Chronic vomiting in cats: its really not hairballs (Proceedings)

• Overview
• Most chronic vomiting and chronic diarrhea in cats originate in the small bowel

• Many small bowel diseases are segmental

• Endoscopic biopsies are a very poor way to diagnose most cases
• Location: stomach + 1-2 cm of duodenum OR colon

• Sample Size: about 1 mm piece of tissue; not full thickness

• Chronic small bowel disease is manifested as chronic vomiting, chronic diarrhea, or both.

• Typical history
• “My cat has vomited all of its life. The vomiting was occasional for months to years. Then it became 1-2 times per month. Now it is daily. Otherwise, he/she feels good and eats good.”
• Think small bowel, not stomach.

• “My cat has had soft stools (“not diarrhea”) all of its life. The soft stool was occasional for months to years. Then it became 1-2 times per month. Now it is daily. Otherwise, he/she feels good and eats good.”

• Alternative: “has been losing weight”  “ has a tremendous appetite.”

• The diarrhea is typically small bowel diarrhea.

• Small Bowel Diarrhea vs. Large Bowel Diarrhea

  Small Bowel Large Bowel # per day 1 or 2 5 or more Volume Nor/large small Mucus No Yes Blood Melena Hematochezia Steatorrhea Yes No Urgency No Yes Tenesmus No Yes Weight loss Yes Usually no Vomiting Probably Maybe

• Cobalamin/Folate
• They are not synthesized in the cat.

• Folate: absorbed in the upper small bowel.

• Cobalamin: absorbed in the lower small bowel.

• If their levels are low, it tells you what part of the bowel is diseased.
• Low folate: rare in the cat.

• Low cobalamin: common in the cat.

• Most chronic small bowel disease occurs in the jejunum and ileum.
• This explains why endoscopic biopsies fail to be diagnostic.

• Recovery from chronic small bowel disease requires successful treatment.
• Cobalamin/B12 injections.

• Diagnosed with fasted blood sample: IDEXX and Texas A&M GI Laboratory.

• Treatment for low serum cobalamin
• 100-250 mcg/cat SC q7d for 6 weeks followed by 100-250 mcg q14d for 6 weeks (3 injections), and another injection (100-250 mcg) 4 weeks later.

• Using the 1000 mcg/ml concentration, this is a very tiny dose (0.1-0.25 ml). I give 1 ml (1000 mcg) per dose because it is not toxic and often stimulates the appetite at this dose.

• Treatment for low serum folate
• Rarely, if ever, needed.

• 5 mg q24h PO. (1 mg tablets available)

• Symptomatic Therapy for Chronic Vomiting
• Diet
• i/d (Hill's)

• OM (Purina)

• Low Residue (Iams)

• Medications
• Suppressing vomiting is not curative.

• Cerenia – approved for up to 5 days of use.

• Hairball remedies/food.

• My preference: none unless the owner is insistent.

• Symptomatic Therapy for Chronic Diarrhea
• Diet
• i/d (Hill's)

• DM/OM (Purina)

• Low Residue (Iams)

• Anti-diarrheals
• Diphenoxylate: ½ tablet q12h PO
• Caution about overdosing due to small size of tablet.

• Occasional bizarre behavior (hallucinations?)

• A controlled substance; drug log entry required.

• Loperamide: ¼ tablet (0.5 mg) q12h PO
• Liquid has mint taste; objectionable to most cats

• LifestyleCauses
• Hairballs
• Cats groom; cats swallow hair; it must be eliminated by vomiting or in the stool.

• Vomiting hairballs is normal for cats if it occurs occasionally.

• If it is frequent, it may be a sign of a motility disorder (IBD, LSA).

• Grass
• Many cats love the taste of grass.

• They eat it because they like it; not to “purge' themselves.

• Grass causes gastritis resulting in vomiting.

• Infectious Causes
• Risk assessment is essential when pursuing this option.
• Multicat household or facility invites contagion
• Catteries, shelters, and rescuers are high risk.

• History should reveal that multiple cats in the same household are affected.

• More likely in cats less than 1 year old.

• Fecal Floatation
• Coccidia: found with careful observation.

• Giardia: often poor sensitivity and specificity.

• Ascarids rarely cause chronic diarrhea or vomiting.

• Hookworms are rare in cats.

• Tapeworms are virtually non-pathogenic (except for the gross-out factor).

