Spitz Dogs Research Articles

Comparison between melatonin versus melatonin and photobiomodulation versus photobiomodulation in the treatment of Alopecia X in German Spitz dogs: Clinical, randomized, double-blind, parallel, non-inferiority protocol.

Canine Alopecia X is a non-inflammatory hair loss disorder of unknown etiology that predominantly affects German Spitz dogs. Treatment modalities include hormone and/or melatonin supplementation and low trauma microneedling. Melatonin influences hair growth and pigmentation in several species and presents a low risk of adverse effects when used in dogs with Alopecia X. Photobiomodulation (PBM) is frequently used in human androgenetic alopecia and alopecia areata; despite this, PBM remains unexplored in canine Alopecia X. To address this knowledge gap, sixty dogs of both sexes will be randomly assigned to three groups: (i) melatonin only group (3 mg/Kg, n = 20); (ii) PBM only group (diode laser, wavelength 660nm, 100mw power, with 3 J/point, 2 sessions/week for 3 months, n = 20); (ii) PBM + melatonin group (n = 20). The objective is to determine the potential of PBM alone or in conjunction with melatonin supplementation in promoting hair regrowth (hair density and diameter) by means of dermatoscopy and planimetry over a period of 90 days.

Surgical repair of incarcerated umbilical hernia in a white German Spitz

BackgroundAn umbilical hernia is common, but its incarcerated form is quite rare in dogs. An incarcerated hernia is characterized by the entrapment of herniated contents within the hernial sac, often accompanied by a constricted or narrower ring. It is usually refractory to the conservative approach, i.e., manual reduction, and surgical treatment is crucial to avert the risk of ischemia that can potentially lead to necrosis and gangrene in the involved tissues.Case presentationA 7-month-old female white German Spitz of 13.22 kg was presented with an ovoid swelling in the umbilicus, including a history of intermittent vomiting, progressive hyporexia, and weakness. Physical examinations led to a presumptive diagnosis of irreducible umbilical hernia after ultrasonography had shown a defect in abdominal wall continuity. Surgical intervention further confirmed an umbilical hernia with the incarceration of an omental flap. Herniorrhaphy was performed after resolving the incarceration and returning the content (i.e., omental flap) to the abdominal cavity. Postoperatively, supportive medications and routine care were provided. The external sutures were removed after two weeks, and periodic follow-ups revealed no complications. Ultrasonography was performed again on the 78th postoperative day, which indicated no breach in the abdominal wall integrity around the umbilicus. To the authors’ knowledge, this is the first documented case of a successfully treated incarcerated umbilical hernia in a white German Spitz.ConclusionsUmbilical hernias in young Spitz dogs can undergo incarceration over time if left untreated during the early stages. Meticulous diagnosis and specific treatment including surgical correction are essential for optimal outcome, avoiding further complications.

Recurrent spontaneous pneumothorax in four surgically treated Japanese Spitz dogs

AbstractFour Japanese Spitz dogs between 5 and 11 months old were presented for acute dyspnoea. Thoracic radiographs and CT identified bilateral pneumothorax and pulmonary cavitary lesions. The median lesion size was 30 mm (range 7‒50 mm). After initial stabilisation, one dog underwent median sternotomy, while three dogs underwent intercostal thoracotomy. Surgical exploration found grossly haemorrhagic pulmonary bullous lesions in all cases. Histopathology revealed blood‐filled cavities with interstitial fibrosis and pneumocyte hyperplasia. Dyspnoea recurred in all dogs postoperatively, with recurrence of lesions confirmed either radiographically or via CT in three of four cases. The median time from surgery to recurrence of pneumothorax was 9 days (range 5‒15 days). The mortality rate was 100%, and the median postoperative survival time was 22 days (range 5‒558 days). This report aims to raise awareness of this group of dogs presenting with spontaneous pneumothorax at a young age and with high recurrence rates despite surgery, contrary to the literature.

