Anu K. Lappalainen

Clinical, bronchoscopic, histopathologic, diagnostic imaging, and arterial oxygenation findings in West Highland White Terriers with idiopathic pulmonary fibrosis.

BACKGROUND Idiopathic pulmonary fibrosis (IPF) is a chronic, interstitial lung disease primarily affecting West Highland White Terriers (WHWTs). OBJECTIVE To describe the clinicopathological and diagnostic imaging features in WHWTs with IPF. ANIMALS Twelve WHWTs with IPF and 14 healthy control WHWTs. METHOD Prospective study. Clinical signs and findings of physical examination, blood and arterial blood gas analyses, radiography, high-resolution computed tomography (HRCT), bronchoscopy and bronchoalveolar lavage (BAL) of IPF dogs were obtained and compared with controls. Histopathologic changes in IPF dogs were evaluated. RESULTS Mean partial pressure of oxygen was significantly lower in IPF (mean ± SD, 65.5 ± 15.4 mmHg) than in controls (99.1 ± 7.8 mmHg, P<.001). The alveolar-arterial oxygen gradient was significantly higher in IPF (50.1 ± 17.3 mmHg) than in controls (17.5 ± 4.9 mmHg, P<.001). In HRCT, ground glass opacity (GGO) was detected in all IPF dogs, traction bronchiectasis in 4, and honeycombing in 1. Bronchoscopic airway changes were noted in all IPF dogs. On BAL fluid (BALF) cytology, the total cell count (TCC) was higher in IPF dogs, and the numbers but not the percentages of macrophages, neutrophils, and mast cells were increased. On histopathology, multifocal or diffuse interstitial fibrosis, type II pneumocyte hyperplasia, prominent intraalveolar macrophages, distortion of alveolar architecture, and emphysematous change were detected. CONCLUSION AND CLINICAL IMPORTANCE IPF causes substantial hypoxemia. In HRCT, GGO is a consistent finding. IPF dogs have concurrent airway changes and an increase in BALF TCC.

Genome-Wide Association Study in Dachshund: Identification of a Major Locus Affecting Intervertebral Disc Calcification

Intervertebral disc calcification and herniation commonly affects Dachshund where the predisposition is caused by an early onset degenerative process resulting in disc calcification. A continuous spectrum of disc degeneration is seen within and among dog breeds, suggesting a multifactorial etiology. The number of calcified discs at 2 years of age determined by a radiographic evaluation is a good indicator of the severity of disc degeneration and thus serves as a measure for the risk of developing intervertebral disc herniation. The aim of the study was to identify genetic variants associated with intervertebral disc calcification in Dachshund through a genome-wide association (GWA) study. Based on thorough radiographic examinations, 48 cases with ≥ 6 disc calcifications or surgically treated for disc herniation and 46 controls with 0-1 disc calcifications were identified. GWA using the Illumina CanineHD BeadChip identified a locus on chromosome 12 from 36.8 to 38.6 Mb with 36 markers reaching genome-wide significance (P(genome) = 0.00001-0.026). This study suggests that a major locus on chromosome 12 harbors genetic variations affecting the development of intervertebral disc calcification in Dachshund.

A Missense Change in the ATG4D Gene Links Aberrant Autophagy to a Neurodegenerative Vacuolar Storage Disease

Inherited neurodegenerative disorders are debilitating diseases that occur across different species. We have performed clinical, pathological and genetic studies to characterize a novel canine neurodegenerative disease present in the Lagotto Romagnolo dog breed. Affected dogs suffer from progressive cerebellar ataxia, sometimes accompanied by episodic nystagmus and behavioral changes. Histological examination revealed unique pathological changes, including profound neuronal cytoplasmic vacuolization in the nervous system, as well as spheroid formation and cytoplasmic aggregation of vacuoles in secretory epithelial tissues and mesenchymal cells. Genetic analyses uncovered a missense change, c.1288G>A; p.A430T, in the autophagy-related ATG4D gene on canine chromosome 20 with a highly significant disease association (p = 3.8 x 10-136) in a cohort of more than 2300 Lagotto Romagnolo dogs. ATG4D encodes a poorly characterized cysteine protease belonging to the macroautophagy pathway. Accordingly, our histological analyses indicated altered autophagic flux in affected tissues. The knockdown of the zebrafish homologue atg4da resulted in a widespread developmental disturbance and neurodegeneration in the central nervous system. Our study describes a previously unknown canine neurological disease with particular pathological features and implicates the ATG4D protein as an important autophagy mediator in neuronal homeostasis. The canine phenotype serves as a model to delineate the disease-causing pathological mechanism(s) and ATG4D function, and can also be used to explore treatment options. Furthermore, our results reveal a novel candidate gene for human neurodegeneration and enable the development of a genetic test for veterinary diagnostic and breeding purposes.