• ELISA Giardia Test
• Much better sensitivity and specificity than fecal flotation.

• Not as good as PCR.

• Since the diagnostic workup should include other organisms, a Giardia test is usually obtained as part of a more comprehensive PCR profile.

• Infectious PCR Profile
• An expensive profile but the most sensitive and specific tests we have.

• Tritrichomonas, Cryptosporidium, Giardia, Salmonella, Clostridium perfringens, Toxoplasma, feline panleukopenia virus, feline coronavirus.

• Especially indicated for multicat situations: shelters, catteries, rescuers.

• Therapy
• Panacur + Albon
• Giardia + coccidia

• A good initial treatment pending or in lieu of laboratory tests.

• I use DM diet with them.

• Cryptosporidium
• Supposed to be self-limiting.

• Azithromycin: 7-15 mg/kg q12h PO X 5-7 (or 14) days.

• Tylocin: 11 mg/kg q12h PO for 28 days.

• Tritrichomonas
• Self-limiting in 5-24 months.

• Ronidazole: 30 mg/kg q12h PO for 14 days.

• Potentially neurotoxic
• Usually reversible after the drug is stopped.

• Non-Infectious Causes
• Differential list
• Food intolerance

• Inflammatory bowel disease

• Neoplasia without mass formation
• Small cell lymphoma

• Lymphoblastic lymphoma

• Note: Mast cell tumor, adenocarcinoma, small cell lymphoma, and lymphoblastic lymphoma can cause chronic small bowel signs, but a mass forms resulting in rapid weight loss and vomiting (partial to full obstruction). The mass is found by palpation, ultrasound, or surgery.

• Typical history
• Chronic vomiting and/or small bowel diarrhea (or both)

• Was infrequent for months to years

• Frequency became 1-2 times per month.

• Now 5+ times per week.

• If vomiting only, the cat is often otherwise healthy.
• It is usually diagnosed as hairballs and treated accordingly.

• If diarrhea only, weight loss has started recently (small bowel diarrhea).
• The cat is otherwise normal.

• The cat possibly has a history of vomiting or polyphagia.

• Diagnostics
• When the clinical picture is presented to me I recommend
• Small intestinal ultrasound.
• If the walls are thick (0.28 cm or more), I recommend a full-thickness biopsy of the small bowel via laparotomy.

• Possible exception: food trial first, but 6+ weeks are lost so you must consider the consequences of that.

• Objections to this approach
• Cannot do ultrasound.

• What an ultrasound study does:
• Allow you to document small bowel thickening.

• Allows the owner to see it.

• Makes a laparotomy much easier to sell.

• The laparotomy and biopsies get a diagnosis leading to specific treatment.

• Pays for the ultrasound machine.

• Why palpation fails to get a diagnosis
• Mild to moderate small bowel thickening is not palpable.

• Heavy cats are hard to palpate.

• Segmental disease occurs.

• Small bowel biopsy technique
• You need a full-thickness sample.

• Cut out a wedge beginning on the antemesenteric side of the bowel.

• Alternate: 6 Fr biopsy punch (better sample per my pathologist)

• Trim away excess mucosa so you suture muscle and serosa to muscle and serosa.

• Use simple interrupted through-and-through sutures of 4-0 PDS placed 1 mm apart.

• When the bowel is closed, test with a saline injection.

• Consider biopsy of the mesenteric lymph node if it is enlarged.

• Miscellaneous observations and comments
• On ultrasound, the wall thickness is not half the diameter of the bowel loop due to the luminal contents.
• Measure from the outside of the wall (serosa) to the near edge of the lumen.

• Enlargement of the mesenteric lymph node is not diagnostic or prognostic.
• A biopsy of the LN will not substitute for a full-thickness biopsy of the small bowel. Sometimes the LN will be reactive and the bowel wall neoplastic.

• Biopsy of the LN rarely adds to the diagnosis.

• Biopsy of the LN is an optional procedure.

• It is a friable organ; close it with mattress sutures.

• Do not cut the mesenteric artery. Take a superficial biopsy.

• Small masses may accompany thickened loops and be very hard to find with palpation or ultrasound.

• Take more than one biopsy as the disease is segmental. Often, some samples will be normal and some abnormal.

• Ropey bowel loops
• May be due to severe IBD or due to lymphoma.

