Case Studies
Appendix D. Case Studies
Anaphylaxis/Anaphylactoid Reactions
The following examples represent dogs with anaphylaxis or anaphylactoid reactions that are possibly or probably associated with ProHeart 6.
1. Case 200202319
Signalment: Age: 8 months Breed: Mexican Hairless Gender: Neutered male Weight: 21 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: Neutered on 4/16/02 Date of Injection: 4/17/02 Dose: Labeled Concomitant Vaccinations or Drugs: ketamine, Valium, isoflurane Outcome: Euthanasia Necropsy: Not performed Causality Assessment Category: Probably drug-related The dog recovered from surgery and received a ProHeart 6 injection the next day in the hospital. He collapsed within 20 minutes and was transferred to an emergency clinic. Radiographs revealed no significant findings. He was treated supportively with intravenous fluids. The attending veterinarian was unable to stabilize his blood pressure, and the owners elected euthanasia. 2. Case 200306896
Signalment: Age: 3 years Breed: Schnauzer
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Weight: 12.5 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 12/17/03 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Died Necropsy: Not performed Causality Assessment Category: Probably drug-related
The dog began to vomit within 20 minutes of the injection. She became depressed and collapsed shortly after injection. She was treated with epinephrine, Benadryl, dexamethasone, and intravenous fluids. She recovered initially, but died during the night. 3. Case 200400552
Signalment: Age: 7 years Breed: Wire Haired Fox Terrier Gender: Spayed female Weight: 24.6 lb History: Heartworm Status: Not provided Health Statu endobj
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5. Case 200403885
Signalment: Age: 3 years Breed: Staffordshire Bull Terrier Gender: Female Weight: 62 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 6/18/04 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered Necropsy: Not applicable Causality Assessment Category: Probably drug-related The dog began vomiting within 30 minutes of the injection. She became recumbent with pale membranes within 1 hour. She was given Benadryl and dexamethasone and recovered. CVM also had concern about anaphylaxis/toid events reported among dogs that received ProHeart 6 concurrently with a vaccine or another drug. The following examples represent a sample of cases with causality assessment scores of zero or above for anaphylaxis/anaphylactoid reactions in the concomitant drug and vaccine subgroup. 6. Case 200200791
Signalment: Age: 4 years Breed: Miniatur endobj
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History:
Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 2/11/02 Dose: Labeled Concomitant Vaccinations or Drugs: Distemper vaccination Outcome: Progressed with multiple clinical signs, recovered Necropsy: Not applicable Causality Assessment Category: Possibly drug-related
The dog collapsed within 2 hours of injection, was treated with fluids, steroids and diphenhydramine, and released. She presented later that evening to the emergency clinic at Michigan State University (MSU) with a seizure. She recovered, but presented to her regular veterinarian the next day with a papular skin eruption on the neck and back and wheals on the head. She was referred to MSU for a skin biopsy. No biopsy results were submitted to CVM, but the dog was progressing well clinically on 4/16/02 re-evaluation.
7. Case 200203569
Signalment: Age: 3 years Breed: Pug Gender: Neutered male Weight: 25.6 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions
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2. Case 200104935
Signalment: Age: 7 years Breed: German Shepherd Mix Gender: male Weight: 100 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 10/15/01 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered, ongoing treatment Necropsy: Not applicable Causality Assessment Category: Possibly drug-related The dog presented with seizures 30 hours after injection. He was treated with phenobarbital and Valium. The dose of phenobarbital was decreased in late October. As of late November, no additional seizures were reported. The veterinarian listed
differential diagnoses of idiosyncratic drug reaction or epilepsy. 3. Case 200202452
Signalment: Age: 18 months Breed: endobj
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Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered, ongoing treatment Necropsy: Not applicable Causality Assessment Category: Possibly drug-related Vomiting, diarrhea, and inappetence began an hour after the injection and were ongoing for 3 days. He was examined on 4/22/02 and treated with Baytril, dexamethasone, and
cimetidine. The dog began having seizures 9 days after injection. Blood tests showed elevated liver enzymes. He was treated with Valium and phenobarbital. On 5/5/02 (14 days after injection) the dog was trembling and had severe pain when he opened his mouth. A magnetic resonance imaging (MRI) test and a cerebrospinal fluid (CSF) tap identified no cause for the seizures. 4. Case 200207752
Signalment: Age: 3 years Breed: Golden Retriever Gender: Male Weight: 107 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 12/27/02 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered, onging treatment Necropsy: Not applicable Causality Assessment Category: Possibly drug-related
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discontinue phenobarbital in February 2003, but the dog had another seizure and was started on the phenobarbital again. No additional seizures were noted at a 2 month follow-up visit. 5. Case 200301322
Signalment: Age: 10 years Breed: Miniature Schnauzer Gender: Spayed female Weight: 30 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 3/1/03 (3
rd
dose)
Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Euthanasia Necropsy: Not performed Causality Assessment Category: Possibly drug-related
The dog had a seizure 4 days after she was given her third dose of ProHeart 6 and developed elevated liver enzymes 7 days later. A veterinary neurologist developed a differential diagnosis that included a forebrain lesion due to encephalitis, neoplasia, or a cerebral vascular incident. The dog was euthanized without a necropsy 25 days following her injection. 6. Case 200301797
Signalment: Age: 2.5 years Breed: Weimaraner
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Weight: Not provided History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 3/21/03 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Progressive neurological disease and visual impairment, survived Necropsy: Not applicable Causality Assessment Category: Possibly drug-related
Twenty-four hours after injection, the dog developed bloody diarrhea, vomiting, ataxia and a head tilt. She progressed to a prancing gait and partial blindness and was referred to the Louisiana Statue University (LSU) veterinary school. Fungal and tick titers were negative. MRI revealed dilated optic vessels and subtle changes in the occipital area of the cerebrum, thalamus, and optic radiation. CSF tap revealed mild lymphocytic inflammation. Distemper titers were 1:80 indicating vaccination, infection, or exposure. No diagnosis was made and the dog was sent home on tapering doses of prednisone. When the owner tried to wean her off her medication, clinical signs returned.
