Misplaced Pages

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104-547: This breed has a thick and dense double coat ; the Leonberger is a large, muscular, and elegant dog with balanced body type, medium temperament, and dramatic presence. The head is adorned with a striking black mask . Remaining true to their early roots as a capable family and working dog and search-and-rescue dog (particularly water), the surprisingly agile Leonberger is sound and coordinated, with both strength in bearing and elegance in movement. A sexually dimorphic breed,

208-443: A d/d dilution of black pigment, a grey colouration that is grey from birth, but has a wide range of breed-specific meanings. In Kerry Blue Terriers , Poodles , and Bearded Collies , "blue" refers to colouration that is black at birth and progressively greys out as the dog matures. In Australian Shepherds , Rough Collies , and Shetland Sheepdogs , blue means a blue (black-based) merle . In Australian Silky Terriers , blue means

312-463: A St. Bernard—not a stable and recognized breed—and a product of a popular fad or fashion for large and strong dogs, fomented in part by Essig's prodigious marketing skills (he gave dogs to the rich and famous). The modern look of the Leonberger, with darker coats and black masks, was developed during the latter part of the 20th century by reintroducing other breeds, such as the Newfoundland. This

416-477: A cancer is formed, it usually has genome instability . This instability is likely due to reduced DNA repair or excessive DNA damage. Because of such instability, the cancer continues to evolve and to produce sub clones. For example, a renal cancer, sampled in 9 areas, had 40 ubiquitous mutations, demonstrating tumor heterogeneity (i.e. present in all areas of the cancer), 59 mutations shared by some (but not all areas), and 29 "private" mutations only present in one of

520-409: A dog called red is usually a clear sable (with little to no eumelanin tipping on hairs) or a ruddy recessive yellow. In some breeds, "red" refers to what would usually be called brown, chocolate, or liver. A "red merle" is always a liver-based merle. In Australian Cattle Dogs , "red" stands for a densely ticked liver-based colouration with an overall red-grey appearance. Gold refers specifically to

624-717: A dog's coat, however in general, a double coat, like that of the Newfoundland and most livestock guardian dogs , is referred to as a fur coat , while a single coat, like that of the Poodle , is referred to as a hair coat . Domestic dogs exhibit diverse coat colours and patterns . In many mammals, different colour patterns are the result of the regulation of the Agouti gene , which can cause hair follicles to switch from making black or brown pigments to yellow or nearly white pigments. The most common coat pattern found in modern wolves

728-454: A life expectancy of 10 years for the breed compared to an average of 12.7 for purebreeds and 12 for crossbreeds . A 2015 French study found a life expectancy of 8.75 years. A 2005 Swedish study of insurance data found 74% of Leonbergers died by the age of 10, higher than the overall rate of 35% of dogs dying by the age of 10. An analysis of Leonberger pedigree found an inbreeding coefficient of 0.29 with just 22 founding dogs. From 1989 to 2004

832-535: A long, straight, and non-wired coat in the Pomeranian . Additionally, breeds show variation in patterns of growth - that is to say, parts of the dog's body where the coat may be longer or shorter. The same gene that controls wiriness of hair also causes furnishings to be present (e.g. beard, moustache, eyebrows) - compare the bearded collie , furnishings present, to the border collie , which lacks furnishings. Some breeds show feathering: fringes of longer hair on

936-561: A lymphoid cell proliferation as neoplastic. The word tumor or tumour comes from the Latin word for swelling , which is one of the cardinal signs of inflammation. The word originally referred to any form of swelling , neoplastic or not. In modern English, tumor (non-US spelling: tumour) is used as a synonym for a neoplasm (a solid or fluid-filled cystic lesion that may or may not be formed by an abnormal growth of neoplastic cells) that appears enlarged in size. Some neoplasms do not form

1040-808: A member of the Working Group on January 1, 2010, alongside the Icelandic Sheepdog and the Cane Corso . It was the 167th breed to be recognized by the AKC. The Lifetime TV movie Grumpy Cat's Worst Christmas Ever features a Leonberger that becomes a victim of a dognapping , co-starring with the famous Grumpy Cat . In the story Murphy and the Great Surf Rescue in Gill Lewis' Puppy Academy series of children's books, Murphy

1144-491: A minority of sporadic cancers have a deficiency in DNA repair due to mutation in a DNA repair gene. However, a majority of sporadic cancers have deficiency in DNA repair due to epigenetic alterations that reduce or silence DNA repair gene expression. For example, of 113 sequential colorectal cancers, only four had a missense mutation in the DNA repair gene MGMT , while the majority had reduced MGMT expression due to methylation of

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1248-410: A mutator phenotype. The protein-coding DNA within the nucleus is about 1.5% of the total genomic DNA. Within this protein-coding DNA (called the exome ), an average cancer of the breast or colon can have about 60 to 70 protein altering mutations, of which about 3 or 4 may be "driver" mutations, and the remaining ones may be "passenger" mutations. However, the average number of DNA sequence mutations in

1352-433: A patch of abnormal tissue may arise. The figure in this section includes a photo of a freshly resected and lengthwise-opened segment of the colon showing a colon cancer and four polyps. Below the photo, there is a schematic diagram of how a large patch of mutant or epigenetically altered cells may have formed, shown by the large area in yellow in the diagram. Within this first large patch in the diagram (a large clone of cells),

