Alexander F. Koutinas

Canine leishmaniosis - new concepts and insights on an expanding zoonosis: part one

Recent research has provided new insights on the epidemiology, pathology and immunology of canine leishmaniosis (CanL) and its genetic basis. The prevalence of infection in endemic areas is considerably higher than that of apparent clinical illness. In addition, infection spreads rapidly among dogs in the presence of optimal conditions for transmission. Infection involves a variety of granulomatous and harmful immune-mediated responses, and susceptibility to the disease is influenced by a complex genetic basis. These concepts will be instrumental for devising control programs. This review, the first in a series of two articles on CanL, presents an updated view on progress in elucidating the epidemiology and pathogenesis of this challenging disease, and the second part focuses on advances in diagnosis, treatment and prevention.

Clinical considerations on canine visceral leishmaniasis in Greece: a retrospective study of 158 cases (1989-1996)

The medical records of 158 dogs with visceral leishmaniasis confirmed cytologically and/or serologically were reviewed. Ages of affected dogs varied from nine months to 15 years, with a male-to-female ratio of 1.3. The most common clinical manifestations of the disease were variable cutaneous lesions such as exfoliative dermatitis and skin ulcerations, chronic renal failure, peripheral lymphadenopathy or lymph node hypoplasia, masticatory muscle atrophy (i.e., chronic myositis), ocular lesions (i.e., conjunctivitis, keratoconjunctivitis sicca, blepharitis, and uveitis), and poor body condition. Ascites, nephrotic syndrome, epistaxis, polyarthritis, and ulcerative stomatitis were seen only in a small number of cases. Clinical splenomegaly was not a common finding. The clinicopathological abnormalities were nonregenerative anemia, hyperproteinemia, glomerular proteinuria, and symptomatic or asymptomatic azotemia. In this study, an indirect immunofluorescence assays diagnostic sensitivity was found to be higher than that of lymph node aspiration cytology.

A cross-sectional study of Leishmania spp. infection in clinically healthy dogs with polymerase chain reaction and serology in Greece.

A total of 73 clinically healthy hunting dogs, experiencing an outdoor lifestyle and originating from an area where canine leishmaniasis is endemic, were included in the study. Polymerase chain reaction (PCR) and indirect immunofluorescent antibody test (IFAT) for Leishmania spp. were done on bone marrow and serum samples, respectively, obtained from all 73 dogs, just before the beginning of the sandfly season. PCR was found positive in 46/73 (63%) whereas, IFAT only in 9/73 (12.3%) of the dogs. The prevalence and the incidence of Leishmania infection by PCR were 61.9 and 47.1%, respectively. No association was found between the breed, age, sex, length of hair coat of the dog, urban or rural life and the presence of ample vegetation and water collections in the proximity of their living quarters, and the result of PCR. These findings clearly demonstrate that most of the dogs residing areas where leishmaniasis is endemic become infected but usually remain seronegative. Serological screening of the general canine population in these areas may result in an underestimation of the true prevalence of the infection rate.

A randomised, blinded, placebo-controlled clinical trial with allopurinol in canine leishmaniosis.

A total of 45 non-uremic dogs, with clinical signs indicating leishmaniosis, entered the study. Diagnosis was confirmed by indirect immunofluorescence assay (IFA) on serum and polymerase chain reaction (PCR) on bone marrow samples. The dogs were randomly allocated into Group A (n=37) that received allopurinol (10mg/kg B.W., per os, twice daily) for 4 consecutive months, and Group B (n=8) that were placebo-treated. Clinical signs were scored just before and at monthly intervals throughout the study period, in a blinded and independent fashion. Complete blood count, serum biochemistry profile, urinalysis, lymph node and bone marrow parasitology, IFA and enzyme-linked immunosorbent assay (ELISA) serology and bone marrow PCR were carried out at the beginning and at the end of the trial. A total of three Group A and one Group B dogs died of end stage kidney disease that developed during the trial. In Group A animals that endured the trial there was a significant improvement in the general body condition, conjunctivitis, peripheral lymphadenopathy, splenomegaly, masticatory muscle atrophy, ulcerative stomatitis, epistaxis, exfoliative dermatitis, cutaneous ulcerations, blepharitis and nasodigital hyperkeratosis. The same observation was made for anemia, lymphopenia, hyperproteinemia, hyperglobulinemia, hyperphosphatemia, increased alkaline phosphatase activity and the low albumin/globulin ratio. By contrast, no improvement of any kind was seen in Group B dogs. Lymph node and bone marrow parasite numbers were significantly decreased in Group A animals. In Group B, that occurred only in the lymph nodes. Apart from remission of clinical signs and restoration to normal of clinicopathological abnormalities, allopurinol did not eliminate Leishmania organisms, as the PCR result on bone marrow was still positive in all the dogs that finished the trial.

Flea species from dogs and cats in northern Greece: environmental and clinical implications

Fleas were identified after being collected from 129 dogs and 38 cats of random breed, sex and age. All these animals, infested with fleas and admitted to the Clinic of Medicine of the Veterinary Faculty in Thessaloniki for routine procedures, were from different habitats and originated from various parts of northern Greece. Ctenocephalides canis was the most common species found on the dogs (71.3%). Conversely, its prevalence in the 14 cats was substantially lower (5.3%). Ctenocephalides felis was found on 97.4% of the cats and 40.3% of the dogs surveyed. Of the other flea species, with much lower prevalence, Pulex irritans (0.8%) and Xenopsylla cheopis (0.8%) were observed only on the dogs. Seventeen dogs (13.2%) and one cat (2.6%) had mixed infestations. Flea-associated dermatoses were observed in 26 dogs (20.2%) and four cats (10.5%). Flea-allergic dermatitis, with its typical manifestations, was seen in ten of the dogs (38.5%) with skin lesions. Three out of four flea-allergic cats presented miliary dermatitis and one symmetrical hypotrichosis.