An un-commissioned randomized, placebo-controlled double-blind study to test the effect of deep sea fish oil as a pain reliever for dogs suffering from canine OA

BackgroundAn un-commissioned randomized, double-blinded, placebo controlled clinical study was planned using a deep sea fish oil product for pets. Seventy-seven client-owned dogs with osteoarthritis were randomly assigned to supplement the food with either the fish oil product or corn (=placebo) oil. Our main outcome variables were force platform variables peak vertical force (PVF) and impulse, the validated Helsinki Chronic Pain Index (HCPI) and the use of rescue NSAIDs. Secondary outcome variables were a locomotion visual analog scale (VAS), a Quality of life VAS, a comparative questionnaire, a veterinary assessment, owners’ final assessment of outcome and guessing the product given.ResultsWhen comparing the two test groups at the end of the trial (16 weeks) there was no significant difference in any of the main outcome variables but owners of dogs that had taken fish oil were significantly happier with the treatment at the end visit and did significantly better at guessing what group their dogs had been in, compared to the placebo group. When comparing variables within the fish oil group as change from baseline to trial end, there were significant positive changes in PVF, HCPI, NSAID use, Quality of life VAS, as well as in all three scores in the comparative questionnaire (locomotion, every-day situations, and skin & coat). There were similar positive trends in force platform impulse and in the veterinary assessment variables, although they did not reach significance. Within the placebo group there were significant positive changes only in the HCPI and a significant deterioration according to veterinary assessment.ConclusionsWhen compared to placebo, there was not a major statistically significant benefit in using deep sea fish oil as a pain reliever in our study population of dogs suffering from osteoarthritis. However, the fish oil treated patients improved significantly in many of the variables, when comparing baseline values to the study-end values within the group, indicating a true but small relief in symptoms. Deep sea fish oil supplementation could be considered a part of the multimodal pain relieving approach currently recommended for dogs suffering from OA, especially for individuals that do not tolerate anti-inflammatory drugs.

A Novel GUSB Mutation in Brazilian Terriers with Severe Skeletal Abnormalities Defines the Disease as Mucopolysaccharidosis VII

Hundreds of different human skeletal disorders have been characterized at molecular level and a growing number of resembling dysplasias with orthologous genetic defects are being reported in dogs. This study describes a novel genetic defect in the Brazilian Terrier breed causing a congenital skeletal dysplasia. Affected puppies presented severe skeletal deformities observable within the first month of life. Clinical characterization using radiographic and histological methods identified delayed ossification and spondyloepiphyseal dysplasia. Pedigree analysis suggested an autosomal recessive disorder, and we performed a genome-wide association study to map the disease locus using Illumina’s 22K SNP chip arrays in seven cases and eleven controls. A single association was observed near the centromeric end of chromosome 6 with a genome-wide significance after permutation (pgenome  = 0.033). The affected dogs shared a 13-Mb homozygous region including over 200 genes. A targeted next-generation sequencing of the entire locus revealed a fully segregating missense mutation (c.866C>T) causing a pathogenic p.P289L change in a conserved functional domain of β-glucuronidase (GUSB). The mutation was confirmed in a population of 202 Brazilian terriers (p = 7,71×10−29). GUSB defects cause mucopolysaccharidosis VII (MPS VII) in several species and define the skeletal syndrome in Brazilian Terriers. Our results provide new information about the correlation of the GUSB genotype to phenotype and establish a novel canine model for MPS VII. Currently, MPS VII lacks an efficient treatment and this model could be utilized for the development and validation of therapeutic methods for better treatment of MPS VII patients. Finally, since almost one third of the Brazilian terrier population carries the mutation, breeders will benefit from a genetic test to eradicate the detrimental disease from the breed.

