Canine Hepatitis | Hepatitis in Dogs

The complexity of canine hepatitis is just beginning to be appreciated and understood. Lack of adequate characterization of these diseases and the temptation to extrapolate directly from medical literature in human patients to say that hepatitis in dogs is identical to those long studied in humans may be preventing more progress being made in veterinary medicine.

Canine hepatitis comprises a spectrum of hepatic diseases that share similar historic, clinical and possibly histopathologic features. Dogs with hepatitis are ill for weeks to months with combinations of anorexia, weight loss, lethargy, polyuria and polydipsia, jaundice, abdominal effusion and hemorrhagic tendencies.

Occasionally, high serum liver enzyme activities are detected during routine evaluation before elective surgery in asymptomatic dogs. In addition, there may be clinically relevant hepatic disorders in which liver enzyme activities are silent but there is other evidence of serious hepatic disease. A liver biopsy is crucial for accurate diagnosis and prognosis, although there is great overlap in histopathologic findings among canine hepatitis.

To better understand the role of the immune system in the development of hepatitis in dogs, studies sought to determine the frequency of serum antibodies directed at cell nuclear material, smooth muscle mitochondria, and liver membrane in 21 and 24 dogs with confirmed hepatitis respectively. These studies have demonstrated the presence of certain autoantibodies in dogs with hepatitis, but the clinical significance of these findings remains to be clarified.

Canine Hypothyroidism | Hypothyroidism in Dogs

Structural or functional abnormalities of the thyroid gland can lead to deficient production of thyroid hormones. A convenient classification scheme for hypothyroidism in dogs has been devised that is based on the location of the problem within the hypothalamic-pituitary-thyroid gland complex. Primary hypothyroidism in dogs is the most common form of this disorder; it results from problems within the thyroid gland, usually destruction of the thyroid gland.

The two most common histologic findings in this disorder are lymphocytic thyroiditis and idiopathic atrophy of the thyroid gland. Lymphocytic thyroiditis is an immune-mediated disorder characterized by a diffuse infiltration of lymphocytes, plasma cells, and macrophages into the thyroid gland. The factors that trigger the development of lymphocytic thyroiditis are poorly understood, but genetics factors undoubtedly play a role.

Idiopathic atrophy of the thyroid gland is characterized by loss of the thyroid parenchyma. There is no inflammatory infiltrate, even in areas where small follicles or follicular remnants are present. The cause of idiopathic thyroid atrophy is not known, but it may be a primary degenerative disorder. It may also represent an end stage of autoimmune lymphocytic thyroiditis.

Hypothyroidism symptoms in dogs

Clinical signs of the more common forms of primary hypothyroidism in dogs usually develop during middle age. Clinical signs tend to develop at an earlier age in breeds at increased risk than other breeds. There is no apparent sex-related predilection.

Dog Breeds that have an increased prevalence of hypothyroidism:

Pointer
English Pointer
German Wirehaired Pointer
Boxer
Kuvasz
American Staffordshire Terrier
American Pit Bull Terrier
Giant Schnauzer
Golden Retriever
Chesapeake Bay retriever
Brittany Spaniel
Australian Shepherd
Malamute
English Setter
Skye Terrier
Old English Sheepdog
Maltese
Petit Basset Griffon
Beagle
Dalmatian
Rhodesian Ridgeback
Shetland Sheepdog
Siberian Husky
Borzoi
Doberman Pinscher
Cocker Spaniel

Clinical signs are quite variable and depend in part on the age of the dog at the time a deficiency in thyroid hormone develops. Clinical signs may also differ between breeds. For example, truncal alopecia may dominate in some breeds, whereas thinning of the haircoat dominates in other breeds. In adult dogs, the most consistent clinical signs of hypothyroidism result from decreased cellular metabolism and its effect on the dog’s mental status and activity.

Most dogs with hypothyroidism show more mental dullness, lethargy, exercise intolerance or unwillingness to exercise, and a propensity to gain weight without a corresponding increase in appetite or food intake. These signs are often gradual in onset, subtle, and not recognized by the owner until after thyroid hormone supplementation has been initiated. Additional clinical signs of hypothyroidism in dogs typically involve the skin, less commonly, the neuromuscular system.

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Dogs in Heat

Q. What are dogs in heat?

A. Heat is a synonym for the estrous cycle. It is during this cycle that bitches may get pregnant.

Q. What are the symptoms of dogs in heat?

A. Bitches tend to bleed from the vagina when they’re on heat and swelling of the vulva occur. They also experience increased urination. For small breeds, there is usually not much bleeding so owners may need to pay close attention to their female dog to notice her 1st cycle.

Q. When does a bitch come on heat?

A. Usually, the bitch has her 1st cycle at around 6 months old. Some bitches start earlier and other female dogs later. When owners get a new female dog, they should monitor her and note when she has her 1st cycle. If the bitch is 14 months of age and still has not been in heat yet, owners should get the opinion of a pet clinician.

