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When is it likely that vomiting in your canine patient is the result of a GI foreign body (FB)? You would like to think your client would know, however, we frequently find client histories to be unreliable. So what’s a veterinarian to do?

There are a number of clues to consider:

1. Most dogs that swallow a FB are young or have a prior history of chewing on foreign objects.

2. Vomiting secondary to a FB is frequently recurrent. With intestinal obstructions the volume of vomitus can be quite large. It is usually bile-tinged and it can have a fetid odor. By contrast the vomitus in dogs with gastric FBs rarely contains bile, usually is of smaller volume, and can contain blood and phlegm. Vomiting episodes in dogs afflicted with non-GI diseases are typically more sporadic.

4. Most dogs with FBs seem quite willing to keep on drinking -- unlike those with gastric upset from liver or pancreatic disease.

5. Diarrhea is uncommon in dogs with FBs.

6. On physical exam, vital signs in dogs with FBs are usually normal (unless a perforation and peritonitis has occurred). Dogs can be quite alert and active unless severely dehydrated. Their bellies may or may not be painful. Occasionally you can palpate the FB.

7. Labwork in patients with FB obstructions is usually normal.

8. If you are lucky, you will see the foreign body on radiographs. Other radiographic clues consistent with a FB include fluid and gas distention of the stomach and/or intestines. The longer the obstruction has been present, the more dilated the bowel will become. This is especially true of obstructions in the distal intestines. Dehydrated dogs may not show bowel distention due to the general lack of fluid in the body. Repeating the radiographs after rehydrating the pet with IV fluids can significantly change the radiographic pattern resulting in more obvious distention of the bowel.

9. Many foreign bodies can actually be seen on ultrasound exam. Fluid accumulation will frequently be seen within the intestines proximal to a suspected obstruction. Bunching of the intestines will be seen with linear FBs. Also, ultrasound will identify other potential causes for the vomiting (such as pancreatitis) or detect the presence of concurrent unrelated diseases. The presence of free fluid in the abdomen could indicate intestinal leakage and peritonitis.

10. A barium-contrast GI study can confirm the presence of an intestinal obstruction. Unfortunately, poor GI motility (ileus) associated with other conditions such as pancreatitis and gastritis can interfere with barium flow mimicking the presence of a FB.

11. Finally, exploratory surgery can be pursued but has its obvious risks and expenses.

C O M p A n I O nCOMPANION is a publication for the veterinary community of

San Antonio and South Texas from South Texas Veterinary Specialists.

To receive COMPANION via email, please contact Avery Bradshaw at avery@stvetspecialists.com.

www.stvetspecialists.com

medical Directors: Andy Anderson DVM, DACVS, and Fred Williams Jr., DVM, DACVS

hospital administrator: Shawn McLallen

south texas veterinary specialists503 E. Sonterra Blvd, Suite 102 San Antonio, TX 78258 p. 210.930.8383 F. 210.930.8040

www.stvetspecialists.com

Dear Colleagues,

One of South Texas Veterinary Specialists’ primary visions is to provide our community with educational opportunities. Outside of caring for our shared patients, our partnership with your practice is the most important aspect of what we do day to day. Whether hosting CE talks, visiting practices, or providing tele-medicine support, STVS is always here to help in any way we can. I want to introduce our seasonal newsletter that will offer you and your practice interesting, educational articles. It is our sincere wish that our patients and our partnership with you will benefit from this exchange of information.

Over the last 12 years we have built a strong family of dedicated specialists to support your practice in the areas of surgery, oncology, critical care, internal medicine, neurology, neurosurgery, dermatology and sports medicine. We have recently added two talented members to the STVS family: neurologist Jeanene Harris, DVM, DACVIM-neurology, and Internist Kristin Lewis, DVM, DACVIM-Small Animal Internal Medicine. We hope you will join us in welcoming them to San Antonio and South Texas. They are available to assist you by telephone or through receiving your referrals in their respective areas.

I would also like to introduce Avery Bradshaw, our outreach coordinator. Many of you may have already met Avery as she begins to make her way around the area to visit with you at your practice. Avery brings a wealth of talent to STVS in terms of multimedia and communications. She will be staying in contact with you and your staff to look for ways we can serve you better. Avery has a new golden retriever named “Hubble” who is bringing the joys and lessons of puppyhood to Avery’s life. please take time to visit with Avery, if possible, when she stops by.

