Saturday, August 15, 2015

Could it be a tick? Paralysis tick, that is.

If I had to ponder what the most common diagnosis made by pet owners, and cross referenced that with the most common question I get asked, it would have to be "Could it be a tick?"

In Australia, we have a paralysis tick, Ixodes Holocyclus. The toxin this tick releases whilst it is feeding causes a paralysis, hence its original name "The Paralysis Tick".

Like any other parasite, the effects it has on the host is usually predictable. Given that it is a common parasite along the Eastern seabord of Australia, it is also a reasonable question for pet owners to ask, "Could it be a tick" when their pet is unwell.

The beauty of our cats, is that it is one of the few situations where the way they show up with tick poisoning is classic
 -  their meow sounds like they have sung too many songs at the karaoke bar
- in the early stages, they walk with their body very close to the ground
- in the advanced stages, if you pick them up, their legs go all over the place
Pandora (the boss) staying as far away from ticks as she can. 

In fact, one of my first after hour cases as a new graduate vet (back in 1990) was a tick poisoning in a cat - except I didn't recognise it at the time.  I stayed back at the vets until midnight trying to figure it out, (which I did eventually), and the cat recovered fine (me, I still remember that night vividly!)

Now, dogs! Well, they can present as virtually anything.

The typical signs are
- the weakness in the back legs, progressing to the front legs.
- the heavy breathing
- dilated pupils in the eyes
- loss of voice (again the karaoke bar thing)
- gagging and coughing

When I was a vet student (yes, many years ago), I was privileged to attend a lecture given by a prominent veterinary neurologist (who I shall call Dr Rick for the purpose of the story).  It was a small group lecture, and I, again, was fortunate enough to be sitting next to Dr Rick during the lunch break.  In between munching on my yummy chicken wrap, I asked him the question -

"What is the strangest presentation of tick poisoning have you seen"

You see, the week prior, at the vet hospital I was volunteering at, the vets had seen a dog that had been weak in all four limbs for about 10 days - it didn't get better, it didn't get worse. All legs were equally weak, and the dog was otherwise fairly alert.  The vet had done spinal xrays, which were normal, and the job was then given to me (because I was a student)  to do a neurological examination.

As a student (and even as a vet), performing neurological examinations either fills you with dread, or with excitement.   As a systematic person, I just followed the steps, collated the results, which,  pointed to a lower motor neurone (LMN) disease..... and the most common LMN disease was tick poisoning.

 Ok, so have you ever been in a position where you had to tell two people who were much higher than you on the food chain, that they had missed a tick? And when they find the tick, watch as they pass this information onto the owner?

Fortunately, it ended well. The dog was treated, and made a full recovery. 

The Paralysis tick of Australia
Dr Rick  shared a similar story, except that neuro examination didn't show any lower motor neurone signs (well not early on) and this dog went on to have the full neuro workup (which included MRI and spinal taps), until a tick was found 10 days later (hiding as they do). Of  course, a happy dog after tick treatment was given. Even specialists can be fooled.

So, to answer the pet owner's question when they bring their "aint doing well" pet in, "Could it be a tick?", well,  yes, it could.

I have seen 
- a pet unable to blink in one or both eyes (with a tick found nearby causing local paralysis)
- gagging or vomiting only but walking normally until 3 days later
- a heavy grunt when they breath out only (we call it expiratory grunting) but walking normally

I remember a story where the pet had come down with tick poisoning signs 4 weeks after visiting a tick area (lucky they saw a vet who was clued in on the signs). 

So tick cases don't always follow the textbook or the rules.

But what tick poisoning doesn't do -
- it doesn't cause pets to be lame
- it doesn't cause pain
- it doesn't cause a temperature or fever (or the dry nose)
- it is not a cause of panting alone (although it can cause panting)
- it doesn't cause trembling legs
- it doesn't stop pets from eating (they will still eat with tick poisoning, they just may struggle to swallow it properly).

If in any doubt, do a full tick search  - because you never know!

You will recall there was some mention of "hiding places" for ticks.  Well, they love to be around the front legs, under the neck, and the lips.  They really do love the lips and eyelids of dogs.

The most horrible spots I have seen and heard about include up the nostrils, in the mouth itself, in the vagina or prepuce.  I have seen ticks down the ears, but as its  a spot we check, it isn't a real hiding place from us!

As we are heading into tick season, now is the time to start taking precautions in all of your pets. Any mammal (except the bandicoot), can come down with paralysis, so never assume your pet is "immune". 

If you need advice on the best options for your particular circumstance, do not hesitate to drop in to us at Russell Vale vets, and speak with myself, or my vet nurses Dirk and Tegan.   If you are not local, then ask your local vet instead.

As vets, we see the tick poisoning cases, so we have a fair idea of what tick preventatives do work, and what don't.  Vets should be the people you should be asking for the best tick preventative advice, not the pet shop or supermarket check out person.

I am Dr Liz, the mad vet from Bellambi.  If there are any questions or comments, just sing out!