1456-430: A proliferative advantage, generating a field defect. Although the mutations/epimutations in DNA repair genes do not, themselves, confer a selective advantage, they may be carried along as passengers in cells when the cells acquire additional mutations/epimutations that do provide a proliferative advantage. The term neoplasm is a synonym of tumor . Neoplasia denotes the process of the formation of neoplasms/tumors, and

1560-427: A rich reddish-yellow and its variants, whereas yellow can refer to any shade of yellow and tan. Terms used include yellow-gold, lion-colored, fawn, apricot, wheaten, tawny, straw, yellow-red, mustard, sandy, honey, blond, and lemon. Dogs called golden or yellow tend to be recessive yellow, but can also be sable. Cream refers to a pale yellowish or tannish colour which can be almost white. Fawn typically refers to

1664-478: A saddle-type black and tan pattern, where the black parts of the coat progressively fade to a steel grey as the dog matures and in Australian Cattle Dogs , blue stands for a densely ticked black-based colouration with an overall blue-grey appearance. Grey simply means a grey colouration of any shade. It can be used as an alternative synonym of blue, but tends to mean some other type of grey than

1768-422: A second such mutation or epigenetic alteration may occur so that a given stem cell acquires an advantage compared to other stem cells within the patch, and this altered stem cell may expand clonally forming a secondary patch, or sub-clone, within the original patch. This is indicated in the diagram by four smaller patches of different colors within the large yellow original area. Within these new patches (sub-clones),

1872-484: A silver is a quicker to clear, much lighter grey that can range from a pale platinum to a steel grey. Both are black at birth with minimal markings to indicate future change. Similarly, café au lait is a slower and darker and silver beige a quicker and lighter progressively greying brown, i.e. liver. White : Such a light cream that it is seen and described as pure white, making them distinct from albino dogs. A white dog, as opposed to an albino one, has dark pigment around

1976-410: A solid skeleton formed by sticky cells and an organic liquid filling the spaces in which cells can grow. Under this type of model, mechanical stresses and strains can be dealt with and their influence on the growth of the tumor and the surrounding tissue and vasculature elucidated. Recent findings from experiments that use this model show that active growth of the tumor is restricted to the outer edges of

2080-665: A tumor. Examples are arteriovenous fistulae or aneurysms (with or without thrombosis), biliary fistulae or aneurysms, sclerosing cholangitis, cysticercosis or hydatid cysts, intestinal duplications, and pulmonary inclusions as seen with cystic fibrosis. It can be dangerous to biopsy a number of types of tumor in which the leakage of their contents would potentially be catastrophic. When such types of tumors are encountered, diagnostic modalities such as ultrasound, CT scans, MRI, angiograms, and nuclear medicine scans are employed prior to (or during) biopsy or surgical exploration/excision in an attempt to avoid such severe complications. DNA damage

2184-402: A tumor; these include leukemia and most forms of carcinoma in situ . Tumor is also not synonymous with cancer . While cancer is by definition malignant, a tumor can be benign , precancerous , or malignant . The terms mass and nodule are often used synonymously with tumor . Generally speaking, however, the term tumor is used generically, without reference to the physical size of

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2288-434: A variety of circumstances, including the introduction of other dogs. Proper control and early socialization and training are essential, as this is a giant breed. "This is an outstanding water rescue dog . Only a short period of training it needed to augment its natural instincts." Its double-layered waterproof coat traps air and aids in buoyancy . Webs between the toes make for a powerful swimmer. A 2024 UK study found

2392-400: A yellow, tan, light brown, or cream dog that has a dark melanistic mask. With Weimaraners , fawn refers to their typical brownish grey colouration that with other breeds is usually called lilac. Black is a pure black that can get grizzled as the dog ages, or have a tendency to gain a brownish cast when exposed to the elements. Blue is a cool-toned, metallic grey. It typically means

2496-556: Is agouti , in which the upperside of the body has banded hairs and the underside exhibits lighter shading. The colour yellow is dominant to the colour black and is found in dogs across much of the world and the dingo in Australia. In 2021, a study of whole genome sequences taken from dogs and wolves focused on the genetic relationships between them based on coat colour. The study found that most dog colour haplotypes were similar to most wolf haplotypes, however dominant yellow in dogs

2600-479: Is a Leonberger puppy whose special skill is swimming. The graphic music video " Deutschland " by German rock band Rammstein portrays the symbolic figure of Germania giving birth to Leonberger puppies. Leonberger dogs are represented in many stamps from around the world. In Norwegian author Karin Fossum 's Inspector Sejer series, the title character has a Leonberger named Kollberg. Three Leonberger dogs (one

2704-464: Is a pro-inflammatory compound. It is critical to note once again that canines are unable to interconvert between omega fatty acids and over supplying linoleic acid promotes excessive inflammation in the body, which can potentially reverse the coat benefits seen by supplying omega fatty acids in the diet. In contrast, linoleic acid is also required for epidermal lipid function and water retention, which benefits coat shine. Having linoleic acid present in

2808-536: Is an anti-inflammatory compound. Linolenic acid is found in the oil from flaxseeds, soybean and canola. Some better known examples of linolenic acid are the metabolic derivatives eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA). EPA inhibits the enzyme delta-5-desaturase, which prevents the synthesis of arachidonic acid which is an inflammatory omega 6. DHA acts even earlier in omega 6 metabolism, by inhibiting delta-6-desaturase . The anti-inflammatory properties of omega 3s stem from their ability to inhibit

