination of imidacloprid 10% and permethrin 50% was more effective than fipronil 10% and methoprene 12%, with the differences being statistically significant at day +28 p.t. (group A = 98.43%, group B = 77.56%).     

Treatment of 10 dogs with discospondylitis by fluoroscopy-guided percutaneous discectomy

Ten dogs suffering from discospondylitis were treated by percutaneous discectomy and local and systemic antibiotic therapy. With fluoroscopic guidance, a cylinder 5 mm in diameter was removed from the centre of the intervertebral space, yielding a fenestration and decompressing the disc without producing any spinal instability. The causative bacteria were identified in nine of the 10 biopsy specimens, but in only three urine cultures and four blood cultures. In two cases, the antibiotics used initially had to be changed owing to the organisms' antibiotic resistance. The clinical signs of the dogs improved markedly after two to nine days (mean 4.2 days) and had resolved completely after five to 14 days (mean 9.1 days). In all the cases the disease could be classified histologically as either acute or chronic, and the disease was classified as chronic in one dog. No side effects were observed.     

Treatment rationale for dogs poisoned with aldicarb (carbamate pesticide)

The treatment rationale for dogs poisoned by aldicarb is reviewed from a pharmacological perspective. The illegal use of aldicarb to maliciously poison dogs is a major problem in some parts of the world. In South Africa, it is probably the most common canine poisoning treated by companion animal veterinarians. Aldicarb poisoning is an emergency and veterinarians need to be able to diagnose it and start with effective treatment immediately to ensure a reasonable prognosis. Successful treatment depends on the timely use of an anti-muscarinic drug (e.g. atropine). Additional supportive treatment options, including fluid therapy, diphenhydramine, benzodiazepines and the prevention of further absorption (activated charcoal) should also be considered. Possible complications after treatment are also briefly discussed.     

Interspecies transmission of equine influenza virus (H3N8) to dogs by close contact with experimentally infected horses

In horse populations, influenza A virus subtype H3N8 (equine influenza virus, EIV) is a very important pathogen that leads to acute respiratory disease. Recently, EIV has emerged in dogs, and has become widespread among the canine population in the United States. The interspecies transmission route had thus far remained unclear. Here, we tested whether the interspecies transmission of EIV to dogs could occur as a result of close contact with experimentally EIV-infected horses. Three pairs consisting of an EIV-infected horse and a healthy dog were kept together in individual stalls for 15 consecutive days. A subsequent hemagglutination inhibition test revealed that all three dogs exhibited seroconversion. Moreover, two of the three dogs exhibited virus shedding. However, the dogs exhibited no clinical signs throughout the course of the study. These data suggest that the interspecies transmission of EIV to dogs could occur as a result of close contact with EIV-infected horses without clinical symptoms. Although the interspecies transmission of EIV is unlikely to become an immediate threat to canine hygiene, close contact between EIV-infected horses and dogs should be avoided during an EI epidemic.     

No evidence of horizontal infection in horses kept in close contact with dogs experimentally infected with canine influenza A virus (H3N8)

Background

Since equine influenza A virus (H3N8) was transmitted to dogs in the United States in 2004, the causative virus, which is called canine influenza A virus (CIV), has become widespread in dogs. To date, it has remained unclear whether or not CIV-infected dogs could transmit CIV to horses. To address this, we tested whether or not close contact between horses and dogs experimentally infected with CIV would result in its interspecies transmission.

Methods

Three pairs of animals consisting of a dog inoculated with CIV (10^8.3 egg infectious dose₅₀/dog) and a healthy horse were kept together in individual stalls for 15 consecutive days. During the study, all the dogs and horses were clinically observed. Virus titres in nasal swab extracts and serological responses were also evaluated. In addition, all the animals were subjected to a gross pathological examination after euthanasia.

Results

All three dogs inoculated with CIV exhibited clinical signs including, pyrexia, cough, nasal discharge, virus shedding and seroconversion. Gross pathology revealed lung consolidations in all the dogs, and Streptococcus equi subsp. zooepidemicus was isolated from the lesions. Meanwhile, none of the paired horses showed any clinical signs, virus shedding or seroconversion. Moreover, gross pathology revealed no lesions in the respiratory tracts including the lungs of the horses.

Conclusions

These findings may indicate that a single dog infected with CIV is not sufficient to constitute a source of CIV infection in horses.     

Taurine deficiency in dogs with dilated cardiomyopathy: 12 cases (1997-2001)

OBJECTIVE: To determine signalment, history, clinical signs, blood and plasma taurine concentrations, electrocardiographic and echocardiographic findings, treatment, and outcome of dogs with low blood or plasma taurine concentrations and dilated cardiomyopathy (DCM). DESIGN: Retrospective study. ANIMALS: 12 client-owned dogs with low blood or plasma taurine concentrations and DCM. PROCEDURE: Medical records were reviewed, and clinical data were obtained. RESULTS: All 12 dogs were being fed a commercial dry diet containing lamb meal, rice, or both as primary ingredients. Cardiac function and plasma taurine concentration improved with treatment and taurine supplementation. Seven of the 12 dogs that were still alive at the time of the study were receiving no cardiac medications except taurine. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that consumption of certain commercial diets may be associated with low blood or plasma taurine concentrations and DCM in dogs. Taurine supplementation may result in prolonged survival times in these dogs, which is not typical for dogs with DCM. Samples should be submitted for measurement of blood and plasma taurine concentrations in dogs with DCM, and taurine supplementation is recommended while results of these analyses are pending.     

