| Question |
Answer |
| Canine filariasis Dirofilaria immitis |
|
| Dog Heartworm Canine Heartworm |
|
| Is heartworm zoonotic |
Yes |
| Definitive hosts for heartworm |
Dogs, cats, foxes and wolves (also sea lions, seals, bears and ferrets) |
| What are the incidental findings of heartworm |
Calcified lesions in skin and/or lungs |
| What are the clinical signs of heartworm |
Fever, cough, chest pain and eosinophilia |
| Are cats good hosts for Dirofilaria |
No, infection prevalence is <10% of unprotected dogs in any area |
| What shape tails do adult male Dirofilaria have |
Coiled, 15-20CM |
| What shape tails do adult female Dirofilaria have |
Straight - 25-30CM |
| What colour are adult heartworms |
White |
| Where do adult heartworms reside |
In the pulmonary arteries and right ventricle |
| True or False - female Dirofilaria are larviporous/viviparous |
TRUE |
| What are the pre-larvae called in Dirofilaria |
Microfilaria |
| Where do microfilariae circulate |
In the blood |
| Where do microfilariae develop (L1-L3) |
In malphigian tubules of mosquitoes |
| Where are the MF deposited from mosquito mouthparts |
Next to the feeding site |
| How long to L3's have to make it into the site of feeding |
3-5 minutes |
| Where do MF molt to L4 larvae |
In the SQ tissues |
| How long does the molt from L3 to L4 take |
304 days |
| How long do juvenile worms migrate for (L4/L5) |
2-3 months |
| Where does L5 migrate to |
The heart |
| How long does L5 to adult maturation take |
3 months |
| When do mosquitoes feed more |
In the evening |
| How long can IH mosquitoes survive for |
600 days, overwinter in burrows |
| Can transplacental transmission take place in heartworms |
Yes |
| What is the prepatent period of heartworm |
6 months |
| How long is the patent period of heartworm |
5-6 years |
| How long can circulating MF survive in the host |
Up to 2 years |
| At what temperature does development of Dirofilaria cease to happen |
Under 57oC |
| Is transmission seasonal |
Yes, summer months more prevalent |
| Where do mosquito IH for Dirofilaria overwinter |
Rodent burrows |
| What two behavioural activities can influence transmission of Heartworm |
Closeness to water and being outdoors |
| What five conditions affect occult infections |
Abberant migrations, single sex infections, immune mediated removal, drug sterilization and prepatent infections |
| What is the (underestimated) prevalence in canines (USA) |
25% or 9 out 1000 (make sense |
| What are the clinical signs in an early infection of heartworm |
No clinical signs |
| What are the clinical signs in a moderate disease infection |
Coughing, abnormal lung sounds and exercise intolerance |
| What are the clinical signs in severe disease infections |
Dyspnea, hepatomegaly, syncope, ascites + death |
| What do dogs mainly exhibit in heartworm infections |
Cardiopulmonary disease signs (soft to deep chest cough, rapid breathing, exercise intolerance, fatigue, inappetence and anemia |
| In very serious cases congestive heart failure may occur, what are the signs |
cardiac arrythmias, hemoglobinuria, icterus and edema |
| Are heartworm infections in cats easy to diagnose |
No, may be asymptomatic or respiratory signs and death |
| What is the most common clinical sign in hearrtworm infected cats |
Respiratory signs |
| What does HARD stand for |
Heartworm Associated Respiratory Disease |
| What are the outcomes of HARD |
Vascular and airway disease, allergic bronchitis due to death of immature worms in respiratory passages |
| What percentage of infections are occult infections in cats |
80% are occult (low circulating antigen, 1-2 worms) |
| Are antigen or antigen tests good for detecting cat infections |
No |
| What are the pathology and clinical signs related to |
Worm burden and location, duration of infection, age and size of the dog, activity of the dog |
| Obstructive pulmonary arterial disease causes clinical disease - name two |
Endarteritis (villous/rugae formation), Thrombus formation (arterial obstruction) |
| What are the sequelae of chronic obstructive disease |
Enlargement of pulmonary artery and caudal lobar branches, reverse "D", congestive right heart failure |
| What does thromboembolism look like |
Pruned tree in dogs, pulmonary pathology of lungs |
| How does liver damage occur in heartworm infections |
From obstructed flow |
| How does kidney damage occur in heart worm infections |
Renal capsular inflammation |
| Does interstitial pneumonitis affect both cats and dogs |
