Two-dimensional echocardiography for diagnosis of dirofilariasis in nine dogs

Two-dimensional echocardiography (real-time ultrasonography) of the heart was used to detect adult Dirofilaria immitis in the right ventricle and atrium of a 2-year-old Labrador Retriever with occult heartworm disease and in 8 microfilaremic dogs. Adult worms were easily identified as parallel echogenic lines separated by a hypoechoic region. Images of worms fixed in formalin after recovery from dogs with experimentally induced heartworm infection had an identical appearance. The sensitivity of this imaging procedure was tested on the 8 dogs with naturally acquired infection, and worms were observed in the right ventricle of 7 of the dogs. Two-dimensional echocardiography appears to be a sensitive noninvasive procedure, which can be used in combination with thoracic radiography and serotests to improve accuracy of diagnosis of canine occult heartworm disease.     

Serum creatine kinase activities in dogs with dirofilariasis.

Total serum creatine kinase (CK) and its isozyme activities were determined in dogs with dirofilariasis. Before heartworm removal, total CK and isozyme activities in dogs of the mild group were not different from those in dogs of the heartworm-free group. BB activity was higher in dogs of the hemoptysis group. Dogs of the ascites group displayed a mild increase in MM activity. In dogs of the caval syndrome (CS) group, total CK and MM activities were highest among the heartworm-free and heartworm-infected dogs, and MM isozyme accounted for most (75%) of total CK activity. MB and BB activities were also higher. However, there were no significant differences in CK activities between the surviving and non-surviving cases. In dogs with pulmonary heartworm disease (mild and ascites groups), MM activity correlated significantly with the number of heartworms (r = 0.45), hematocrit value (Ht, r = -0.40), serum alanine aminotransferase (ALT, r = 0.42) and lactate dehydrogenase (LDH, r = 0.46) activities, mean pulmonary arterial pressure (r = 0.64) and total pulmonary resistance (r = 0.50). In dogs with CS, MM activity did not correlate with any parameter, but BB activity correlated with the number of heartworms at the right atrium (r = 0.61), Ht (r = -0.53), ALT (r = 0.80), LDH (r = 0.73) and serum urea nitrogen (r = 0.47). At 1 week after heartworm removal, BB and MM activity decreased in dogs of the hemoptysis and ascites groups, respectively. In dogs of the CS group, total CK and MM isozyme activities decreased markedly (P less than 0.01) regardless of their prognosis.     

Regional hypoxic pulmonary vasoconstriction in dogs with asymptomatic dirofilariasis

The pulmonary hemodynamic response to unilateral alveolar hypoxia was investigated in pentobarbital-anesthetized dogs with mild heartworm (HW) disease and in dogs free of HW (HWF). Left lung nitrogen ventilation in HWF dogs resulted in a decrease in the fraction of the cardiac output (QT) perfusing the left lung (QL) from 0.37 +/- 0.03 (SEM) to 0.20 +/- 0.02 (P less than 0.01). In contrast, dogs with mild HW disease did not develop a significant decrease in QL/QT which decreased from 0.38 +/- 0.02 to 0.33 +/- 0.02. This attenuated pulmonary vascular response to regional alveolar hypoxia in dogs with HW disease was associated with a normal pulmonary arterial pressure (14.8 +/- 1.5 mm of Hg) that was not different from that seen in HWF dogs (15.8 +/- 1.7 mm of Hg). These results indicate that mild HW disease interferes with the ability of hypoxic pulmonary vasoconstriction to redistribute pulmonary blood flow away from hypoxic regions of the lung.     

Some observations on the population and natal patterns among purebred dogs in Malaysia

The results of a study of 28, 220 birth registration and 773 import records between 1980 and 1982 of the Malaysian Kennel Association are reported. The German Shepherd Dog was by far the most common breed followed by the Dobermann, Dachshund and Boxer. Most breeds made up only a small percentage of birth registrations. No distinct seasonal distribution of whelping was evident among the purebred litters studied. Mean litter size was 4–7 puppies per litter with larger breeds tending to produce larger litters. A sex ratio of 51 males per 100 births was computed. There was a steady decline in the number of imported dogs.     

Renal microcirculatory and correlated histologic changes associated with dirofilariasis in dogs

Nine 7-month-old Beagle dogs were inoculated with 200 third-stage larvae of Dirofilaria immitis. The development of cardiac disease secondary to heartworm infection was confirmed by thoracic radiography, echocardiography, and angiography with blood pressure measurements. The only indication of renal disease was mild-to-moderate proteinuria. The dogs were euthanatized approximately 18 months after inoculation. The mean microfilarial count in blood at the time of euthanasia was 88,700/ml, with a mean of 89 adult heartworms in the vena cavae, heart, and pulmonary arteries. The kidneys were perfused for microangiographic and correlative histologic examination of the intrarenal microvasculature and associated renal morphologic features. Angiograms of whole kidneys from 6 dogs revealed attenuation or truncation of the major renal vessels. Microangiograms of all kidney slices revealed attenuation in the microangiographic appearance of the glomerular capillaries. Histologic examination of all kidney slices revealed mild-to-intense, diffuse, chronic interstitial nephritis and generalized membranoproliferative glomerulonephritis. Microfilariae were observed within the glomerular capillaries and the medullary vessels. The microangiographic changes correlated with and were explained in part by the histologic changes in the renal parenchyma.     