As always, we would like to say, “Thank you for your continued support and partnership with STVS.” We know we must earn your trust and confidence on every case and that you have a choice in when and to whom you refer. We remain committed to providing the highest level of service and medical expertise possible. In addition, we will continue to be the most affordable and available family of veterinary specialists for you and your clients. Our doctors and staff are a part of the fabric of San Antonio and South Texas. We live, work and play right here every day along side you and your team. Our lives and jobs depend upon meeting your needs in every way. Just like you and the bank on TV, “We’re From Here” and we will be there when you need us. “always have and always will.”

In this issue we will highlight on atopic dermatitis, neuro back pain, pain management for cancer patients, and much more. I hope that you find this to be a useful tool in the coming months.

Enjoy and thank you,

Andy Anderson, DVM Fred Williams, DVMDiplomate, ACVS-Small Animal Diplomate, ACVS-Small Animal

meDical Directors’ column

Look what the dog ate!

Ultrasound examination of the abdomen can be very useful for confirming the presence of a FB.

Gas and fluid filled bowels on radiographs is suspicious for, but not definitive proof that a FB is present.

Services surgeryC. Collins “Andy” Anderson DVM, DACVSFred Williams Jr. DVM, DACVSJohn Dahlinger DVM, DACVSSarah Israel DVM, DACVS

critical careBradley Book DVM, DACVECC, DABVp

internal meDicineStacy Randall DVM, DACVIMLucia Alvarez DVM, DACVIMKristin Lewis DVM, DACVIM

oncologyJennifer Wiley DVM, DACVIM-Oncology

neurologyJeanene Harris DVM, DACVIM-neurology

DermatologyBrian Scott DVM

What are the most frequent causes of back pain and/or rear limb weakness in dogs?Small breed dogs, especially dachshunds, beagles, and shih-tzus, are usually afflicted with intervertebral disc disease to which they may have a genetic predisposition. Trauma, infections, emboli and even tumors can cause similar signs. The patient’s signalment, history and exam findings can be helpful in differentiating the potential causes.

is testing always indicated? When should a neurologist evaluate these dogs? You need to evaluate any dog with rear limb weakness. Those with back pain alone might benefit from pain management and strict confinement, if they are otherwise healthy. However, consider an evaluation by a neurologist if there is a persistence of these signs – and an immediate referral should be considered if there is a deterioration in these signs.

What if the condition does not improve? and what about the dog who cannot use the hind limbs at all?We highly recommend that these patients be evaluated further. We consider those patients with severe paresis or paralysis to be emergencies. Reducing the length of time until treatment can be instituted in these patients may be essential, if these dogs are to have a chance to recover.

a Pain in the Back

SNIFF……Meet our Specialist

Jeanene harris, Dvm, Dacvim-neurology

South Texas Veterinary Specialists is sure happy that Dr. Jeanene Harris, MS, DVM, DACVIM-Neurology, did not fulfill her childhood dreams of becoming an astronaut. It was the passion for animals, not the lack of brains, that made her decide against the space program. Dr. Harris completed her residency in medical and surgical neurology at Washington State University, while simultaneously completing her graduate degree in veterinary clinical services. She also completed her neurology board certification, making her one of only 200 veterinary neurologists in the US.

you’re an expert in neurology and neurosurgery. What is the opposite side of your personality? What are you a mess at? I am a total mess at anything that requires artistic ability. I can’t sing (just ask my dogs), I can’t dance, I can’t act, paint, draw, sculpt, etc. I am hopelessly talentless – yeah, besides the whole veterinary neurologist thing.

tell us about your own pets. I technically have five pets. The two normal cats stayed in Virginia with “Grandma,” and the three remaining neurologic animals made the trip to Texas with me. Vivi is my 5-year-old-ish border collie mix who I adopted my first year of residency. She was found on the side of the road in rural Washington State. Her foster parents brought her in to see me because she was clumsy and had seizure-like episodes. It was love at first sight! I had to keep her.

Sophie is my 2-year-old cavachon (cavalier King Charles spaniel and bichon frise mix). She was brought to me at 5 months of age for acute paralysis in all four limbs. Her owners could not afford to pay for her care, and were going to put her to sleep. I decided to foster her, and eventually adopted her. I performed surgery to stabilize the bones in her neck.

how did you keep your sanity with five pets, studying, and going to school? I was fortunate enough to have some really great and supportive friends also going through the same thing! My family has also been very supportive as well and is happy I finally have a REAL job!

What was your first job? I was a barista at a coffee shop in a mall called Gloria Jean’s. I earned minimum wage and learned that putting a 17-year-old in charge of a cash register was a bad idea.

What was the best piece of advice you were ever given?My mother always told me that “those who matter don’t mind, and those who mind don’t matter.”

