Tick paralysis

Question 1

When is the dangerous time for paralysis ticks?

Answer 1

Aug - Nov

Question 2

Explain the 3-host tick life cycle

Answer 2

Question 3

Who is the main resovoir of Ixodes holocyclus?

Answer 3

Bandicoots - they are immune due to constant re-infestation

Question 4

What environment would you see Ixodes holocyclus in?

Answer 4

Warm, moist climates on the coast.
Die in environment in absence of a host.
Die quickly in hot dry weather
Where the resovoir (bandicoot) host is

Question 5

What is the host range of Ixodes holocyclus?

Answer 5

o Cattle
o Bats
o Kangaroos
o Dogs
o Cats
o Mice/rats
o Humans

Question 6

What are the clinical signs associated with tick paralysis?

Answer 6

• Forced breathing
• Grunting while breathing
• Coughing/gagging, sometimes vomiting from difficulty in swallowing
• Weakness in legs or inability to get up, flaccidity in the tail with ascending paralysis
• Lethargy, inappetence
• Change of voice
• Glazed look in the eyes
• Drooling

Question 7

Does removing the tick halt progressions of signs?

Answer 7

No, it does not immediately halt progression of signs as the toxin binds strongly to the receptor

Question 8

How is tick paralysis classified?

Answer 8

Using both a neuromuscular score (1-4) and respiratory score (A-D)

NOTE: animals that present with 3C-4D have a guarded prognosis

Question 9

Does tick paralysis cause chocking in dogs?

Answer 9

Yes, megaoesophagus is associated with tick paralysis

Question 10

Where are the most common places for ticks to attach?

Answer 10

Common attachment sites:
- neck
- ears

Esoteric attachment sites:
- Around eyes
- On/around and under lips
- Under collar
- Inside ears
- Between tows
- Around anus

Question 11

What are the two phases of tick engorgement?

Answer 11

Slow phase:
- first 3-5 days
- Slow secretion of toxin
Rapid phase
- Lasts 12-24 hours (roughly a tenfold increase in weight
- rapid secretion of toxin

Question 12

How much weight gain do we see in an engorged tick?

Answer 12

100x

Question 13

What are the other sequellae of tick bites?

Answer 13

Papules as a result of nymphs

Question 14

List the factors that are not directly related to toxicity

Answer 14

• Size of the tick
• number of attached ticks
• duration of attachement

Question 15

How is tick paralysis treated?

Answer 15

• Expensive treatment
  1. Locate and remove tick(S) - DO NOT squeeze. Give acetylpromazine (sedative, hypotensive and anti-emetic), other drug options include atropine and dexamethasone and adrenaline for cats OR if previous treatment of ATS in dogs.
  2. ATS administered SLOWLY - combined with supportive therapy (if required). Most cases improve 6-12 hours. After discharge, keep quiet for 7-10 days

Question 16

What is ATS produced in?

Answer 16

Rabbits or dogs

Question 17

How many CSIRO antitoxin units per mL is required to be in ATS?

Answer 17

500 CSIRO antitoxin units per mL

Question 18

Can ATS be given multiple times per season?

Answer 18

No, there is a risk of serum sickness (anaphylaxis)

Question 19

What control measures can be in place to decrease the chances of tick paralysis?

Answer 19

• Concerted examination (particularly in the months of high risk)
• Tick collars, spot-ons, chewable tablets and regular washes
• Insect repellent containing DEET
• Control of the environment - dog and cat runs, walking in bushland, fences and netting

Question 20

What are some differential diagnosis of tick paralysis?

Answer 20

o Botulism
o Organophosphate toxicity
o Idiopathic polyradiculoneuritis (“Coonhound paralysis”)
o Polyneuropathy
o Snake bite – brown, black & death adder
o Fish poisoning – tetrodotoxin (toadfish) & Ciguatera

Question 21

What are python ear tags (deltamethrin) used for?

Answer 21

Control of paralysis ticks in cattle in QLD

Question 22

What is

Question 23

What is the name of this tick?

Answer 23

• Haemaphysalis longicornis AKA bush or scrub tick
• mainly a parasite of cattle
• found on the east coast of Aus from QLD to VIC
• It is a vector of Theileria orientalis

Question 24

What are the characteristic features of Haemophysalis longicornis?

Answer 24

o Anal groove indistinct
o Legs all brown
o Short mouthpart
o Rounded scum and festoons
o Flared palps

Question 25

What tick is this?

Answer 25

• Rhipicephalus sanguineus AKA brown dog tick
• Inland tick

Question 26

What are the important ticks of dogs?

Answer 26

o Ixodes holocyclus (paralysis tick; coastal)
o Rhipicephalus sanguineus (dog tick; inland)
o Haemaphysalis longicornis (bush tick, coast and ranges)

Question 27

What are the important ticks of cattle?

Answer 27

o Rhipicephalus australis (cattle tick; Qld)
o Haemaphysalis longicornis (bush tick)
o Ixodes holocyclus (on calves)