Sanitary, hygienic, and welfare aspects of keeping Pomeranian Spitz in a breeding private kennel

The market situation regarding the breeding of decorative dogs of the Pomeranian breed and providing consumers with appropriate services in this field of activity dictate the rules and create the conditions of competition between market participants, which encourages improvement, development, and constant monitoring of it in terms of novelties and needs that provide opportunities for comfortable care and decent maintenance of pupils. The work aimed to analyze the impact of sanitary and hygienic factors and ensuring healthy housing conditions on the functional state of the body and mental health of Pomeranian Spitz dogs in the conditions of the private breeding kennel Fluffy Luxury Pom in the suburbs of Lviv. To fulfill this task, a study of the hygienic parameters of the air environment, compliance with the hygiene of feeding and drinking of the wards, peculiarities of the care of the wool coat, and compliance with the concept of animal welfare – the principle of “Five Freedoms” was carried out. It has been established that the technological solutions for keeping Pomeranian Spitz dogs in the conditions of this kennel are characterized by compliance with hygienic requirements for the air environment at the proper level and meeting sanitary standards. Thus, the air temperature was 17 °C, and its movement speed was 0.15 m/s. In the absence of the smell of ammonia, the illuminance ratio corresponded to 1:2. The animals are fed with industrial complete ration super premium 1st Choice feed, the use of which, according to recommendations, helps dogs strengthen the immune system, slow down the aging process, maintain health and activity. This type of food requires constant free access of dogs to clean water, and the containers are kept clean by changing the filling every day. Regarding the quality characteristics of the water, it was established that it fully meets the standard. Dogs of this breed are characterized by a beautiful, lush coat requiring special care. Evaluating the level of compliance with individual hygienic procedures, it was established that they are carried out at a high level, as evidenced by the appearance of the animals. According to the statements of John Webster, the welfare of animals is defined by advocating the main three conditions - to live a natural life, to be healthy, and to be happy. The dogs in this kennel are provided with a good life; the behavioral reactions of the wards themselves confirm this. During the research, the dogs behaved calmly, naturally, and playfully, which indicates the socialization of dogs; the purpose is to make the pet feel comfortable and calm in various life situations without causing trouble to its owner and his surroundings.

Characteristics of the hairline of Japanese, German and Pomeranian Spitz

This study examines the structure of the fur of three breeds of Spitz dogs: Japanese, Pomeranian, and German. The purpose of the study is to characterize the fur of these dogs in a comparative aspect. For a long period, differences between the standards of these breeds were not approved, and to this day, many experts perceive Spitz varieties as a single breed. The results of this research can be used in practice by specialists in the field of cynology, grooming, and exhibition activities to evaluate the fur coat of representatives of the Pomeranian, German and Japanese Spitz breeds. After collecting samples and processing them, the highest indicators of curliness and comfort factor were observed in Japanese Spitz dogs. This breed had the highest comfort factor (92,4%), with longer guard hairs and undercoat compared to the other studied breeds (guard hairs – 6,22 cm, undercoat – 4,16 cm). German Spitz dogs had the thickest fibers (diameter – 22,7 microns), and the highest number of hairs (4554 hairs). The thinnest fibers were observed in Pomeranian Spitz dogs (diameter – 19 microns). It is worth noting that female Japanese Spitz dogs had more hair than males, while male German Spitz dogs had more hair than females. Also, the mean fiber diameter in male Japanese and Pomeranian Spitz dogs was higher than in females. In terms of average curliness, the hair of female Japanese Spitz dogs was more curly than in males, whereas male Pomeranian Spitz dogs had more curly hair than females.

Preliminary characterization of a novel form of progressive retinal atrophy in the German Spitz dog associated with a frameshift mutation in GUCY2D.

To describe the clinical, preliminary electroretinographic and optical coherence tomography features of a newly identified form of progressive retinal atrophy (PRA) in German Spitzes, and identify the causal gene mutation. Thirty-three client-owned German Spitz dogs were included. All animals underwent a full ophthalmic examination, including vision testing. In addition, fundus photography, ERG, and OCT were performed. A DNA-marker-based association analysis was performed to screen potential candidate genes and the whole genomes of four animals were sequenced. Initial fundus changes were pale papilla and mild vascular attenuation. Oscillatory nystagmus was noted in 14 of 16 clinically affected puppies. Vision was impaired under both scotopic and photopic conditions. Rod-mediated ERGs were unrecordable in all affected dogs tested, reduced cone-mediated responses were present in one animal at 3months of age and unrecordable in the other affected animals tested. Multiple small retinal bullae were observed in three clinically affected animals (two with confirmed genetic diagnosis). OCT showed that despite loss of function, retinal structure was initially well-preserved, although a slight retinal thinning developed in older animals with the ventral retina being more severely affected. Pedigree analysis supported an autosomal recessive inheritance. A mutation was identified in GUCY2D, which segregated with the disease (NM_001003207.1:c.1598_1599insT; p.(Ser534GlufsTer20)). Human subjects with GUCY2D mutations typically show an initial disconnect between loss of function and loss of structure, a feature recapitulated in the affected dogs in this study. We identified early-onset PRA in the German Spitz associated with a frameshift mutation in GUCY2D.

