Prevalence of Pneumonyssoides caninum infection in dogs in Sweden

Pneumonyssoides species infestation in two Pekingese dogs in the UK

Two male, neutered, Pekingese dogs aged four years and 12 years were presented for acute-onset nasal pruritus and sneezing following a visit to a beach in northern Scotland. Routine nasal investigations revealed the presence of the canine nasal mite Pneumonyssoides both by direct visualisation and histopathologically. Resolution of clinical signs was observed following selamectin treatment. To the authors' knowledge, this report describes the first cases of Pneumonyssoides infestation in non-travelled UK dogs.

Efficacy of selamectin in the treatment of nasal mite (Pneumonyssoides caninum) infection in dogs

In a laboratory study to evaluate the efficacy of selamectin for treatment of canine nasal mite infection, 12 purpose-bred beagles were experimentally infected with Pneumonyssoides caninum (P. caninum). Six of the dogs were treated with selamectin applied to the skin of the back at dosages of 6 to 24 mg/kg for three times at 2-week intervals. The remaining six dogs were an untreated control group. At necropsy 39 to 46 days after inoculation, no P. caninum mites were found in any of the treated dogs. In contrast, nasal mites were found in five of the untreated dogs. This difference was statistically significant at P=0.015.

Inheritance and determinants of pulmonary oedema in Swedish hunting dogs

By using information derived from questionnaires sent to registered owners of drever dams and sires in Sweden with offspring born in 1992 and/or 1994, two groups of offspring were identified: one with one parent said to have had breathing difficulties after hunting, and another with both parents unaffected. Questionnaires were sent to the owners of these offspring, and multiple logistic regression was used to analyse the offspring data, with the status of their sire and dam with respect to breathing difficulties after hunting included as covariates. For the outcome 'breathing difficulties after hunting' in the 266 offspring, the odds ratio (OR) was 4.4 (95 per cent confidence interval [CI] 1.8 to 10.8) if the dam was affected and 3-9 (95 per cent CI 1.2 to 11.1) if the sire was affected. The OR for male offspring was 2.4 (95 per cent CI 1.1 to 5.7). The heritability of the condition was estimated to be 0.34 from the dogs born in 1992, and 0.28 from the dogs born in 1994.

Demonstration of circulating antibodies to Pneumonyssoides caninum in experimentally and naturally infected dogs

Antibodies to the canine nasal mite, Pneumonyssoides caninum, were demonstrated by ELISA in sera from four experimentally and 77 naturally infected dogs employing a crude P. caninum antigen. In sera from the four experimentally infected dogs, antibodies to P. caninum were first detected on day 11 post-inoculation (p.i.). Optical density (OD) values remained high throughout the observation period of 14 weeks. Two major protein bands with apparent molecular weights of 83 and 74kDa were visible by western blot (WB) from day 11 p.i. On day 14 p.i., another three major protein bands at 44, 37, and 34kDa were visible. The protein pattern then remained essentially constant until the end of the experiment except for some weak bands between 250 and 30kDa which were sometimes visible. In sera obtained from a non-inoculated control dog, no P. caninum antibodies were detected, neither by the ELISA nor by the WB. With sera from 77 naturally infected dogs with a verified diagnosis of P. caninum infection, the OD values varied between 0.24 and 0.95. When sera from four of these dogs were analysed by WB, the protein pattern observed was equivalent with that seen with sera from the experimentally infected dogs on day 25 p.i. Sera from four experimental Beagles, in which no P. caninum mites were found at necropsy, were also analysed by the P. caninum ELISA, the OD values demonstrated never exceeded 0.15. In addition, 48 sera obtained from dogs infected with or allergic to other arthropods were used for studies of possible cross-reactivity. With 10 sera, elevated OD values were found by the ELISA. Eight of them showed a similar banding pattern by the WB as did the experimentally infected dogs on day 25 p.i. This was, therefore, interpreted as an effect of a concurrent P. caninum infection.