2016 WINTER: Medicating Fearful Pets | Anesthesia Risk | Bleeding Greyhound | Plasma | Dr. Brian Young – Critical Care | Dr. Noah Bander – Surgery
Medication for the Anxious, Fearful Dog and Cat
Jill Sackman, DVM, PhD, DACVS
Transporting and handling a fearful and anxious dog or cat in a veterinary practice can be challenging. It has been reported that nearly 80% of dogs that visit veterinary practices for examination exhibit signs of anxiety or fear (Doring, et al 2009). Fearful dogs and cats resist restraint and may display signs of aggression when handled. Although fear-based aggression in dogs and cats is not uncommon, one negative visit has the impact of making every subsequent visit even worse!
Acepromazine is a dissociative agent; it inhibits logical environmental assessment. Often referred to as “ace,” acepromazine is routinely used to sedate fearful or aggressive dogs. Research has shown that acepromazine functions primarily as a chemical restraint without affecting the animal’s emotional behavior. However, while under the influence of “ace,” animals still have strong anxiety, avoidance or arousal responses, but they either don’t display these reactions, or they are delayed in reacting. The dog may appear calm but is still having an intense emotional reaction. Fear may intensify to a level in which it overrides the physiological sedative effects of “ace”; the animal seems ‘out of it,’ but the intense emotional reaction causes him to bite. This increased fear will certainly be remembered.
What should we do?
What else can we do to reduce the stress and upset that these visits often trigger? Pharmacologic agents that have anxiolytic and sedative properties administered in a noninvasive way are ideal.
Anxiolytic drugs – Benzodiazepines
Benzodiazepines such as alprazolam (Xanax®), clonazepam, (Klonopin®), clorazepate (Tranxene®) and lorazepam are alternative drugs which affect the central nervous system and reduce anxiety, stress and fear. They have a calming and amnesic effect on the patient. These drugs have fast-acting effects that begin within 30 minutes to 2 hours after oral administration. They have the benefits of rapid onset of action and potent anxiolytic action and can be especially useful for episodic anxieties.
Alprazolam is used to treat anxiety in dogs and cats. Uses include treatment of thunderstorm and other phobias, separation anxiety and situational fears (such as car travel and veterinary visits). Like other benzodiazepines, alprazolam may be used as a muscle relaxant, anticonvulsant or appetite stimulant. Although generally safe, the most common side effect is excessive sedation and loss of motor control. These effects occur at doses greater than those needed for its anxiety-reducing effect. In some, alprazolam may cause a paradoxical excitement or worsen aggression. Long-term treatment with alprazolam can lead to physical dependence, which can result in undesirable behavior changes if the drug is abruptly discontinued.
Benzodiazepines are best given one to two hours before the exam and repeated 30 minutes before the exam. Most benzodiazepines are scored and easily cut further with a pill cutter, but they melt if hands or surfaces are damp. For patients that do not take tablets well, benzodiazepines can be made into a paste with a tiny bit of water and smeared on the gums or tongue. As soon as the patient licks or swallows, the medication enters the system.
Trazodone is a serotonin antagonist and reuptake inhibitor (SARI) used for anxiety disorders in dogs and cats. Recently, (Orlando, J Feline Med Surg 2015) trazodone was used to sedate cats prior to stressful veterinary visits and exams and evaluated for safety and efficacy. The observed sedation resulted in no adverse effects with the use of trazodone at 50-100 mg. Likewise in dogs, trazodone has been effectively used to support post-surgical confinement in dogs (Gruen, et al JAVMA 2014) at 7 mg/kg PO q 12 hours.
Trazodone is available as tablets in 50 mg, 100 mg, 150 mg, and 300 mg. Based on owner reports, the onset of action in dogs is approximately 1 hour, so if using for travel anxiety, dosing in advance is recommended.
Trazodone was used in a recent study (Gruen, unpublished results) as a single agent at doses of 5-30 mg/kg/day (divided q8-12 hours). The mean dose for this population was 15 mg/kg/day. When used as an adjunctive medication, starting doses for trazodone are typically lower, and dose is titration used to achieve clinical success. Dogs may require incremental dose increases as they become tolerant to the effects of trazodone.
Trazodone has a large safety margin for the majority of our canine patients. As an antidepressant, trazodone is prescribed in humans at up to 600 mg/d. The LD50s for mice, rats, and rabbits are 610 mg/kg, 486 mg/kg, and 560 mg/kg respectively.