Long‐Term Outcome and Use of 6‐Minute Walk Test in West Highland White Terriers with Idiopathic Pulmonary Fibrosis

Background Idiopathic pulmonary fibrosis (IPF) is an incurable interstitial lung disease occurring mainly in West Highland White Terriers (WHWTs). The effects of IPF on survival and on exercise tolerance in WHWTs are unknown. Objectives To evaluate survival, prognostic factors, and exercise tolerance in WHWTs with IPF. Animals Privately owned WHWTs; 15 with IPF and 11 healthy controls. Methods Prospective case‐control study conducted in 2007–2012. For survival, descriptive statistics and Kaplan–Meier (KM) survival curves with Cox proportional hazard ratios were performed. For the prognostic factor study, KM curves, Cox regression analysis, and logistic regression models were used. The 6‐minute walk test (6MWT) was used for measurement of exercise tolerance. Results The median IPF‐specific survival of deceased WHWTs (7/15) with IPF was 32 (range 2–51) months from onset of clinical signs. The risk of death from birth in WHWTs with IPF in age‐adjusted Cox model was significantly higher (hazard ratio 4.6; 95% confidence interval 1.05–19.74, P = .04) than in control WHWTs. No significant prognostic factors were identified. In 6MWT, WHWTs with IPF walked a shorter distance, median 398 m (range 273–519 m), than healthy controls, median 492 m (420–568 m), P = .05, and the partial pressure of oxygen in arterial blood in diseased dogs had a moderate positive correlation with walking distance (Kendall′s tau‐b = 0.69, P = .06). Conclusion and Clinical Importance IPF had a negative impact on life expectancy, but individual survival varied considerably. 6MWT proved to be a well‐tolerated, noninvasive test to evaluate exercise tolerance.

Calcification of the Intervertebral Discs and Curvature of the Radius and Ulna: A Radiographic Survey of Finnish Miniature Dachshunds

The vertebral column of 124 randomly selected miniature dachshunds, representing 4.5% of the population registered by the Finnish Kennel Club during the years 1988 to 1996, were radiographed. The front legs were also radiographed in order to evaluate the curvature of the radius and ulna. Calcified discs were found in 75.9% of the longhaired miniature dachshunds and in 86.7% of the wirehaired ones. The occurrence of signs associated with IDD was 16.5% in longhaired and 15.6% in wirehaired miniature dachshunds. The occurrence of signs of IDD in dogs with calcified discs was 20.0% and 17.9% in long-haired and wirehaired miniature dachshunds, respectively. In dogs without calcifications only one dog showed signs of IDD. The curvature of the radius and the ulna did not differ between the dogs with signs of IDD and the healthy ones, or between the dogs with and without intervertebral calcifications. Our results indicate that radiographic eradication based on the presence of intervertebral calcifications is not suitable for breeding purposes for the Finnish miniature dachshund population because the percentage of dogs without calcifications is small.SammanfattningKalsifikation av intervertebrala diskar samt böjningenav radius och ulna: en röntgenologisk undersökning av finska dvärgtaxar..Ryggkotpelaren hos 124 slumpvis utvalda dvärgtaxar, som representerar 4.5% av den registrerade populationen hos Finska Kennelklubben under åren 1988-1996, undersöktes med hjälp av röntgen. Även frambenen röntgades och böjningen av radius ochulna uppmättes. Förkalkade diskar konstaterades hos 75.9% av de undersökta långhåriga dvärgtaxarna och hos 86.7% av de strävhåriga. Hos 16.5% av de långhåriga och 15.6% av de strävhåriga dvärgtaxarna förekom symptom på intervertebral disksjukdom.Förekomsten disksjukdom hos hundar med förkalkningar i diskmassan var 20.0% samt 17.9% hoslånghåriga respektive strävhåriga dvärgtaxar. Av de hundar som inte hade förkalkningar var det bara en som visade symptom på intervertebral disksjukdom. Böjningsgraden på radius och ulna skilde sig inte mellan hundar med symptom på disksjukdom ochfriska individer, eller mellan hundar med förkalkningar och sådana som saknade förkalkningar. Våra resultat indikerar att det inte är lämpligt, när det gäller populationen dvärgtaxar i Finland, att utesluta individer från avel genom röntgenologisk påvisning av förkalkningar mellan kotkropparna, på grund av det förhållandevis låga antalet hundar utan förkalkningar.

