Term
|
Definition
-calms patient for physical exam, hoof care, dentistry, repro
-facilitation of IV catheter
-reduced SNS output to surgical stimulation
-reduced anesthesia requirements
-promotes smooth induction and recovery
-standing surgical procedures |
|
|
Term
| What are the major components of equine patient evaluation? |
|
Definition
| -signalment, history, physical examination, diagnostics |
|
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Term
| What are the major components of equine handling and restraint? |
|
Definition
-patient temperament
-handler experience
-sedated animals can still bite or strike |
|
|
Term
| What are the major restraint techniques used for horses? |
|
Definition
-stocks
-twitch: hand on the lip or ear, roll twitch, rope/ chain
-tail holding with foals |
|
|
Term
| What are special about draft breeds? |
|
Definition
-can be more sensitive to alpha-2 agonsits
-invariable receptor density |
|
|
Term
| What is special about donkeys and mules? |
|
Definition
-30% drug dose than hroses
-smaller airways
-thicker skin |
|
|
Term
| What are the possible side effects of standing sedation? |
|
Definition
-severe ataxia
-extreme cases recumbency
-intra-arterial injection: seizures, death, injury |
|
|
Term
| What is the major concern with perivascular injections in horses? |
|
Definition
| -can damage the recurrent laryngeal n |
|
|
Term
| What occurs with sedation in horses? |
|
Definition
-head drop
-droopy lips
-sweating
-standing ataxia
-loss of menace response |
|
|
Term
| Describe the effects of Phenothiazine in horses. What receptors are affected? |
|
Definition
-inhibit conditioned avoidance & reduction in spontaneous motor activity
-Adrenergic (alpha-1), Muscarinic, Dopaminergic (D2), Serotonergic, Histamine (H1) |
|
|
Term
| What is the hallmark sign of sedation with Acepromazine in horses? |
|
Definition
|
|
Term
| What are the side effects of Acepromazine in horses? |
|
Definition
-paraphimosis: goes away in a few hours
-decreased systemic vascular resistance: hemodynamic impact is variable, dec PCV, result of splenic engorgement |
|
|
Term
| What is an example of a Benzodiazepine used for sedation in horses? |
|
Definition
-Gamma Aminobutyric Acid
-primari inh NT in the CNS, enhance endogenous GABA binding, inc CL: conductance => hyperpolarization |
|
|
Term
| Why do we use GABA in combo in horses? |
|
Definition
|
|
Term
| Is Diazepam water soluble or not? How is it administered? |
|
Definition
-poorly water soluble
-can give IV, IM, rectally, and nasally (pain on IM)
-light sensitive and will bind to plastic |
|
|
Term
| How does Midazolam compare to Diazepam, another benzodiazepin, for equine sedation? |
|
Definition
| -faster onset and water soluble |
|
|
Term
| How do alpha-2 agonsits work in horses? |
|
Definition
| -sedation, analgesia, and muscle relaxation |
|
|
Term
| Where are alpha-2 receptors located in horses? |
|
Definition
-nueronal and non-neuronal tissue
-organs
-extra-synaptically on vascular tissue and platelets
-sub classifications of the alpha-2 Rc |
|
|
Term
| How do alpha-2 agonists affect the equine SNA? |
|
Definition
-sedation: locus soeruleus & rostroventral lateral medulla
-analgesia: dorsal horn, brianstem, and peripherally |
|
|
Term
| HOw do alpha-2 agonists affect the respiratory system of horses? |
|
Definition
-minimal effect if any when used alone
-causes mucous membranes to turn a muddy/pale/grey-blue |
|
|
Term
| Why do alpha-2 agonsits alter the color of equine mucous membranes? |
|
Definition
| -peripheral vasoconstriction: oxygen extraction is increased, greater aount of deoxy Hb at the end capillary, arterial tensions are near to normal |
|
|
Term
| How do alpha-2 agonists affect the CV system of horses? How do we fix it? |
|
Definition
-overall dec in cardiac output: inc in SVR, vagal mediated bradycardia
-dec in tissue blood flow (not uniform)
-fix with ephedrine |
|
|
Term
| How do alpha-2 agonsist affect the equine GI tract? |
|
Definition
-GI motility dec
-delayed gastric emptying |
|
|
Term
| What other effects do alpha-2 agonists cause in horses? |
|
Definition
-insulin antagonist: hyperglycemia
-diuresis: always use a urinary catheter
-sweating in horses |
|
|
Term
| What is the most commonly used alpha-2 agonsits in horses? Why? |
|
Definition
-xylazine
-inexpensive and works well |
|
|
Term
| What is the one special consideration for administering alpha 2 agonsist IM in hroses? |
|
Definition
|
|
Term
| Which other alpha-2 agonsit is administered to horses giving increased sedation but also increased ataxia when compared to xylazine? |
|
Definition
-Detomiding
-longer analgesia and sedation |
|
|
Term
| Which other alpha-2 agonist is used in equine with longer duration than xylazine but less ataxia? |
|
Definition
-Romifidine
-longer peak action time |
|
|
Term
| Which three drugs can be used for alpha-2 agonist reversal? |
|
Definition
| -Tolazoline, Yohimbine, and Atipamazole |
|
|
Term
| List the alpha-2 agonsit reversal agents from most specific to least specific for alpha-2 Rc's in horses. |
|
Definition
| -atipamazole > Yohimbine > Tolazoline |
|
|
Term
| Why do we titrate alpha-2 agonsit reversal agents? |
|
Definition
|
|
Term
| What are the opioid receptors in the CNS and GI? |
|
Definition
|
|
Term
| How do opioids affect GI motility? |
|
Definition
|
|
Term
| What are some possible side effects of opioids in horses? |
|
Definition
| -excitement and dysphoria, especially in non-painful animals |
|
|
Term
| Which receptors does Butorphanol (an opioid) affect? |
|
Definition
| -kappa agonist, mu antagonist |
|
|
Term
| Describe the duration of action of Butorphanol? |
|
Definition
|
|
Term
| HOw is Butorphanol (opioid) administered in horses? Side effect? |
|
Definition
-IV, IM, or CRI
-can cause twitching and excitement |
|
|
Term
| Which opioid receptor does Morphin work on? How is it administered? |
|
Definition
-pure mu agonist
-SLOW IV or IM every 4-5h |
|
|
Term
| Which opioid receptor does Methadone work on? How is it adminsitered? |
|
Definition
-mu agonist with NMDA rc activity
-IV or IM |
|
|
Term
| Which drug classes do we use for foal sedation? |
|
Definition
-alpha-2 agonists
-benzodiazepines
-phenothizines |
|
|
Term
| How do we reverse benzodiazepines in foals? |
|
Definition
|
|
Term
| What class of drugs do we avoid with pregnant mares? Why? |
|
Definition
-alpha-2 agonist
-uterine contractions in the 3rd trimester, dec overall uterine blood flow, drugs cross the placental barrier, impair fetal oxygenation, cause fetal stress |
|
|
Term
| What are the advantages of regional anesthesia/ epidurals? |
|
Definition
| -less sedative drug and easier to use in standing procedures |
|
|
Term
| Where do we do an equine epidural? What is the max dose? |
|
Definition
-lumbosacral and coccygeal
-not to exceed 12 mLs |
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