Q. How long does dogs in heat last?

A. Around 3 weeks or twenty-one days. In some female dogs, the heat only lasts 2 weeks, although in some breeds it may last 4 weeks.

Q. How often are dogs in heat?

A. Most bitches have regular estrous cycles; every 6 to 8 months.

Q. When can bitches pregnant?

A. Female dogs can only get pregnant when on heat. The rule-of-thumb is that the most fertile period is between eleven to fifteen days of the estrous cycle. During that time, female dogs will most likely let any male dogs to mount her and mating occurs.

Canine Esophageal Neoplasms Esophageal | Neoplasms in Dogs

Primary esophageal sarcomas in dogs are often due to Spirocerca lupi. Primary esophageal carcinomas are of unknown etiology in dogs and cats. Leiomyomas are found at the lower esophageal sphincter in older dogs. Thyroid carcinomas and pulmonary alveolar carcinomas may invade the esophagus in dogs. Squamous cell carcinomas are the most common esophageal neoplasm in cats.

Dogs and cats with primary esophageal tumors may be asymptomatic until the tumor is far advanced, and these animals are diagnosed fortuitously when thoracic radiographs are obtained for other reasons. Regurgitation, anorexia, and/or fetid breath may occur if the tumor is large or causes esophageal dysfunction. If the esophagus is involved secondarily, clinical signs may result from esophageal dysfunction or tumor effects on other tissues.

Plain thoracic radiographs may reveal a soft tissue density in the caudal lung fields. These tumors may be difficult to radiographically discern from pulmonary lesions and usually require contrast esophagrams to make this distinction. Esophagoscopy easily finds intraluminal and intramural masses or strictures and is sensitive in finding extraluminal masses causing esophageal stricture (i.e., the endoscopist will not be able to normally distend the esophageal lumen). Retroflexing the tip of an endoscope while it is within the stomach is the best method of identifying lower esophageal sphicter leiomyomas and leiomyosarcomas in dogs and cats.

Not much a clinician can do for treatment of esophageal neoplasms in dogs and cats. Surgical resection is rarely curative (except for leiomyomas at the lower esophageal sphincter) because of the advanced nature of most esophageal neoplasms when they are diagnosed. Resection may be palliative though. Photodynamic therapy may be beneficial in dogs and cats with small superficial esophageal neoplasms. For all those reasons, the pronostic for dogs and cats with esophageal neoplasms is usually poor unfortunately.

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Canine Fever | Fever in Dogs

The term fever in dogs refers to a syndrome of malaise (or nonspecific systemic clinical signs) and pyrexia (or hyperthermia). Dog fever constitutes a protective physiologic response to both infectious and noninfectious causes of inflammation that enhances the host’s ability to eliminate a noxious agent.

A variety of stimuli, including bacteria, endotoxins, viruses, immune complexes, activated complement, and necrotic tissue, trigger the release of endogenous pyrogens by the phagocytic system (mainly the mononuclear cells, or macrophages). These endogenous pyrogens include interleukin-1, tumor necrosis factor, and interleukin-6, among others. They activate the preoptic nucleus of the hypothalamus, raising the set point of the thermostat by generating heat (through muscle contraction and shivering) and conserving heat (through vasoconstriction).

In humans, several patterns of fever have been associated with specific disorders; however, this does not apear to be the case in dogs with fever. In people with continuous fever, the pyrexia is maintained for several days or weeks; this type of fever is associated with bacterial endocarditis, central nervous system lesions, tuberculosis, and some malignancies. In people with intermittent fever, the body temperature decreases to normal but rises again for periods of 1 to 2 days; this is seen in brucellosis and some malignancies. In remittent fever the temperature varies markedly each day but is always above normal (i.e., 39.2 degrees Celsius); this type of fever is associated with bacterial infections. The term relapsing fever is used to refer to febrile periods that alternate with variable periods of normal body temperature, as seen in humans with malaria.

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Canine Infections | Infections in Dogs

Anaerobic infections in dogs are commonly associated with infections of the oropharynx, the central nervous system, the subcateous space, the musculoskeletal system, the gastrointestinal tract, the liver, and the female genital tract, and they are relatively common in animals with aspiration pneumonia or consolidated lung lobes. Dogs and cats with gingivitis/stomatitis, rhinitis, retrobulbar abscesses, aspiration pneumonia, pyothorax, otitis media or interna, bite wounds, open wounds, open fractures, osteomyelitis, peritonitis, bacterial hepatitis, pyometra, vaginitis, bacteremia, and valvular endocarditis should be suspected to be infected with anaerobes.

Improving the blood supply and oxygenation of the infected area is the primary goal for treatment of dog infections. Antibiotic therapy should be used concurrently with drainage or debridement. Parenteral antibiotics should be administered for several days in dogs with infections like pyothorax, pneumonia, peritonitis, and clinical signs consistent with bacteremia. Penicillin derivatives, clindamycin, metronidazole, cephalosporins (first and second generation), chloramphenicol are used commonly for the treatment of infections in dogs.