2912-535: Is an outward indicator of internal well-being. For this reason, coat health is an important aspect of pet care to many dog owners. Dog coats can be impacted by nutritional components from the diet. Below is a table that summarizes the effects of several nutrients (minerals, vitamins) on the domestic canine coat, based on current evidence: Zinc contributes to hair growth and can prevent hair from becoming dry and brittle. In addition to, zinc when supplemented in combination with linoleic acids has been found to improve

3016-422: Is composed of two layers: a top coat of stiff guard hairs that help repel water and shield from dirt, and an undercoat of soft down hairs , to serve as insulation. Dogs with both under coat and top coat are said to have a double coat . Dogs with a single coat have a coat composed solely of guard hairs, with little or no downy undercoat. The terms fur and hair are often used interchangeably when describing

3120-436: Is considered to be the primary underlying cause of malignant neoplasms known as cancers. Its central role in progression to cancer is illustrated in the figure in this section, in the box near the top. (The central features of DNA damage, epigenetic alterations and deficient DNA repair in progression to cancer are shown in red.) DNA damage is very common. Naturally occurring DNA damages (mostly due to cellular metabolism and

3224-416: Is crucial to achieve optimal benefits. Proper omega 6:3 ratios have been shown to diminish allergy triggered immune responses, thus improving overall coat condition. The National Research Council (NRC) recommends a 2.6:1 to 26:1 omega 6:3 ratio for adult dog maintenance diets. The proper ratio of these fatty acids is crucial because each has an opposing role in inflammation within the body and both compete for

Leonberger - Misplaced Pages Continue

3328-734: Is durable, relatively straight, lies flat, and fits close. A mature, masculine Leonberger exhibits a pronounced mane. Similarly, his tail is very well furnished from the tip to the base where it blends harmoniously with the breech's furnishings. Climate permitting, his undercoat is soft and dense. Apart from a neatening of the feet, the Leonberger is presented untrimmed. These dogs are ill-suited to hot climates. Several coat colours are acceptable, including all combinations of lion-yellow, red, red-brown, and sand. Nose leather, foot pads, and lips should always be black. Faulty colours include brown with brown nose leather, black and tan, black, white, or silver, and eyes without any brown. A small patch of white on

3432-704: Is evidence that more than 80% of the somatic mutations found in mutator phenotype human colorectal tumors occur before the onset of terminal clonal expansion. Similarly, Vogelstein et al. point out that more than half of somatic mutations identified in tumors occurred in a pre-neoplastic phase (in a field defect), during growth of apparently normal cells. Likewise, epigenetic alterations present in tumors may have occurred in pre-neoplastic field defects. An expanded view of field effect has been termed "etiologic field effect", which encompasses not only molecular and pathologic changes in pre-neoplastic cells but also influences of exogenous environmental factors and molecular changes in

3536-446: Is from Ancient Greek νέος- neo 'new' and πλάσμα plasma 'formation, creation'. A neoplasm can be benign , potentially malignant, or malignant ( cancer ). Neoplastic tumors are often heterogeneous and contain more than one type of cell, but their initiation and continued growth are usually dependent on a single population of neoplastic cells. These cells are presumed to be monoclonal – that is, they are derived from

3640-403: Is often used as a synonym for a cystic (liquid-filled) growth or solid neoplasm (cancerous or non-cancerous), with other forms of swelling often referred to as "swellings" . Related terms occur commonly in the medical literature, where the nouns tumefaction and tumescence (derived from the adjective tumescent ) are current medical terms for non-neoplastic swelling. This type of swelling

3744-700: The ARHGEF10 gene and in the GJA9 gene, and an autosomal recessive variant in the CNTNAP1 gene. Another disease described in the breed is the juvenile-onset leukoencephalomyelopathy caused by an autosomal recessive variant in the NAPEPLD gene. The Leonberger has a predisposition to hemangiosarcoma and osteosarcoma . A study in the UK of more than 900,000 dogs looking at the annual prevalence of osteosarcoma found

3848-514: The Saint Bernard ). Later, according to Essig, a Pyrenean Mountain Dog was added, resulting in very large dogs with the long, white coats that were the fashion for the time, and a pleasant temperament. The first dogs registered as Leonbergers were born in 1846 and had many of the prized qualities of the breeds from which they were derived. The legend is that the dogs were bred to be an homage of

3952-449: The d/d dilution of black. Synonyms include silver, pepper, grizzle, slate, blue-black grey, black and silver, steel. Greys of a dusty or brownish cast are often lilac, a d/d dilution of liver, and this colouration does not have much of a commonly recognised name. Across various breeds, it is called lavender, silver-fawn, isabella, fawn, café au lait or silver beige. In Poodles, a blue is a very slowly fading, very dark steel grey, whereas

4056-445: The hair that covers its body. Dogs demonstrate a wide range of coat colors, patterns, textures, and lengths. As with other mammals, a dog's fur has many uses, including thermoregulation and protection from cuts or scratches; furthermore, a dog's coat plays an important role in the showing of purebred dogs . Breed standards often include a detailed description of the nature and attributes of that breed's ideal coat. A dog's coat