Disseminated histoplasmosis in dogs: 12 cases (1981-1986)

Diarrhea, intestinal blood loss, anemia, and lethargy were predominant clinical findings in 12 dogs with disseminated histoplasmosis. Young dogs were affected most commonly, with 6 dogs being 1 to 3 years old. A diagnosis of disseminated histoplasmosis was established on the basis of histologic or cytologic detection of Histoplasma organisms in intestinal or rectal mucosa in 7 dogs, in circulating leukocytes in 5 dogs, in bone marrow in 3 dogs, and in multiple tissues at necropsy in 1 dog (4 dogs had Histoplasma organisms detected in greater than 1 site). Anemia was detected in 10 dogs (PCV less than 20% in 3 dogs), and the anemia was inadequately regenerative or nonregenerative in 7. Hypoalbuminemia was detected in 9 dogs, and serum albumin concentrations were low (less than 1.0 g/dl) in 4 of the 9 dogs. Of 5 dogs treated with ketoconazole, 2 were in remission for greater than or equal to 1 year. Corticosteroid therapy may have exacerbated the disease in 4 dogs. Histoplasma infection of multiple organs was detected in 5 necropsied dogs.     

Treatment of clinically normal and cystinuric dogs with 2-mercaptopropionylglycine

In a pharmacokinetic and tolerance study, 2 healthy Beagles were given 13.2 to 39.5 mg of 2-mercaptopropionylglycine (2-MPG)/kg of body weight orally once daily in increasing doses for 3 weeks. A third dog was given 10 mg of 2-MPG/kg of body weight, IV. The drug was well tolerated. After these initial studies, 15 cystinuric dogs were treated with 2-MPG orally once daily for 5 to 45 months and with sodium bicarbonate for urine alkalinization and fluid diuresis. Pharmacokinetic studies were done in 7 dogs on the third day of oral treatment with 2-MPG. After oral administration of 15.6 to 31.3 of 2-MPG/kg of body weight, maximal serum/plasma concentrations were from 28.6 to 76.3/mumol/L after 1 to 3 hours in 6 cystinuric dogs. The mean urinary excretion was 22% (range, 0.3 to 58.9%) of the dose. Ten of 15 cystinuric dogs had no re-formation of uroliths. Of 4 dogs with uroliths at the beginning of treatment, 3 had total urolith dissolution on continuous treatment. During treatment, further growth of the uroliths was inhibited in one dog, and in another dog with re-formed uroliths, they dissolved. We concluded that 2-MPG is well tolerated and promising for treatment of cystinuric dogs, but the pharmacokinetic studies should be expanded to include different dosage regimens, and results of long-term treatment should be evaluated. Our recommendations for treatment of dogs with cystine uroliths include surgical intervention if the dog has urethral obstruction or has dysuria.(ABSTRACT TRUNCATED AT 250 WORDS)     

Adhesive fimbriae produced in vivo by Escherichia coli O139:K12(B):H1 associated with enterotoxaemia in pigs

Two strains of E. coli O139:K12 (B):H1 were compared in vitro and in the intestinal environment. Both strains colonized the small intestines of experimentally inoculated pigs and exhibited in vivo a similar relationship to the microvillus border as enterotoxigenic E. coli (ETEC). Strain 107/86 grown on blood agar expressed numerous long flexible non-haemagglutinating fimbriae which were antigenically distinct from the known fimbriae of porcine ETEC. It adhered in vitro to porcine enterocyte brush border fragments. Strain 124/76 grown on blood agar was devoid of fimbriae and did not adhere to brush border fragments. However, fimbriae morphologically and antigenically indistinguishable from those of strain 107/86 were detected in the intestinal environment by direct immunofluorescence and by immuno electron microscopy.     

Treatment of inflammatory bowel disease (IBD) in dogs and cats

The treatment of inflammatory bowel disease (IBD) possesses numerous difficulties owing to the unclear etiology of the disease. This article overviews the drugs used in the treatment of IBD depending on the intensity of clinical symptoms (Canine Inflammatory Bowel Disease Activity Index and Canine Chronic Enterophaty Clinical Activity Index). Patients demonstrating mild symptoms of the disease are usually placed on an appropriate diet which may be combined with immunomodulative or probiotic treatment. In moderate progression of IBD, 5-aminosalicylic acid (mesalazine or olsalazine) derivatives may be administered. Patients showing severe symptoms of the disease are usually treated with immunosuppressive drugs, antibiotics and elimination diet. Since the immune system plays an important role in the pathogenesis of the disease, the advancements in biological therapy research will contribute to the progress in the treatment of canine and feline IBD in the coming years.     

