A survey conducted in 2004, by the American Heartworm Society, revealed ___ dogs were diagnosed with heartworm disease across the United States.
The first case of heartworm diesase was identified in the canine population more than __ years ago, with the first case of feline heartworm disease found in 1920's.
HW diseases means what 2 things?
1. has heartworms 2. the animal suffers from the debilitating symptoms
What is the family for heartworm diease?
Dirofilaria immitis with its definitive host the __
What are the stages of heartworm?
Stage 1- Microfilaria- 1st adult and mosquito
Stage 2- No Name Stage-Mosquito only
Stage 3- Infective Stage-mosquito and 2nd adult
Stage 4- Pre-adult Stage 2nd adult only
Stage 5a- Immature Adult Stage- 2nd adult only
Stage 5- Mature Adult Stage- 2nd adult only
Of all known species of mosquito some __# are known to transmit D.immitis; however recent studies indicate that some species are more prone to take blood meals from dogs and some from cats.
The __ mosquito is common in the homes of people in the US and effects both dogs and cats.
__ % of dogs positive on occult test for dirofilaria immits, are known to be negative for microfilaria.
What are some reasons why we dont see microfilaria?
1. same sex
2. WBC attacks
What transmit heartworms?
What transmit Acanthochelonema reconditum?
the flea! (Ctenocephalis felis)
What are 5 ways to diagnosis heartworm diseas using blood samples?
Direct smear 64%
modified knot's test 84%
Difil test- best microfilaria test
What are 3 other ways to diagnosis heartworms besides blood samples?
History, Radiology, Echocardiography
What does ELISA stand for?
Enzyme linked immunosorbent assay
Any test that detects antigens or antibodies is considered an __
It was once written that all antigen test required at least __ mature females
What are the top 4 heartworm symptoms noted by the owner are:
2. loss of stamina
4. front legs bowed outward
What are 4 causes of false negatives on a blood sample antigen test?
1. blood sample is not warmed up to room temperature
2. infection is light
3. female worms have yet to mature
4. they are only males in this infection
Why are ELISA test not as senstive to heartworms in cats?
1. Due to low heartworm burden 2. immature female heartworms in the early stages of the life cycle 3. a male heartworm infection
Overall, the msot useful tests to confirm heartworm infection in cats are:
1. serology (Antibody levels or antibody test), thoracic radiographs or an echocardiography
The changes typically seen in canine radiographs with heartworms include:
1. enlargement of the pulmonary artery at 1 o'clock
2. enlargement of the right side of the heart commonly called the "inverted D"
What are some changes in the radiograph of a cat with heartworms?
1. enlargement of the main lobar and peripheral pulmonary arteries
2. the pulmonary artery is gretater that 1/6 times the width of the ninth rib
There are two views that are a must for determining the SEVERITY of heartworm infection:
1. Lateral view- heart more than 5 ribs in length and sits on the sternum
2. Ventral Dorsal View
a. enlarged pulmonary artery-1 o clock
b. enlarged right side of heart- inverted D
Macrocyclic lactones includes the following preventive mdications:
2. milbemycin oxime
The macrocyclic lactones are highly therapeutic possessing, anthelminthic activity against what 4 things?
2. 3rd and 4th stage larvae
3. and some instances young adult heartworm S5a
Nemcide, Dirocide, Filaribits
Diethylcarbamazine citrate- Pfizer
ivermectin- Merial (Merick)
Moxidecting- Ft. Dodge
Moxidectin+ Imidacloprid - Bayer
What are the 3 products that produce a reaction when animal has microfilira?
Is Diethylcarbamazine citrate a macrocyclic lactone?
What is the liquid diethylcarbamazine phosphate?
When is it okay to give DEC to a dog with heartworm?
occult infections (adult only) usually prior to microfiliaria infection and under 5 months
Ivermectin (Heartgard) kills what stage of heartworm?
It is well knonw that some __ dogs (autosomal recessive inheritance) and other glycoprotein deficient dogs are unusally sensitive to high does of ivermectin. In excessive of 16 times the minimum effective prophylaxis does.
What stage of heartworm does intercepter kill?
L3 and L4
What are two topical preventatives for heartworms?
1. Selamectin- Revolution
2. Moxidectin with imidacloprid - Advantage multi
Whats the injectable product for heartworms?