4160-457: The lion in the town crest and coat-of-arms animal of Leonberg, the lion. The Leonberger dog became popular with several European royal households, including Napoleon II , Empress Elisabeth of Austria , the Prince of Wales , Otto Von Bismarck , Emperor Napoleon III , and Umberto I of Italy . Essig's claim of breeding the dog as described is disputed. Records from as early as 1585 may indicate

4264-585: The vizslas , to the wiry coat of a Scottish Terrier and the corded coat of the Puli and the Komondor . Generally, coats vary along three categories: length (long vs. short), texture (curly vs. straight), and coarseness (wire-haired vs. non-wire). These three categories all interact with one another; thus, one can see a short, curly, and wired coat in the Wirehaired Pointing Griffon , and

Leonberger - Misplaced Pages Continue

4368-472: The 20th century, Leonbergers were imported by the government of Canada for use as water rescue/ lifesaving dogs. The breed continues in that role today, along with the Newfoundland , Labrador Retriever , and Golden Retriever ; they are used at the Italian School of Canine Lifeguard . They have been used successfully as flock guard dogs. The Leonberger received American Kennel Club recognition as

4472-405: The Leonberger possesses either a strongly masculine or elegantly feminine form, making gender immediately discernible. The breed has webbed paws . Height at withers : Weight: Capable of demanding work, the Leonberger is a dog of ample substance. Its frame is supported with well-muscled, medium to heavy bone in direct proportion to its size. A roomy chest is sufficiently broad and deep for

4576-555: The Leonberger to have the second highest rate, at 1.48%, compared to 0.037% overall. In the 1830s, Heinrich Essig, a dog breeder and seller and mayor of the town of Leonberg near Stuttgart in Baden-Württemberg , Germany, claimed to have created the Leonberger by crossing a female Landseer Newfoundland with a " barry " male from the Great St Bernard Hospice and Monastery (which would later create

4680-531: The MGMT promoter region (an epigenetic alteration). Five reports present evidence that between 40% and 90% of colorectal cancers have reduced MGMT expression due to methylation of the MGMT promoter region. Similarly, out of 119 cases of mismatch repair-deficient colorectal cancers that lacked DNA repair gene PMS2 expression, PMS2 was deficient in 6 due to mutations in the PMS2 gene, while in 103 cases PMS2 expression

4784-437: The UK identified cataracts in 90 out of 211 Leonbergers surveyed. A study found a high prevalence of neurological conditions in the Leonberger, which is likely due in large part to limited genetic diversity. Multiple hereditary forms of polyneuropathy that are similar to the human disease Charcot-Marie-Tooth have been described in the Leonberger. A study concluded the most likely causes are autosomal dominant variants in

4888-438: The allergenicity more than breed or gender." The nature and quality of a purebred dog 's coat is important to the dog fancy in the judging of the dog at conformation shows . The exact requirements are detailed in each breed's breed standard and do not generalise in any way, and the terminology may be very different even when referring to similar features. See individual breed articles for specific information. A dog's coat

4992-411: The areas of the cancer. Various other terms have been used to describe this phenomenon , including "field effect", "field cancerization", and "field carcinogenesis ". The term "field cancerization" was first used in 1953 to describe an area or "field" of epithelium that has been preconditioned by (at that time) largely unknown processes so as to predispose it towards development of cancer. Since then,

5096-568: The body begins to produce the usual hair growth and color it would before the deficiency took place. Polyunsaturated fatty acids found in the diet play a critical role in the maintenance of a healthy coat in dogs, and have even been shown to improve coat condition when supplemented in the diet. Furthermore, diets lacking essential fatty acids in their diet will manifest as unkept, matted coat. Omega fatty acids 3 and 6 are highly unsaturated fatty acids, making them especially metabolically active. The proper combination of these omega fatty acids

5200-531: The body is present in breeds such as the Chinese Crested or the Xoloitzcuintli . Shedding of hair can occur continuously, but in many breeds is strongly influenced by hormones. Seasonal shedders shed most in spring and fall, following an increase or decrease in day length, and least in summer and winter, in response to constant day length. Cold temperatures stimulate hair growth, so that

5304-402: The breed's saviors, bringing them back from almost extinction. Leonbergers today can have their ancestry traced to the eight dogs that survived World War II. Traditionally, Leonbergers were kept as farm dogs and were much praised for their abilities in watchdog and draft work. They were frequently seen pulling carts around the villages of Bavaria and surrounding districts. Around the beginning of

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5408-642: The canine diet is an important aspect of coat health. The fat soluble vitamins (A, D, E and K) require lipids present in the diet for absorption, transport and deposition in canine adipose tissue. The specific role of vitamins A and E for coat health are explored elsewhere in this article, as they pertain to immune function. Another pet food regulating body, the Association of American Feed Control Officials (AAFCO), recommends that Vitamin E supplementation increase as polyunsaturated fatty acids are added to diet in order to counteract lipid oxidation and maintain

5512-632: The cell to divide and expand uncontrollably. A neoplasm can be caused by an abnormal proliferation of tissues, which can be caused by genetic mutations . Not all types of neoplasms cause a tumorous overgrowth of tissue (such as leukemia or carcinoma in situ ), however similarities between neoplasmic growths and regenerative processes, e.g., dedifferentiation and rapid cell proliferation, have been pointed out. Tumor growth has been studied using mathematics and continuum mechanics . Vascular tumors such as hemangiomas and lymphangiomas (formed from blood or lymph vessels) are thus looked at as being amalgams of

