Samoyed Dogs Research Articles

Statistical agreement of gonioscopy performed as a puppy and as an adult in the Samoyed dog.

To assess whether gonioscopy performed on Samoyed puppies (6-14 weeks of age) is a reliable predictor of their gonioscopy results as adults (>11 months of age). A retrospective medical record search was performed to identify Samoyed dogs that had undergone gonioscopy as a puppy (6-14 weeks of age). A second prospective gonioscopy examination was performed as an adult (>11 months of age) and the results were compared. Gonioscopy was assessed on two characteristics: percent of iridocorneal angle (ICA) unaffected by pectinate ligament abnormalities (PLA) and ICA width, with PLA results categorized into unaffected ( 75% open), moderately affected (50%-74% open), and severely affected (<50% open) and the width categorized into wide, moderate, narrow, and closed groups. A multivariate model was created that considered factors such as PLA, angle width, sex, puppy age, neuter status, and time between examinations. The eyes of 77 Samoyed dogs (154 eyes) met inclusion criteria. When assessing PLA, 90% of dogs had the same categorization as a puppy and as an adult. When assessing ICA width, 53.2% of dogs had the same width classification as a puppy and as an adult. There is strong evidence that variation between puppy and adult results increases with time between examination (p = .03). Puppies unaffected by PLA and with a wide ICA angle, are likely to retain these features as adults. Selection of puppies with desirable gonioscopic traits may help breeders to choose dogs likely to retain these traits as adults for breeding. This may reduce the incidence of glaucoma in the breed. Puppy examinations should be performed in both eyes. Examination of adults prior to breeding remains prudent.

RACHUNEK EKONOMICZNY UTRZYMANIA PSÓW RASY SAMOYED

The aim of this study was to evaluate the effects and expenditures related to maintenance of Samoyed dogs, specifying the contribution of individual factors affecting the overall economic account. The research material consisted of data obtained from surveys conducted among 111 owners of Samoyeds kept in Poland. The survey asked questions about the costs associated with owning a dog. The results were compiled with the minimum, maximum and average costs, and distinguished the percentage share of individual annual costs. The obtained results were the basis for the conclusion that owners of male dogs incur higher annual costs than owners of bitches. The largest share in the annual costs was related to feeding, and in one-off costs it was the purchase of an animal. In addition to the financial aspects of having a dog, also taken into account should be the effects and non-measurable costs associated with it. It seems that awareness of the costly nature of owning a pure-bred dog can increase the responsibility and reduce the number of abandoned dogs.

Lymphoepithelial Thymoma Characterized by Proliferation of Spindle Cells in a Samoyed Dog

Lymphoepithelial thymoma was diagnosed in a 14-year-old Samoyed dog with clinical symptoms of myasthenia gravis at 6 months of age. At necropsy, dark red-colored mass with many nodular protuberances was found in the anterior mediastinal area. Histologically, the mass consisted of solid proliferation of neoplastic cells with spindle nuclei and cytoplasm and a few lymphocytes, which is separated by an abundant fibrous and adipose tissue. Immunohistochemically, spindle cells were positive for cytokeratin, and infiltrating lymphocytes were positive for CD3. On the basis of these findings, this tumor was diagnosed as lymphoepithelial thymoma, which is morphologically similar to type A thymoma in humans.

Alport Syndrome with Diffuse Leiomyomatosis: When and When Not?

Alport Syndrome with Diffuse Leiomyomatosis: When and When Not?