To reduce fear in anxious canine patients, α2-adrenergic agonists have been used parenterally. Although a commercially available oral transmucosal (OTM) formulation of detomidine is approved for sedation and restraint in horses, there are currently no reports on its use in dogs, and no α2-agonist has been approved for OTM administration in dogs.
A recent study (Hopfensperger, et al 2013) evaluated the behavioral and physiological effects of OTM detomidine gel (Dormosedan Gel; Pfizer Animal Health, Madison, NJ) in dogs. Based on pre- and post-treatment assessments, dogs were deemed to be more sedated, less anxious and easier to handle. The gel was safely administered, and the dose (0.35mg/m2) resulted in measurable signs of sedation and anxiolysis.
Medications for fear and anxiety in cats and dogs
|Medication||Cat Dosage||Dog Dosage|
|Alprazolam||0.0125-0.025 mg/kg by mouth every 8 hours||0.01-0.1 mg/kg by mouth every 4-5 hours|
|Clonazapam||0.1 to 0.5 mg/kg orally every 8 hours||0.1 to 0.5 mg/kg orally every 8 hours|
|Clorazepate||0.2 to 0.4 mg/kg every 12 to 24 hours||1 to 2 mg/kg orally every 8 to 12 hours|
|Lorazepam||0.05 mg/kg by mouth every 12-24 hours up to 0.125-0.25 mg/cat||0.02-0.1 mg/ kg by mouth every 8-12 hours.|
|Maropitant citrate (Cerenia®) – for travel nausea||NA||2-8 mg/kg by mouth every 24 hours|
|Midazolam||0.05-0.3 mg/kg SQ, IM or IV only. Consider more for sedation except at lower doses that are anxiolytic.||0.05-0.3 mg/kg SQ, IM or IV only. Consider more for sedation except at lower doses that are anxiolytic.|
|Trazodone||0.5 mg/kg (approximately 2.5-3 mg per cat) by mouth every 8 hours||2-3 mg/kg by mouth every 12-24 hours|
An Invisible Risk
The occupational exposure to anesthetic gases is almost impossible to avoid in veterinary facilities where gas anesthesia is utilized. Gas can escape from the anesthesia machine itself due to poor, misaligned or loose fitting connections between its various components as well as from worn seals and gaskets. Anesthetic gas can also escape into the air from holes in the reservoir bag or the anesthetic tubing, a poorly fitted anesthetic bag, loose connections to the endotracheal tube or accessory devices such as a CO2 monitor, and from an inadequate inflation of the endotracheal tube cuff. Poorly functioning waste gas scavenger systems, poorly fitted face masks and leaking anesthetic chambers are also a source of exposure. And, let us not forget the anesthetic gas that is exhaled by the patient during recovery or the gas that escapes when we open the anesthetic chamber to retrieve the patient or when we fill the vaporizer with the liquid agent.
What’s the risk?
Vaporizers can be fitted with adaptors that will minimize leakage of the anesthetic agent when being filled.
The most common gas anesthetic agents used in the veterinary field include halothane, isoflurane and sevoflurane. The Occupational Safety and Health Administration (OSHA) has not set permissible exposure limits regulating these agents. Their recommendation is merely to limit your exposure to anesthetic gas as much as possible.
The risks associated with exposure to general gas anesthetics, especially the newer agents, have not been well studied. The available information comes from studies performed using animal models, as well as from surveys of individuals who routinely work with anesthetic gases. These studies suggest that individuals exposed to gas anesthesia may be more likely to demonstrate reproductive problems such as abortions and difficulty conceiving children. Exposure to gas anesthesia has not been strongly linked to developmental problems or a tendency for mutations.
The most common complaints from individuals exposed to anesthetic gases include transient nausea, dizziness, headaches, fatigue and irritability.
- Check the anesthesia machine and anesthetic circuit prior to each use. This means checking all connections, inspecting all the hoses for damage, making certain the gas scavenging system is operating and determining the ability of the circuit to maintain a constant pressure, i.e. there are no leaks.
- Fill the vaporizer in a well ventilated area using one of the appropriate specialized spouts (integrated fused filling adaptor) produced for this purpose.
- The vaporizer should be turned on only when the anesthetic circuit is connected to the patient.
- Use an appropriately sized endotracheal tube and make certain the cuff is adequately inflated. Test for leakage by squeezing the gas reservoir bag with the exhaust system closed.
- If using a mask, make certain it fits the patient’s face well to minimize gas leakage. Minimize the time a mask is used, as they all leak.
- If using an anesthesia induction chamber, do so in a well ventilated room. Make certain the box does not leak. Connect the chamber to the anesthetic gas scavenging system and evacuate the anesthetic gas prior to removing the patient by blowing oxygen alone (turn off the vaporizer) for a short period.