Diagnosis and surgical treatment open ductus arteriosus in corgi and pomeranian dogs

The paper presents the results of a clinical and experimental study of determining the clinical effectiveness of surgical treatment of animals with patent ductus arteriosus using open ligation and endovascular occlusion using the example of dogs of the Corgi and Spitz breeds. A retrospective study, the morphofunctional state of the cardiovascular system was assessed before and after surgery. The total sample consisted of 25 animals. Diagnosis of this defect was carried out by auscultation and using echocardiography [ultrasound]. During auscultation, a systolic-diastolic murmur is heard. On ultrasound, the normalized parameters were compared before and after surgery. Animals with critical pulmonary hypertension were excluded from the study, since this complication is a contraindication for surgical treatment. In the postoperative period, the animals after open correction of the defect recovered longer and needed more prolonged analgesia than animals after endovascular treatment. After open treatment with thoracotomy, the animals were in the intensive care unit for a day, and after transcatheter surgery - 6-12 hours. After that, all animals were discharged for outpatient treatment. After closure of the duct, all dogs with a congenital defect became more active, their general condition improved, shortness of breath during physical exertion disappeared, and the respiratory rate decreased significantly. It was found that corgi are more difficult to tolerate this defect than Spitz dogs. They had a more frequent complication in the form of pulmonary hypertension. One year after the surgical treatment, when performing echocardiography, the indicators of the morphofunctional state of the heart were normalized.

Inbreeding on litter size of German Spitz dogs

The objective of the present study was to assess the association between the inbreeding coefficient (F) of German Spitz dogs (litter, sires, and dams) and number of live newborn dogs for this breed. Records of dams and sires of a breeding system were used to calculate the F of 105 litters and their sires and dams and the number of live newborn dogs. The analysis performed through the GLM procedure showed a negative influence of F of litter and [...]

Partial replacement of soybean meal with red gram and lentil as vegetable proteins in limited ingredients homemade diets for pet dogs

AbstractAs part of the efforts to look for new feed resources, an experiment was conducted to ascertain the effects of replacing part of the soybean meal protein with red gram and lentil on the nutritional profile of dogs as influenced by the frequency of feeding. Fifteen adult Spitz dogs were divided into three equal groups and fed three diets containing soybean meal (SBM) alone or in combination with red gram (RGM) and lentil (LTL) as the protein sources. The entire study duration of 10 weeks was divided into two equal periods wherein the dogs were fed either twice or once daily. Results indicated that the food intake was similar (P > 0.05) among the three groups, irrespective of the frequency of feeding. The digestibility of dry matter, organic matter, and carbohydrates were higher (P < 0.05) in the LTL group when the dogs were fed twice daily. However, the digestibility of nutrients remained similar (P > 0.05) when the dogs were fed once daily except for crude fiber digestibility, which was found higher (P < 0.05) in the LTL group. The fecal quality data indicated a lower (P < 0.05) pH accompanying higher water content in dogs under the RGM group. The blood metabolites measured at three different periods during the study did not vary (P > 0.05) among the dietary groups. It is concluded that both red gram and lentil could effectively replace a part (50%) of the soybean meal protein without any adverse effects on the nutrient utilization and metabolic profile of dogs. Moreover, based on the results, lentil appears to have the edge over red gram as a potential vegetable protein source when used in the diet of dogs.

Studies on Pulsed-wave Doppler Echocardiographic Parameters of Blood Flow through Mitral, Tricuspid and Aortic Valves in Healthy Indian Spitz Dogs