What is the heartworm found in large cats primary in Africa?
What does the head of dirofiliaria immitis look like?
What does the head of Ancathochelonema recondium?
Button hooked tail/blunt head
What are some symptoms/signs of a dog with heartworms?
1. weight loss
4. accumulation of abdominal fluid
5. labored breathing
6. increased temperature
7. cyanotic membranes
What aren't more animals protected from heartworms?
1. 24% of all pet owners, spend nothing at vet
2. clients do not understand the disease
3. pricing of treatment and prevention deter many clients from starting on a prophylaxis
Why do clients go to vet hosipitals?
1. 1/3 go for vaccinations
2. 1/3 of all go only when ill
NOTE: presuading clients to further health care for there pets is communication and consistency
What product can be used for demodectic mange?
Advantage multi- moxidectin with imidacloprid
What is an injectable product for heartworms?
Proheart 6 (Moxidectin)
Macrocyclic lactones chemoprophylaxis will do what 3 things?
1. clear microfilariae from the blood of dogs
2. retard repopulation by gradually suppressing embryogenesis
3. shorten the life of the adult
What are treatments for adult heartworms?
1. Melarsomine dihydrochloride (Immiticide)
2. Thiacetarsamide sodium (Caparsolate)
Immiticide is administered in deep __ muscles
All macrocyclic lactones have a "__" of two months
This drug has been used as an adulticide for heartworms since the mid 60's and is still available in Asia and parts of Europe
What are some other heartworm adulticide not in use today?
Why was levamisole taken off the market?
unsafe (organophosphate like symptoms)
What is the drug of choice for microfilaricide treatment?
What are the 6 microfilaria treatments today and yesterday?
2. Selamectin (Revolution)
3. Milbemycin oxime (Interceptor)
4. Dithiazine Iodine (Dizan)
5. Levamisole HCl
Adult worms when treated with the adulticide will die in ___
9 months to 1 year
What is class 1 of heartworms?
asymptomatic to mild heartworm disease
no radiographic signs
no signs of anemia
What is class 2 of heartworms?
moderate heartworm disease
radiographic signs are present
anemia is present PCV less than 30%
What is class 3 heartworms
severe heartworm disease
stabilized and alternate dosage
What is caval syndrome also known as?
Most filarial nematodes, including D. immitis, harbor obligate, intracellualar, gram negative bacterica called?
It is hypothesized that Wolbachia contributes to _ and _ inflammation
pulmonary and renal producing endotoxins
What is the lifecycle of Dirofilaria immitis?
Dog #1 has adults (S5) and microfilaria (S1)
Mosquito takes blood and picks up S1
S1 molts to S3 in mosquito, time temp depend
Mosquito inserts S3 & saliva in dog #2
s3 molts to s4 in SQ tissue
S4 stays in SQ for 100 days
S4 molts to S5 (preadult) and it moves to pa
S5 preadult stays in PA for 80days and then molts to adult S5
What is the formala to convert celcius to F*
9/5 x C + 32 = F
why treat for microfilaria
a dog positive for microfilaria is potential threat to other dogs
pathological changes associated with high #s of microfilaria make the treatment of the dog for adults more complex
If the dog is positive, and an owner where to buy DEC resulting in shock or death
What is type 1 hypersensitivity (anaphylactic)
mast cells (basophils) release histamines that:
dilate blood vessels
hypotension insues resulting in a decreased in cardiac output
loss of tone in the capillary walls and sphincters
blood pools in all peripheral vessels
blood cannot get back to heart and lungs to receive O2
animal goes into coma and dies of hypoxia
symptoms of anaphylactic shock
reaction occurs within 20 mins time frame
WBC goes down in 1 hour
What are some options in treatment for dogs with heartworms
adulticide and microfilaricide
or just microfilaricide
Signs of heartworms disease in cats usually develop during on of what two stages:
arrival of the immature S5 in the pulmonary artery
death of adult heartworms
The ititial phase of feline heartworm disease is often diagnosed as asthma or allergic bronchitis but is actually part of a syndrome now known as :
Heartworm- associated respiratory disease (HARD)
what is AHA?
american heartworm association
what is the gold standard for dog occult test?
What is the earliest detection for antibody, radiographs, echocardiograph, antigen