Assessment of cross‐reactivity among five species of house dust and storage mites

In vitro cross-reactivity among two house dust (Dermatophagoides farinae, D. pteronyssinus) and three storage (Acarus siro, Tyrophagus putrescentiae, Lepidoglyphus destructor) mites was examined in 20 mite-sensitive dogs with natural occurring atopic dermatitis (group A), 13 high-IgE beagles experimentally sensitized to D. farinae (group B), and five healthy beagles (group C). Intradermal testing (IDT) and serology for allergen-specific IgE demonstrated that co-sensitization for all possible pairs of the five mites was generally 45% or higher among group A dogs. In the same dogs, enzyme-linked immunosorbent assay cross-inhibition results indicated that each one of D. farinae, A. siro and T. putrescentiae was a strong inhibitor of all the remaining mites, whereas D. pteronyssinus was a strong inhibitor of L. destructor. A high number of positive IDT and serology test results for D. pteronyssinus, A. siro, T. putrescentiae and L. destructor were recorded among group B dogs. No conclusive evidence of exposure to these mites was found upon analysis of dust samples from their environment and their food for the presence of mites and guanine. Also, the number of positive test results was generally higher among group B than among group C dogs. Enzyme-linked immunosorbent assay cross-inhibition revealed that D. farinae was a strong inhibitor of D. pteronyssinus, A. siro and T. putrescentiae. Collectively, these results demonstrated extensive in vitro cross-reactivity among house dust and/or storage mites that can explain false-positive results upon testing of dust mite-sensitive dogs with atopic dermatitis.

A survey on the prevalence of gastrointestinal parasites of dogs in the area of Thessaloniki, Greece

Faecal specimens randomly taken from 232 healthy dogs living in the area of Thessaloniki were screened for internal parasites. In 39.2% of the examined dogs excretion of Sarcocystis bovicanis (1.3%), Isospora ohioensis/burrowsi (3.9%), Giardia lamblia (0.8%), Hammondia heydorni (0.4%), Dicrocoelium dendriticum (0.8%) Diplopylidium nolleri (0.4%), Joyeuxiella pasqualei (0.8%), taeniids (0.4%), Toxocara canis (22.4%), Toxascaris leonina (1.3%), Uncinaria stenocephala (3.0%), Trichuris vulpis (2.6%), Spirocerca lupi (0.4%), or Linguatula serrata (0.4%) was detected. The overall rate of infection did not show any significant difference concerning sex or age. T. canis, however, was significantly more often found in the youngest age group (1-3 months).

Factors affecting the occurrence, duration of hospitalization and final outcome in canine parvovirus infection

The objectives of this matched case-control study in a veterinary teaching hospital were to investigate the influence of signalment and historical data on the odds of occurrence of canine parvovirus (CPV) enteritis and the potential usefulness of the clinical signs and clinicopathologic abnormalities recorded on admission as prognostic indicators of mean duration of hospitalization (DOH) and outcome of the disease. Ninety-four puppies with natural CPV enteritis and 188 age-matched controls were studied. The odds to develop CPV enteritis were higher in purebreds compared to mixed-breed puppies. Vomiting and depression at the time of admission were associated with a prolongation of DOH by 2 and 1.75 days, respectively. The lymphopenic and hypoalbuminemic dogs were hospitalized for 1.9 and 2.5 more days, respectively, compared to those without these abnormalities. The odds of non-survival were higher in those puppies with evidence of systemic inflammatory response syndrome (SIRS) at the time of admission.

Feline lower airway disease: A retrospective study of 22 naturally occurring cases from Greece

In this retrospective study of 22 cats with lower airway disease of either intermittent (23%) or persistent nature (77%), the Siamese breed (55%) was significantly over-represented. Females (68%) were slightly but not significantly over-represented. No significant association was found between the clinical stage of disease and the physical findings, thoracic radiographic changes or the response to treatment. Cough, the most common presenting complaint, was the only symptom detected in the cats with intermittent disease, yet the two most severely affected animals did not show it. Thoracic auscultation did not reveal any abnormality in 41% of the cats. Haematology revealed eosinophilia in 46% of the cats. A bronchial pattern was the most common radiographic abnormality (73%), followed by alveolar (32%) and interstitial patterns (23%). Interestingly, thoracic radiographs were normal in 23% of the cats. The combination of short-term corticosteroids and bronchodilators resulted in complete and long-term remission of symptoms in nine cats, while the other 11 required ongoing medication because of relatively frequent relapses. One of the remaining two cats died during an asthmatic crisis, while the other was lost to follow up.

Prevalence of microfilaraemia in episodic weakness and clinically normal dogs belonging to hunting breeds

Blood samples from 50 dogs with episodic weakness and 50 clinically normal dogs, all belonging to hunting breeds, were examined for microfilariae using the modified Knotts method. The prevalence of microfilaraemia in dogs belonging to the episodic weakness group was 10% for Dirofilaria immitis, 30% for Dirofilaria repens and 8% for Acanthocheilonema reconditum. In the clinically normal group, the figures were 14% for Dirofilaria repens and 4% for Acanthocheilonema reconditum. The overall percentage of dogs with microfilaremia in the episodic weakness group was 44 and that of the clinically normal group 16, with a statistically significant difference (P < 0.01). The prevalence of microfilaremia due to the nonpathogenic filarial species (Dirofilaria repens, Acanthocheilonema reconditum) was 34% and 16% for the episodic weakness group and the clinically normal dogs, respectively, with no significant difference.