CVE Control & Therapy Series – December 2011, Issue 265 Reply to Tick paralysis in the cat C&T Nos. 5148 & 5149, Issue 264, Sept 2011 C&T No. Frank Gaschk BVMS Vetwell Veterinary Group, Brisbane QLD Grrinninbear Designs (Studio) E. franko@grrinninbear.com.au The Brisbane Exhibition (the ‘EKKA!’) marks the annual start of tick season for this vet. However, this year after the summer of Eastern Australia floods and very wet summer, it seems that my colleagues and local emergency centres have been seeing paralysis tick cases throughout winter (personal communication). The replies and protocols have made me realise that the ‘11-step Treatment Protocol for Tick Paralysis in Cats (2008/09)’ has not had any recent updates (see last page). The original document was developed, and still holds knowledge, from annual continuing education talks presented by ‘Professor Tick’ – Professor Rick Atwell of Queensland University – and the feline practitioners at The Cat Clinic practices in Brisbane. That being said, I realise I missed the 2011 ‘Tick Talk’ by Professor Atwell, so would be interested in any practical treatment advances, from those who attended. Here are some discussion points in addition to the protocol that I think are important when treating cats:- Centre for Veterinary Education – www.cve.edu.au CVE Control & Therapy Series – December 2011, Issue 265 Feline Patients and Tick Paralysis ‘Cats are not dogs’, said the feline practitioner. Respiratory signs can predominate over ataxia in the feline patient. Note: ’Something is caught in the cat's throat’ should alert the reception nurse taking the initial phone call Knowing a potential tick paralysis case is on its way in to the practice can help in making treatment preparations Not all cats are the same. A ‘senior’ cat would be treated more cautiously with underlying renal considerations in mind, than a young cat Remove any obvious ticks If the owner has done this already, they should be instructed to bring the tick with them Weigh the cat, ideally on paediatric scales, and write the weight down straight away. Consider sequestering a recently-arrived-at-the-practice, anxious ‘choking’ cat in a warm, quiet, well oxygenated space to attempt resolution of the respiratory symptoms before proceeding with further handling and treatment. First treatment is a small dose of 'time to settle down' Use of Sedatives Try and minimise acepromazine (ACP) use with the longer term view of preserving the functioning renal tissue in a feline patient. ACP is anxiolytic for the vet because the cat becomes sedated. Consider treating the cat with anxiolytics; some are listed in the protocol, rather than a sedative. If the vet really needs to reduce his or her own anxiety and dose the cat with ACP, use the tiny dose rate of 0.03mg/kg please.* Intravenous Access An IV line is handy, if you can get it without stressing the patient (see the protocol). Applying EMLA cream to desensitise the skin is worth doing while the cat settles in an oxygen cage. It takes 10 minutes to work. A PCV/ TP and blood smear can be performed from the drop of blood in the clear stylus well Excessive application of very sticky (pink Elastoplast) tape may prove difficult to remove at the end of treatment - as for any bandage application, consider the comfort of the staff that may have to remove or replace the tape Suggestions? Premedication Draw up adrenaline, atropine, and be prepared to crack the vial of SoluDelta Cortef (prednisolone sodium succinate) in case clinical signs hypersensitivity develop during treatment. Centre for Veterinary Education – www.cve.edu.au CVE Control & Therapy Series – December 2011, Issue 265 Pre-medicating the cat with SoluDelta Cortef can be prudent, if the patient has received tick antitoxin serum (TAS) in previous seasons Many Ways to Treat a Cat (IV or IP?) Routine, general practice, feline tick paralysis cases can receive tick antitoxin serum via various routes of administration. Two examples:1. If you have an IV line in place in a low stress patient, then that is an obvious route of tick antitoxin serum (TAS) administration. Diluting the TAS and administering over 20 minutes via an IV syringe pump is perfect. Do not give the TAS as a bolus! 2. If you have a stressed patient, it's the middle of the night or the middle of something else, you're a recent graduate or a stranded vet without a bag of cat handling tricks, then give the TAS as an intraperitoneal bolus. It's not fancy but it works. o The situation dictates the response. The aim is to administer the TAS: i. with the least amount of stress to the cat to minimise the acute respiratory signs, ii. with the least amount of scarring to the vet and; iii. in a timely manner to mop up all the unbound toxin ASAP o I am yet to deliver TAS SC but have given compliant, conscious cats fluid boluses of up to 100mL SC (in home treatment of end stage renal disease). o In discussions with a feline medicine specialist, they advised that they do not see routine cases; the tick paralysis cases they see tend to be 3C and worse. They use the IV route with a measured dose pump to deliver the TAS dose over greater than 20 minutes. o 2011 is already a dangerous tick season in Queensland. Contemporary anecdotal reports communicate that there are more cases and more severe cases with high tick paralysis scores. With immobile paralysis cases, the IV route with premedications is being found to be the most clinically effective for saving feline patients. Some practitioners and emergency centres are using 2 to 4 mL/kg of TAS, despite the current peer-reviewed, published science