7. Case 200302409
Signalment: Age: 18 months Breed: Papillon Gender: Neutered male Weight: 6.7 lb History: Heartworm Status: Negative Health Status: Good
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Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Died Necropsy: Meningoencephalitis; cardiac lesions Causality Assessment Category: Possibly drug-related (seizure) Remotely drug-related (encephalitis, cardiac lesions) This dog began to have seizures 48 hours after his second injection of ProHeart 6. He had two seizures one hour apart. On 4/29/03 he was started on phenobarbital. He had a seizure and died 16 days after the ProHeart 6 injection. Necropsy revealed severe necrotizing granulomatous and eosinophilic meningoencephalitis. Moxidectin levels in the brain were run and were not found at the limits of detection. In the heart, the right ventricle was dilated and flabby with dark red foci of the epicardium. Turk s procedure (a special histopathology stain) indicated right ventricular hypertrophy.
8. Case 200404520
Signalment: Age: 4 years Breed: Chihuahua Gender: Spayed female Weight: 7.4 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 5/14/04 (2
nd
dose)
Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Died
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10. Case 200201651
Signalment: Age: 3 years Breed: Mixed Gender: Neutered male Weight: Not recorded History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 3/11/02 Dose: Not provided Concomitant Vaccinations or Drugs: Distemper, rabies, and Lyme vaccinations Outcome: Euthanasia Necropsy: Multifocal ischemia of the brain Causality Assessment Category: Possibly drug-related
This dog had a seizure 6 days after the ProHeart 6 and vaccine administration. He was euthanized 11 days after the injections when he failed to respond to treatment. A veterinary neurologist at Cornell University examined the brain, noting multifocal
ischemic lesions which may have been secondary to the seizures. No evidence of
inflammation was found to support a diagnosis of infectious disease or a post-vaccinal condition. 11. Case 200103297
Signalment: Age: 1.5 years Breed: Miniature Pinscher endobj
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Concomitant Medical Conditions: None Date of Injection: 6/27/01 Dose: Labeled Concomitant Vaccinations or Drugs: Monthly imidacloprid for fleas Outcome: Progressive neurological disease, survived Necropsy: Not provided Causality Assessment Category: Possibly drug-related The dog s signs started with ataxia and incoordination 12 hours after ProHeart 6 injection and progressed to dysmetria, tremors, abnormal reflexes, and stiffness by 18 days. He was treated successfully through September and weaned off prednisone. A progress review in December 2001 indicated that he still had tremors when excited. 12. Case 200207622
Signalment: Age: 2 years Breed: Pit Bull Terrier Gender: Neutered male Weight: 66.4 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 12/13/02 Dose: Labeled Concomitant Vaccinations or Drugs: Distemper, rabies, and Lyme vaccinations Outcome: Ongoing seizure disorder Necropsy: Not applicable Causality Assessment Category: Possibly drug-related
The dog started to vomit and have diarrhea within an hour of the ProHeart 6
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Breed: Pit Bull Terrier Gender: Male Weight: 58 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 10/8/02 Dose: Underdosed by 0.20 mL Concomitant Vaccinations or Drugs: None Outcome: Died Necropsy: Not performed Causality Assessment Category: Possibly drug-related
The dog had bloody diarrhea and began vomiting within 10 minutes of the injection. By 2 hours his condition had progressed to collapse, cyanosis, and pulmonary congestion. He was sent to an emergency referral clinic where he was treated with crystalloids, cefazolin, enrofloxacin, famotidine, and sucralfate. He failed to improve, became
oliguric, and was referred to a specialist. His SGPT/ALT was as high as 20,773. He died by day 3 following the injection. He was included in both the anaphylaxis/anaphylactoid reaction category and the liver category. 3. Case 200303279
Signalment: Age: 10 years Breed: Labrador Retriever Gender: Spayed female Weight: 72 lb History: endobj
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Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Survived Necropsy: Not applicable Causality Assessment Category: Possibly drug-related The dog was lethargic and anorexic on the evening of her first injection. By the third day following injection, she was jaundiced and diagnosed with elevated liver enzymes. Liver biopsy revealed chronic active hepatitis. 4. Case 200401208
Signalment: Age: 3 years Breed: Jack Russell Terrier Gender: Spayed female Weight: 17 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 8/14/04 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered after several months Necropsy: Not applicable Causality Assessment Category: Possibly drug-related
The dog presented 2 weeks after injection with vomiting, anorexia, and depression. She was diagnosed at an emergency veterinary center with elevated liver enzymes and a heart murmur. She was extensively evaluated by two veterinarians and a specialist and her workups included radiographs and ultrasound examination. No ot endobj