Background: Pulsed-wave Doppler measures blood flow at specific point and provides information on velocity, direction and uniformity of blood flow throughout cardiac cycle. Till date, there is no published data on study of cardiac parameters using pulsed-wave Doppler echocardiography in Indian Spitz dogs.Methods: Twenty-four clinically normal Indian Spitz dogs were subjected to pulsed-wave Doppler echocardiography to determine the reference intervals for Doppler parameters of blood flow through mitral, tricuspid and aortic valves. Mitral peak E and A-wave velocities, E/A ratio, deceleration time, isovolumic relaxation time, E and A-wave velocity time integral, E duration and A duration were 0.69±0.09 m/s, 0.43±0.12 m/s, 1.69±0.45, 111.25±35.94 ms, 48.50±24.77 ms, 0.07±0.01 m and 0.04±0.02 m, 196.88±44.38 ms and 181.25±64.89 ms, respectively. Tricuspid peak E and A-wave velocities, E/A ratio and E and A-wave velocity time integral were 0.57±0.11 m/s, 0.38±0.08 m/s, 1.56±0.32 and 0.07±0.02 m and 0.05±0.01 m, respectively. Aortic peak velocity, velocity time integral and ejection time were 0.87±0.07 m/s, 0.11±0.02 m and 0.25±0.04 s, respectively. Conclusion: The reference values of flow parameters across mitral, tricuspid and aortic valves using pulsed-wave Doppler echocardiography were determined. Mitral, tricuspid and aortic valve flow variables were unaffected by gender whereas isovolumic relaxation correlated positively with body weight.

Alopecia X em cães: revisão

Alopecia in dogs is a frequent finding at veterinary dermatological consultations, may be caused by various skin diseases and even systemic. Alopecia X is a dermatopathy that occurs most often in Nordic breeds, especially in German Spitz dogs, about which there is not much scientific knowledge today. Its pathogenesis has not been well understood and is currently believed to be caused by an inherited component associated with changes in sensitivity to hair follicle hormone receptors. The most used treatment is the castration of these animals, associating the administration of some drugs in certain cases and the diagnosis is made by observing the patient's response to the treatment instituted. Being a disease about which there is not much published literature, this article aims to gather important information about this dermatopathy.

Echocardiographic study of healthy Indian Spitz dogs with normal reference ranges for the breed.

Aim:The present study was aimed to determine the normal reference values of M-mode echocardiographic measurements in healthy Indian Spitz dogs and evaluate the influence of gender and body weight on these measurements.Materials and Methods:M-mode echocardiography was performed in twenty-four clinically healthy conscious Indian Spitz dogs, aged 3-5 years and weighing 7-18 kg. Measurements were made from the right parasternal long axis left ventricular outflow tract view of the heart. The parameters recorded were: Left ventricular internal dimension, interventricular septal thickness and left ventricular posterior wall thickness during diastole and systole, left atrial diameter, aortic root diameter, left ventricular systolic functional parameters, and indices and mitral valve parameters.Results:M-mode echocardiographic measurements in healthy Indian Spitz dogs were standardized. Gender had no influence on echocardiographic measurements except mitral valve excursion amplitude and time interval between onset and end of mitral valve closure, which were significantly (p<0.05) higher in females than males. Left ventricular internal dimension at end-diastole, left ventricular internal dimension at end-systole, left ventricular posterior wall dimension at end-systole, end-diastolic volume, end-systolic volume, stroke volume, cardiac output, left ventricular ejection time, and mitral valve excursion amplitude correlated significantly (p<0.05) with body weight in Indian Spitz dogs.Conclusion:Data obtained in the present study can be used as breed-specific reference values for cardiac disease diagnosis as well as for future studies in Indian Spitz dogs.

Effect of age and body weight on transmitral and transaortic pressure gradient in different age groups of healthy Spitz and Labrador retriever dogs

Thirty four healthy dogs of Spitz and Labrador retriever divided in three age groups were subjected to Spectral Doppler echocardiography. Transmitral and transaortic pressure gradient were estimated through Doppler derived valvular velocity. Mean±S.D values of pressure gradients in all the groups in two breeds were statistically compared and correlated with age and body weight. No significant difference was found between the groups and breed. In linear regression line very weak correlation was noticed between pressure gradient with age and body weight. There was non significant effect of age and body weight over transvalvular pressure gradient.

OCA2 splice site variant in German Spitz dogs with oculocutaneous albinism.

We investigated a German Spitz family where the mating of a black male to a white female had yielded three puppies with an unexpected light brown coat color, lightly pigmented lips and noses, and blue eyes. Combined linkage and homozygosity analysis based on a fully penetrant monogenic autosomal recessive mode of inheritance identified a critical interval of 15 Mb on chromosome 3. We obtained whole genome sequence data from one affected dog, three wolves, and 188 control dogs. Filtering for private variants revealed a single variant with predicted high impact in the critical interval in LOC100855460 (XM_005618224.1:c.377+2T>G LT844587.1:c.-45+2T>G). The variant perfectly co-segregated with the phenotype in the family. We genotyped 181 control dogs with normal pigmentation from diverse breeds including 22 unrelated German Spitz dogs, which were all homozygous wildtype. Comparative sequence analyses revealed that LOC100855460 actually represents the 5’-end of the canine OCA2 gene. The CanFam 3.1 reference genome assembly is incorrect and separates the first two exons from the remaining exons of the OCA2 gene. We amplified a canine OCA2 cDNA fragment by RT-PCR and determined the correct full-length mRNA sequence (LT844587.1). Variants in the OCA2 gene cause oculocutaneous albinism type 2 (OCA2) in humans, pink-eyed dilution in mice, and similar phenotypes in corn snakes, medaka and Mexican cave tetra fish. We therefore conclude that the observed oculocutaneous albinism in German Spitz is most likely caused by the identified variant in the 5’-splice site of the first intron of the canine OCA2 gene.