- Once the anesthetic procedure is complete, turn off the vaporizer and allow oxygen to continue to flow through the anesthetic circuit to flush anesthetic gases into the scavenging circuit before unhooking the patient.
Note: Because commonly used gas anesthetic agents do not have a strong odor at low concentrations, the absence of an odor does not mean you are not being exposed. The presence of an odor suggests that you are being exposed to higher concentrations of the agent.
What about spills?
Small volumes of liquid anesthetic agents will frequently evaporate before you have had the opportunity to attempt a clean-up. For small spills, the best solution may be to leave the room for a short period and ensure that the room is subsequently well ventilated. For large spills, the recommendations noted on the material safety data sheet for the anesthetic agent should be followed. This typically entails using an absorbent material to soak up the agent, which should then be placed into a tight sealed container.
Critical Care Corner: The Bleeding Greyhound
Case snapshot: A 36 kg, 9-year-old male neutered retired racing greyhound, survived severe hemorrhagic shock secondary to a minor bite wound, after receiving epsilon aminocaproic acid (EACA).
History: This dog was bitten by a housemate over the cranial part of his ventral abdomen, after which he was acting painful. There were no obvious punctures, and veterinary care was not immediately sought. Tramadol was given for suspected pain by the owner. Persistent pain was treated with meloxicam by the referring veterinarian. Four days later the patient became lethargic with a reduced appetite and developed severe bruising and swelling on his ventral abdomen and thorax.
Initial findings: The patient was quiet, hydrated and assessed to be well perfused. He vomited during the physical examination, and the ventral swelling/bruising progressed rapidly. No bite wounds were located.
Diagnostics, treatment and outcome: The patient was not initially anemic (PCV 49%) but did have a relatively low total solids (4.8 g/dL). PT and aPTT were within the normal ranges, and an in-house platelet count was 133,000/uL (reportedly normal for this breed). The patient had a mild neutrophilia and monocytosis, as well as mildly increased creatinine (1.9 mg/dL; range 0.5-1.8). These changes all improved during the patient’s ICU stay and were presumed to be secondary to hemorrhage. Thoracic and abdominal radiographs, as well as abdominal ultrasound were relatively normal, with no evidence of internal bleeding or neoplasia.
This patient was started on an aggressive intravenous crystalloid rate (120 ml/kg/d), intravenous maropitant 1 mg/kg, as well as intravenous epsilon aminocaproic acid (EACA) 50 mg/kg q6h, which was subsequently lowered to 1 g IV q8h (28 mg/kg). He developed signs of hypovolemia/hemorrhagic shock by the next morning, believed to be due to progressive bruising/bleeding (tachycardia, severe anemia, hypoproteinemia, and hypotension). His blood pressure normalized with a crystalloid bolus, but the tachycardia persisted. An electrocardiogram revealed ventricular tachycardia at 200 beats per minute, which was successfully treated with an intravenous lidocaine bolus of 2 mg/kg, followed by a continuous rate infusion of 50 mcg/kg/min. A packed red blood cell transfusion was given after the PCV had dropped to 16%, and a hetastarch continuous rate infusion (20 ml/kg/d) was added to the fluid plan for colloidal support. The patient was transitioned from lidocaine to oral sotalol at 1 mg/kg q12h. After three nights, he was sent home on sotalol and a 5 day course of oral EACA: 1 g PO q8h. His anemia was regenerative at that point and his PCV had increased up to 29%.
The patient is presumed to have suffered the consequences of breed-related hyperfibrinolysis that responded to EACA, a medication that is a potent inhibitor of fibrinolysis, slowing clot breakdown by preventing activation of plasminogen into plasmin on the surface of the fibrin clot. This medication did seem to work, allowing the patient to stabilize his PCV in the hospital and for clinical progression of the hemorrhage to cease. The coagulation system can be more thoroughly evaluated, and deficits of fibrinolysis diagnosed using thromboelastography (TEG), which is not available at all institutions.
It is presumed that the ventricular dysrhythmia was secondary to hemorrhagic shock, either from poor myocardial perfusion or secondary to circulating cytokines. An echocardiogram was declined, so underlying cardiac dysfunction could not be ruled out.
Take home points: Greyhounds are prone to hemorrhage post-trauma and surgery compared to other breeds. This bleeding can be minimized and/or treated with a short course of EACA (500-1000 mg PO q8h x5 days), which is available in both injectable and oral formulations. Aggressive supportive care and monitoring are necessary in cases of hemorrhagic shock, being aware of potential consequences of shock such as cardiac dysrhythmias.
