Vet224 Research Project
Hailey Booker
M210327JS0
4/19/2026
, Understanding common diseases is important for the veterinary technician, as this can aid
them in educating clients and assisting doctors. Diseases can be infectious, parasitic, immune-
mediated, congenital, neoplastic, metabolic, toxic, or congenital. A disease from each of these
classifications will be discussed in this writing. The in-depth discussion of each disease will
include the causative agent, species affected, clinical signs, tests, treatment, prevention, and
control programs. Species discussed will include canines, felines, equines, ruminants, and avians.
Canine dirofilaria immitis is a parasitic infection, known as heartworm disease.
Heartworm disease primarily affects canines but can also be found in cats and ferrets.
Heartworm disease starts with mosquitoes. Female mosquitoes ingest microfilariae from an
infected host. Microfilariae molt and change inside the mosquito until they migrate to the mouth
parts of the mosquito. While in the mouth, microfilariae are able to spread disease. When a
mosquito bites a dog to feed, it infects the dog with the larvae. Eventually, these larvae evolve
into heartworms. After the mosquitoes have infected a host, the microfilariae migrate from the
infection site into the heart and lungs. The microfilariae eventually mature and become
heartworms inside the dog, eventually causing catastrophic problems. As they mature, the female
heartworms reproduce and complete the lifecycle. The adult worms can survive in a dog for 5-7
years (Collins, n.d). Although the heartworms can survive inside the dog for lengthy periods,
they cause severe symptoms and clinical signs for the patient.
Ideally, patients are positive on an antigen test before clinical signs are shown, but that is
not always the case. Education on clinical signs and severity is important to ensure a diagnosis
can be made. There are four classes of infection in dogs: mild, moderate, severe, and Caval
syndrome (Ames, 2025). A mild infection can have minimal to no clinical signs, but a sign noted
,at this stage is a possible cough. A moderate infection's clinical signs include exercise
intolerance, abnormal lung sounds, and a cough. As the disease progresses to a moderate
infection, clinical signs include all those noted in the previous stage and difficulty breathing,
fainting, enlargement of the liver, and death. The final class of infection includes low-output
heart failure and red blood cell destruction. As the disease progresses, secondary conditions are
more likely to occur. Pneumonitis is inflammation of the lungs, which causes many patients to
cough. Furthermore, advanced disease of the heart is imminent as the disease progresses, such as
right-sided congestive heart failure. Other conditions include pulmonary thromboembolism and
pulmonary hypotension. Heartworm disease is catetrophic to the patient, thus should be
prevented with yearly testing to catch the disease as early as possible.
Yearly testing for heartworm disease uses antigens. ELISA tests are able to test for an
antigen produced by female heartworms but are unable to detect male heartworms (Dryden,
2017). Therefore, if a female heartworm is inside the patient, it will produce an antigen and will
be detected. False positive antigen tests are possible; it is recommended to perform an additional
test to confirm the patient is truly positive. Examination of the blood via Knott's testing
determines if microfilariae are in the bloodstream, which confirms the diagnosis. Radiography of
the thorax allows for evaluation of the severity of the disease and the damage caused by the
disease. Echocardiography can be used to confirm a diagnosis, but it is not efficient if the
severity of the disease is minimal.
Before treatment can commence, an examination of the animal is done. This is done to
assess the severity of the disease and to assist in choosing the right treatment protocol. Dogs are
rated high or low risk for post-adulticide thrombosis or embolism during this assessment (Ames,
, 2025). Low risk includes those without any clinical signs, and high risk includes those with
clinical signs or abnormal findings on radiography. The biggest concern for treatment is ensuring
exercise restriction is completed. Exercise restriction prevents the possibility of a blockage inside
the heart. Owners are relied on heavily within the treatment plan to complete this. There are four
different treatment protocols. One is treatment with the antibiotic Doxycycline and the adulticide
Melarsomine, but Melarsomine is given in three doses. This treatment protocol is recomended by
the American Heartworm Society (AHS), a group that provides information and preventive
treatment protocols for animals infected with heartworms. This option renders most dogs
antigen-negative and kills 99% of heartworms (Ames, 2025). A similar option is the use of
Doxycycline and only two doses of Melarsomine. This option is appropriate for clients with
financial constraints, but it is not as effective as the first treatment option. The third option
includes Doxycycline and preventive doses of Ivermectin. This option takes longer than the first
two, and the time of death for heartworms is unknown. This treatment plan is appropriate when
the dog has a guarded to grave prognosis. There is a fourth option, but it is not recommended by
AHS. It is known as the”slow-kill” method, which involves only using Ivermectin. This option
can take up to two years and requires non-stop exercise restriction. This method is not
recommended as there is nothing being used to prevent mosquitoes from acquiring the disease
from the infected dog. The disease can also progress over this time, increasing the risk of lung
disease, respiratory complications, and cardiovascular complications. While treating for
heartworm disease, the patient's quality of life must be considered. The excessive exercise
restriction can quickly decrease the quality of life for many patients, which is why the best
medicine is preventative care.
