Dog diseases : Intervertebral Disk Disease

The vertebral column, or backbone, consists of 34 individual bones called vertebrae. The vertebral column also includes the spinal cord and nerves, tendons, muscles, ligaments, intervertebral disks, and blood supply. The vertebral column protects the spinal cord and many internal organs, serves as a base of attachment for tendons and ligaments, provides structural support, connects the upper and lower body, and enables a wide range of body movement. The bones in the vertebral column also store minerals and produce red blood cells. The disks separate the vertebrae from each other. 

These "cushions" absorb the stress and shock that the body incurs during movement. IVD degeneration occurs in all breeds of dogs; however, it is observed most frequently in the chondrodystrophoid breeds (Dachshund, Pekingese, French bulldog, Beagle, Basset Hound, American Cocker Spaniel, Shih Tzu, Lhasa Apso, and generally dogs with short thick legs). The intervertebral disk protrusion, characterized by partial protrusion, is seen more commonly in the non-chondrodystrophoid dogs, and usually develops in dogs of 6-10 years of age.

Structure of Intervertebral Disc
The intervertebral disk consists of two regions: the outer layer called annulus fibrosus of cartilage-like material and the central region called nucleus pulposus. The central region is a gel-like structure in the young animal which becomes progressively dehydrated and less gel-like with age.

Dog diseases : Kartagener Syndrome and L-2-hydroxyglutaric Acidemia

Kartagener Syndrome

Kartagener syndrome (KS), also known as Primary Ciliary Dyskinesia (PCD), Kartagener Triad, Kartagener's Syndrome, Kartagener's Triad, and Siewert Syndrome, is is a rare congenital condition associated with abnormal retention of mucus and bacteria in the respiratory tract. The syndrome is caused by mutations of genes encoding proteins which are components of sperm and cilia in the respiratory and the reproductive tracts. Cilia are hairlike structures found in various bodily tissues. Patients with KS may have exercise intolerance and chronic, thick, discharge from the nose. Nasal polyps and ear disease are commonly seen affected individuals. Males with KS may be infertile due to impaired sperm motility.

Ciliated epithelium covers most areas of the upper respiratory tract, including the nasal mucosa, nasal passages, middle ear, eustachian (auditory) tube, and pharynx (throat). The lower respiratory tract contains ciliated epithelium from the trachea to the respiratory bronchioles. Cilia propel overlying mucus via a 2-part ciliary beat cycle. 

Dogs : Lens Luxation And Subluxation

Dislocation, or luxation, of the lens arises as a result of rupture of the zonular fibers, which suspend the lens from the ciliary body. In the dog, lens luxation is most frequently encountered as a primary, heritable condition in which there appears to be an inherent weakness of the zonule. In subluxation the lens remains in its normal position, but will be shifted down or to one side. 

In anterior luxation the lens may go through the pupil and lie in the anterior chamber, where it may rub against the cornea and cause corneal inflammation. Two forms of lens luxation have been described in dogs: traumatic and primary. Traumatic form is characterized by a severe concurrent intraocular damage. Traumatic lens displacements usually have a poor prognosis due to the severity of ocular damage.

Primary lens luxation is seen most frequently in the Wirehaired Fox Terrier, Sealyham, Welsh and Manchester Terrier, and occasionally in the Boston Terrier, Basset Hound, Border Collie, and Cocker Spaniel. The lens usually does not displace, however, until the individual is 2 to 5 years old. 

Dogs : Adrenal Cortical Atrophy

Adrenal cortical atrophy is the destruction of the outer layer of the adrenal glands which results in insufficient production of mineralocorticoid and glucocorticoid hormones. The adrenals are two crescent-shaped glands that sit on top of each kidney and secrete hormones directly into the bloodstream. They are divided anatomically and functionally into two main parts: the medulla (middle) and the cortex (rind). Furthermore, each division of an adrenal gland consists of internal layers that produce different hormones. Constant stress and poor nutrition can weaken the adrenal glands.