5616-525: The chest or toes is permitted. First and foremost a family dog, the Leonberger's temperament is one of its most important and distinguishing characteristics. Well socialized and trained, the Leonberger is self-assured, insensitive to noise, submissive to family members, friendly toward children, well composed with passersby, and self-disciplined when obliging its family or property with protection. Robust, loyal, intelligent, playful, and kindly, they can thus be taken anywhere without difficulty and adjust easily to

5720-412: The coat of canines by reducing water loss in the trans-epidermal layer of the skin. Dogs can obtain zinc in their diet, through the addition of various ingredients, including; red meats, whole grains, poultry by-product meals, and fish meals. Copper is a trace mineral that is required in the diet of canines at 7.3 mg/kg. Copper is involved in multiple enzymatic pathways. In dogs, a lack of copper in

5824-406: The colons of humans eating a high fat diet, also cause DNA damage and contribute to colon cancer . Katsurano et al. indicated that macrophages and neutrophils in an inflamed colonic epithelium are the source of reactive oxygen species causing the DNA damages that initiate colonic tumorigenesis (creation of tumors in the colon). Some sources of DNA damage are indicated in the boxes at the top of

5928-715: The colour relationships between modern dogs and wolves, white wolves from North America, yellow dogs, and yellowish wolves from Tibet. The study concludes that during the Late Pleistocene, natural selection laid the genetic foundation for modern coat colour diversity in dogs and wolves. During evolution of the dog from their wolf ancestors, coat colors in dogs were probably the inadvertent outcome of some other selective process, and were not likely initially selected for intentionally by humans. Research has found that tameness brings associated physical changes, including coat colouring and patterning. Domestic dogs often display

6032-438: The diet has demonstrated a positive effect on skin, and thus by extension, coat. Neoplasia A neoplasm ( / ˈ n iː oʊ p l æ z əm , ˈ n iː ə -/ ) is a type of abnormal and excessive growth of tissue . The process that occurs to form or produce a neoplasm is called neoplasia . The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if

6136-433: The diet, leading to a copper deficiency, results in incomplete keratinization. This leads to a dry coat, hypo-pigmentation, and discoloration of the coat. Selenium is another one of the many trace minerals essential for a dog's diet. Selenium is typically required in lower levels in comparison to other minerals. It is involved in the prevention of oxidative damage as well as the production of anti-oxidants. Selenium aids in

6240-510: The ears, belly, tail, and back of the legs (e.g., Saluki and any of the setters ). Dogs also vary in the thickness of the undercoat. Some dogs have only a single (rather than a double) coat, or a very reduced undercoat (e.g. the Vizsla ), which results in a thinner coat. Certain breeds, especially spitz-type breeds , tend to have a thicker undercoat, which helps retain heat in cold and wet weather. Furthermore, complete hairlessness on parts of

6344-405: The entire area of the field defect. Deficiencies in DNA repair cause increased mutation rates. A deficiency in DNA repair, itself, can allow DNA damages to accumulate, and error-prone translesion synthesis past some of those damages may give rise to mutations. In addition, faulty repair of these accumulated DNA damages may give rise to epimutations. These new mutations or epimutations may provide

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6448-457: The entire genome (including non-protein-coding regions ) within a breast cancer tissue sample is about 20,000. In an average melanoma tissue sample (where melanomas have a higher exome mutation frequency ) the total number of DNA sequence mutations is about 80,000. This compares to the very low mutation frequency of about 70 new mutations in the entire genome between generations (parent to child) in humans. The high frequencies of mutations in

6552-579: The existence of Leonberger-type dogs; documents dating from 1601 held by the Metternich family describe similar dogs used to deter the theft of livestock. Either way, no doubt exists that Essig named and registered the breed first. A black-and-white engraving of the Leonberger was included in The Illustrated Book of the Dog by Vero Shaw (at p. 488) in 1881. At the time, Essig's Leonbergers were denounced as an indifferent knockoff of

6656-434: The eye rims and nose, often coupled with dark-colored eyes. There is often some coat identifiable as cream between the dog's shoulder blades. Extreme piebald dogs can also appear all white, but are caused by a separate factor. The same pattern may be referred to differently in different breeds. Basset Hound Dogs demonstrate an enormous diversity in coat length and texture, from the very short and smooth coat seen in

6760-400: The eyes are set into the skull upon a slight oblique; the eyes are medium-sized, almond-shaped, and colored dark brown. The ears are fleshy, moderately sized, and pendant-shaped, with sufficient substance to hang close to the skull and drop the tip of the ears level with the inside corners of the mouth. The Leonberger's ears rise from halfway between the eye and the top of the skull to level with

6864-700: The field defects surrounding those cancers. The Table, below, gives examples for which the DNA repair deficiency in a cancer was shown to be caused by an epigenetic alteration, and the somewhat lower frequencies with which the same epigenetically caused DNA repair deficiency was found in the surrounding field defect. Some of the small polyps in the field defect shown in the photo of the opened colon segment may be relatively benign neoplasms. Of polyps less than 10mm in size, found during colonoscopy and followed with repeat colonoscopies for 3 years, 25% were unchanged in size, 35% regressed or shrank in size while 40% grew in size. Cancers are known to exhibit genome instability or