With the exception of Bacteroides fragilis, penicillin derivatives have excellent activity against anaerobes. If gram-negative coccobacilli are detected cytologically in a neutrophilic exudate, particularly if associated with the oral cavity, metronidazole, a first-generation cephalosporin, or clindamycin should be administered instead of a penicillin derivative. Because concurrent anaerobic and aerobic dog infection occur frequently, combination antimicrobial treatment is often indicated, particularly if life-threatening signs of bacteremia exist.

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Canine Leukemia | Leukemia in Dogs

In dog leukemias constitute fewer than 10% of all hemolymphatic neoplasms and are therefore considered rare. However, the leukemia to lymphoma ratio is approximately 1:7 to 1:10. This ratio is artificially high, because most dogs with lymphoma are treated by their local clinicians, whereas most dogs with leukemia are referred for treatment. Although most leukemias in dogs are considered to be spontaneous in origin, radiation and viral particles have been identified as possible etiologic factors in dogs with cancer.

Acute myeloid leukemias in dogs are more common than acute lymphoid leukemias, constituting approximately three fourths of the cases of acute leukemia. It should be remembered, however, that morphologically, most acute leukemias are initially classified as lymphoid. After cytochemical staining of the smears or immunophenotyping is performed, approximately one third to one half of them are then reclassified as myeloid. Approximately half of the dogs with myeloid leukemia are found to have myelomonocytic differentiation when cytochemical staining or immunophenotyping is performed.

Leukemias in dogs are malignant neoplasms that originate from hematopoietic precursor cells in the bone marrow. These cells are unable to undergo terminal differentiation, therefore, they self-replicate as a clone of usually immature (and non-functional) cells. The neoplastic cells may or may not appear in peripheral circulation, thus the confusing term aleukemic and subleukemic are used to refer to leukemias in which neoplastic cells proliferate within the bone marrow but are absent or scarce in the circulation.

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Dog Allergies | Allergies in Dogs

Allergies in dogs are basically an immune system overreaction. The nasal cavity is an uncommon primary site for allergic disease in dogs and it has not been well characterized yet. However, dermatologists provide anecdotal reports of atopic dogs rubbing the face (possibly indicating nasal pruritus) and experiencing serous nasal discharge, in addition to dermatologic signs. Dog allergies are generally considered to be a hypersensitivity response within the nasal cavity and sinuses to airborn antigens. Other antigens are capable of inducing a hypersensitivity response as well, and thus the differential diagnoses must include parasites, other infectious diseases and neoplasia.

Dogs with allergies experience sneezing and/or serous mucopurulent nasal discharge. Signs may be acute or chronic. Careful questioning of the owner may reveal a relationship between signs and potential allergens. For instance, signs of dog allergies may be worse during certain seasons; in the presence of cigarette smoke; of after the introduction of a new brand of furniture or fabric in the house.

Dog allergies treatment

Removing the offending allergen from the dog’s environment is the ideal treatment for dog allergies. When this is not possible, a beneficial response may be achieved with antihistamines. Chlorpheniramine can be administered orally. Glucocorticoids can be used if antihistamines are unsuccessful. If treatment is effective, the dog’s allergy signs will generally resolve within a few days. Medication is continued only as long as needed to control the signs.

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Dog Names – Find a Name for your Dog

Dog Names

Give a name to your dog

The name you will choose for your dog is tied to your personality. It reflects the relationship you will have with your dog. Depending of the role of your dog (is it a therapy dog?A pet? A rescue dog?), it is very important to choose a dog name that projects the right image.

Click here for a complete list of dog names.

Canine Arthritis | Arthritis in Dogs

A disorder resembling human arthritis rarely results in erosive polyarthritis and progressive joint destruction in dogs. Small and toy breeds are most commonly affected by dog arthritis. The age of onset is variable (9 months to 13 years), but most affected dogs are young or middle-aged. Initially, dog arthritis is indistinguishable from idiopathic nonerosive polyarthritis, but the joints are destroyed over time, with distal joints most severely affected.

Arthritis in dogs may result when a triggering event or inciting antigen initiates an immune reaction against endogenous antigens, causing immune complexes to form. Immune complexes are deposited in the synovium, resulting in complement activation, the chemotactic attraction of inflammatory cells, the intraarticular release of cytokines, synovial cell proliferation, and progressive, severe, erosive inflammatory joint disease.

Granulation tissue arises from the inflamed synovium and extends across the joint underneath the articular cartilage. This vascular granulation tissue (e.g., pannus) begins to erode cartilage, and joint swelling and periarticular inflammation cause the joint capsule to stretch and collateral ligaments to rupture. Early treatment of arthritis in dogs is important to prevent irreversible changes and progressive disease.

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