Muscular dystrophy in the Japanese Spitz: an inversion disrupts the DMD and RPGR genes.

An X-linked muscular dystrophy, with deficiency of full-length dystrophin and expression of a low molecular weight dystrophin-related protein, has been described in Japanese Spitz dogs. The aim of this study was to identify the causative mutation and develop a specific test to identify affected cases and carrier animals. Gene expression studies in skeletal muscle of an affected animal indicated aberrant expression of the Duchenne muscular dystrophy (dystrophin) gene and an anomaly in intron 19 of the gene. Genome-walking experiments revealed an inversion that interrupts two genes on the X chromosome, the Duchenne muscular dystrophy gene and the retinitis pigmentosa GTPase regulator gene. All clinically affected dogs and obligate carriers that were tested had the mutant chromosome, and it is concluded that the inversion is the causative mutation for X-linked muscular dystrophy in the Japanese Spitz breed. A PCR assay that amplifies mutant and wild-type alleles was developed and proved capable of identifying affected and carrier individuals. Unexpectedly, a 7-year-old male animal, which had not previously come to clinical attention, was shown to possess the mutant allele and to have a relatively mild form of the disease. This observation indicates phenotypic heterogeneity in Japanese Spitz muscular dystrophy, a feature described previously in humans and Golden Retrievers. With the availability of a simple, fast and accurate test for Japanese Spitz muscular dystrophy, detection of carrier animals and selected breeding should help eliminate the mutation from the breed.

CEREBRAL GLUCOSE UTILIZATION MEASURED WITH HIGH RESOLUTION POSITRON EMISSION TOMOGRAPHY IN EPILEPTIC FINNISH SPITZ DOGS AND HEALTHY DOGS

In human epileptic patients, changes in cerebral glucose utilization can be detected 2-deoxy-2-[(18) F] fluoro-D-glucose positron emission tomography (FDG-PET). The purpose of this prospective study was to determine whether epileptic dogs might show similar findings. Eleven Finnish Spitz dogs with focal idiopathic epilepsy and six healthy dogs were included. Dogs were examined using electroencephalography (EEG) and FDG-PET, with epileptic dogs being evaluated during the interictal period. Visual and semi-quantitative assessment methods of FDG-PET were compared and contrasted with EEG findings. Three independent observers, unaware of dog clinical status, detected FDG-PET uptake abnormalities in 9/11 epileptic (82%), and 4/8 healthy dogs (50%). Occipital cortex findings were significantly associated with epileptic status (P = 0.013). Epileptic dogs had significantly lower standardized uptake values (SUVs) in numerous cortical regions, the cerebellum, and the hippocampus compared to the control dogs. The lowest SUVs were found in the occipital lobe. White matter normalized and left-right asymmetry index values for all pairs of homologous regions did not differ between groups. Visual evaluation of the EEGs was less sensitive (36%) than FDG-PET. Both diagnostic tests were consensual and specific (100%) for occipital findings, but EEG had a lower sensitivity for detecting lateralized foci than FDG-PET. Findings supported the use of FDG-PET as a diagnostic test for dogs with suspected idiopathic epilepsy. Visual and semiquantitative analyses of FDG-PET scans provided complementary information. Findings also supported the theory that epileptogenesis may occur in multiple brain regions in Finnish Spitz dogs with idiopathic epilepsy.