Treatment of X-linked hereditary nephritis in samoyed dogs with angiotensin converting enzyme (ACE) inhibitor

X-linked hereditary nephritis (HN) in Samoyed dogs is a model for human HN (Alport's syndrome). Angiotensin converting enzyme (ACE) inhibitors have been shown to slow the progression of renal disease in animal models and human patients. To determine the effect of ACE inhibitor treatment on X-linked HN in Samoyed dogs, a group of affected and a group of normal males were each randomly divided into two subgroups, which were either treated with an ACE inhibitor or left untreated. ACE inhibitor treatment caused significant increases (P < 0.05) in plasma renin activity in normal and affected dogs, confirming its effectiveness, but did not lower systemic blood pressure. Three of four affected treated dogs had improved weight gains and, overall, treated dogs survived 1.36 times longer than affected untreated dogs (P < 0.05). ACE inhibitor treatment of affected dogs significantly delayed (P < 0.05) the onset of an increase in serum creatinine concentration, tended to delay the decline of glomerular filtration rate and effective renal plasma flow (ERPF), significantly improved (P < 0.05) the ERPF at 110-154 days of age, and significantly slowed (P < 0.01) the rate of increase of proteinuria. Affected treated dogs showed a significant (P < 0.05) transient reduction in glomerular basement membrane splitting. Thus, ACE inhibitor treatment of Samoyed dogs with X-linked HN produced beneficial effects with respect to renal function, renal structure, and survival.

Biological Variability and Measurement Error Variability in Ocular Biometry in Samoyed Dogs

A-scan ultrasonography was performed in 40 healthy Samoyeds aged 2-5 years. Mydriasis and cycloplegia were induced in all dogs and 25 of the dogs were also sedated prior to the ultrasound examination. Five consecutive A-scans were taken on each eye and the intrasubject variance (measurement error) and true intersubject variance (true biological variation) were computed. The true biological variation was found to be of the same magnitude in both sedated and unsedated dogs, whereas the measurement errors were considerably larger in the group of unsedated dogs compared to the sedated ones. Magnitudes of the measurement errors for the anterior chamber depth and length of the vitreous body in the unsedated group were unacceptable. The sizes of the measurement errors in the sedated dogs were all within an acceptable range.