Hailey Booker
M210327JS0
4/19/2026
, Understanding common diseases is important for the veterinary technician, as this can aid
them in educating clients and assisting doctors. Diseases can be infectious, parasitic, immune-
mediated, congenital, neoplastic, metabolic, toxic, or congenital. A disease from each of these
classifications will be discussed in this writing. The in-depth discussion of each disease will
include the causative agent, species affected, clinical signs, tests, treatment, prevention, and
control programs. Species discussed will include canines, felines, equines, ruminants, and avians.
Canine dirofilaria immitis is a parasitic infection, known as heartworm disease.
Heartworm disease primarily affects canines but can also be found in cats and ferrets.
Heartworm disease starts with mosquitoes. Female mosquitoes ingest microfilariae from an
infected host. Microfilariae molt and change inside the mosquito until they migrate to the mouth
parts of the mosquito. While in the mouth, microfilariae are able to spread disease. When a
mosquito bites a dog to feed, it infects the dog with the larvae. Eventually, these larvae evolve
into heartworms. After the mosquitoes have infected a host, the microfilariae migrate from the
infection site into the heart and lungs. The microfilariae eventually mature and become
heartworms inside the dog, eventually causing catastrophic problems. As they mature, the female
heartworms reproduce and complete the lifecycle. The adult worms can survive in a dog for 5-7
years (Collins, n.d). Although the heartworms can survive inside the dog for lengthy periods,
they cause severe symptoms and clinical signs for the patient.
Ideally, patients are positive on an antigen test before clinical signs are shown, but that is
not always the case. Education on clinical signs and severity is important to ensure a diagnosis
can be made. There are four classes of infection in dogs: mild, moderate, severe, and Caval
syndrome (Ames, 2025). A mild infection can have minimal to no clinical signs, but a sign noted
,at this stage is a possible cough. A moderate infection's clinical signs include exercise
intolerance, abnormal lung sounds, and a cough. As the disease progresses to a moderate
infection, clinical signs include all those noted in the previous stage and difficulty breathing,
fainting, enlargement of the liver, and death. The final class of infection includes low-output
heart failure and red blood cell destruction. As the disease progresses, secondary conditions are
more likely to occur. Pneumonitis is inflammation of the lungs, which causes many patients to
cough. Furthermore, advanced disease of the heart is imminent as the disease progresses, such as
right-sided congestive heart failure. Other conditions include pulmonary thromboembolism and
pulmonary hypotension. Heartworm disease is catetrophic to the patient, thus should be
prevented with yearly testing to catch the disease as early as possible.
Yearly testing for heartworm disease uses antigens. ELISA tests are able to test for an
antigen produced by female heartworms but are unable to detect male heartworms (Dryden,
2017). Therefore, if a female heartworm is inside the patient, it will produce an antigen and will
be detected. False positive antigen tests are possible; it is recommended to perform an additional
test to confirm the patient is truly positive. Examination of the blood via Knott's testing
determines if microfilariae are in the bloodstream, which confirms the diagnosis. Radiography of
the thorax allows for evaluation of the severity of the disease and the damage caused by the
disease. Echocardiography can be used to confirm a diagnosis, but it is not efficient if the
severity of the disease is minimal.
Before treatment can commence, an examination of the animal is done. This is done to
assess the severity of the disease and to assist in choosing the right treatment protocol. Dogs are
rated high or low risk for post-adulticide thrombosis or embolism during this assessment (Ames,
, 2025). Low risk includes those without any clinical signs, and high risk includes those with
clinical signs or abnormal findings on radiography. The biggest concern for treatment is ensuring
exercise restriction is completed. Exercise restriction prevents the possibility of a blockage inside
the heart. Owners are relied on heavily within the treatment plan to complete this. There are four
different treatment protocols. One is treatment with the antibiotic Doxycycline and the adulticide
Melarsomine, but Melarsomine is given in three doses. This treatment protocol is recomended by
the American Heartworm Society (AHS), a group that provides information and preventive
treatment protocols for animals infected with heartworms. This option renders most dogs
antigen-negative and kills 99% of heartworms (Ames, 2025). A similar option is the use of
Doxycycline and only two doses of Melarsomine. This option is appropriate for clients with
financial constraints, but it is not as effective as the first treatment option. The third option
includes Doxycycline and preventive doses of Ivermectin. This option takes longer than the first
two, and the time of death for heartworms is unknown. This treatment plan is appropriate when
the dog has a guarded to grave prognosis. There is a fourth option, but it is not recommended by
AHS. It is known as the”slow-kill” method, which involves only using Ivermectin. This option
can take up to two years and requires non-stop exercise restriction. This method is not
recommended as there is nothing being used to prevent mosquitoes from acquiring the disease
from the infected dog. The disease can also progress over this time, increasing the risk of lung
disease, respiratory complications, and cardiovascular complications. While treating for
heartworm disease, the patient's quality of life must be considered. The excessive exercise
restriction can quickly decrease the quality of life for many patients, which is why the best
medicine is preventative care.