When stress continues over prolonged periods of time, the body's hormonal and energy reserves become depleted, and the glands may either shrink in size or enlarge. The destruction of the adrenal glands is a gradual process. Initially partial destruction of the adrenal cortex produces symptoms that are only obvious during stressful situations such as boarding, travel or surgery. 

Dogs : Acute Peritonitis

Peritonitis is an inflammation of the peritoneum, the membrane lining the walls of the abdominal and pelvic cavities and covering contained internal organs. In small animals, acute septic peritonitis is a relatively common and important condition with high mortality rates.

Fluids, organic debris, cells, infectious organisms, and pus accumulate in the cavity in acute peritonitis. The causes can be from external injury or internal infections or diseases, such as bowel puncture from trauma, rupture from disease or ingested foreign bodies, with escape of contaminated bowel contents into the abdominal cavity; infections from abdominal cavity puncture, or after surgery, or spreading from infections in other abdominal organs or other areas of the body; damage to the urinary system, with escape of urine into the abdominal cavity; damage to the pancreas or liver with escape of bile or pancreatic enzymes into the abdominal cavity; and rupture of an infected uterus or prostate gland. 

Dogs : Canine Cone Degeneration and Acromegaly

Canine Cone Degeneration

Achromatopsia, also called rod monochromacy, is an inherited condition characterized by decreased visual acuity, absent color vision, photophobia, and nystagmus. Achromatopsic humans report that colored objects appear in shades of gray. Two forms of this condition have been described in humans. 

Complete achromatopsia is a congenital vision disorder in which all cone function is absent or severely diminished. The incomplete (atypical) form is defined as dyschromatopsia, in which the symptoms are similar to those of the complete achromatopsia (typical) form but with less visual dysfunction. 

In dogs, the condition is referred to as canine cone degeneration. Cones are light-sensitive retinal photoreceptors in the vertebrate eye. Although cone cells account for only 5% of photoreceptors, they are essential for high-acuity daylight-vision and discrimination of color. Canine cone degenration is caused by mutation in the canine GNGB3 gene. In the Alaskan Malamute, the complete gene is deleted, while in the German Shorthaired Pointer, the gene has substituted amino acids. 

Dogs diseases : Acral Lick Dermatitis

Acral lick dermatitis, also referred to as lick granuloma, is a type of skin disorder that is characterized by recurrent skin lesions. There is often a history of poor or partial response to many therapeutic treatments. Bald, red, eroded or ulcerated lesions are created and maintained by constant licking or chewing. Large breed dogs, especially Doberman Pinschers, Great Danes, Golden and Labrador retrievers, German Shepherd Dogs and Boxers appear to be predisposed. Onset of lesions can occur at any age, but it is more common in dogs more than 5 years of age. 

If the underlying condition can be determined, the prognosis is good. The causes are many, including atopic dermatitis, food, psychogenic causes, boredom, bacterial folliculitis, foreign bodies, neurologic disorders, local trauma, andjoint or bone diseases. Independent of the contributing factor, once the lesion has developed it will contribute to the perpetuation of the compulsive licking behavior.

Dogs diseases : Actinomycosis

Actinomycosis

Actinomycosis is a slowly progressive, pus-forming infection caused by branching bacteria of the genus Actinomyces. Classically, actinomycosis is a disease of cattle, but it also occurs in other animal species, and as a facial and oral infection in man. Actinomycesbacteria normally live in the mouth, the nasal passages near the throat, and the bowels.Actinomyces may cause disease due to poor oral hygiene, dental and periodontal problems, trauma and following oral surgical procedures. Pulmonary actinomycosis may develop as a result of aspiration of actinomyces that originated from dental plaque and diseased gums. Several species are associated with the disease in dogs: Actinomyces bovis, Actinomyces hordeovulneris, and Actinomyces viscosus. Hunting or field dogs in southern areas are most commonly affected. Actinomyces bovis causes loose teeth and difficulty breathing due to swelling of the nasal cavity. Actinomyces hordeovulneris causes abscesses in the liver and spleen and generalized infections in the cavities surrounding the lungs and bacterial arthritis.