suggesting that increasing the dose should have no improvement in treatment effect. The clinical observation is that the badly affected cats respond better to the higher dose IV. Centre for Veterinary Education – www.cve.edu.au CVE Control & Therapy Series – December 2011, Issue 265 Nursing is Important Most of the ‘11-step Treatment Protocol for Tick Paralysis in Cats (2008/09)’ is notes on suggested nursing. Be kind and appreciative to any staff who nurse a patient through a tick paralysis episode. The point made in other articles about local paralysis (e.g. facial nerve paralysis) is important. A cat that develops an eye ulcer due to desiccation of the cornea while paralysed may be euthanased due to budgetary constraints for further treatment. Attentive nursing is important. The toxin can take quite some time to dissipate fully from a patient. It is prudent to be aware of this during aftercare i.e. keep cats indoors for several days after discharge. The Best Prevention - ‘Walk your cat once a day’ The best prevention for most things is education. Educating pet owners about the risk management of pets and paralysis ticks is best. It is a common discussion point during vaccination and various scheduled health checks. Educating staff to cover the topic with each client is important. Educational posters, displays or client care seminars are appropriate during ‘tick season’. Frontline Spray is effective as a topical preventative for cats. Unfortunately the application can also dissolve the cat/owner bond. The regular application of an insect ectoparasite treatment spot-on treatment is a good preventative health measure for cats in general. Review your clinical records as to the evidence of correlation between cats on regular flea control preventative treatment and incidence of paralysis tick treatment. Advising cat owners to pat their cats is always well received. Delving deeper into suggesting walking their cats daily can prove to be intriguing. Explaining that ‘finger walking’ over a pet cat, starting from a nose tickle, through an ears scratch and a scratch under the neck and proceeding logically to cover the full feline topography will likely be a pleasurable purposeful adaptation of a daily interaction. *Editor’s Note – Many practitioners find low dose acepromazine 0.03 – 0.05 mg/kg safe and effective in this setting. Centre for Veterinary Education – www.cve.edu.au 11-step Treatment Protocol for Tick Paralysis in Cats (2008/09) (Vetwell Veterinary Group, Brisbane QLD by Frank Gaschk BVMS) AIMS: Remove tick(s), neutralise unbound toxin, patient support until bound toxin unbinds 1. ‘Score’ gait and respiration (e.g. ‘1C’). Ask: Has cat had TAS before for tick paralysis? (8a) Gait Score (1 - 4) Can walk. Able to stand from recumbency and ambulate. Normal landing from 30 - 40cm drop A Normal character and rate (<30 bpm) B Unable to walk. Requires aid to standing position but can maintain stance. Does not land normally from 30cm drop Normal character and increased rate (=>30 bpm) C Altered character (restrictive / obstructive) with sigh or grunt (undefined rate) 3 Can’t stand. Unable to maintain standing position D 4 Can’t right. Unable to maintain sternal recumbency Severe dyspnoea and cyanosis with progressive reduction in respiratory rate 1 2 2. 3. 4. 5. 6. 7. 8. 9. Remove tick(s) by direct pull method Assess degree of distress: a. Consider leaving cat alone for a few minutes until calmer Does the patient require anxiolytics/ sedation? Consider IM injection: 1. Methadone 0.2mg/kg 2. Diazepam 0.2mg/kg 3. Midazolam 0.05 to 0.1mg/kg IV or SC 4. (ACP <0.03mg/kg) 5. (Anaesthesia?) Oxygen reduces respiratory fatigue a. Oxygen box, if distressed; b. Nasal oxygen if compliant Place IV catheter Collect samples for PCV/TP, UA; a. Full analysis if older cat (jugular v, if compliant); b. Consider careful IV fluids: 1. Dehydrated (e.g. if cat has been missing for a few days) 2. Renal compromise (e.g. older patient); 3. Suspicious of other concurrent disease Medications to have ready; a. Consider Prednisolone sodium succinate (SoluDelta Cortef) 510mg/kg IV 5 min pre TAS* (previous TAS tx?) b. Consider Atropine 0.040.06mg/kg (0.06-0.1mL/kg) If hypersalivation severe If bradycardic Drawn up in syringe to have ready in case of anaphylaxis: Adrenalin (Epinephrine) 0.02mg/kg or, 0.1 ml / cat* of 1:1000 (1mg/mL) IV, IM, SC, Intratracheal (IT) 10. TAS 1mL/kg @ room temp * Do not use as a premed. Use as anaphylaxis tx Respiratory Score (A - D) a. b. IP bolus IV diluted in 25mL saline infused over >20 min 1. Severely affected cats: IV delivery 11. Nursing & monitoring - repeat cycle a. Cage timer/reminder reset b. Maintain normothermic cat c. Clear respiratory tract 1. Suction; (e.g. Tomcat catheter on end of syringe); 2. Extend the neck to maintain clear airway 3. Important: Monitor RR changes for mucus plug blockage in airway (Consider a tracheostomy in severe URT obstruction. Size 3 ET tube). d. e. Nil per os (NPO) Postural Positioning Let cat find own position Sternal is best, if able; Head down, neck extended, shoulders as highest point, LEFT lateral recumbency (R lung is larger) f. Consider chest radiograph (ddx: pulmonary oedema) Tx: Frusemide 1-2mg IV q6h g. Eye lubrication & subdued lighting due to mydriasis h. Repeat tick search 1. 2-3 independent (different people) 2. ‘Finger walking’ and/or combing searches 3. Consider coat clip. Care re: stressing patient i. Frontline spray (note(s): wet coat may predispose to hypothermia. Flammable) 1. Consider Proban 0.5 tablet PR (off label use)
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