References: Marin, LA et al. Retrospective evaluation of the effectiveness of epsilon aminocaproic acid for the prevention of postamputation bleeding in retired racing Greyhounds with appendicular bone tumors: 46 cases (2003-2008). JVECC 2012; 22(3):332-340.
Santoro SK, LD Garrett, M Wilkerson. Platelet concentrations and platelet-associated IgG in greyhounds. JVIM 2007;21(1):107-12.
For every unit of packed red blood cells, a unit of plasma is produced. Due to the high demand for packed red blood cells, we often have a relative abundance of plasma, the majority of which is stored plasma (SP) or frozen plasma (FP). Frozen plasma differs from fresh frozen plasma (FFP) in the production process and storage time.
Plasma, when frozen within six hours of collection, is considered FFP and contains all components of normal canine plasma. This includes practically every molecule involved in hemostasis. It has all the clotting factors, albumin, fibrinogen, von Willebrand factor (vWF), antithrombin (AT), plasminogen and inhibitors of fibrinolysis.
If the plasma is stored for longer than one year, or separated from blood longer than six hours after collection and then frozen, it is considered FP or SP. Frozen plasma is deficient in the more labile clotting factors including factors V, VIII and vWF. It does contain two other clotting factors, albumin and globulins.
The clearest indication for plasma transfusions is in cases of bleeding disorders. These include von Willebrand disease, hemophilia A (factor VIII deficiency), hemophilia B (factor IX deficiency), anticoagulant rodenticide toxicity, coagulopathy secondary to liver disease, blood loss (dilutional) coagulopathy and disseminated intravascular coagulation (DIC). Plasma (either FFP or FP) may be used for the treatment of hypoalbuminemia; however, large volumes (at least 45 ml/kg) are typically required to increase the plasma albumin significantly (1 g/dl). In large dogs this may become cost prohibitive, but in smaller animals, it can be beneficial. Other reported uses include parvovirus and pancreatitis; however, evidence for use in these disease processes is lacking, and we do not routinely use plasma in these cases.
FFP may be used to treat all causes of the bleeding disorders mentioned above. FP can be used to treat anticoagulant rodenticide toxicity, coagulopathy secondary to liver disease, blood loss (dilution) coagulopathy, hemophilia B (factor IX deficiency), and to a lesser extent DIC; however, von Williebrand’s disease, hemophilia A, and DIC are best treated with FFP. As the majority of the coagulopathies we see are usually acquired, FP may be an appropriate choice.
FROM THE MEDICAL DIRECTOR
The new year is officially upon us. It’s this time of year when we reflect on the past and plan for a successful future – both personally and within our veterinary practices. In that spirit, I’d like to introduce myself to you as the Senior Medical Director for the BluePearl hospitals in Michigan. I am a Michigan native and grew up participating in 4-H, riding horses, raising dogs and always being fascinated by science, medicine and animals!
I’m a board-certified veterinary surgeon but have always been interested in cognition and behavior in all species. That fascination has led me to pursue a board certification in behavioral medicine and to bring those services to our partners in the Michigan veterinary community. I am available for consults and see patients in both Southfield and Grand Rapids.
2016 brings exciting additions for BluePearl in Michigan. Our Grand Rapids hospital has expanded yet again, this time accommodating a large meeting space for our team and primary care DVM community events. We also anticipate full-time ophthalmology services there in the spring. Many new clinicians joined us during the last part of 2015, and we wanted to make sure we introduced them:
|Critical Care:||(Southfield) Brian Young, VMD, DACVIM, DACVECC|
|Emergency:||(Southfield) Jordan Assenmacher, DVM
(Macomb, Southfield) Kate Brackney, DVM
(Auburn Hills) Maisy Grassie, VMD
|Surgery:||(Ann Arbor) Noah Bander, DVM|
All of these clinicians are here to provide your clients and their pets with the highest quality of care in their time of need. I’m delighted to be working with such a fine team in Michigan and hope that all of our hospitals can serve as your partner in patient care.
While our medical leadership may have changed, our commitment to you remains the same:
- We will treat you as our partner.
- We will treat your patients as we would treat our own pet.
- We will treat your clients as we would treat a family friend.
As always, we would love to hear from you. Please feel free to share feedback or provide a topic or question for us to address in an upcoming issue of the Companion newsletter. We offer warm wishes through the cold weather and hope this year brings much health and prosperity to you and your teams.
