Sterile panniculitis in dogs: new diagnostic findings and alternative treatments

The objective of this study was to analyse the underlying diseases, diagnostic findings and treatment outcomes in 10 dogs with sterile panniculitis. There was no significant breed association in this study (P = 0.86).The median age of the dogs was 7.4 years. Concurrent diseases included atopic dermatitis (four dogs), acute pancreatitis (two dogs) and primary hypoadrenocorticism (one dog), with no concurrent conditions detected in three dogs. There was no significant association with the sterile panniculitis (P = 0.57). Well-circumscribed firm nodules were noted in seven dogs, and ill-defined soft nodules were observed in three dogs. Bacterial and fungal cultures of biopsy samples were negative in all cases. Fine-needle aspiration cytology of the nodules revealed pleomorphic mesenchymal cells in all of the well-circumscribed firm nodules, whereas numerous inflammatory cells and adipose cells were evident in soft nodules. These results indicate that firm nodules in panniculitis could be misdiagnosed as tumours. Immunosuppressive therapy was used in eight cases. Topical dexamethasone was used in four dogs, intralesional dexamethasone in one dog, oral prednisolone plus ciclosporin in two dogs and oral prednisolone only in one dog. The remaining treatments were surgical excision and systemic cefalexin in one dog each. The lesions regressed within 1 week in all cases, with more rapid remission following systemic immunosuppressive therapy. This study suggests that cytology may be misinterpreted as neoplastic, especially with firm lesions. In addition, topical glucocorticoid therapy should be further evaluated as a potential treatment for canine sterile panniculitis.     

A retrospective study of inflammatory colorectal polyps in miniature dachshunds

Medical records of dogs with colorectal polyps were retrospectively reviewed, and clinical presentation of inflammatory colorectal polyps in miniature dachshunds was evaluated. Of 33 dogs found to have colorectal polyps, miniature dachshunds were markedly over-represented with 16 dogs (48%), of which 12 (75%) were found to have inflammatory polyps. Multiple polyps localized between the rectum and the descending colon was the most common finding in miniature dachshunds with inflammatory polyps. Twenty dogs (80%) out of 25 miniature dachshunds with inflammatory colorectal polyps responded to immunosuppressive therapy using prednisolone and cyclosporine. The results of this study indicate that miniature dachshunds are predisposed to develop inflammatory colorectal multiple polyps, for which immunosuppressive therapy may be a treatment option.     

Polymorphisms in the canine glutamate transporter-1 gene: identification and variation among five dog breeds

Excitatory amino acid transporters (EAATs) are important for terminating glutamatergic neurotransmission and protect central nervous system (CNS) neurons from glutamatergic excitotoxicity. We selected these genes as targets that may relate to canine behavioral traits. After screening four EAAT genes (glutamate transporter-1; GLT-1, excitatory amino acid transporter 4; EAAT4, excitatory amino acid carrier; EAAC1, glutamate/aspartate transporter; GLAST) for single nucleotide polymorphisms (SNPs), we identified two silent SNPs (C129T and T471C) in the GLT-1 gene. We genotyped 193 dogs of 5 breeds and found significant variation among breeds in these two SNPs in GLT-1. The C129T polymorphism was not observed in Malteses and Miniature Schnauzers. These results suggest that polymorphisms in the GLT-1 gene may be useful markers for examining how the genetic background relates to the behavioral traits of dogs.     

Prevalence of calcium oxalate uroliths in miniature schnauzers.

