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January 2023
JAAHA Abstracts
Abstracts from the latest issue of the Journal of the American Animal Hospital Association.
59.1 JAN/FEB 2023
Veterinary Practice Guidelines
2023 AAHA Senior Care Guidelines for Dogs and Cats
Ravinder Dhaliwal, Elizabeth Boynton, Sheila Carrera-Justiz,
Nicole Cruise, Mary Gardner, Janice Huntingford, Heidi Lobprise, Elizabeth Rozanski
Veterinary professionals are taught to recognize that “old age is not a disease.” However, clients may have the perception that older dogs and cats undergo an unavoidable physical, mental, and behavioral decline attributable simply to old age. The veterinary team’s role includes providing medical care and support to senior pets to maintain their quality of life, as well as supporting and educating clients on proper senior animal care and addressing any misconceptions about the aging process. These Guidelines describe a systematic approach to the healthcare of the senior pet that is based on an evidence-guided assessment of both healthy and unhealthy canine and feline patients. By using evidence-guided medicine, which may include conventional and integrative approaches as well as environmental management for the senior pet, the patient’s quality of life can be enhanced and potentially extended during this vulnerable life stage. Developing a senior program for the veterinary practice requires appropriate training of the entire healthcare team and includes a robust client education program that focuses on the wellbeing of the senior pet. Palliative and hospice care should be included in the education and information provided for both the veterinary team and the families of senior pets.
Case Reports
Successful Use of Mycophenolate Mofetil as Adjunct to Prednisolone for Treatment of Acute Kidney Injury Secondary to Human Serum Albumin Administration in a Dog
Mariana Almeida, Adam Mugford, Pieter Defauw
The use of human serum albumin (HSA) is described in dogs receiving critical care. However, despite the high degree of homology, anaphylactic and delayed hypersensitivity reactions are reported. Delayed type III hypersensitivity reactions can lead to glomerulonephritis and acute kidney injury (AKI). Undiluted 20% HSA was administered to a 4.8 yr old intact male Labrador retriever with severe hypoalbuminemia, following surgical management of septic peritonitis of gastrointestinal origin. Nineteen days after HSA administration, the dog developed peracute high magnitude renal proteinuria and AKI. Rapid immunosuppression, using a combination of prednisolone and mycophenolate mofetil, resulted in full resolution of AKI, hypoalbuminemia, and proteinuria. Addition of mycophenolate mofetil may have resulted in the first documented case of full renal recovery from hypersensitivity-induced AKI caused by HSA administration.
Case Reports
Treatment of Superficial Necrolytic Dermatitis with Copper Chelation in a Dog with Copper-Associated Hepatitis
Cindy Talbot, Shawn Kearns, Pamela J. Mouser
A 7 yr old castrated male Cavalier King Charles spaniel presented for evaluation of liver enzyme elevations. Abdominal ultrasound revealed a small liver with mixed echogenicity, small hypoechoic nodules, and an irregular surface. Histologic examination and copper quantification of the liver obtained by laparoscopy diagnosed copper-associated hepatitis. One month later, the dog developed hyperkeratosis of all four foot pads and ulcerations of feet, legs, and rectum. Punch biopsies confirmed superficial necrolytic dermatitis. After a total of 2 mo of chelation with no changes to medications, skin lesions began to improve, continuing over the following 6 wk to almost complete resolution. At this point, the skin lesions returned and had minimal response to four amino acids infusions. The dog was switched from penicillamine to trientine. Zinc acetate was initiated 6 wk after the switch to trientine, and skin improvement was noted soon thereafter. At the time of death, skin lesions were improving, and the dog was clinically comfortable. Copper-associated hepatitis should be considered as a possible etiology for superficial necrolytic dermatitis. Treatment of superficial necrolytic dermatitis is often unrewarding, and copper chelation, when copper-associated hepatitis has been confirmed, represents another therapeutic option.
Original Studies
Efficacy of a Silver-Based Shampoo for Treatment of Canine Malassezia: A Pilot Study
Selene Jones, Paul Bloom
Malassezia pachydermatis is a commensal of canines associated with Malassezia dermatitis. Consensus guidelines recommend topical and/or systemic treatment, but resistance to antifungals has been reported. The objective of this pilot study was to determine the efficacy of a 0.003% colloidal silver nanoparticle-based shampoo in the treatment of canine Malassezia dermatitis. Dogs were included based on compatible history, presentation, and at least one positive cytology. Fourteen privately owned dogs were bathed every 48 hr for up to 28 days, allowing 5–10 min of contact time. The mean Malassezia organisms for 10 oil immersion fields at each Malassezia dermatitis–affected body area was recorded at days 0 and 14. Dogs positive on day 14 had cytologies performed on day 28. Eleven dogs (78.6%) were cytologically negative by day 28. Nine (81.8%) of these were negative by day 14. One dog (7.14%) had partial resolution (negative in 3/4 Malassezia dermatitis areas) by day 28. These results suggest that silver nanoparticle-based shampoo may be effective in the treatment of canine Malassezia dermatitis. Larger, controlled studies are needed to further investigate efficacy, optimal concentration, and ideal application frequency.