Two forms of actinomycosis are usually seen in dogs. The more common is a skin abscess or mycetoma. This form, resulting from a skin wound, usually responds well to treatment.Actinomyces viscosus causes chronic pneumonia, inflammation of cavities surrounding the lungs, and skin abscesses associated with fever, pain and swelling of the skin. Canine interdigital actinomycosis is especially likely to result from foxtail, grass awns, or quills foreign body penetration.

Skin form of actinomycosis is diagnosed based on skin cell examination, bacteriologic culture, or tissue examination. Abscesses, draining fistulous tracts, and granulomas that develop can be misinterpreted as neoplasms on radiographs or ultrasonograms. Treatment of actinomycosis depends on the bacterium species that causes the disease. The skin form of actinomycosis may require surgical cleaning, drainage, and administration of antibiotics. High doses of penicillins given for prolonged periods (weeks to months) is the treatment of choice.1 Amoxycillin and clindamycin may or may not be effective.2 Minocyclin hydrochloride (Minosin, Arestin), and rifampin (Rifadin, Rifactane) have also been used. Major limiting factor associated with rifampin is rapid development of resistance, thus the need to combine this antibiotic with other agents. The drug is very toxic to the liver.4 In some dogs there may be recurring infections that will require several surgical procedures.

Dogs Addison Disease

Addison disease, also known as hypoadrenocorticism, is a type of adrenal gland disease that results from the atrophy of the adrenal glands and is characterized by insufficient production of the hormone cortisol. Adrenocortical hormones are vital for life. Aldosterone is the most important naturally occurring mineralocorticoid, while cortisol represents the most important glucocorticoid. 

Both hormones are synthesized from cholesterol.3 Cortisol is the principal glucocorticoid secreted by the adrenal cortex which helps metabolize nutrients, mediate physiologic stress, and regulate the immune system. Intense heat or cold, infection, trauma, exercise, obesity and debilitating diseases influence cortisol production. Addison disease is the opposite of Cushing disease in which cortisol is overabundant. However, in Addison disease, cortisol production is not the only problem, because other adrenal hormones will also be insufficiently produced by the pituitary gland or thehypothalamus. 

Dogs : Canine Achondroplasia and Acrochordonous Plaque, Fibroepithelial Polyps

Canine Achondroplasia

Achondroplasia is variously referred by orthopedic specialists as asachondroplastic dwarfism, chondrodystrophia fetalis, chondrodystrophy syndrome, congenital osteosclerosis, dwarf, and osteosclerosis congenita. These various definitions mean the same abnormal development of bone from cartilage.1 Offspring can look normal at birth and weaning, but at the age of 2.5 to 4 months the longitudinal growth of the spine and leg bones can retard in the dwarfs compared with the normal littermates. Most dwarfs perform well, even in the field.5 Canine achondroplasia can be a mild condition, with slightly bowing or simply short legs, causing no discomfort to the animal. Severe achondroplasia requires extensive orthopedic surgery to both alleviate pain and allow the dog to function normally. This surgery, most frequently an ulna, or radius surgery, is generally performed at one year of age when bone growth is nearly complete. Surgical success is variable.

Acrochordonous Plaque, Fibroepithelial Polyps

Acrochordons, also called skin tags, soft fibromas, fibroepithelial polyps, fibroma pendulans, pedunculated fibromas, and soft warts, are tumor-like lesions of the skin that occur both in humans and animals. Sometimes they become numerous, closely located growths forming a plaque, predominantly located at the neck. An acrochordon is usually skin colored or of darker color, and it may appear as surface nodules or papillomas on healthy skin. Most acrochordons vary in size from 2-5 mm in diameter, although larger acrochordons up to 5 cm in diameter are sometimes seen. The most frequent localizations are the neck and the armpits, but any skin fold, including the groin, may be affected.3 Although the exact cause of these lesions remains unclear, hormone imbalances have been suggested to facilitate their development. In addition, there is a predisposition in bulldog-like breeds.1 On rare occasions, fibroepithelial polyps can undergo malignant transformation into basal or squamous cell carcinoma. If fibroepithelial polyps occur in the urinary tract, animals may develop urinary incontinence, urinary tract infection, and/or increased thirst and abnormally frequent urination.2