Epidemiologic data were evaluated from all dogs admitted to the University of Minnesota, Veterinary Teaching Hospital (UMVTH) between June 1981 and November 1989. Of 69,890 admissions, 2,077 were Miniature Schnauzers. Uroliths were retrieved from 63 of the 2,077 Miniature Schnauzers admitted. In 20 of the 63 urolith episodes, calcium oxalate was the predominant mineral identified. By comparison, calcium oxalate uroliths were identified in only 56 of the remaining 67,813 non-Miniature Schnauzer canine admissions. The odds that uroliths from Miniature Schnauzers were composed of calcium oxalate was 11.8 times greater than for other canine breeds evaluated at the UMVTH (95% confidence interval = 6.8 to 20.1). Data also were evaluated from files of uroliths retrieved from dogs and submitted to the Minnesota Urolith Center for quantitative mineral analysis, between June 1981 and November 1989. Of 3,930 uroliths analyzed, 615 (15.6%) uroliths were obtained from Miniature Schnauzers. of the 615 uroliths, 175 (28.4%) were calcium oxalate. By comparison, only 550 (16.6%) of the remaining 3,315 from dogs of breeds other than Miniature Schnauzers were calcium oxalate. The odds that uroliths submitted for analysis were composed of calcium oxalate was 2 times greater for Miniature Schnauzers than for dogs of other breeds (95% confidence interval = 1.6 to 2.4). Calcium oxalate uroliths were retrieved more frequently in males than females. The risk for males developing calcium oxalate uroliths was greater than 3 times the risk for females in both groups of data evaluated. The mean age of all Miniature Schnauzers admitted to the UMVTH with calcium oxalate uroliths was 9 years. Calcium oxalate uroliths were not detected in Miniature Schnauzers younger than 1.7 years.     

Serum C-reactive protein concentrations in healthy Miniature Schnauzer dogs

Background: C‐reactive protein (CRP) is a sensitive marker for inflammation in people and dogs. In people, an association between CRP concentration and atherosclerosis has been reported. Atherosclerosis is rare in dogs, but the Miniature Schnauzer breed may be at increased risk for developing this vascular disease. It is not known if CRP concentrations in Miniature Schnauzer dogs differ from those in other dog breeds. Objectives: Our objectives were to validate an automated human CRP assay for measuring CRP in dogs and compare CRP concentrations in healthy Miniature Schnauzer dogs with those in non‐Miniature Schnauzer breeds. Methods: Sera from 37 non‐Miniature Schnauzer dogs with inflammatory disease were pooled and used to validate a human CRP immunoturbidimetric assay for measuring canine CRP. Blood was collected from 20 healthy Miniature Schnauzer dogs and 41 healthy dogs of other breeds. Median serum CRP concentration of healthy Miniature Schnauzer dogs was compared with that of healthy non‐Miniature Schnauzer dogs. Results: The human CRP assay measured CRP reliably with linearity between 0 and 20 mg/L. CRP concentration for healthy Miniature Schnauzer dogs (median 4.0 mg/L, minimum–maximum 0–18.2 mg/L) was significantly higher than for the healthy non‐Miniature Schnauzer dogs (median 0.1 mg/L, minimum–maximum 0–10.7 mg/L); 17 of the 20 Miniature Schnauzer dogs had values that overlapped with those of the non‐Miniature Schnauzer dogs. Conclusions: Median CRP concentration of Miniature Schnauzer dogs was slightly higher than that of other breeds of dogs. A relationship between higher CRP concentration in Miniature Schnauzer dogs and idiopathic hyperlipidemia, pancreatitis, and possible increased risk for atherosclerosis remains to be determined.     

Polymorphisms in the canine glucocorticoid receptor alpha gene (NR3C1α)

Corticosteroids are one of the most extensively used class of therapeutic agents in dogs. In human patients, response to corticosteroid therapy has been correlated with the presence of certain polymorphisms of the glucocorticoid receptor gene (NR3C1). Depending on the polymorphism present, patients may show either increased sensitivity to glucocorticoid‐induced adverse effects or resistance to their therapeutic effects. Because response to corticosteroid therapy in dogs can also be variable and unpredictable, we hypothesized that genetic variability exists in the canine NR3C1 gene. The aim of this study was to sequence the coding regions of the canine NR3C1 gene in a representative sample of dogs. Samples from 97 dogs from four previously identified genetic groupings of domestic breeds (Asian/Ancient, Herding, Hunting, and Mastiff) were sequenced and evaluated. Four exons contained polymorphisms and four exons showed no variation from the reference sequence. A total of six single nucleotide polymorphisms (SNPs) were identified including four synonymous SNPs and two nonsynonymous SNPs (c.811A>T and c.2111T>C). No dogs were homozygous for either variant allele, while 23 dogs were heterozygous for the c.811A>T allele and 2 were heterozygous for c.2111T>C allele. The amino acid changes caused by c.811A>T (serine to cysteine) and c.2111T>C (isoleucine to threonine) were both predicted by in silico analysis to be ‘probably damaging’ to structure and function of the resulting protein. We conclude that NR3C1 polymorphisms occur in dogs and may cause individual variation in response to corticosteroid therapy.     