6968-578: The figure in this section. Individuals with a germline mutation causing deficiency in any of 34 DNA repair genes (see article DNA repair-deficiency disorder ) are at increased risk of cancer . Some germline mutations in DNA repair genes cause up to 100% lifetime chance of cancer (e.g., p53 mutations). These germline mutations are indicated in a box at the left of the figure with an arrow indicating their contribution to DNA repair deficiency. About 70% of malignant (cancerous) neoplasms have no hereditary component and are called "sporadic cancers". Only

7072-510: The figure) cause increased DNA damages (level 5 in the figure) which result in increased somatic mutations and epigenetic alterations (level 6 in the figure). Field defects, normal-appearing tissue with multiple alterations (and discussed in the section below), are common precursors to development of the disordered and improperly proliferating clone of tissue in a malignant neoplasm. Such field defects (second level from bottom of figure) may have multiple mutations and epigenetic alterations. Once

7176-414: The flesh. The Roman medical encyclopedist Celsus ( c. 30 BC–38 AD) described the four cardinal signs of acute inflammation as tumor , dolor , calor , and rubor (swelling, pain, increased heat, and redness). (His treatise, De Medicina , was the first medical book printed in 1478 following the invention of the movable-type printing press.) In contemporary English, the word tumor

7280-556: The fur. Although breeds such as poodles , Bedlington terriers , bichons , yorkies , and wire-haired terriers are commonly represented as being hypoallergenic due to reduced shedding, the reaction that an individual person has to an individual dog may vary greatly. In a report, describing dog allergen extracts of dog hair, belonging to patients' dogs or from dogs of the same breed, with low molecular mass that are absent in extracts of commercial allergen test kits, it has been found that "[f]actors related to individual dogs seem to influence

7384-407: The hair development, most stages of growth are completed, but it was found that in the last stage, where biotin levels were insufficient, there was an incorrect keratinization of the root of the hair, causing the hair to fall out of the body. The supplementation of biotin cannot reverse affects caused by deficiency, but as soon as supplementation is given and biotin levels are restored to adequacy,

7488-399: The hair follicle growth cycle: "[D]ogs are a relevant source of allergens, but diagnosing dog-related allergies may present difficulties .." Some dog breeds have been promoted as hypoallergenic (which means less allergic , not free of allergens) because they shed very little. However, no canine is known to be completely nonallergenic. Often the problem is with the dog's saliva or dander, not

7592-750: The heaviest shedding is in spring on dogs living in cold climates. Artificial lighting can alter the seasonal shedding pattern of dogs who live indoors. Other hormonal influences include dietary factors, reproductive hormones in intact dogs, and various medical conditions and disorders. Shedding that is done in a short period of time is known as "blowing the coat" or "blowing coat". Among the other coat types, dogs with fine silky coats (e.g., spaniels) are generally moderate shedders, those with an intermediate coat texture (e.g., mountain dogs) are generally heavy shedders, and those with thick stand-offish coats (e.g., spitzes) are generally very heavy shedders. "Non-shedding" dogs have greatly-reduced shedding due to alterations to

7696-438: The importance of biotin in coat pigmentation. There different stages of hair development, as shown in clinical studies using mice. Each stage of hair development has a different sensitivity to biotin present in the body. For example, the shaft development is not greatly affected by biotin access. During the last stage, the amount of biotin available for use by the body will alter the success of that development greatly. Throughout

7800-499: The inflammatory action of omega 6 fatty acids. A functional minimum has not been set forth by AAFCO, as one has yet to be determined. A reduction in inflammation of somatic tissues, skin especially, supports coat health. Omega 6 fatty acid, also known as linoleic acid , is found in poultry fat and the oil from safflower, sunflower, corn and flaxseed. Arachidonic acid is a well known metabolic derivative of linoleic acid, found only in animal sources. As mentioned above, arachidonic acid

7904-519: The initial clone, and sub-sub-clones inside those, then colon cancers generally should be associated with, and be preceded by, fields of increasing abnormality reflecting the succession of premalignant events. The most extensive region of abnormality (the outermost yellow irregular area in the diagram) would reflect the earliest event in formation of a malignant neoplasm. In experimental evaluation of specific DNA repair deficiencies in cancers, many specific DNA repair deficiencies were also shown to occur in

8008-430: The lesion. More specifically, the term mass is often used when the lesion has a maximal diameter of at least 20 millimeters (mm) in the greatest direction, while the term nodule is usually used when the size of the lesion is less than 20 mm in its greatest dimension (25.4 mm = 1 inch). Tumors in humans occur as a result of accumulated genetic and epigenetic alterations within single cells, which cause

8112-502: The life expectancy dropped from 9.4 years to 7.7 years. Almost half suffered from at least one health condition and 21.5% suffered from neoplasia . The next most common group of conditions were orthopaedic and neurological at 15.8% and 14.8% respectively. The most common individual conditions were arthritis , polyneuropathy , hypothyroidism , gastric torsion , and dilated cardiomyopathy . A Norwegian study found 25% of Leonbergers had hip dysplasia after 18 months of age. A study in

8216-420: The local microenvironment on neoplastic evolution from tumor initiation to patient death. In the colon, a field defect probably arises by natural selection of a mutant or epigenetically altered cell among the stem cells at the base of one of the intestinal crypts on the inside surface of the colon. A mutant or epigenetically altered stem cell may replace the other nearby stem cells by natural selection. Thus,