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Gender: Neutered male Weight: 52 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 7/5/01 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Euthanasia Necropsy: Not performed Causality Assessment Category: Possibly drug-related This dog presented for lethargy and depression 14 days post-injection and was diagnosed with immune-mediated hemolytic anemia the next day. He was treated with Oxyglobin (artificial hemoglobin), steroids, and antibiotics but did not respond. He was euthanized 12 weeks after his ProHeart 6 injection. 2. Case 200200772I
Signalment: Age: 12 years Breed: Yorkshire Terrier Gender: Spayed female Weight endobj
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Causality Assessment Category: Possibly drug-related
This dog was diagnosed with immune-mediated hemolytic anemia 27 days after injection. She had a packed cell volume of 10% and died overnight at the local veterinary emergency clinic. 3. Case 200201234
Signalment: Age: 1 year Breed: Labrador Retriever Mix Gender: Neutered male Weight: 67 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 2/26/02 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered Necropsy: Not applicable Causality Assessment Category: Possibly drug-related
This dog vomited and was depressed 6 hours after injection and was treated with dexamethasone, Benadryl, and fluids. Eight days later, he was diagnosed with immune-mediated hemolytic anemia. He tested negative for Lyme and Ehrlichia. He was treated with prednisone and Immuran and recovered. 4. Case 200203935I
Signalment:
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Health Status: Good Concomitant Medical Conditions: None Date of Injection: 4/13/02 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Unknown Necropsy: Not applicable Causality Assessment Category: Possibly drug-related (IMHA and low platelets) This dog presented with exercise intolerance 5 weeks after ProHeart 6 injection. Blood tests showed a Coombs Positive hemolytic anemia and thrombocytopenia. He was treated with cyclosporine and
prednisone. The outcome of the case was not provided. 5. Case 200303433
Signalment: Age: 2 years Breed: Dachshund Gender: Neutered male Weight: 40 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: Obesity; narcolepsy Date of Injection: 5/26/03 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Died Necropsy: Centrilobular hepatic necrosis; pulmonary vascular thrombosis Causality Assessment Category:
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due to severe anemia. He also had cholestasis, hemosiderosis of the spleen, and pulmonary vascular thrombosis. 6. Case 200305624
Signalment: Age: 3 years Breed: Poodle Gender: Spayed female Weight: 15 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 5/22/03 Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered Necropsy: Not applicable Causality Assessment Category: Possibly drug-related This dog was diagnosed with immune-mediated hemolytic anemia 7 days after ProHeart 6 injection. Her tick panel was negative. She was treated with azathiaprine, prednisone, doxycycline, and cyclosporine and two whole blood transfusions. She gradually improved and by six months post-injection, was off all medications. 7. Case 200200725 I
Signalment: Age: 11 years
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Concomitant Medical Conditions: Grade 3 heart murmur Date of Injection: 1/29/02 Dose: Labeled Concomitant Vaccinations or Drugs: Distemper Vaccination Outcome: Euthanasia Necropsy: Not performed Causality Assessment Category: Possibly drug-related
This dog presented to an emergency clinic 8 days after her injections with pale mucous membranes. Her packed cell volume was 8.5%, and she was diagnosed with immune-mediated hemolytic anemia. She was Coombs , Lyme, and Ehrlichia negative and was treated with a blood transfusion and prednisone. She was euthanized at day 33 post-injection. 8.
Case 200307034
Signalment:
Age: 6 years Breed: Beagle mix Gender: Neutered male Weight: 50 lb History: Heartworm Status: Negative Health Status: Good Concomitant Medical Conditions: None Date of Injection: 9/27/03 (4
th
dose)
Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Recovered Necropsy: Not applicable Causality Assessment Category: Possibly drug-related The dog developed a hot spot (pyoderma of the sk
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Age: 8 years Breed: Keeshond Gender: Neutered male Weight: 45 lb History: Heartworm Status: Not provided Health Status: Good Concomitant Medical Conditions: None Date of Injection: 5/9/02 (2
nd
dose)
Dose: Labeled Concomitant Vaccinations or Drugs: None Outcome: Died Necropsy: Not performed Causality Assessment Category: Possibly drug-related (IMHA and low platelets) There were no reported problems after the initial dose of ProHeart 6 on 11/2/01. This dog presented with depression and lethargy 14 weeks after the second injection. His PCV was 11% with agglutinating red cells. Platelets were estimated at 22,000. He was treated with two blood transfusions, prednisone, and cytoxin but died in 3 days.
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