Case Reports
Suspected Generalized Neonatal Tetanus in a Litter of Puppies
Vincent Mayousse, Caroline Soete, Aurélien Jeandel
Tetanus, caused by Clostridium tetani neurotoxin, is extensively described in adult dogs and is frequently associated with a recent history of wounds. Although this condition is reported in 2–3 mo old puppies, tetanus has not been described in neonates. Herein, we report the clinical signs of 3–5 day old American Bully puppies from the same litter, presenting with an acute onset of marked generalized stiffness of the extensor muscles, trismus, and an inability to suckle. Three puppies died because of tetanus: one died during consultation, one was euthanized owing to respiratory distress, and the third died 1 mo after initial presentation following deterioration. All three of these puppies were clinically affected by omphalitis. Complete blood work, toxicological screening (including strychnine assay), serology, and polymerase chain reaction tests for selected infectious diseases were unremarkable. Necropsy of the euthanized puppy confirmed suppurative omphalitis, which may have contributed to the C. tetani infection. These are the first cases of suspected neonatal tetanus in puppies, which is a frequent condition in newborn humans and is associated with omphalitis as the route of infection.
Case Reports
In-Transit Metastasis in a Dog with High-Grade Soft-Tissue Sarcoma: A Case Report
Kelly Hicks, Tanya LeRoith, Brittanie Partridge, Nikolaos Dervisis
A 6 yr old male castrated American Staffordshire terrier was referred for a nonhealing wound at the site of a previously incompletely excised, high-grade soft-tissue sarcoma. Physical examination revealed right popliteal lymphadenopathy and a fungating mass of the right pelvic limb at the level of the hock. Thoracic and abdominal computed tomography revealed mild lymphadenopathy of multiple iliac and inguinal lymph nodes. Right pelvic limb amputation and inguinal lymphadenectomy were performed. Histopathology was consistent of a high-grade soft-tissue sarcoma with diffuse spread through the lymphatic vessels of the right pelvic limb up to the right inguinal lymph node but not affecting the lymph node itself.
Doxorubicin chemotherapy was elected postoperatively as adjuvant therapy. Approximately 4 mo following initiation of chemotherapy, the patient developed a firm, tubular subcutaneous mass starting near the previous amputation site with tracking toward the thorax. Fine-needle aspiration of the new mass was consistent with atypical spindle cell proliferation. Palliative care was elected, and the patient was euthanized 3 mo later because of progressive disease. In-transit metastasis is a rare behavior for soft-tissue sarcomas across all species, and this is the first report of such a presentation for canine soft-tissue sarcoma.
Case Reports
Negative Antigenuria in a Dog with Suspected Central Nervous System Localized Blastomycosis
Harry Cridge, Emily Tryon, Erica Burkland, Adam Moeser
A 7 yr old spayed female mixed-breed dog was presented for a 1 wk history of neck pain and pelvic limb weakness. Examination revealed nonambulatory paraparesis and thoracolumbar hyperesthesia. Magnetic resonance imaging revealed extensive intramedullary T2-weighted/short tau inversion recovery hyperintensity and diffuse severe T1-postcontrast meningeal enhancement of the thoracolumbar spinal cord. An L5–L6 cerebrospinal fluid sample revealed a suppurative pleocytosis (81% neutrophils, total protein 4362.5 mg/dL, and nucleated cell count 352,000/µL). While awaiting the results of the infectious disease testing, the dog was treated for suspected meningoencephalitis of unknown etiology with corticosteroids, cyclosporine, and a cytarabine arabinoside infusion. The dog neurologically declined and was started on broad-spectrum antibiotics. The dog continued to decline despite antibiotics, and infectious disease titers subsequently revealed serum antibody positivity for blastomycosis. The dog was then referred to a multispecialty referral hospital and was treated with amphotericin B followed by fluconazole. Prednisone was continued at anti-inflammatory doses. Urine blastomycosis antigen testing was submitted for subsequent disease monitoring but was negative. Five months after presentation, the dog was clinically doing well with no identifiable neurologic deficits. This case demonstrates that neurologic blastomycosis may have negative urine antigen concentrations in some dogs and that other diagnostic modalities should be pursued when central nervous system fungal disease is suspected.