Cytologic diagnosis of generalized cutaneous sporotrichosis in a hunting hound

A 1-year-old male Foxhound/Walker Hound mix was presented to the small animal internal medicine service at Louisiana State University School of Veterinary Medicine with a 6-week history of progressive, multifocal, ulcerative and draining, well-circumscribed lesions in a generalized distribution. Prior to referral, a presumptive diagnosis was made of sterile pyogranulomatous disease; immunosuppressive therapy was instituted but resulted in clinical deterioration. At presentation, the dog had marked neutropenia (1100 neutrophils/microL), and a mild toxic left shift (400 bands/microL). Cytologic findings in the exudates from a draining skin lesion included high numbers of markedly degenerate neutrophils (about 95% of nucleated cells) as well as low numbers of macrophages, small mature lymphocytes, and eosinophils. Low numbers of intracellular (within neutrophils and macrophages) and extracellular, pleomorphic, cigar-to-ovoid shaped organisms ( approximately 3x9 microm) consistent with Sporothrix were observed. Histopathologic examination of a skin biopsy showed marked, chronic, active, ulcerative, pyogranulomatous dermatitis and panniculitis, with intralesional yeast consistent with Sporothrix sp. The etiologic agent was confirmed as Sporothrix schenckii by macerated tissue fungal culture. The patient was treated with itraconazole, enrofloxacin, and clindamycin, with clinical resolution occurring over a 3-month period. This case is a rare example of the cytologic diagnosis of Sporothrix schenckii in a canine patient. Diagnosis of canine sporotrichosis is often challenging and usually requires tissue culture, as infected dogs typically harbor very few organisms. The patient's prior immunosuppressive therapy likely contributed to higher numbers of organisms in exudates from the cutaneous lesions, facilitating cytologic diagnosis.     

Canine meibometry: establishing baseline values for meibomian gland secretions in dogs

Meibomian lipid secretions are essential in preventing tear evaporation. Disorders of the meibomian glands may therefore play an important role in the pathogenesis of some forms of keratoconjunctivitis sicca (KCS). Until now, meibomian lipid secretions have never been quantitatively evaluated in dogs. With the aim of establishing baseline values of canine meibomian lipid secretions, meibometry was conducted in 42 healthy dogs, 16 of which were Miniature Schnauzers. The mean meibomium level in 84 eyes of the 42 dogs was 179+/-60 Meibometer units. Age, gender and side did not affect the results. However, meibomium levels were significantly lower in the Miniature Schnauzers, a breed that is susceptible to KCS, compared to other breeds. This report demonstrates that meibometry is a simple and minimally invasive technique that may be readily used in conscious dogs to quantify meibomian gland secretions and explicate tear film dynamics in normal and dry canine eyes.     

NHLRC1 repeat expansion in two beagles with Lafora disease

Lafora disease is a fatal genetic disorder characterised by neurotoxic deposits of malformed insoluble glycogen. In humans it is caused by mutation in the EPM2A or NHLRC1 genes. There is a known mutation in miniature wirehaired dachshunds which has not been documented in other dog breeds, including beagles, in which the disease is relatively commonly reported. This case report describes the causative defect in two affected beagles, namely the same massive expansion as in miniature wirehaired dachshunds of a 12‐nucleotide repeat sequence that is unique to the canine NHLRC1 gene. This is the first mutation described in beagles with Lafora disease, and so far the only Lafora disease genetic variant in dogs.     

Sterile nodular dermatitis in dogs.

