Cat and dog non GIT nematodes Flashcards
Heartworm is and common in
Dirofilaria immitis
Dogs
Rarely cats (rarely patent)
Very rarely people (not patent; SQ and lung nodules)
Who is the DH of heartworm
Domestic and wild canids normal DH
How do animals get heartworm
Mosquito vectors
Numerous genera
Seasonal transmission
Only during mosquito season
Where is heartworm common
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)
Why is important to know where heartworm is endemic
Advise those travelling
Look at dogs coming from those areas closely
Go to Ddx first then heartworm if not prevalent
Diagnosis of non GI nematodes is by
Diagnosis- antigen testing of blood, modified knott’s test, radiographs
Life cycle of heartworm
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
Pathogenesis and clinical signs of heartworm
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
Diagnosis of heartworm
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
Prevention of heartworm
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
Monthly prevention for heartworm
(kill L3 and L4)
Ivermectin
Milbemycin
Selamectin
Moxidectin
*resistance developing
Adulticids for heartworm
kill adults)
Melarsomine (immiticide)
Microfilaricides prevention for heartworm
(kill L1)
Ivermectin
Moxidectin
Heartworm testing recommendations
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)
Why test for heartworm
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
Lung parenchyma is and common in
Aelurostrongylus abstrusus
Cats in BC and atlantic Canada
Often asymptomatic, may cause coughing, even death
ML, fenbendazole
Life cycle of Aelurostrongylus abstrusus
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
Lung worms of dogs
Filaroides (Oslerus) osleri (airways
Wild canids and dogs who hunt
Life cycle of Filaroides osleri (Oslerus)
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
Pathogenesis of Filaroides
F.osleri
Often asymptomatic
Pathognomonic cough/retch triggered by exercise, cold
Nodules may abstract air, cyanosis and collapse in pups
management of Filaroides (Oslerus) osleri
Decontaminate environment, break vertical transmission (hand rear pups), repeated treatment with ML or fenbendazole
Capillaries life cycle
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)
Capillaria aerophila (eucoleus aerophilus) common in and where do they live
Dogs, cats, wild canids
Adults live in trachea and bronchi, shed eggs in feces
Capillaria (Eucoleus) boehmi common in and live in
Dogs and wild canids
Adults live in nasal and sinus cavities, shed eggs in feces
Capillaria (Pearsonema) plica is common in
Dogs and cats, wild canids
Adults live in bladder, shed eggs in urine, +/- cystitis
Dioctophyma renale (giant kidney worm) DH
DH: dogs, wild canids, mustelids
Dioctophyma renale (giant kidney worm) looks like and common in
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
Life cycle of Dicotophyma renale
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