Treatment of periodontitis in dogs with tinidazole

The efficacy of tinidazole administered in addition to a single course of scaling was evaluated in the treatment of periodontitis in 14 small dogs. Periodontal parameters, such as pocket depth, gingival bleeding after probing, furcation involvements and tooth mobility, were examined at baseline, 14 days, and three and six months. After thorough scaling and root planing, tinidazole (15 to 25 mg/ kg) or placebo was given orally twice daily for seven days. Tinidazole plus scaling resulted in a statistically significant decrease from the baseline values in the mean pocket depth, percentage of deep (greater than 3 mm) pockets and frequency of gingival bleeding for six months. In the placebo plus scaling group, mean pocket depth, percentage of deep pockets, frequency of gingival bleeding and number of furcation involvements were significantly lower at 14 days than at baseline. The decrease in bleeding tendency was significantly greater in the tinidazole than in the placebo group at the first two follow-up visits. Similarly, pocket depth and the percentage of deep pockets at the last two visits had decreased significantly more in the tinidazole group than in the placebo group. The use of tinidazole in addition to scaling seems to result in longer lasting improvement of the periodontal condition in dogs with periodontitis than scaling alone.     

Treatment and outcome of dogs with leptospirosis: 36 cases (1990-1998)

OBJECTIVE: To characterize serologic and clinical features and outcome of dogs with leptospirosis that were treated conservatively (i.e., medical management alone) or with hemodialysis. DESIGN: Retrospective study. ANIMALS: 36 dogs with leptospirosis. PROCEDURE: History; results of physical examinations, ultrasonography, and serologic, hematologic, and serum biochemical analyses; time to resolution of azotemia; and outcome were obtained from medical records. Dogs were treated conservatively (n = 22) or with hemodialysis (14). RESULTS: Between 1990 and 1998, amount of rainfall was positively correlated with number of cases of leptospirosis identified per year. Serum antibodies against 6 Leptospira serovars were measured, and titers were highest to Leptospira pomona in 16 (44%) dogs, L bratislava in 9 (25%) dogs, and L hardjo in 1 (3%) dog. Eight (22%) dogs had equally high titers to L pomona and L bratislava, 1 (3%) had equally high titers to L grippotyphosa and L canicola, and 1 (3%) had high titers to L grippotyphosa, L pomona, L canicola, and L bratislava. During initial evaluation, all dogs were azotemic. Thirty (83%) dogs survived, including 12 of 14 (86%) dogs treated with hemodialysis and 18 of 22 (82%) treated conservatively. Serum creatinine concentration was similar in both groups after resolution of clinical signs. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with L pomona and L bratislava was recognized as a cause of leptospirosis in dogs, and resulted in development of acute renal failure with various degrees of azotemia. Prognosis for dogs with mild to moderate azotemia was good with conservative treatment, whereas treatment with hemodialysis appeared to improve prognosis for dogs with severe azotemia.     

Treatment of dogs infected with Hepatozoon americanum: 53 cases (1989-1998)

OBJECTIVE: To determine clinical and pathologic findings before and after short-term (group 1) and long-term (group 2) treatment in dogs with Hepatozoon americanum infection. DESIGN: Retrospective study. ANIMALS: 53 dogs with H. americanum infection. PROCEDURE: Medical records of dogs that were treated for hepatozoonosis diagnosed on the basis of meront or merozoite stages in skeletal muscle were reviewed. RESULTS: Circulating gametocytes of H. americanum were identified in 12 of 53 dogs. Dogs were treated with various drugs, including toltrazuril, trimethoprim-sulfadiazine, clindamycin, pyrimethamine, and decoquinate. Mean WBC counts prior to treatment were 85,700 and 75,200 cells/microl in groups 1 and 2, respectively, and 1 month after initiation of treatment were 12,600 and 14,600 cells/microl, respectively. Initial response to treatment was excellent in all dogs. Twenty-three of 26 dogs in group 1 relapsed at least once and died within 2 years; mean (+/- SD) survival time was 12.6+/-2.2 months. Twenty-two of 27 group-2 dogs survived; 11 dogs had no clinical signs and were still receiving decoquinate (mean duration of treatment, 21 months), 11 dogs had no clinical signs after treatment for 14 months (range, 3 to 33 months; mean survival time, 39 months [range, 26 to 53 months]), 2 dogs were lost to follow-up, and 3 dogs were euthanatized because of severe disease. CONCLUSIONS AND CLINICAL RELEVANCE: Although no treatment effectively eliminated the tissue stages of H. americanum, treatment with trimethoprim-sulfadiazine, clindamycin, and pyrimethamine followed by long-term administration of decoquinate resulted in extended survival times and excellent quality of life.