• May dehisce easily when biopsied.

• Usually have a bad prognosis.

• Small bowel aspiration

• Isolate the desired site(s).

• Insert a 22 ga. needle through the bowel wall at an acute angle.

• Vigorously “vacuum” the opposite mucosa to recover “snot.”

• Advantages
• Multiple locations in little time.

• No dehiscence.

• Disadvantages
• Not a full-thickness biopsy.

• This is not usually significant for ropey bowel loops.

• Loss of layering of the bowel wall
• There is a strong correlation with neoplasia.

• But, many cats with lymphoma have normal layering.

• Anesthesia and Surgery on Geriatric Cats
• Pre-Anesthetic Workup
• Good physical examination

• Chemistry panel with electrolytes (and TT4)

• PCV (or CBC)

• Careful cardiac auscultation

• Single-lead ECG with Biolog (DVM Solutions; 1-866-373-9627)

• Anesthetic Induction
• Isoflurane (or sevoflurane) by face mask
• In my practice we do this 5-10 times per day

• Problems with face mask induction are due to
• Wrong size mask (Jorgensen; 5.5” diameter

• Improper restraint

• Lack of cleanliness

• Medications
• Pre-op
• Buprenorphine: 0.2 mg/kg IM or SC

• Antibiotics: Baytril + ampicillin injectables

• Fluids: IV or SC

• Intra-op
• Atropine PRN for bradycardia (HR <90 bpm)

• Post-op
• Acepromazine for rough recovery
• Dilute 1:10; 1 mg/kg concentration

• Give 0.05 mg/# IM or SC

• Buprenorphine
• 0.2 mg/kg q12h PO X 5-7

• Alternative analgesic
• Metacam
• SC injection pre-op with SC or IV fluids

• Oral: Half the canine dose; give q24h

• Tramadol
• 12.5 mg/cat q12h PO (50 mg tabs)

• Surgical Monitoring
• Parameters
• Respiration rate *

• Heart rate *

• Temperature *

• ECG tracing

• Blood pressure

• Pulse Ox

• End Tidal CO2

• Equipment
• VetGard (DVM Solutions; 1-866-373-9627)

• Temperature Control during Surgery
• Warm IV fluids

• Hot Dog (Augustine BioMedical; 1-952-465-3500)

• ChillBusterVet (ThermoGear, Inc.; 1-503-697-1900) ***

• Body Wall Closure
• Needs to be secure and fast

• Muscle

• 2-0 PDS

• Simple interrupted pattern about 1-1.5 cm apart

• Continuous pattern from end to middle and middle to end.

• Subcutaneous tissue             
• 4-0 PDS in continuous pattern

• Skin
• 4-0 Braunamid/Polymid

• Ford interlocking pattern.

• Recovery
• Very rapid due to the anesthetic protocol used.

• Wrap in warm bath towel

• Beanies and Chillbuster for warmth

• Heating pad below the cage rack PRN

• Watch brachycephalic cats for airway obstruction during recovery.

• Post-op Protocol
• Continue IV fluids for 24 hours post-op and keep the cat NPO.

• Then, offer food and keep the cat another night.

• If the cat eats and does not spike a fever, it goes home on the second post-op day (after two nights in the hospital).

• Important factors that determine whether or not an owner will treat a chronic disease on a long-term basis? (Ref: AVMA, 2007)    
• Love for the Pet                                               %

• Pet's Age                                                        %

• Pet Pain                                                           %

• Life Quality                                                     %

• Cost-Related                                    %

• Survival Chances                                            %

• Discussed with Others                    %

• Veterinarian                                                     %

• Therapy
• General prognoses
• Good: food reaction, inflammatory bowel disease, small cell lymphoma, mast cell tumor.

• Bad: lymphoblastic lymphoma, adenocarcinoma.

• Food reaction
• There is a technical difference in food allergy vs. food intolerance, but it is not clinically feasible to make the distinction. This distinction is skirted by using the term ‘food reaction.'

• As a rule, anti-inflammatories are not effective or may be effective for only a few days to weeks.

• Food trials based on novel protein diets (rabbit, duck, venison) or hydrolyzed protein diets (z/d by Hill's).

• The food trial should go 6 weeks before deeming it to be a failure.

• Inflammatory bowel disease
• Diet: novel protein, hydrolyzed, or high fiber may help some cats.