Contribution of live heartworms harboring in pulmonary arteries to pulmonary hypertension in dogs with dirofilariasis

To investigate whether adult heartworms harboring in the pulmonary arteries contribute to pulmonary hypertension, we determined the cardio-pulmonary values immediately before and after removal of heartworms from the pulmonary arteries and before and after insertion of live worms in their place. In 10 heartworm-infected dogs, 8 to 46 worms were removed. The mean pulmonary arterial pressure fell significantly from 24.5 +/- 7.9 mmHg to 16.3 +/- 4.9 mmHg (p less than 0.01) immediately after removal. The right cardiac output decreased in 7 of the 10 cases. The total pulmonary resistance and right ventricular stroke work index also decreased. At 24 hours after removal, live heartworms were put back into the pulmonary arteries of their host dog. The mean pulmonary arterial pressure elevated significantly (p less than 0.01) immediately after insertion. The right cardiac output further decreased in 7 of the 10 dogs, and the total pulmonary resistance and right ventricular stroke work index increased. Separate from this, 12 to 42 heartworms were transplanted into the pulmonary arteries of 5 heartworm-free dogs. Immediately after transplantation, the pulmonary arterial pressure did not show any significant change. However, the stroke volume decreased, and the total pulmonary resistance increased. These facts suggest a contribution of live heartworms to the pulmonary hypertension, although there is a complicated interaction among the presence of heartworms, the pulmonary lesions and the pulmonary hypertension.     

Survey of thyroglobulin autoantibodies in dogs

An enzyme-linked immunosorbent assay was used to detect autoantibodies to thyroglobulin in dogs with and without clinical evidence of thyroid disease. Autoantibodies were found in 59% of 34 clinically hypothyroid dogs, 43% of 65 dogs with nonthyroidal endocrine diseases, 47% of 64 healthy dogs closely related to antibody-positive canine hospital patients, and 13% of 1,057 canine hospital patients without endocrine disorders. Dogs with bacterial skin disease and alopecia of unknown causes had an increased prevalence of autoantibodies compared with the prevalence of autoantibodies in healthy dogs and dogs with other diseases. Three breeds of dogs, Great Danes, Irish Setters, and Old English Sheepdogs, had an increased occurrence of autoantibodies compared with that in other breeds and dogs of mixed breeding. A familial tendency to thyroid autoimmunity was demonstrated in a group of Great Dane dogs. The occurrence of autoantibodies was not influenced by age or sex. Thyroid function, as assessed by total thyroxine estimation, was depressed in hospitalized dogs compared with the thyroid function in healthy dogs, irrespective of thyroglobulin-antibody status. Two of 11 autoantibody-positive dogs monitored for an 18-month period developed low thyroxine concentration and depressed thyroid responsiveness to exogeneous thyrotropin stimulation.     

Survey of travel-related problems in dogs

The aim of this study was to quantitatively assess the kind of transport dogs undergo, the behaviours displayed during transport, the prevalence of travel-related problems in dogs and owners' interventions to solve these problems. A convenience sample of 907 dog owners completed a questionnaire containing 16 multiple-choice questions. All dogs had been transported by car at least once, but 4.7 per cent were no longer transported. 76.2 per cent of animals always responded positively to car transport, the rest showing or having shown problems (6.7 per cent always reacted negatively). Dogs were found to be more excited than inhibited during car transport. The vast majority (86.0 per cent) had become used to travelling by car as puppies; this made them less likely to develop problems (6.3 per cent v 24.1 per cent; χ(2)=19.886, P=0.000). If dogs were transported only to veterinary clinics, they were more prone to respond negatively to car transport (46.4 per cent v 22.7 per cent; χ(2)=7.245, P=0.007). For dogs reported as problematic (23.8 per cent of the sample), 96.3 per cent of the owners did not administer any treatments or other substances, 48.7 per cent did not seek any advice, and 40.4 per cent of them made attempts to solve the problem by themselves.     