Retrospective Studies
Precipitation as a Possible Risk Factor for Development of Lyme Nephritis in Dogs
Patrick C. Carney
To determine whether increased precipitation in the months before diagnosis is predictive of Lyme nephritis in dogs, a symmetrical bidirectional case-crossover study was performed on 87 dogs with presumptive Lyme nephritis. Cases were geographically linked to the nearest precipitation monitoring station, and monthly total precipitation for the 4 mo preceding diagnosis was compared to monthly total precipitation 1 yr before and 1 yr after. Breeds affected included Labrador retrievers (n = 31), mixed-breed dogs (n = 19), and golden retrievers (n = 10), with a possible seasonal bimodal peak in spring and fall. In age-adjusted analysis, each additional inch of precipitation 3 mo before diagnosis was associated with an increase in the odds of developing Lyme nephritis (odds ratio 1.13, 95% confidence interval 1.01–1.25). The results suggest that increased precipitation is a possible risk factor for Lyme nephritis in dogs. These findings may provide useful information for the accurate diagnosis of dogs with protein-losing nephropathy and may guide future studies of risk factors for Lyme nephritis. The methodology employed here reinforces the concept that case-crossover designs have utility beyond acute exposures and outcomes and offer an attractive alternative for studies in companion animals.
Retrospective Studies
Clinical Utility of Cytology from Preoperative Percutaneous Fine-Needle Aspirates of Solitary Liver Masses in 220 Dogs: A Retrospective Study (2009–2019)
Megan Cray, Jessica Hokamp, Brittany Abrams, Brian D. Husbands, Janet A. Grimes, Hadley Gleason, David McChesney, Sue A. Casale, Laura Elizabeth Selmic
When a solitary liver mass is identified in a dog, a fine-needle aspirate (FNA) is commonly employed to attempt to obtain a diagnosis. Little information is provided in the literature evaluating the sensitivity/specificity of FNA cytology for solitary liver masses. We hypothesized that liver lesion size nor the presence of cavitation would impact the success of cytological diagnosis. Medical records were obtained for 220 client-owned dogs. Inclusion criteria included preoperative abdominal imaging, percutaneous FNA of a solitary hepatic mass with cytologic interpretation by a board-certified pathologist, and a surgical biopsy or mass excision yielding a histopathological diagnosis. Six dogs (2.7%) experienced a complication after FNA, none considered severe. The agreement rate for correct cytologic diagnosis was 22.9% (49/220). Of the neoplastic masses, 18.9% (35/185) were correctly diagnosed via cytology. The overall sensitivity was 60%, and the specificity was 68.6%. Neither institution (P = 0.16), lesion size (P = 0.88), cavitation (P = 0.34), or needle gauge (P = 0.20) had an association with correct diagnosis. This study demonstrates that, although there is a low risk of complications following FNA of a hepatic mass, overall success rate for correct cytologic diagnosis based on FNA was low compared to histopathologic diagnosis.
Case Reports
Concurrent Parathyroid Adenoma and Thyroid Carcinoma in a Domestic Shorthaired Feline
Abigail Elizabeth DeRouen
A 10 yr old female spayed domestic shorthair was referred for an 11 mo history of persistent total hypercalcemia and elevated ionized calcium with intermittent episodes of lethargy, vomiting, and diarrhea with a history of recurrent urinary tract infections and intermittently elevated kidney values. An abdominal ultrasound, thoracic radiographs, cervical ultrasound, and ionized calcium level, parathyroid hormone (PTH), and PTH-related peptide (PTHrp) levels were assessed. Results were consistent with chronic kidney disease, splenomegaly, diffuse thickening of small intestines, nodular lesions noted in the left thyroid and right parathyroid, and elevated ionized calcium, PTH, and PTHrp levels. A left thyroidectomy and right cranial parathyroidectomy were performed.
Hypocalcemia and anemia developed postoperatively, which were managed with calcium carbonate, calcitriol, and calcium gluconate and benign neglect of anemia. Histopathology was consistent with a left thyroid carcinoma and right cranial parathyroid adenoma. Thyroid carcinoma and parathyroid adenomas have not previously been reported to occur concurrently in domestic felines and should be considered when ionized calcium is elevated with both PTH and PTHrp levels increased in addition to ultrasonographic lesions.