8320-863: The majority of the 49 colon cancers evaluated by Facista et al. Epigenetic alterations causing reduced expression of DNA repair genes is shown in a central box at the third level from the top of the figure in this section, and the consequent DNA repair deficiency is shown at the fourth level. When expression of DNA repair genes is reduced, DNA damages accumulate in cells at a higher than normal level, and these excess damages cause increased frequencies of mutation or epimutation. Mutation rates strongly increase in cells defective in DNA mismatch repair or in homologous recombinational repair (HRR). During repair of DNA double strand breaks , or repair of other DNA damages, incompletely cleared sites of repair can cause epigenetic gene silencing . DNA repair deficiencies (level 4 in

8424-498: The most common terms used to refer to the bb-dilution of black pigment to a dark brown . Depending on breed and exact shade, terms such as mahogany, midtone brown, grey-brown, blackish brown are used. Sedge and deadgrass are used to describe the desired Chesapeake Bay Retriever color that resembles "that of its working surroundings" as closely as possible. Red refers to reddish shades of orange, brown, and tan. Terms used include orange, red-gold, cinnamon, tan, and ruby. Genetically

8528-665: The original trigger is removed. This abnormal growth usually forms a mass, which may be called a tumour or tumor . ICD-10 classifies neoplasms into four main groups: benign neoplasms , in situ neoplasms , malignant neoplasms , and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology . Prior to the abnormal growth of tissue, such as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia . However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word neoplasm

8632-677: The outermost layer of the skin for the cortisol cells of the hair follicle. A deficiency in vitamin A can cause the common symptoms of dermatitis (dry, scaling skin and dull coat). Vitamin B7, also known as biotin , is a water-soluble nutrient that is known to play a role associated with the maintenance and development of hair starting from the follicle . Although it has not been clinically shown to improve hair growth with supplementation alone, it has been shown to reverse deficiency in dogs born deficient. Symptoms of biotin deficiency include alopecia and achromotrichia . A clinical study of biotin showed

8736-455: The photo is external to the outer wall of the colon. In the segment of colon shown here, the colon was cut open lengthwise to expose the inner surface of the colon and to display the cancer and polyps occurring within the inner epithelial lining of the colon. If the general process by which sporadic colon cancers arise is the formation of a pre-neoplastic clone that spreads by natural selection, followed by formation of internal sub-clones within

8840-401: The polyps, 6mm, 5mm, and two of 3mm, and a cancer about 3 cm across in its longest dimension). These neoplasms are also indicated, in the diagram below the photo, by 4 small tan circles (polyps) and a larger red area (cancer). The cancer in the photo occurred in the cecal area of the colon, where the colon joins the small intestine (labeled) and where the appendix occurs (labeled). The fat in

8944-493: The potency. In addition, high fat diets in dogs were shown to dramatically improve coat sheen and appearance. It is thought excess cholesterol esters are incorporated into the hair follicle, leading to the improved coat appearance. The same study, by Kirby, Hester and Bauer (2007), stated the optimal approach to an improved coat in dogs is a combination of increased dietary fat and the proper amount of polyunsaturated fatty acids. Omega 3 fatty acid, also known as linolenic acid ,

9048-446: The predator or prey. An alternative explanation is that the dorsal and ventral sides of an animal experience different selection pressures (from the need to blend into different backgrounds when viewed from above and below) resulting in differing coloration. The same colour may be referred to differently in different breeds. Likewise, a same term may mean different colourations in different breeds. Brown , chocolate and liver are

9152-603: The process is referred to as a neoplastic process. The word neoplastic itself comes from Greek neo 'new' and plastic 'formed, molded'. The term tumor derives from the Latin noun tumor 'a swelling', ultimately from the verb tumēre 'to swell'. In the British Commonwealth, the spelling tumour is commonly used, whereas in the U.S. the word is usually spelled tumor . In its medical sense, tumor has traditionally meant an abnormal swelling of

9256-401: The process may be repeated multiple times, indicated by the still smaller patches within the four secondary patches (with still different colors in the diagram) which clonally expand, until stem cells arise that generate either small polyps or else a malignant neoplasm (cancer). In the photo, an apparent field defect in this segment of a colon has generated four polyps (labeled with the size of

9360-509: The promotion of coat growth. Lack of selenium in the diet of a dog can contribute to the occurrence of sparse coat growth. Dogs can obtain selenium in their diet through the addition of various ingredients including; tuna fish, halibut, sardines, beef, chicken, and egg. Vitamin A deficiency can lead to rough coat, scaling of skin, and other dermatitis issues like alopecia . It is also essential for cells to properly proliferate keratinocytes, which are epithelial cells that produce keratin on

9464-593: The properties of DNA in water at body temperatures) occur at a rate of more than 10,000 new damages, on average, per human cell, per day. Additional DNA damages can arise from exposure to exogenous agents. Tobacco smoke causes increased exogenous DNA damage, and these DNA damages are the likely cause of lung cancer due to smoking. UV light from solar radiation causes DNA damage that is important in melanoma . Helicobacter pylori infection produces high levels of reactive oxygen species that damage DNA and contributes to gastric cancer. Bile acids , at high levels in

9568-403: The purpose of work. Seen in profile, the chest curves inward from the prosternum, tangentially joins at the elbow to its underline at 50% of the withers ' height, and then continues slightly upward toward the stifle . The head is well balanced in proportion to the size of the dog and is deeper than broad with the length of muzzle and the length of skull roughly equal. With close-fitting eyelids,