Survey of campylobacter, salmonella and mycoplasmas in house crows (Corvus splendens) in Malaysia

House crows (Corvus splendens) in Selangor, Malaysia were examined for the presence of Campylobacter species, Salmonella species, Mycoplasma gallisepticum and Mycoplasma synoviae by serology, culture and pcr. For the detection of Campylobacter and Salmonella species swabs were taken either from the intestine or cloaca. For the detection of mycoplasmas, swabs were taken either from the choanal cleft or trachea for culture and pcr and serum samples were tested by the rapid serum agglutination (rsa) and monoclonal antibody-blocking elisa (mbelisa) for antibodies to M gallisepticum and M synoviae. For campylobacter, 25.3 per cent of the crows were positive by culture, and the species identified were Campylobacter jejuni and Campylobacter coli. No Salmonella species were isolated. Four of 24 swabs were positive for M gallisepticum dna but none gave positive results for M synoviae dna. No M gallisepticum or M synoviae antibodies were detected by rsa but 60 per cent of the sera gave positive reactions for M gallisepticum and 13 per cent gave positive reactions for M synoviae by mbelisa.     

Seroepidemiology of leptospirosis, toxoplasmosis, and leishmaniosis among dogs in Ankara, Turkey

Seroprevalence of five different Leptospira interrogans serovars, Toxoplasma gondii and Leishmania infantum in stray dogs in Ankara was investigated. A total of 116 dog sera collected from apparently healthy stray dogs were tested for L. interrogans serovars by microscopic agglutination test (MAT), for T. gondii antibodies by Sabin-Feldman dye test (SFDT), and for L. infantum antibodies by indirect fluorescence antibody test (IFAT). Of the 116 dogs, 51 (43.96%) were seropositive for leptospirosis, 72 (62.06%) for T. gondii and 3 (2.58%) for L. infantum. No statistically significant difference was observed between male and female dogs in the seroprevalences of toxoplasmosis and leptospirosis (P>0.05), but statistically significant difference was observed among different age groups in the seroprevalences of toxoplasmosis and leptospirosis (P<0.05). Although the seroprevalence of L. infantum was low, asymptomatic animals should be considered as a reservoir for the spread of the disease.     

Molecular evidence of rat bocavirus among rodents in Peninsular Malaysia

Rat bocavirus (RBoV) and rodent bocavirus (RoBoV) have previously been detected in Rattus norvegicus; however, these viruses have not been reported in rodent populations in Malaysia. We investigated the presence of RBoV and RoBoV in archived rodent specimens. DNA barcoding of the rodent cytochrome c oxidase gene identified five different species: Rattus tanezumi R3 mitotype, Rattus tiomanicus, Rattus exulans, Rattus argentiventer, and Rattus tanezumi sensu stricto. Three spleens were positive for RBoV (1.84%; 3/163), but no RoBoV was detected. Phylogenetic analyzes of the partial non-structural protein 1 gene grouped Malaysian RBoV strains with RBoV strains from China. Further studies among rats from different geographical locations are warranted for this relatively new virus.     

Echocardiographic diagnosis of dirofilariasis in a ferret

Heartworm disease is described in a 14-month-old neutered female ferret (Mustela putorius furo) which had a three-week history of sneezing, anorexia and dyspnoea. Echocardiography revealed the presence of heartworms as hyperechoic densities within the right atrial and ventricular cavities. At necropsy, four Dirofilaria immitis parasites (three females, one male) were found in the right heart, the cranial vena cava and the caudal vena cava. Histopathological findings were similar to those reported in canine heartworm disease. Echocardiography may be a useful method of diagnosis of heartworm disease in the ferret.     

Survey of gastrointestinal parasitic infections in quarantined dogs in Taiwan

Intestinal helminth and protozoan infection in the quarantined dogs in Taiwan were examined using fecal examination between January to December, 2004. Of the 376 dogs imported from 11 countries, 63 (16.8%) were found to be infected with at least one species of intestinal parasite. The parasites detected were oocysts of Isospora canis and eggs of Toxocara canis, Trichuris vulpis and hookworms. Of the 63 infected dogs, 11 were found to have a mixed infection of two different species of parasites. This paper illustrates that parasites are transmitted from one country to another through the transport of animals. Moreover, there is also a possibility of parasitic infection among quarantined dogs as well as the zoonotic potential for quarantine officers during the quarantine period.     

Chylothorax associated with dirofilariasis in a cat

A 4-year-old castrated domestic shorthair cat was referred for treatment of chylothorax. Thoracic duct lymphangiography revealed partial obstruction of the cranial vena cava, as evidenced by filling of mediastinal lymphatics with dye instead of all of the dye entering the vena cava. The thoracic duct was ligated via left 10th intercostal space thoracotomy. Immediate postligation lymphangiography revealed successful duct ligation. Results of a serum ELISA for adult heartworm antigen that was performed before surgery were positive. Drug treatment for the heartworm disease was not recommended, because the pleural effusion had ceased (as determined by radiographic examination 3.5 and 9 months after surgery) and the cat was doing well clinically. Sixteen months after surgery, the owner reported that the cat was doing well and did not have signs of respiratory problems.