Cat and dog non GIT nematodes

Question 1

Heartworm is and common in

Answer 1

Dirofilaria immitis
Dogs
Rarely cats (rarely patent)
Very rarely people (not patent; SQ and lung nodules)

Question 2

Who is the DH of heartworm

Answer 2

Domestic and wild canids normal DH

Question 3

How do animals get heartworm

Answer 3

Mosquito vectors
Numerous genera
Seasonal transmission
Only during mosquito season

Question 4

Where is heartworm common

Answer 4

This parasite is endemic only in certain areas of canada. It has not been found as a locally acquired case in Alberta or Saskatchewan. It is found in southern Okanagan Valley of BC, southern MB, southern ON, southern Qc, and parts of NB
Low provenance in canada (0.32% in 2019)

Question 5

Why is important to know where heartworm is endemic

Answer 5

Advise those travelling
Look at dogs coming from those areas closely
Go to Ddx first then heartworm if not prevalent

Question 6

Diagnosis of non GI nematodes is by

Answer 6

Diagnosis- antigen testing of blood, modified knott’s test, radiographs

Question 7

Life cycle of heartworm

Answer 7

Mosquito pick sup eggs from dog
Grow in mosquito for approx 14 days at temps above 14*C
L3 is deposited in dog by mosquito
PPP 6-7mos
Adults live 5-7yrs
L1 live 2 yrs

Question 8

Pathogenesis and clinical signs of heartworm

Answer 8

Often asymptomatic
Decreased exercise tolerance, coughing, anorexia, weight loss
Severe cases: Right heart failure, hepatic congestion, ascites, syncope, death
Caval syndrome (small dogs, rarely cats): worms block the caudal vena cava/tricuspid valve: requires immediate surgical removal of worms

Question 9

Diagnosis of heartworm

Answer 9

History (geographic location, travel)
Clinical signs
radiographics/ultrasound
Enlarged pulmonary arteries and right heart
May see worms
Diagnostic tests
Microfilarial concentration test (modified Knotts)*
Immunodiagnosis
Adult female antigen detection (DOGS)*
Antibody detection (CATS)
AHS recommends do both annually
Cannot diagnose until infected 6-7 months infected on a blood smear
Antigen tests take just as long

Question 10

Prevention of heartworm

Answer 10

Preventative medications are recommended for those dogs and/or travelling to endemic areas in North America
These drugs work by killing circulating L3 and early L4 larvae in recently infected dogs
Preventative medications are given to dogs one month after mosquito season starts until one months after it ends
Given per month (mostly)
Numerous products - all work well
Resistance reported in highly endemic regions
Recommended to test prior to starting preventatives

Question 11

Monthly prevention for heartworm

Answer 11

(kill L3 and L4)
Ivermectin
Milbemycin
Selamectin
Moxidectin
*resistance developing

Question 12

Adulticids for heartworm

Answer 12

kill adults)
Melarsomine (immiticide)

Question 13

Microfilaricides prevention for heartworm

Answer 13

(kill L1)
Ivermectin
Moxidectin

Question 14

Heartworm testing recommendations

Answer 14

Who? Pets living in or travel to endemic regions
What tests? Antigen, Knotts, or antibody (cats)
Where? Annually in endemic regions
When? At least 6 months after last possible exposure (spring in canada)

Question 15

Why test for heartworm

Answer 15

Prior to starting preventatives (anaphylaxis)
If suspect noncompliance in endemic region
To monitor success of treatment
Many drug companies will not cover the cost of adulticidal treatment if pets are not tested annually

Question 16

Lung parenchyma is and common in

Answer 16

Aelurostrongylus abstrusus
Cats in BC and atlantic Canada
Often asymptomatic, may cause coughing, even death
ML, fenbendazole

Question 17

Life cycle of Aelurostrongylus abstrusus

Answer 17

First stage larvae in feces of BAL
L1-L3 in snail/slug
can eat the slug directly or a paratenic host containing L3 after eating IH

Question 18

Lung worms of dogs

Answer 18

Filaroides (Oslerus) osleri (airways
Wild canids and dogs who hunt

Question 19

Life cycle of Filaroides osleri (Oslerus)

Answer 19

Atypical direct life cycle
Oviviparous
L1 is shed and infective stage
L1 are also shed in saliva and vomit, may be transmitted to pups via regurgitated food

Question 20

Pathogenesis of Filaroides

Answer 20

F.osleri
Often asymptomatic
Pathognomonic cough/retch triggered by exercise, cold
Nodules may abstract air, cyanosis and collapse in pups

Question 21

management of Filaroides (Oslerus) osleri

Answer 21

Decontaminate environment, break vertical transmission (hand rear pups), repeated treatment with ML or fenbendazole

Question 22

Capillaries life cycle

Answer 22

Direct or indirect life cycles (earthworm host P or I??)
Eggs are shed stage, have polar plugs
L1 develops in eggs, ineffective stage (like trichuris vulpis)

Question 23

Capillaria aerophila (eucoleus aerophilus) common in and where do they live

Answer 23

Dogs, cats, wild canids
Adults live in trachea and bronchi, shed eggs in feces

Question 24

Capillaria (Eucoleus) boehmi common in and live in

Answer 24

Dogs and wild canids
Adults live in nasal and sinus cavities, shed eggs in feces

Question 25

Capillaria (Pearsonema) plica is common in

Answer 25

Dogs and cats, wild canids
Adults live in bladder, shed eggs in urine, +/- cystitis

Question 26

Dioctophyma renale (giant kidney worm) DH

Answer 26

DH: dogs, wild canids, mustelids

Question 27

Dioctophyma renale (giant kidney worm) looks like and common in

Answer 27

Live in the renal pelvis, generally of the right kidney, sometimes free in peritoneum
Destroy kidney parenchyma but usually subclinical (unilateral)
Incidental finding on spay
Relatively common in MB and northern ON
*very rarely infect people

Question 28

Life cycle of Dicotophyma renale

Answer 28

Eggs in urine
oligocheate in IH
L1-3 in IH
can eat IH
Most common L3 in paretenic host is eaten
PPP is 4-5 months