9672-412: The remnants of countershading , a common natural camouflage pattern. The basic principle of countershading is when the animal is lit from above, shadows will be cast on the ventral side of the body. These shadows could provide a predator or prey with visual cues relating to the movement of the animal. By being lighter colored on the ventral side of the body, an animal can counteract this, and thereby fool

9776-400: The same cell, and all carry the same genetic or epigenetic anomaly – evident of clonality. For lymphoid neoplasms, e.g. lymphoma and leukemia , clonality is proven by the amplification of a single rearrangement of their immunoglobulin gene (for B cell lesions) or T cell receptor gene (for T cell lesions). The demonstration of clonality is now considered to be necessary to identify

9880-479: The same enzymatic pathway. Dogs, like many mammals, lack the desaturase enzymes capable of interconverting omega 3 and 6 fatty acids. Therefore, the amount of inflammation in the body is dependent on the ratio between omega 3 and 6 fatty acids. Too little inflammation suppresses the immune system and the body's ability to heal, however excessive inflammation can irritate the skin and reduce the coat's overall appearance. Aside from omega fatty acids, lipid content in

9984-404: The terms "field cancerization" and "field defect" have been used to describe pre-malignant tissue in which new cancers are likely to arise. Field defects are important in progression to cancer. However, in most cancer research, as pointed out by Rubin "The vast majority of studies in cancer research has been done on well-defined tumors in vivo, or on discrete neoplastic foci in vitro. Yet there

10088-435: The top of the skull. Though level bites and slight anomalies not affecting the robustness of the lower jaw are common, the ideal Leonberger possesses a strong scissor bite with full dentition. Both a necessity for work and a defining attribute of the breed, the Leonberger has a dense water-resistant long double coat on the body that is complemented by the shorter, fine hair on the muzzle and limbs. The long, profuse, outer coat

10192-446: The total nucleotide sequences within cancers suggest that often an early alteration in the field defects giving rise to a cancer (e.g. yellow area in the diagram in this section) is a deficiency in DNA repair. The large field defects surrounding colon cancers (extending to at about 10 cm on each side of a cancer) were shown by Facista et al. to frequently have epigenetic defects in 2 or 3 DNA repair proteins ( ERCC1 , XPF or PMS2 ) in

10296-937: The tumor and that stiffening of the underlying normal tissue inhibits tumor growth as well. Benign conditions that are not associated with an abnormal proliferation of tissue (such as sebaceous cysts ) can also present as tumors, however, but have no malignant potential. Breast cysts (as occur commonly during pregnancy and at other times) are another example, as are other encapsulated glandular swellings (thyroid, adrenal gland, pancreas). Encapsulated hematomas, encapsulated necrotic tissue (from an insect bite, foreign body, or other noxious mechanism), keloids (discrete overgrowths of scar tissue) and granulomas may also present as tumors. Discrete localized enlargements of normal structures (ureters, blood vessels, intrahepatic or extrahepatic biliary ducts, pulmonary inclusions, or gastrointestinal duplications ) due to outflow obstructions or narrowings, or abnormal connections, may also present as

10400-615: Was a female, and two males) played the main character Buck in The Call of the Wild: Dog of the Yukon (1997), a Canadian rendition of Jack London 's Call of the Wild which stars Rutger Hauer as John Thornton and is narrated by Richard Dreyfuss . The breed chosen in this movie was not the one identified as Buck in the novel. Coat (dog) The coat of the domestic dog refers to

10504-462: Was closely related to white in arctic wolves from North America. This result suggests a common origin for dominant yellow in dogs and white in wolves but without recent gene flow, because this clade was found to be genetically basal to the golden jackal and genetically distinct from all other canids. The most recent common ancestor of the golden jackal and the wolf lineage dates back to 2 million years ago. The study proposes that 35,000 years ago there

10608-705: Was deficient because its pairing partner MLH1 was repressed due to promoter methylation (PMS2 protein is unstable in the absence of MLH1). In the other 10 cases, loss of PMS2 expression was likely due to epigenetic overexpression of the microRNA, miR-155 , which down-regulates MLH1. In further examples, epigenetic defects were found at frequencies of between 13%-100% for the DNA repair genes BRCA1 , WRN , FANCB , FANCF , MGMT, MLH1 , MSH2 , MSH4 , ERCC1 , XPF , NEIL1 and ATM . These epigenetic defects occurred in various cancers, including breast, ovarian, colorectal, and head and neck cancers. Two or three deficiencies in expression of ERCC1, XPF or PMS2 occur simultaneously in

10712-469: Was genetic introgression into the Late Pleistocene grey wolf from a ghost population of an extinct canid which had diverged from the grey wolf lineage over 2 million years ago. This colour diversity could be found 35,000 years ago in wolves and 9,500 years ago in dogs. A closely related haplotype exists among those wolves of Tibet which possess yellow shading in their coats. The study explains

10816-502: Was necessary because breeding stocks of the Leonberger were seriously affected by the two world wars. Only five Leonbergers survived World War I and were bred until World War II when, again, almost all Leonbergers were lost. During the two world wars, Leonbergers were used to pull the ammunition carts, a service to the breed's country that resulted in the Leonbergers' near-destruction. Karl Stadelmann and Otto Josenhans are credited as

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