The types of canine sterile nodular dermatitis discussed in this article have in common the clinical presentation of nodules or plaques; however, they differ in many aspects such as breed predilection, distribution and evolution of cutaneous lesions, systemic involvement, response to therapy, and prognosis. The definitive diagnosis should be based on multiple skin biopsy results. Other ancillary tests may be indicated in cases of systemic involvement. In addition, serum alpha1 antitrypsin can be measured to demonstrate the association between nodular panniculitis and serum alpha1 antitrypsin deficiency. A better understanding of the etiopathogenesis of each of these interesting skin conditions necessitates extensive and systematic diagnostic approaches.     

Evaluation of canine heat shock transcription factor 4 (HSF4) as a candidate gene for primary cataracts in the Dachshund and the Entlebucher Mountain dog

OBJECTIVE: Testing of the cataract-causing insertion/deletion mutation in the canine HSF4 gene for its linkage and association with primary cataracts (CAT) in Dachshunds and Entlebucher Mountain dogs. MATERIALS: Exon 9 with flanking intronic regions of the canine HSF4 gene was sequenced in 24 Dachshunds and 20 Entlebucher Mountain dogs. The HSF4 cDNA sequence of lens tissue was analyzed in a CAT-unaffected mixed-breed dog and in three CAT-affected dogs of different breeds, including a Wire-haired Dachshund, a Dachshund-mix and a German Shepherd dog. RESULTS: In all dogs investigated here, the previously reported CAT-causing mutation did not exist. We found a single nucleotide polymorphism (SNP) in intron 9, which was neither associated nor linked with the CAT phenotype in the two dog breeds. CONCLUSION: The CAT phenotype in the two dog breeds investigated here was not caused by the same mutation found to be associated with early-onset CAT in the Staffordshire Bull Terrier and Boston Terrier. The intronic SNP may be useful to test HSF4 for linkage with CAT in further dog breeds.     

Canine urolithiasis: epidemiology and analysis of urinary calculi

The incidence of canine urolithiasis was found to lie between 0–5 to 1 per cent of the canine population. Epidemiological and analytical data were collected for 1731 urinary stones, and causal relationships investigated. Calculi were found in 72 breeds. While they were relatively common among dachshunds, dalmatians, cocker spaniels, Pekingese, bassets, poodles, schnauzers and small terrier breeds, urinary stones were relatively rare among German shepherd dogs, boxers, collies, chow chows, old English sheepdogs, spitz and rottweiler breeds. Struvite, which was found in 55-6 per cent of all calculi, proved to be the most common constituent, followed by cystine (22-5 per cent) and ammonium urate (6-6 per cent). Xanthine calculi were rare (six cases), while silicium dioxide calculi were present in only one case. The likelihood of calculi in male animals was twice that of bitches, although the latter were found to be more prone to infection of the urinary tract. Adiposity was present in 29 per cent of all dogs with calculi. The average age of the animals was seven years. In 98-7 per cent of all cases the calculi were found in the lower urinary tract, and surgical removal of the stones was required in 87-5 per cent of cases. The main types of calculi appear among specific breeds, which indicates that a careful breeding programme may help to reduce the frequency of urinary calculi.     

Sterile idiopathic pedal panniculitis in the German shepherd dog - clinical presentation and response to treatment of four cases

Four cases of sterile idiopathic pedal panniculitis are described in the German shepherd dog. All the dogs presented with characteristic clinical signs of localised panniculitis dorsal to the midline of the carpal or tarsal pads of one or more legs. Diagnostic procedures did not identify a cause for the panniculitis and none of the cases had a history of penetrating foreign bodies. All cases failed to respond to antibiotic therapy but did respond to anti-inflammatory doses of prednisolone. The lesions in three dogs relapsed once the levels of steroids were reduced. However, in two of the cases oral vitamin E therapy at a dose of 300 iu twice daily acted in a steroid sparing capacity. In a fourth case, vitamin E acted to control the clinical signs without steroid therapy.     

