Case Studies In Small Animal

Cardiovascular Medicine

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Case 27

Follow-Up Exam

Presenting Complaint

bulletMicrofilaricidal Rx

Pertinent History

bulletMarso presents to the Cardiology Service today for microfilaricide administration. He was diagnosed on 11/13/99 with heartworm disease and has undergone three IM injections of melarsomine 100mg (11/13/99) and 88mg (12/16/99, 12/17/99). His first injection was followed by lethargy, anorexia and difficulty breathing.
bulletThe owners report that Marso has had a healthy appetite since returning home from his last visit. There has been no dyspnea, sneezing vomiting or diarrhea. Marso does still cough following eating, drinking, or when nervous, probably as a sequelae of debarking surgery. He is kept indoors except when allowed out in the yard for defecation/urination.

Physical Examination

bulletGen: BARH, nervous. BCS 5/9; T=100.5, P=120, R=pant
bulletInteg: Two shaved areas over dorsum.
bulletEENT: Normal
bulletMS: Symmetrical muscling. No gait abnormalities noted.
bulletCV: No murmurs or arrhythmias ausculted. mm=pink, CRT=1.5s. Good femoral pulses.
bulletResp: Normal
bulletGI: Normal
bulletGU: Normal
bulletNS: No gross deficits.
bulletLN: WNL.


bulletS/O: An Interceptor (milbemycin) tablet for a 51-100lb dog was administered at 11:15 AM. No tachypnea, dyspnea or tachycardia was noted through the course of the afternoon and into the evening.
bulletA: Microfilaricidal treatment with no complications.
bulletP: Retest for microfilariae in one month and repeat treatment if test is positive. If negative, begin monthly heartworm preventative. Repeat antigen test in three months and if positive, possibly give another course of melarsomine. Recommend Marso be allowed to gradually return to normal activity after several days of rest.

Discharge Instructions

bulletMarso presented to the Cardiology Service for treatment to clear the heartworm larvae (microfilariae) present in his bloodstream. He was given Interceptor (milbemycin) at 11:15 AM and observed through the course of the day for any adverse reactions. None were observed.
bulletMarso will need to be retested for the heartworm larvae (microfilariae) in one month. If he tests positive, today's treatment will need to be repeated. If he is negative at that time, you can begin to give him a monthly heartworm preventative such as Heartgard or Interceptor.
bulletHe will also need to be retested in three months for adult heartworms. If he is positive, he may need another injection of melarsomine.
bulletIt is important to keep Marso quiet for the next several days. Over a week, gradually allow him to increase activity and by a week he can go back to a normal life-style.
bulletPlease observe him for signs of difficulty breathing, such as increased respiratory rate and restlessness. If you notice these signs, please call us or take him to your local veterinarian immediately.
bulletThank you for bringing Marso to the VMTH. He is a very handsome and sweet dog. Please do not hesitate to contact us if you have any questions or concerns.


Correct Quiz

Mark D. Kittleson, D.V.M., Ph.D. All rights reserved.