Jill Sackman, DVM, PhD, DACVS
Senior Medical Director
Brian C. Young, VMD, DACVIM, DACVECC
Critical Care Service
Working in the emergency and critical care service is emotionally and intellectually challenging as well as being incredibly rewarding. Cases come to us for second and third opinions or even a “last ditch effort.” Many times we try extensive treatment regimens not expecting the patient to pull through. Frequently however, I am reminded that one does not know the outcome until the patient is given the full opportunity to persevere in the face of severe illness. Time and again, I have been awestruck at the body’s capability for resilience and healing.
It is an exciting time when people are willing to put forth great effort and resources to give their furred family members the same quality of medicine they expect for themselves. Although there are certainly specific treatments for most of the diseases we encounter, much of the foundation of intensive care is reestablishing equilibrium for the body, giving it a chance to heal itself. Specifically, maintaining blood pressure, hydration, correcting acid/base/electrolyte disturbances, and providing supplemental nutrition are a few of the main ways we try to reestablish this balance. I can recollect a variety of cases, from IMHA and sepsis to gastroenteritis and pneumonia, with patients appearing to be on death’s door even though they were all receiving the “correct treatments.” After 24-48 hours of intensive care, they began to show signs of improvement. Keeping the body nourished and perfused, in addition to administering necessary treatments aimed at the disease itself, gives the patient time to heal.
To remind us of the possibility of recovery despite the odds, I collect photographs of “miracle patients”: dogs and cats that survived a prolonged or unpredictable hospitalization. These patients give us hope and can bring a smile to our faces on those days of sadness associated with intensive care. So, even when the circumstances seem dire and a diagnosis may not be clear, I would encourage seeking the benefit of advanced care. Often a day or two of getting back on track, with the added input from advanced imaging and diagnostic testing can make all the difference. It takes a village!
Dr. Bander sees his role with the primary care veterinarian as a partnership. His goal is to work together with the primary care veterinarian to provide the best care, not only for the patients, but for the clients as well. He believes that working together, communicating and being flexible keeps everyone happy.
Communication is also key in his relationships with clients. He believes in setting clear expectations in the beginning of those relationships in an effort to alleviate client concerns and finds that client appreciate his thorough communication. Building this kind of relationship is especially helpful if something unexpected happens.
So what keeps Dr. Bander interested in cases day after day? This one is easy for him. He says that life in the surgery service is never boring. Each day brings different challenges and exciting cases, and every patient and owner bring something different. He is continually rewarded by being part of the team that helps so many families take their beloved family member home. With a great network of primary care veterinarians, as well as a rapidly growing emergency service, he is kept on his toes with new consults and referrals.
Meet Dr. Alicia Mulero
Busy Kalamazoo area veterinarian weighs in on her experiences with BluePearl in Grand Rapids
We sat down with Dr. Alicia Mulero of Pet Vet Family Pet Care Center in Kalamazoo to get her perspective on working with the clinicians at our Grand Rapids hospital. She shared the types of cases she refers, her clients’ experiences and why she chooses BluePearl over other referral and emergency hospital options.
What kind of cases do you send to us?
I refer all of my oncology cases to Dr. Christine Swanson and many difficult internal medicine cases to Dr. Kristopher Sharpe. I lean on Dr. Sharpe when I have exhausted all of our in-house diagnostic capabilities. I send him all my difficult Cushing’s cases, thyroid cases, unregulated diabetes and other weird cases.
It is so nice that all specialties are there, in one building. The collaboration for example between oncology and surgery saves the client time and money. I really appreciate the fact that they send back to us cases to do routine blood work and checkups where appropriate.
Why do you send your clients to BluePearl?
In short, because you are a trustworthy company, and I know you will do a good job. I honestly have no negative comments, and I’ve received no negative feedback from clients. We’ve even had members of our technical staff bring their personal pets to BluePearl, and they have reported amazing and thorough service. I know when I send cases that my clients and their pets will be taken care of. Also, convenience of location is another big reason and the ability to “get in.” Appointments are available in a timely manner compared to other referral options. You really go above and beyond.
What’s it like working with our doctors?
I don’t know how they email, call and fax patient communication so quickly. I am so pleased with this and wonder how the doctors have time to do it. I appreciate the call after the initial consultation to let me know what happened, keeping me in the loop. I find all of the doctors to be sympathetic and cost and situation conscious. The complete discharge summary leaves no question unanswered. Thorough. There is so much communication that there is no guesswork on my end; we are always on the same page.
Is there anything else family veterinarians should know about BluePearl?
My patients and clients are treated royally at BluePearl. And, the availability of after-hours care is a tremendous option when needed.