Canine Chondrodysplasia Caused by a Truncating Mutation in Collagen-Binding Integrin Alpha Subunit 10

The skeletal dysplasias are disorders of the bone and cartilage tissues. Similarly to humans, several dog breeds have been reported to suffer from different types of genetic skeletal disorders. We have studied the molecular genetic background of an autosomal recessive chondrodysplasia that affects the Norwegian Elkhound and Karelian Bear Dog breeds. The affected dogs suffer from disproportionate short stature dwarfism of varying severity. Through a genome-wide approach, we mapped the chondrodysplasia locus to a 2-Mb region on canine chromosome 17 in nine affected and nine healthy Elkhounds (praw = 7.42×10−6, pgenome-wide = 0.013). The associated locus contained a promising candidate gene, cartilage specific integrin alpha 10 (ITGA10), and mutation screening of its 30 exons revealed a nonsense mutation in exon 16 (c.2083C>T; p.Arg695*) that segregated fully with the disease in both breeds (p = 2.5×10−23). A 24% mutation carrier frequency was indicated in NEs and an 8% frequency in KBDs. The ITGA10 gene product, integrin receptor α10-subunit combines into a collagen-binding α10β1 integrin receptor, which is expressed in cartilage chondrocytes and mediates chondrocyte-matrix interactions during endochondral ossification. As a consequence of the nonsense mutation, the α10-protein was not detected in the affected cartilage tissue. The canine phenotype highlights the importance of the α10β1 integrin in bone growth, and the large animal model could be utilized to further delineate its specific functions. Finally, this study revealed a candidate gene for human chondrodysplasias and enabled the development of a genetic test for breeding purposes to eradicate the disease from the two dog breeds.

Dermoid sinus and spina bifida in three dogs and a cat.

This case series describes four cases of concomitant dermoid sinus and spina bifida in a Chinese crested dog, two Swedish vallhunds and a Burmese cat. The diagnosis was confirmed by computed tomography, computed tomography fistulography and pathology. Two dogs that showed abnormalities during neurological examination underwent magnetic resonance imaging. One of them had imaging findings interpreted as syringohydromyelia. All the dogs underwent surgery and the outcome was considered good in all the cases. Based on clinical and pathological examination as well as diagnostic imaging findings, two of the dermoid sinuses were classified as type IV, and two of them showed a previously unreported type of dermoid sinus. This new type is suggested here as type VI.

Co-infections with Respiratory Viruses in Dogs with Bacterial Pneumonia

Background Bacterial pneumonia (BP) is an inflammation of the lower airways and lung parenchyma secondary to bacterial infection. The pathogenesis of BP in dogs is complex and the role of canine respiratory viruses has not been fully evaluated. Objectives The aim of this study was to investigate the occurrence of viral co‐infections in dogs with BP and to assess demographic or clinical variables as well as disease severity associated with viral co‐infections. Animals Twenty household dogs with BP caused by opportunistic bacteria and 13 dogs with chronic (>30 days) tracheobronchitis caused by Bordetella bronchiseptica (BBTB). Methods Prospective cross‐sectional observational study. Diagnosis was confirmed by clinical and laboratory findings, diagnostic imaging, and cytologic and microbiologic analysis of bronchoalveolar lavage or transtracheal wash fluid. Canine parainfluenza virus (CPIV), canine adenovirus, canine herpes virus, canine influenzavirus, canine distemper virus, canine respiratory coronavirus (CRCoV) and canine pneumovirus, as well as B. bronchiseptica and Mycoplasma spp. were analyzed in respiratory samples using PCR assays. Results CPIV was detected in 7/20 and CRCoV in 1/20 dogs with BP. Respiratory viruses were not detected in dogs with BBTB. There were no significant differences in clinical variables between BP dogs with and without a viral co‐infection. Conclusion and Clinical Importance Respiratory viruses were found frequently in dogs with BP and may therefore play an important role in the etiology and pathogenesis of BP. Clinical variables and disease severity did not differ between BP dogs with and without viral co‐infection.