Phenotype, inheritance characteristics, and risk factors for idiopathic epilepsy in Finnish Spitz dogs

To determine the phenotype, inheritance characteristics, and risk factors for idiopathic epilepsy (IE) in Finnish Spitz dogs (FSDs). Prospective epidemiological study. 2,141 FSDs. From 2003 to 2004, questionnaires (n = 5,960) were sent to all owners of 1-to 10-year-old FSDs in Finland. Phone interviews were performed 1 to 2 years later. Estimated prevalence of IE was 5.36% (111/2,069 of FSDs that were still alive). Males were predisposed to IE. The median age of onset was 3 years (range, 0.6 to 10 years). The median seizure frequency was 2 seizures/y (range, 0.5 to 48 seizures/y), and the median duration of the seizure episode was 11.75 minutes (range, 1.5 to 90 minutes). The majority (85%) of the seizures had a focal onset, and 54% were characterized as generalized secondary. A generalized seizure phase was determined to be a risk factor for development of progressive disease. Factors associated with the occurrence of a generalized phase were the age of onset, duration of the seizure, number of feeding times per day, and whether the dog was used for hunting. The seizures were not progressing in 678% of the dogs and were easily controlled by antiepileptic treatment in 78.9% of the dogs. The heritability estimate of IE in FSDs was 0.22; IE was best explained as a polygenic trait. In the present study conducted in Finland, complex focal seizures were the most common seizure type for FSDs with IE, and a generalized seizure phase was a risk factor for progression of the disease. Results suggested a benign course of epilepsy in FSDs.

Analysis of Serum Ascites Albumin Gradient Test in Ascitic Dogs

The aim of the study was to evaluate Serum Ascites Albumin Gradient (SAAG) in ascitic dogs. Study was conducted at Referral Veterinary Poly Clinic, Indian Veterinary Research Institute, Izatnagar. Sick dogs were brought with clinical signs suggestive of distended abdomen and inappetance. General clinical examination, biochemical, ultrasound examination, abdominocentesis and peritoneal fluid examination were performed. Spitz dogs had more incidences of ascites followed by Labrador Retrievers. Male dogs had more incidence than female dogs and most ascites were noticed in 4-5 years aged dogs. Mean ± SE of serum ascites albumin gradients (SAAG) are 1.793 ± 0.185. SAAG can be used as a screening test in ascetic due to chronic liver disease.

Evaluation of alternative cereal sources in dog diets: effect on nutrient utilisation and hindgut fermentation characteristics

AbstractBACKGROUND: Rice is one of the most commonly used cereal grains in pet foods. However, other cereals such as pearl millet, sorghum and maize have good amino acid profiles and could be used as alternatives to rice in the diet of dogs, thus sparing rice for human consumption. The aim of this study was to evaluate the nutritional worth of these cereals for pet dogs.RESULTS: Eight adult Spitz dogs (age ∼10 months, average body weight 6.14 ± 0.58 kg) were used in a 4 × 4 replicated Latin square design to compare the effects of dietary inclusion of four cereals, namely rice, maize, pearl millet and sorghum, on digestibility and hindgut fermentation characteristics. The digestibility of dry matter (DM) was significantly (P &lt; 0.01) reduced when rice was replaced by the alternative cereals. Additionally, the digestibilities of protein, fat and total dietary fibre decreased (P &lt; 0.01) in dogs fed the pearl millet‐based diet. The DM voided in faeces increased (P &lt; 0.05) when rice was replaced by the alternative cereals. Faecal ammonia concentration was higher (P &lt; 0.05) on the rice‐based diet, while faecal lactate concentration was reduced (P &lt; 0.01) on the pearl millet‐ and sorghum‐based diets.CONCLUSION: The results suggest that maize, pearl millet and sorghum are not as effectively utilised as rice as cereal source in the diet of dogs. Copyright © 2009 Society of Chemical Industry

Calcium Diacylglycerol Guanine Nucleotide Exchange Factor I (CalDAG-GEFI) Gene Mutations in a Thrombopathic Simmental Calf

Simmental thrombopathia is an inherited platelet disorder that closely resembles the platelet disorders described in Basset Hounds and Eskimo Spitz dogs. Recently, two different mutations in the gene encoding calcium diacylglycerol guanine nucleotide exchange factor I (CalDAG-GEFI) were described to be associated with the Basset Hound and Spitz thrombopathia disorders, and a third distinct mutation was identified in CalDAG-GEFI in thrombopathic Landseers of European Continental Type. The gene encoding CalDAG-GEFI was sequenced using DNA obtained from normal cattle and from a thrombopathic calf studied in Canada. The affected calf was found to have a nucleotide change (c.701 T>C), which would result in the substitution of a proline for a leucine within structurally conserved region two (SCR2) of the catalytic domain of the protein. This change is likely responsible for the thrombopathic phenotype observed in Simmental cattle and underscores the critical nature of this signal transduction protein in platelets.