Yes, interstitial bronchitis + inflammation |
| What is caval syndrome |
Obstruction of the tricuspid valve - VERY SERIOUS |
| What is the primary diagnosis for heartworm |
Serodiagnosis (ELISA) - based on female antigen detection |
| What are the problems with serodiagnosis (ELISA) as a diagnostic test |
Occult infections, false negatives (rare), too few female worms, immature infections, Ag clearance (spleen + kidneys) |
| How do you identify MF in blood (what test) |
Modified Knott's Test |
| What signs can be picked up in radiography concerning heartworm |
Reverse "D", enlarged, blunt, tortuous pulmonary arteries (good for felids) |
| Which test demonstrates worms in the heart and pulmonary arteries |
Echocardiography (ultrasound) - RH enlargement is rare in cats |
| What is the best treatment |
Prevention |
| What is the basic strategy for prevention of heartworm |
Eliminate adult worms, circulating MF + prevent re-infection |
| Which species is Adulticide not recccommended in and why |
Cats - causes thromboembolism and death |
| What is the drug name and trade name for Adulticide |
Melarsomine dihydrochloride or Immiticide |
| What are the advantages of immiticide or adulticide |
Does not impair liver or kidney function, no sloughing at the injection site, it has high efficacy |
| What is the alternate treatment to adulticide |
Surgical removal of adults (not for cats) |
| What is the post treatment support for heartworm |
Rest, fluids, corticosteroids if needed |
| How do you cause death of microfilaria (microfilaricide) |
NO FDA approved drug - Ivermectin and Milbemycin Oxime |
| What bacteria can be used to detect heartworm, as it has a symbiotic relationship |
Wolbachia, in "slow kill" cases |
| What does tetracycline do to adult female worms |
Results in infertility in female worms |
| What is used for prevention of infection or re-infection of heartworm |
Chemoprophylaxis - marrocyclic lactones (avermectin + milbemycin) + mosquito control with permethrins |
| Why is Dipetalonema reconditum so important as a parasite in dogs |
Can be confused with MF of Dirofilaria immitis duringh diagnosis, but it is NON-pathogenic |
| What is the intermediate host for Dipetalonema reconditum |
Fleas (Ctenocephalides + Pulex) or the Louse (Heterodoxus spiniger) |
| How long does development take in the IH for Dipetalonema reconditum |
7-14 days |
| How long does development of L3 to adult take in Heartworm Mimic |
2-3 months |
| Where do adult worms reside in dog |
SQ + Connective tissues |
| Where do MF circulate in Dipetalonema reconditum |
The blood |
| What is the difference between DI and DR in terms of worm number in infections |
DI - Numerous/ DR - Only a few |
| Which species is smaller DI or DR |
DR - 240-290uM (290-340uM in DR) |
| What is the difference in width between DI and DR |
DI - 6-72uM (5-6uM in DR) |
| The difference when stained with alkaline phosphotase between DI + DR |
DI - localized in anal/buccal areas/DR - uniform staining of body cavities |
| What will the ELISA test show in Dipetalonema infections |
Negative |
| Which criteria are used in Modified Knott's Test preparations |
Length + Width |
| What is the family of Thorny Head Worms known as |
Acanthocephala (Thorny Head) |
| What are the definitive hosts for Thorny Head Worms |
Domestic animals and free ranging laborotory animals (primates, salmon, water-fowl) |
| How do you identify Thorny Head Worms |
Retractable spiny proboscis, pink in colour, flat body, NO digestive tract |
| What does the larva develop into in the Thorny head worm |
Acanthor |
| What is the IH for the Thorny Head Worm |
Arthropods |
| What stage is passed through before becoming encysted infective larva in THW |
Acanthella stage (to become cystacanth) |
| What can happen to the cystacanth once developed |
Re-encysts in PH or can re-encyst in the DH |
| Macracanthorhynchus hirudinaceus |
Thorny Head Worm of Small Intestine (Swine) |
| How do pigs aquire Macracanthorhynchus hirudinaceus |
When rooting for beetle grubs |
| How long is the cystacanth stage in the beetle |
3 months |
| How long is the PPP of Macracanthorhynchus hirudinaceus |
2-3 months |
| What are the clinical signs in pigs with THW infection |
Asymptomatic or diarrhea, emaciation, abdominal pain, and peritonitis (2ndary bacterial infections) |
| What are the depth of clinical signs dependant on |
Depth of the proboscis in the intestinal wall |
| What is the treatment for THW infections |
Ivermectin or benzimidazoles |
Alva Jackson
on 2009-11-05
Biology Lab Midterm