Canine tyrosine hydroxylase (TH) gene and dopamine beta -hydroxylase (DBH) gene: their sequences, genetic polymorphisms, and diversities among five different dog breeds

Dopamine and noradrenaline are catecholamine neurotransmitters that are produced by biosynthetic enzymes such as tyrosine hydroxylase (TH) and dopamine beta -hydroxylase (DBH). As a first step to elucidate the genetic background of canine behavioral traits, we selected these genes as targets and sequenced these canine genes, and found that both were highly homologous with those of human beings. Then brain cDNAs derived from ten unrelated Beagles were used to search for polymorphisms in these genes. Four single nucleotide polymorphisms (SNPs) (C97T, G168A, G180A and C264T), one of which (C97T) will cause amino acid substitution in the TH gene, and two SNPs (C789A and A1819G), both of which will cause amino acid substitutions in the DBH gene were identified. The allelic frequencies among five dog breeds (47 Golden Retrievers, 41 Labrador Retrievers, 40 Malteses, 26 Miniature Schnauzers, and 39 Shibas) were examined and found to have significant variation between them with regards to all these SNPs, except for C97T in the TH gene and A1819G in the DBH gene. The polymorphisms of C97T and A1819G were found only in the Shiba. The present results suggest that the polymorphisms of the genes encoding catecholamine biosynthetic enzymes may become important markers for examining the genetic background of behavioral characteristics in dogs.     

Prevalence of primary breed-related cataracts in the dog in North America

The objective of the study was to determine the prevalence of cataracts in dogs presented to veterinary medical teaching hospitals in North America between 1964 and 2003. A retrospective study of all dogs presented with cataracts to veterinary medical teaching hospitals in North America between 1964 and 2003 was conducted to determine cataract prevalence. The different decades, breeds, gender, and age at time of presentation with cataract were compared. The prevalence of dogs presented with cataract varied by decade and ranged from 0.95% (1964-73), 1.88% (1974-83), 2.42% (1994-2003), to 3.5% (1984-93). The total number of dogs presented with cataracts over the 40-year period was 39,229. From 1964 to 2003 the prevalence of cataract formation in this patient population increased by about 255%. Fifty-nine breeds of dogs were affected with cataracts above the baseline prevalence of 1.61% seen in mixed-breed/hybrid dogs. The breeds with the highest cataract prevalence included: Smooth Fox Terrier (11.70%), Havanese (11.57%), Bichon Frise (11.45%), Boston Terrier (11.11%), Miniature Poodle (10.79%), Silky Terrier (10.29%) and Toy Poodle (10.21%). The breeds with the largest number of cataractous dogs during the entire four decades were the Boston Terrier (11.11%), Miniature Poodle (10.79%), American Cocker Spaniel (8.77%), Standard Poodle (7.00%), and Miniature Schnauzer (4.98%). Gender ratios of cataractous dogs seemed to affect limited breeds. Age of presentation with cataract diagnosis varied among several breeds. In the mixed-breed/hybrid baseline population, cataract formation appeared to be age related with a higher frequency of cataract formation in dogs after 4-7 years. Cataract formation is one of the most prevalent eye diseases in the dog population, and in about 60 breeds of dogs the prevalence of cataract exceeds that of the baseline mixed-breed/hybrid group. The prevalence of cataract is also influenced by age in most purebred dogs and affects 16.80% of the 7-15+-year-old mixed-breed/hybrid dog population. Total and age-related cataract prevalence in dogs seems very similar to that in man.     

Review of pathophysiology and clinical management of narcolepsy in dogs

Narcolepsy is a chronic sleep disorder that affects human beings and animals. Up to 17 breeds of dogs are affected sporadically, and familial forms occur in dobermanns, labrador retrievers and dachshunds. These dogs display characteristics strikingly similar to those of human narcolepsy, including cataplexy (a sudden loss of muscle tone in response to emotional stimulation) and a shorter sleep latency. It has recently been shown that the aetiology of both the familial form (receptor null mutation) and the sporadic form (loss of ligand production) of canine narcolepsy is associated with a deficit in hypocretin/orexin neurotransmission. Hypocretin deficiency can be detected by the measurement of hypocretin-1 in cerebrospinal fluid, and this could be used to diagnose hypocretin ligand deficient cases in clinical practice. Narcolepsy is neither progressive nor life-threatening, but the clinical signs persist throughout life, and lifelong treatment and care are required. This article reviews the recent progress in narcolepsy research in dogs, and describes the diagnosis and treatment of the disease.     

