Importance of Anamnesis and Physical Examination in Canine Heartworm Disease

Abstract

The history and physical examination are the first procedures in veterinary clinical practice. The valuable information collected is essential to determine the rest of the complementary diagnostic tests necessary for the correct management of canine heartworm disease. The objective of this study was to analyze the main findings reported in the anamnesis and physical examination of a group of canine patients infected by Dirofilaria immitis. A total of 192 dogs of 23 different breeds were diagnosed with heartworm through a commercial test for the detection of D. immitis antigens (Urano test Dirofilaria®, Urano Vet SL, Barcelona, Spain) at the University of las Palmas de Gran Canaria Veterinary Faculty, between September 2020 and July 2022. The data from the anamnesis and physical examination were collected systematically. In all cases the owners were informed to participate in the study. The information of the different variables was analyzed through statistical analysis software (BM SPSS Statistics 25.0, New York, USA). The results show 45,31% females and 54,69% males with a mean age of 8,4 years and a mean weight of 16,7 kg. 7,81% were dogs with long hair, 12,5% medium hair and 79,70 short hair. The anamnesis showed that 48,96% animals did not take deworming, 44,27% intermittently and 6,77% did take it rigorously. The most affected breed was the Podenco canario (8,33%). 25% lived outdoors, 23,44% indoors and 51,56% in a mixed environment. It was observed that 14,58% of the animals did not present any symptoms of disease. The main symptoms reported were dry and productive cough (59,75%), dyspnea (31,48%), exercise intolerance (28,12%), syncope (22,22%), hyporexia (25,96%), diarrhea (21,34%), vomiting (13,41%) and hemoglobinuria (5,49%). The progression of symptoms was chronic in 53,65%, subacute in 38,07%, and acute in 8,28%. Physical examination showed a mean heart rate of 134,5 and a respiratory rate of 38,4. The grade of body score condition more observed was 5/9. The presence of heart murmur was determined in 28,13% animals, (38,80% in the right hemithorax, 27,78% in the left hemithorax and 33,42% bilateral), with a mean intensity of III/IV and systolic characterization. 39,06% of animals were reported with pulmonary crackles, 28,65% had wheezing, 7,29% had rales, and 6,77% had stridor. The presence of abnormal respiratory pattern was determined in 34,38 % of the animals. The presence of ascites was observed in 23,44%. The average temperature was 38,17°C. Presence of white mucous membranes with CRT>2sg in 30,73% of the animals. The presence of a weak, asymmetric or synchronous femoral pulse was observed in 28,65% of the animals. The history and physical examination in the canine patient with heartworm disease show high degrees of similarity between the different clinical presentations. The cardiorespiratory findings are the main representatives in this disease and the information obtained through the owner is generally useful. Further future studies in other geographical areas and with a larger number of animals are considered necessary to standardize clinical information and devise specific protocols for the diagnosis of canine heartworm. This study was partially supported by ELANCO SPAIN S.L (CN-240/030/159) and was funded by the Veterinary Medicine Service FULP/ULPGC SD-240/030/0026.