What is the one thing that has happened in your life that has made the biggest impact on who you are today? My father passed away when I was 19 years old from a malignant brain tumor. I can only imagine that has a little something to do with my choice to become a veterinary neurologist.

Feel free to contact Dr. Harris anytime for a consultation on a neurology or neurosurgery case. Thank you so much for your continued support.

How do you treat hyperthyroidism?the numBer oF oPtions availaBle to treat feline hyperthyroidism seems to keep growing. You now have the choice of recommending dietary therapy, oral or topical medications, surgery and radioactive iodine. But which is best? There are a number of factors to consider.

What’s the cost? The cost of a bag of cat food and/or a prescription for anti-thyroid medication is certainly reasonable. But when you consider the need for lifelong therapy and the recommendation for repeated lab work to monitor the patient, surgery and radioactive iodine treatment options are likely to be cheaper, depending on the lifespan of the patient.

Which is safest? Reports of radioactive iodine causing illness are rare. Clinically significant hypothyroidism may be seen. To date there have been no significant complications attributed to feeding a low iodine diet, however, long term data has yet to be compiled. The risks associated with surgery can be significant and life-threatening (anesthetic complications and hypocalcemia). Anti-thyroid medications have been reported to infrequently cause serious liver injury and blood dyscrasias.

Which is easiest to use? Certainly curing the condition with a single injection of radioactive iodine or having someone perform surgery is much simpler for the owner than administering anti-thyroid medications to a cat for the rest of its life. Feeding a low iodine diet seems easy enough unless the patient dislikes the diet or has a concurrent condition that requires its own special dietary intervention. Also, for the low iodine diet to be effective, it needs to be the only food ingested by the cat (i.e. no treats etc.) which can be difficult to enforce in a multiple cat household.

What works now may not work later. As cats age they may develop other conditions, such as inflammatory bowel disease, kidney disease, and heart conditions, each requiring their own treatment. Foresight would suggest it would be much simpler and safer to cure the hyperthyroid condition with radioactive iodine or surgery when the cat is otherwise in good health than to have to deal later in the cat’s life with balancing hyperthyroid dietary or medical treatment with the treatment of another illness requiring its own special diets or medications.

Technetium scan of cat with single hyperthyroid nodule

pain Management for Cancer patients

how successful is the treatment in paralyzed dogs?The first step to treating these patients is to find the lesion. A thorough neurologic exam is imperative for evaluating these patients. Access to MRI and CT scans available here at STVS greatly improves our ability both to characterize and localize the lesion whether it involves the vertebrae, disc spaces, surrounding meninges or nerve roots, or the spinal cord itself. The treatment then varies with the etiology and location of the lesion.

patients with intervertebral disc disease and superficial spinal cord tumors such as meningiomas who have surgery typically recover well if the condition is caught before permanent spinal cord damage occurs. Other diseases causing back pain may respond better to medications or radiation therapy.

the management oF Pain in cancer patients is among our highest priorities. Several options exist for pain management:

non-steroidal anti-inflammatory drugs [nsaiDs]nSAIDs are an essential part of most analgesic regimens. There are both non-selective (COX-1 and COX- 2) and COX-2 selective families of nSAIDs. not only do these drugs reduce mild to moderate pain, they are inexpensive and generally well tolerated. Some COX inhibitors may also have anti-tumor properties by promoting apoptosis or reducing angiogenesis. potential adverse effects are mainly GI related, and, rarely, nephro- or hepatotoxicity. periodic physical examination and monitoring of hematocrit, reticulocyte count (even if not anemic), chemistry profiles, and urinalysis is advised. As a general rule, nSAIDs should never be combined with glucocorticoids due to additive toxicities.

glucocorticoidsShort-acting steroids at anti-inflammatory doses may decrease mild inflammation and pain associated with certain tumors, such as mast cell tumors. Steroids may also be indicated in the treatment of lymphoid neoplasms (lymphoma, multiple myeloma, plasmacytoma, and leukemias) and myelomonocytic/histiocytic malignancies. For two reasons we recommend using steroids only after a definitive diagnosis has been made: premature use of steroids may complicate the establishment of a definitive diagnosis and accurate tumor staging; and, although controversial, they may negatively impact the prognosis if definitive therapy is employed. The potential adverse effects of short term and chronic steroid use include GI ulceration, pU/pD, polyphagia, panting and iatrogenic Cushing’s disease.

opiatesOpiates, indicated for patients with moderate to severe pain, are commonly used in hospitalized patients. Buprenorphine, a potent injectable opiate, is commonly used to treat cats and small dogs. The parenteral preparation, when given per os, is absorbed trans-gingivally. The volume required for this route of administration makes it impractical to use in medium or larger-breed dogs. Carefully selected patients may benefit from fentanyl patches, which provide approximately 4-5 days of pain relief. Tramadol, an inexpensive, orally administered synthetic morphine-like drug, is easily used on an outpatient

basis. Tramadol may have synergistic effects when coupled with an nSAID. potential adverse effects of opiates include respiratory depression, sedation and constipation.