Cystine-containing urinary calculi in dogs: 102 cases (1981-1989).

One hundred and seven cystine-containing urinary calculi from 1 female and 101 male dogs were analyzed. Cystine-containing calculi accounted for 2% (107 of 5,375) of all canine urinary calculi submitted to the urinary stone analysis laboratory from July 1981 through December 1989. Male dogs that formed cystine calculi were compared with 3 other canine populations to determine whether certain breeds were apparently at increased or decreased risk for cystine calculus formation. In one or more of 3 population comparisons, significantly increased risk of cystine calculus formation was found in Mastiffs, Australian Cattle Dogs, English Bulldogs, Chihuahuas, Bullmastiffs, Newfoundlands, Dachshunds, Basenjis, Australian Shepherd Dogs, Scottish Deerhounds, Staffordshire Terriers, Miniature Pinschers, pitbull terriers, Welsh Corgis, Silky Terriers, and Bichon Frises. Significantly low risk of cystine calculus formation was found in German Shepherd Dogs, Poodles, Schnauzers, and mixed-breed dogs.     

Predisposition for primary hyperlipidemia in Miniature Schnauzers and Shetland sheepdogs as compared to other canine breeds

Miniature Schnauzers are the first canine breed, in the United States, reported to suffer from primary hyperlipidemia, but this has yet to be documented in other regions. Using over 900 canine plasma samples collected from over seven different veterinary clinics across Japan, the aim of this study was to compare plasma triglyceride (TG) and cholesterol concentrations between Miniature Schnauzers and other purebreeds in Japan. In addition, we investigated the influence of aging and sex on changes to hyperlipidemia incidence in purebred dogs. Our results indicated that both Miniature Schnauzers and Shetland sheepdogs in Japan exhibited remarkably high concentrations of plasma TG and total cholesterol, which are considered to be signs of hyperlipidemia, as compared to other purebred and mixed (Mongrel) canine breeds. Interestingly, the cause and conditions of primary hyperlipidemia in Miniature Schnauzers and Shetland sheepdogs might be different, with hypertriglyceridemia predominantly occurring with Miniature Schnauzers and hypercholesterolemia occurring in Shetland sheepdogs. However, with the influence of aging, the hyperlipidemia evolves into both hypercholesterolemia and hypertriglyceridemia in both groups indicating that the severity of hyperlipidemia positively correlates with aging. Gender differences were also observed with regards to severity. In fact, a higher severity was prevalent with female Miniature Schnauzers than their male counterparts whereas it was more balanced between genders for Shetland sheepdogs.     

Systemic treatment of sterile panniculitis with tacrolimus and prednisolone in dogs

This report deals with three additional canine cases of sterile panniculitis treated by oral administration of tacrolimus and prednisolone. The oral tacrolimus treatment was proved to be an affordable medical protocol for canine sterile panniculitis with good efficacy and without adverse effects.     

Identification of an cysteine-to-arginine substitution caused by a single nucleotide polymorphism in the canine monoamine oxidase B gene

Monoamine oxidase B catalytically oxidizes biogenic amines such as phenylethylamine and dopamine, and its activity is presumed to be related to particular behavioral traits. In this study, we first identified a single nucleotide polymorphism (T199C) located on the putative third exon of the canine monoamine oxidase B gene, which causes an amino acid substitution from cysteine to arginine. We then examined the allelic frequencies in five dog breeds (Golden Retriever, Labrador Retriever, Maltese, Miniature Schnauzer, and Shiba) and found significant variation among them. The present results suggest that analysis of the monoamine oxidase B polymorphism could be a useful means of elucidating the genetic background of breed-specific behavioral characteristics in dogs.