28 Sept/Oct 2011

At 8:15 am December 23, 2010 thanks to an article on dentistry I wrote for our local Weston, Florida newspaper, a 3 Kg, 15 year old domestic short haired cat, Tigger, presented at our office. The cat had not been to a veterinarian in years. The primary client complaints included significant weight loss, decreased appetite, and marked halitosis. The client felt the halitosis was secondary to oral disease and once treated would allow the cat to eat well again and feel better.

Contributing Author: Jan Bellows, DVM; Diplomate, american Veterinary Dental college; Fellow, academy of Veterinary Dentistry Diplomate; american Board of Veterinary Practitioners; all PetS Dental, Weston, Florida

Tigger’s EarlyChristmas Present

2011 Sept/Oct 29

Physical examination revealed a thin, well hydrated, respon-sive cat with apparent stage four periodontal disease, oral ulceration, halitosis, a rapid heart rate of over 220/min with a systolic murmur, and a respiratory rate of 42/min. The abdomen palpated normally. There was no apparent enlargement in the area of the thyroid glands. The retinas also appeared normal without indication of damage from suspected hypertension. (Figure 1)

The client was advised that general anesthesia would be needed to care for the Tigger’s dental issues. Based on age, history and physical examination findings labora- tory, imaging and electro-cardiograph testing would be needed to proceed further. By 11:30 thanks to the VetScan VS2 and an HM5, we were able to generate an immediate working diagnosis and a direction for additional testing.

Laboratory abnormalities included an elevated ALP 117 U/L (10-90), ALT 331 (20-100), BUN 35 mg/dl, Urine SG was 1.015. Additionally the T4 level was >10 ug/dl (Figure 2)

Radiographs revealed a right middle lung lobe collapse as well as a small soft tissue nodule present within the dorsal aspect of the caudal lung lobe and a slight sternal lymph node enlargement. There was a prominent

Figure 2. Pre-operative blood levels

Figure 1. Stage 4 periodontal disease secondary to excessive plaque and calculus

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30 Sept/Oct 2011

bulge in the aortic arch. The abdominal radiographic study appeared normal. (Figure 3, 4) The electrocardiogram confirmed tachycardia (254) as well as a elongated R and S T amplitudes consistent with left ventricular enlargement. (Figure 5 ) Blood pressure was measured at 164/113.

Significant findings including hyperthyroid-ism, renal failure, and pulmonary masses were discussed with Tigger’s caregivers. An echochardiogram and abdominal ultrasound were recommended next. An echocardiogram revealed hypertrophied left and right ventricles as well as a small internal lumen of the left ventricle. Additionally, prominent encroachment of the septum on the aortic outflow tract was observed. The left kidney was small with poor coricomedulary distinction and abnormal architecture. The right kidney was close to normal in size but irregularly shaped.

Now Tigger’s caregivers had more decisions to make. The most pressing concern was treating his hyperthyroidism followed by managing the renal failure and hypertension. After addressing these issues, the painful dental pathologies could be properly treated. Even with a guarded prognosis his caregivers chose to begin therapy.

Figure 3. Ventral dorsal chest imageFigure 4. Lateral chest image revealing two pulmonary massesFigure 5. Pre-operative electrocardiogram

Treatment for hypertension included benzapril at 1.25 mg daily and amlodipine at 0.625 mg daily. After discussion of surgery, radiation or medical management of hyperthyroidism his caregivers chose to give 2.5 mg methimazole daily initially. A renal diet was prescribed.

Follow-up testing included a urine culture (negative). Two weeks after beginning therapy, the thyroid level was still markedly elevated (18.7 ug/dl). Fortunately, the renal values remained stable. Methimazole was increased to 5 mg bid. One week later the thyroid level was in the normal range 1.4 ug/dl. During the next two months Tigger gained two pounds and did not experience adverse medication reactions. His thyroid level also remained stable.

Tigger’s marked oral pathology still existed. After a long discussion with his caregivers the decision to proceed with oral assessment and treatment was made. A tailored anesthetic protocol based on his echocardiograph and laboratory findings included buprenorphine 0.02 mg/kg and midazolam, 0.2 mg/kg IM, waiting until sedation then placing an intravenous catheter, 1 mg/Kg propofol IV, followed by 0.2mg/kg midazolam IV, followed by 1mg/kg propol IV. Intubation was then possible. Maintenance with isoflurane/oxygen

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2011 Sept/Oct 31

Figure 7. Tigger and Alex happy againFigure 6. Six months post-operative healing

with close monitoring of blood pressure through out the procedure proceeded without incident.

Clinical oral assessment as well as full mouth x-rays were performed next. Dental scaling and polishing as well as extraction of two premolars, a canine and an incisor was accomplished during the 3.5 hour anesthetic procedure.

Tigger soon recovered from surgery. Six months after his initial presentation, he continues to thrive thanks to diligent owners, daily plaque control, and follow-up in clinic testing to monitor his thyroid and renal function while continuing to monitor his response to blood pressure medication. (Figure 6, 7)

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