Adenohypophysitis Associated with Sebaceous Gland Atrophy in a Dog

Sebaceo us adeniti s is a granulomatous or pyogranul ornatous dermatitis with inflammation located around sebaceous glands. In chronic cases, these gland s are replaced by fibrous connective tissue} Many breeds of dogs have been affected , but adult Standa rd Poodles, Sam oyeds, Vizlas, and Akitas are appare ntly predisposed.' Etiologic facto rs are unknown. Seconda ry pyoderma is often a complicati ng factor. Sebaceous aden itis should be considered in the different ial diagnosis of dogs with seborrhea sicca that is unresponsive to medic al therap y.' A 9-year-old, castrated male Samoyed dog was euthanatized and presented to the Colorado Stat e University Veterinary Teaching Hospital for necropsy. It had a 3-year history of a generalized derm at itis and blepharitis that was unresponsive to conventional medical therapy. Serologic and endocrine function tests were never performed. Th e entire hair coat was thin, and the skin was rough, dry, and scaly. Th ere was partial alopecia and crusting of the eyelids . Th e externa l ear canal s were dirty and scaly. A postmort em examination of the abdomen, thorax, and brain revca led no other gross lesions. Th e tissues that were examined histologically were multiple areas of trun cal skin, external auditory canal, upper and lower eyelids, nictitating membrane, th yroid , adrenal, hypophysis, and both eyes. Sebaceo us gland s were absent in all areas ofskin examined. Dorsal thoracic and dorsal lumbar skin had mild to moderate epidermal and follicular orthoke ratotic hyperkeratosis and moderate infiltrat ion aro und hair follicles by lymph ocytes and plasma cells (Fig. I). Ove r 150 sections from one sample of skin were cut and examined. No sebaceo us glands were found in any section. Focal areas of epidermis were mi ldly acanthotic, varying from two to five cell layers thi ck. Sma ll numbers of lymphocytes and plasma cells were scatt ered in the papillary derm is. Hair follicles were in catagen and anagen phases. Apocrine sweat glands were moderately dilated and were often surro unded by a Iymp hoplasmacytic infiltra te. Changes in ventral thoracic skin were simi lar but less pronoun ced. Hair follicles in an externa l auditory canal were hyperkeratotic. Ceruminous glands and hair follicles were surro unded by lymphocytes and lesser numbers of macroph ages, fibroblasts , and a few neutrophils. As in the skin , sebaceous glands were absent. Epith elium of an upp er eyelid was acanthotic and had parakerat otic hyperkeratosis. A superficial crust consisted of keratin debris and neut roph ils. Hair follicles were plugged with kera tin and often con tained neutrophils. Heavy infiltrations of lymphocytes, plasma cells, and macrophages surrounded hair follicles and the tubul ar gland s of Moll. Tarsal glands , which are modified sebaceous glands, were absent. Th e nictit at ing membrane contained a normal am ount of tubular lacrimal gland s with sma ll interstitial accumulations of plasma cells. Th ere were dense accumulatio ns of plasma cells in the subconjunctiva. The zona fasciculata and zona reticularis of an ad renal gland were j udged subjective ly to be thickened in relation to the zona glomeru losa and the medu lla. Examination of thyroid gland revealed no microscop ic abnormalities. Th e eyes had no microscopic lesions. In the adenohypophysis, multiple, large foci contained a Iymph oplasmacytic infiltrate and scattere d cells that were either chro mophobic pitu itary cells, which they closely resembled, or macroph ages. Th ese cells had vesicular , sometim es indented nuclei, and indi stin ct cytoplasm. Acidophilic and basophilic cells were greatly decreased or absent in the inflam ed areas (Fig. 2). Th ere was a pale, eosinophilic, loose, fibrillar matrix in affected foci. A Masson 's trichrome-stained sectio n failed to reveal an increase d amo unt ofcollagen. The neurohypoph ysis was not affected. Sebaceo us glands are normally present in all regions of haired skin.' Th e history, signalment, distribution of skin lesions , and absence of sebaceous gland s in thi s case are compatible with chronic or end-s tage sebaceous adenitis of dogs.'> In contrast to those cases of sebaceous adeniti s previously described in the literatu re, the dermatitis in thi s dog was not granulomato us. It is possible that the leukocytic infiltrate was modified as the sebaceo us glands disapp eared. It is also possible that thi s case represent s a non-granulomatous variant of the disease syndrome.

Relationship of Urinary Amylase Activity and Proteinuria in the Dog

-I In normal dogs and in some dogs with marked hyperamylasemia there is very little urinary amylase a c t i ~ i t y . ' . ~ . ~ . ~ . ~ ~ This is surprising since the molecular weight of purified canine pancreatic amylase determined using a denaturing technique is about 54,000 daltons) which is below the threshold of the glomerular filter. It has been hypothesized that canine amylase does pass the glomerular filter but is totally reabsorbed from the filtrate or is ina~tivated.~ Recently, it has been shown that these mechanisms probably do not play an important role in amylase clearance and that canine amylase probably does not pass the intact glomerular filter.6 It appears that unique characteristics of the canine glomerular filter and amylase might account for the lack of appearance of urinary amylase activity. It has been reported that native human amylase appears as a polymer.8 Since the polymerization phenomenon may be important in understanding the clearance of canine amylase, an estimate of the molecular weight of canine serum amylase and the influence of this weight on glomerular filtration were determined. Four pools of canine sera, each composed of ten canine sera chosen randomly from routine laboratory accessions at the University of Guelph Veterinary Teaching Hospital, were made. Random urine samples were obtained from 13 normoamylasemic 1-year-old Samoyed dogs in a colony bred to propagate the sex-linked trait for hereditary glomerulopathy.' Urine samples were obtained from 16 normoamylasemic, non-hematuric, non-hemoglobinuric dogs with proteinuria. Total amylase activities were determined using a p-nitrophenylmaltohexaoside substrate (Coulter Electronics of Canada, Ltd., Burlington, Ontario, Canada). Urinary protein concentrations were determined by a Ponceau S (Aldrich Chemical Co., Milwaukee, WI) dye binding method and purified human albumin standards (Dade Diagnostics, Inc., Aguada, Puerto R i ~ o ) . ~ Urinary specific gravities were determined refractometrically. The four pools of canine sera were each diluted 300 times in a buffer containing 0.086 M NaC1, 7 mM KCl, 2 mM MgCl,, 7 mM CaCI,, and 0.02 M tris(hydroxymethy1)-aminomethane-HC1 (pH 7.2). Aliquots of diluted pooled sera were concentrated to the original volume of serum using 100 and 300 kilodalton molecular weight cut-off ultrafilters (Amicon Canada Ltd., Oakville, Ontario, Canada). Prior to use, 10 ml of a 0.15 M NaCl solution containing l.Oo/o bovine serum albumin was passed through each ultrafilter to prevent non-specific adherence. The ultrafiltration was done at 4 C and 10 Ib/sq. in. About 20% of albumin is retained by both sizes of ultrafilters (Amicon Canada Ltd., Oakville, Ontario, Canada). Amylase activities in the retentates were determined and results expressed as the percent amylase activity retained by each filter. The relations between urinary protein concentration, specific gravity, and amylase activity were determined by linear --