• Immune suppressants
• Corticosteroids: prednisolone 10 mg q12h PO for 10 days then reduce.

• Cyclosporine (Atopica): 25 mg q24h PO for 15-30 days then 25 mg q48h PO. May change to prednisone for long-term control.

• Megestrol: 5 mg q24h PO for 7 days then 5 mg q48h for 14 days then change to prednisone.

• Chlorambucil: 0.1 mg/kg q24h PO or 6-8 mg/m2 q24h PO. The tablets should never be split, so must cats take 2 mg q24h PO to q3d PO days depending upon the weight of the cat.

• Lomustine (CCNU): 10 mg capsule for cats 5-15 pounds q28d PO. Monitor for leukopenia.

• Others
• Cobalamin injections for hypocobalaminemia.

• Prebiotics and/or probiotics.

• Omega-3 fatty acids.

• Metronidazole + prednisone/prednisolone.

• Small cell lymphoma
• Prednisolone/prednisone: 2 mg/kg q12h PO fo r7-10 days then reduce slowly to 5-10 mg/cat q24h PO. Least expensive approach with fewest side effects. If given alone for several weeks, the response to other chemo protocols may be reduced significantly.

• Modified Wisconsin protocol: 15 treatments in 24 weeks using Modified CHOP) (L-asparaginase, vincristine, cyclophosphamide, chlorambucil, doxorubicin, prednisone); first remission rate 68%; median survival time 225 days. See The Feline Patient editions 2, 3, or 4 for specific protocol. The protocol of choice for most veterinary oncologists.
• Chlorambucil + prednisone
• Chlorambucil: 0.1 mg/kg q24h PO or 6-8 mg/m2 q24h PO. The tablets should never be split, so must cats take 2 mg q24h PO to q3d PO days depending upon the weight of

• the cat. Prednisone/prednisolone: 1-2 mg/kg q24h PO.

• Lomustine + prednisone
• In generally, not considered a first-line chemotherapy agent.

• Lomustine: (CCNU): 10 mg capsule for cats 5-15 pounds q28d PO. Monitor for leukopenia. See Norsworthy study below.

• Prednisone/prednisolone: 1 mg/kg q24h PO.

• Protocol:
• Visit 1: CBC + lomustine; dispense prednisone.

• Visit 2: CBC 2 weeks later.

• Visit 3: lomustine 4 weeks after first dose.

• Visit 4: CBC 2 weeks later.

• Repeat #3 and #4 for a total of 6 (or more) doses.

• Monitor for leukopenia. If it occurs, discontinue lomustine until WBC is in the normal range but continue prednisone. Recheck WBC q14 days. In Norsworthy study it occurred 40% of the time, but all cats were eventually able to get 6 doses or more.

• Usual protocol is to give 6 doses over 5 months. Some cats require up to 9 doses to achieve remission.

• Cost: $196.06/bottle of 20 capsules (3/2010).

• The capsule becomes very sticky when moist
• Use a Pill Popper if needed for clean administration.

• Syringe 2-3 ml of water orally to prevent the capsule from sticking to the esophageal wall and causing an esophageal stricture.

• Norsworthy Study (Data collected March 2010)
• 20 cats with history of chronic vomiting or diarrhea, ultrasound confirmed thickening of small bowel wall, laparotomy, full-thickness biopsies of small bowel, and HP diagnosis of small cell lymphoma.

• 11 (53%) went into remission.

• Remission group
• Average survival time: 582 days (19.4 months); range 6-45 months.

• 3 still alive when data collected: 18, 32, and 45 months.

• Quality of life excellent during and after treatment.

References

Crystal MA. Chemotherapy for Lymphoma. Feline Patient, 4th ed., 2006:692-696. Ames, IA; Blackwell.

Kleinschmidt S, Harder J, Nolte I, et. al. Chronic inflammatory and non-inflammatory diseases of the gastrointestinal tract in cats: diagnostic advantages of full-thickness intestinal and extraintestinal biopsies. J Fel Med Surg. 2010;12:97-103.

Zwingenberger, AL, Marks SL, Baker TW, Moore PF. Ultrasonographic Evaluation of the Muscularis Propria in Cats with Diffuse Small Intestinal Lymphoma or Inflammatory Bowel Disease. J Vet Intern Med. 2010;24:289-292.