Page 68 - Canine-Diseases

anemia (pale gums). Behavioral changes may include squatting to abnormality in dogs that has been associated with various neoplastic,
urinate (versus hiking a limb), reduced sex drive and attraction metabolic, and inflammatory conditions. The fundamental causes
of other male dogs. Breeds at an increased risk include Boxers, are physiologic (caused by exercise) or reactive (secondary to some
German Shepherds, Afghan Hounds, Weimaraners and Shetland cancers, blood loss, or certain drugs). Rarely the condition is caused
Sheepdogs. by a primary bone marrow disorder. Temporary thrombocytosis
may occur in response to exercise, pregnancy and delivery, or
Tetanus: Is a disease caused by the bacteria Clostridium tetani other factors causing increased epinephrine levels in the blood.
following wound contamination. Dogs usually have a resistance to The spleen releases stored platelets in response to temporary
Clostridium tetani bacteria and are not very susceptible to tetanus. increases in blood epinephrine. Clinical problems that may cause a
Tetanus is a serious condition in which a toxin or poison blocks the secondary or reactive thrombocytosis are infections, inflammatory
nerve signals and produces severe contractions of the muscles. The disorders, acute or chronic blood loss, tissue damage from trauma
first sign of tetanus is usually a stiffening of the neck, jaw, and hind or surgery, drugs (steroids, vincristine), hyperadrenocorticism,
legs. Other symptoms include difficulty opening the mouth and splenectomy, cancer and rebound from chemotherapy. The potential
eating, contraction of the facial muscles, and rigid extension of the problems arising in a reactive thrombocytosis include excessive
limbs. Dogs may also get localized tetanus, signs of which include clot (or thrombus) formation due to the increased number of active
stiffness of a limb spreading to the rest of the body. Breeds more platelets and, much less commonly, bleeding as platelet function
susceptible to tetanus include German Shepherds and Labrador may also be defective in reactive thrombocytosis.
Retrievers.
Thyroid cancer: Is rare and usually non-productive in dogs
Tetralogy of Fallot: Is a congenital heart defect in dogs that (unlike in cats, in which it causes hyperthyroidism). One-third of
includes four separate defects: pulmonic stenosis (obstruction thyroid tumors are small benign adenomas; the rest are malignant
of blood flow through the pulmonary valve), a ventricular septal carcinomas, usually large and invasive. Adenocarcinoma of the
defect (a hole between the two ventricles), right ventricular thyroid gland is a malignant tumor, which can metastasize to
hypertrophy (thickening of the heart muscle), and dextropositioning other tissue and organs, including the lungs. Thyroid tumors are
(overriding) of the aorta. Blood shunts from the right ventricle to commonly seen in middle-aged to older large-breed dogs and
the left ventricle through the ventricular septal defect. The blood they account for only 1.2-3.8% of all canine tumors. Symptoms
flows from the right side of the heart to the left side because the commonly related to adenocarcinoma of the thyroid include a large
pulmonic stenosis increases resistance to blood flow out of the fixed or movable mass in the neck, dyspnea (shortness of breath),
right ventricle to a point that it is greater than systemic vascular dysphagia (difficulty in swallowing), polydipsia (excessive thirst),
resistance. The delivery of deoxygenated blood to the systemic polyuria (excessive urination), dysphonia (hoarseness), weight
circulation results in systemic hypoxemia. The hypoxemia is loss, and change in bark. Thyroid tumors are commonly seen in
often severe enough to cause cyanosis (bluish cast to the skin and middle aged to older large breed dogs such as Boxers, Beagles,
mucous membranes), either at rest or with exercise/stress. Other Golden Retrievers, and Siberian Huskies.
symptoms include dyspnea (shortness of breath), weakness, and
fainting. Tetralogy of Fallot is a congenital disease that likely is Tibial tuberosity avulsion fractures: Usually occurs in younger
influenced by genetic factors. Breeds predisposed to tetralogy of dogs due to the area of the tibia not being fully fused to the rest
Fallot include Keeshonds, English Bulldogs, and Wirehaired Fox of the bone. Puppies diagnosed with this type of fracture usually
Terriers. This defect has been recognized in other breeds of dogs. have had some sort of trauma such as falling from a couch or bed
and landing with the knee flexed. The tuberosity of the tibia or
Thrombocytopenia: Is a common condition in dogs characterized tibial tuberosity or tibial tubercle is a large oblong elevation on the
by low blood platelet counts. Platelets are fragments of cytoplasm proximal, anterior aspect of the tibia. The tibial tuberosity attaches
from cells called megakaryocytes that are produced in the bone the patella to the tibia with a strong tendon of the quadriceps
marrow. Platelets are used in clotting the blood, so dogs with this muscle group. A fracture of the tibial tuberosity can result in an
condition may have spontaneous bleeding or prolonged bleeding avulsion fracture and pull the quadriceps muscles. An avulsion
following surgery, injury, or during an estrous cycle. Causes fracture happens when a bone has been broken and a fragment of
include some rickettsial infections such as ehrlichiosis, cancers the bone is being separated by the pull of an attached muscle or
such as hemangiosarcoma, or immune-mediated disease. Dogs tendon. Symptoms include sudden onset of the hind leg, refusing
with a low platelet count may display symptoms such as fever, to bear weight on a hind leg, and swelling and pain around the
lethargy, heart murmur, urinary bleeding, excessive coughing, front of the knee. Small breed dogs, especially toy breeds of any
excessive nasal mucus, and collapse. Thrombocytopenia can be age can also have a tibial tuberosity avulsion fracture occur if they
inherited or acquired. There are inherited platelet defects such as fall or jump off of furniture or steps.
von Willebrand’s disease that are common in certain breeds of
dogs, especially Doberman Pinschers. Congenital platelet defects Tick bite paralysis: Tick paralysis, or tick-bite paralysis, is caused
also occur in Otterhounds, Great Pyrenees, American Cocker by a potent neurotoxin found in the saliva of certain species of
Spaniels, and Basset Hounds. female tick and which is injected into the blood of the dog as the
tick infests the skin of the dog. In North America, Dermacentor
Thrombocytosis: Is a condition characterized by an increased andersoni (the Rocky Mountain wood tick) and Dermacentor
number of circulating platelets. Thrombocytosis is a hematologic

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