Quantitation of anionic sites in glomerular capillar basement membranes of Samoyed dogs with hereditary glomerulopathy

Samoyed hereditary glomerulopathy (SHG) is an X-linked dominant disease characterized by proteinuria and renal failure in affected male dogs. Electron microscopic examination of glomerular capillary basement membranes (GCBM) shows widespread multilaminar splitting of the lamina densa, identical to that in Alport's syndrome. Anionic sites in GCBM of three affected males and five unaffected dogs were labeled using polyethyleneimine to determine whether proteinuria was associated with an alteration in their number. No significant differences were noted in the number of anionic sites in the lamina rara externa, whereas small but statistically significant increases were seen in the number of sites in the lamina rara interna of affected males. In the lamina densa, affected males showed a striking increase in anionic sites, particularly in regions of GCBM which were split. Thus, although proteinuria in some glomerular diseases has been attributed to a reduction in anionic sites in GCBM, this was not so in SHG.

Tremors in Samoyed pups with oligodendrocyte deficiencies and hypomyelination.

Over a 3-year period a breeder of Samoyed dogs observed six litters in which one or more pups at 3 weeks of age showed generalized tremors and an inability to stand. One affected pup, a 5-week-old male, was referred for clinical and pathological evaluation. Gross and microscopic studies including immunocytochemical demonstration of myelin basic protein, revealed a lack of myelin throughout the central nervous system. Ultrastructural studies revealed that a total absence of normal myelin was associated with oligodendroglial deficiencies. Oligodendrocytes were immature in appearance, greatly reduced in number, and incapable of forming compact myelin. Astrocytosis and an increase in the third type of neuroglial cells were observed. The changes differed from those reported in other canine forms of hypomyelinogenesis and were compared with hypomyelinating diseases in other species. The findings suggested that this hypomyelination was the result of retarded gliogenesis.

Canine total hip prosthesis: a case report.

This communication describes the use of a total hip prosthesis to successfully alleviate the symptoms of severe coxofemoral osteoarthrosis in a seven-year-old Samoyed dog. Prior to implantation of the prosthesis, the dog had been treated with analgesic and anti-inflammatory drugs and a bilateral pectineal myectomy had been performed. These measures had achieved only limited control of the symptoms. After total hip replacement there was a rapid improvement in the dog's demeanour and use of the leg which had been operated on. This improvement was maintained during the twelve-month follow-up period.

Intraosseous epidermoid cysts in two dogs.

Epidermoid cyst was seen in the tenth thoracic vertebral body of a 4-year-old female Samoyed dog and in the terminal phalanx of the fifth digit of the left forepaw of a 5-year-old spayed mongrel dog. The cysts contained caseous, gray-white material and were lined with layers of squamous, granular or basal cells filled with keratin. Cholesterol clefts were embedded in the vertebral and phalangeal bones.