6,502
edits
Changes
→Clinical Signs
===Clinical Signs===
===Clinical Signs===
In dogs, historical findings at the time of presentation can vary. Some animals are symptomatic, or cough only occasionally. In countries where heartworm is endemic, it is sometimes routine to test for dirofilariasis at the end of the high-risk season, when weather becomes cooler<sup>3</sup>. Therefore, positive laboratory testing may be the first indication of disease<sup>1</sup>.
In dogs, historical findings at the time of presentation can vary. Some animals are asymptomatic, or cough only occasionally. In countries where heartworm is endemic, animals may be routinely tested for dirofilariasis at the end of the high-risk season, when weather becomes cooler<sup>3</sup>. Therefore, positive laboratory testing may be the first indication of disease<sup>1</sup>. More obvious signs may be seen depending on the severity of disease. Generally, the onset of heartworm disease is insidious, and clinical signs are related either to a high parasite burden, or to an allergic response to the parasite<sup>2</sup>. Affected dogs most often show coughing, and dyspnoea/tachypnoea, exercise intolerance, loss of condition and syncope may also be seen. In severe cases the pulmonary vessels may rupture, leading to haemoptysis or epistaxis. There is a tendency for signs to only manifest during exercise, and so patients with a sedentary lifestyle may never show overt disease. Right-sided congestive heart failure may ensue when worm burden is high, and signs can include jugular disension, ascites, marked exercise intolerance and hepatomegaly. A systolic murmur is sometimes audible on cardiac auscultation.
A classification system for the presentation of heartworm disease exists, outlined in the table below.
{| class="wikitable collapsible"
{| class="wikitable collapsible"
|-
|-
|}
|}
Caval syndrome represents a severe form of heartworm
disease both in dogs and cats. This is characterised
by respiratory distress, intravascular haemolysis and
haemoglobinuria, signs of right-sided heart failu-e and,
frequently, disseminated intrav ascular coagulaktion1.
Although the majority of infected cats are asymptomatic,
Although the majority of infected cats are asymptomatic,