Palliative radiationCoarse fraction radiotherapy plays a crucial role in the management of tumor-related pain. Candidates for palliative radiation include those with non-resectable osteosarcoma, bone metastases, and non-resectable soft tissue sarcomas and carcinomas. Treatments are scheduled once weekly for 3 to 6 treatments. palliative radiation can be used in conjunction with other pain management strategies. Referral to nearby facilities can be offered to STVS clients for palliative radiation.

other medicationsnMDA receptor antagonists are also used as adjunctive drugs (i.e. in combination with other analgesics) to improve the control of pain. Intense and/or chronic painful stimuli result in changes in the central nervous system’s response to input, leading to an amplification of pain intensity. This process of central sensitization is mediated in part by activation of nMDA receptors. By blocking the activation of these receptors, a reduction in CnS hyper-responsiveness can be achieved, allowing other analgesics to function more effectively. Additionally, nMDA receptor antagonists act to increase opioid receptor sensitivity, reduce opioid tolerance and minimize rebound hyperalgesia (the phenomenon of markedly increased pain that occurs when an opioid wears off). Amantadine is the most commonly used oral nMDA receptor antagonist.

Another common pain treatment is gabapentin. Gabapentin is an anti-convulsant medication with significant adjunctive antihyperalgesic action. Its mechanism of action is unclear, though it may act at alpha-2 delta subunits of voltage regulated calcium channels to inhibit spinal neuronal hyperexcitability; peripheral actions have also been postulated. Gabapentin has been used for many forms of chronic pain, though its best application may be for neuropathic pain.

Both amantadine and gabapentin are administered orally, are readily accessible, and are well-tolerated in the majority of patients.

We consider patients with severe paresis or paralysis to be emergencies.

Myelogram showing loss of dye column in caudal thoracic vertebrae

Paralyzed Pekingese

Dr. Jennifer Wiley is stvs’ board certified oncologist. Please give her a call if you have any questions relating to pain management in cancer patients.

south texas veterinary specialists503 E. Sonterra Blvd, Suite 102 San Antonio, TX 78258

p. 210.930.8383 F. 210.930.8040

www.stvetspecialists.com

if you would like to receive an electronic version of Companion, please send an email to georgia Flood at gflood@vseckc.com.

503 E. Sonterra Blvd, Suite 102 San Antonio, TX 78258

the same theory For correction of hyperkalemia and acidemia that applies to cats with urinary obstruction likely applies to dogs with Addison’s disease. Both balanced isotonic crystalloid solutions and 0.9% naCl are likely to be similarly effective for stabilizing electrolyte and blood acid-base abnormalities in these patients until mineralocorticoid and glucocorticoid support has had the opportunity to work. The primary difference is that Addison’s disease can be more chronic in development than urinary obstruction in cats. Chronically low sodium concentrations in Addisonian patients will induce osmotic compensatory mechanisms in the patient’s brain to prevent edema formation. If the low sodium concentration in the blood is corrected too rapidly, then fluid shifts can affect neurologic function. Therefore, utilizing lower sodium containing balanced isotonic crystalloid solutions may be preferred to using 0.9% naCl, allowing a slower resolution of the patient’s hyponatremia.

Despite the fluid type administered, monitoring the Addisonian patient’s laboratory values (especially sodium concentrations) during recovery is recommended to allow adjustments in the intravenous fluid rate and determination of the need for fluid additives. Fluid therapy should be adjusted to increase serum sodium concentrations at a rate of 0.5 mEq/L/hr. patients with low blood glucose concentrations will benefit from dextrose supplementation of the fluids.

The goal for treating Addisonian patients with intravenous fluids is to correct the patient’s hypovolemia, electrolyte imbalances and acid-base abnormalities while ensuring the sodium concentration does not increase too rapidly.

Focus on FluiDs: Fluids in addisonian Patients

VREC’s annual spring CE is May 4, 2013. Be checking your email and faxes for more information.

keep your calendars open!

SAVE THE DATE !

MAY 4 2013