Treatment of Superficial Necrolytic Dermatitis with Copper Chelationina Dog with Copper-Associated Hepatitis.

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.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Retrospective evaluation of canine primary, multicentric, and metastatic intraocular neoplasia.

OBJECTIVE: To provide an updated characterization of the prevalence of primary, multicentric, and metastatic intraocular tumors in the canine patient. PROCEDURES: Medical records databases from 4 veterinary referral hospitals were reviewed from 1999 to present to identify dogs with a diagnosis of intraocular neoplasia histopathologically confirmed following enucleation or necropsy. RESULTS: One hundred seventy-two dogs with 173 intraocular neoplasms met the inclusion criteria. Primary intraocular neoplasms were the most common tumors in the study (128); the two most common types were melanocytic neoplasia (90), followed by iridociliary neoplasia (33). There were 28 cases of intraocular involvement secondary to round cell neoplasia, with 18 cases of lymphoma, seven histiocytic sarcomas, and three undifferentiated round cell neoplasms. There were 17 cases of metastatic intraocular neoplasia, with hemangiosarcoma being the most common (9). CONCLUSIONS: The majority of intraocular tumors in dogs arise from the ocular tissues. However, the eye may also be involved in patients with multicentric neoplasia, and, less commonly, as a site for metastatic disease. Ocular screening for patients with multicentric neoplasia should be considered during staging, and ocular signs should be viewed with suspicion in dogs with neoplasia in other sites.

Iatrogenic ocular trauma associated with infraorbital block performed for rhinoscopy in a cat: case report and preliminary imaging findings.

OBJECTIVES: This paper describes a case of endophthalmitis in a feline patient caused by globe penetration during an infraorbital block performed to provide analgesia during rhinoscopy, and presents additional imaging and dissection data demonstrating risk of iatrogenic ocular trauma during infraorbital blocks in cats when the infraorbital canal is entered. METHODS: Case records and accompanying histopathologic reports were reviewed for the feline patient. Separately, two feline cadavers were imaged using CT following placement of 5/8" 25 G needles or 1" 22 G over the needle catheters in the infraorbital canal. Infraorbital blocks with injection of trypan blue dye followed by dissection were performed in two further feline cadavers to assess the potential for globe penetration and to provide preliminary information regarding the potential efficacy of infraorbital blocks for analgesia during rhinoscopy. RESULTS: Clinical and histopathologic findings support inadvertent globe penetration during infraorbital block as the cause for endophthalmitis in the feline patient described. CT imaging and dye injection studies further demonstrate the risks involved with this local anesthetic technique in cats. CONCLUSIONS AND RELEVANCE: Further study is needed to assess the safety and efficacy of infraorbital blocks performed for rhinoscopy in cats. Catheters may be safer anesthetic delivery devices than needles. Extreme caution should be used when entering the infraorbital canal in cats.

Tophaceous pseudogout in a 12-year-old dog, with a review of applicable laboratory tests.

Pseudogout, also known as calcium pyrophosphate dihydrate (CPPD) deposition disease or chondrocalcinosis, is caused by crystalline deposits of CPPD within the extracellular matrix of articular hyaline cartilage and fibrocartilage, and within articular and periarticular connective tissue. Using a variety of laboratory techniques, we diagnosed pseudogout in the right hindlimb digit V of a 12-y-old Standard Poodle. Histologically, the joint, bone, tendon, and dermis were expanded and effaced by masses of mineralized, rhomboid crystals surrounded by macrophages, multinucleate giant cells, fibrous connective tissue, and chondroid and osseous matrix. Rhomboid crystals exhibiting weak-positive birefringence were identified under polarized light using a first-order red compensator filter. Scanning electron microscopy with energy-dispersive x-ray analysis (SEM-EDXA) revealed that the rhomboid crystals were composed of calcium, phosphorus, and oxygen. Fourier-transform infrared (FTIR) microspectroscopy confirmed the presence of calcium pyrophosphate. In dogs, tophaceous pseudogout, which was the variant of pseudogout in our case, occurs as a single, tumor-like periarticular mass that can be invasive and mimic neoplasia. Having ancillary confirmatory testing (SEM-EDXA and FTIR), particularly in unusual histologic scenarios, such as tophaceous pseudogout in dogs, is desirable for confirming the correct diagnosis, even though it is available only at certain reference centers. The pathogenesis of pseudogout is unknown.

Prevalence of malignancy in masses from the mammary gland region of dogs with single or multiple masses.

OBJECTIVE: To determine the prevalence of malignancy in masses from the mammary gland region of dogs with single or multiple masses. ANIMALS: 95 female dogs from which mammary gland masses had been excised. PROCEDURES: Medical records of all female dogs from which mammary gland tissue was submitted to the Angell Animal Medical Center Pathology Department from 2009 through 2014 were reviewed. For each dog, data were obtained on breed, body weight, age, reproductive status, and number, location, and histologic classification of masses. The prevalence of malignancy was compared between dogs with single versus multiple masses and among the 5 pairs of mammary glands. Dogs with single versus multiple masses were also compared with respect to age and reproductive status. RESULTS: Among 161 evaluated masses, 137 (85%) were classified as benign or nonneoplastic and 24 (15%) as malignant. Five of 95 (5%) dogs had masses that were not of mammary gland origin. Age, reproductive status, and quantity of masses (single vs multiple) were not significantly associated with the prevalence of malignancy. The prevalence of malignancy in masses from the fourth (caudal abdominal) mammary gland was significantly lower than that in the other 4 mammary glands combined. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with multiple masses in the mammary gland region were not significantly more likely than dogs with single masses to have a malignancy, suggesting that these 2 groups could be managed similarly. Further studies are needed to evaluate the clinical relevance of the lower prevalence of malignancy in masses from the fourth mammary gland.

Azygos continuation of the caudal vena cava with segmental aneurysm, lung lobe torsion and pulmonary thromboembolism in a dog.

This case highlights the management and diagnostic evaluation of a dog with two individually rare conditions (lung lobe torsion and vena cava aneurysm) that ultimately resulted in fatal pulmonary thromboembolism.

Fatal venous air embolism during anesthesia in an apparently healthy adult Chihuahua.

An apparently healthy adult female Chihuahua was presented for elective ovariohysterectomy. After induction of general anesthesia, but prior to the start of the surgery, air was inadvertently administered to the patient via the i.v. fluid line. The patient convulsed, became apneic, arrested, and died despite attempted cardiopulmonary resuscitation. At necropsy, the pericardial sac was incised and filled with water to entirely submerge the intact heart. The right ventricular free wall was punctured, releasing several air bubbles from the right ventricle. Death was attributed to venous air embolism based on the clinical history, gross findings, and paucity of underlying gross and microscopic pathology that might have predisposed the dog to an anesthetic-related death. The discussion of this case includes a review of previously reported veterinary cases of fatal venous air embolism, including the varied mechanisms of embolus formation, the potential impact of pre-existing cardiopulmonary disease, and the methods used to detect emboli. This report outlines the events of fatal iatrogenic venous air embolization and emphasizes the importance of considering this entity in the case of sudden death of a patient with an indwelling catheter in order to pursue either appropriate diagnostic tests or necropsy techniques to aid in the diagnosis.

Emergent presentation of a cat with dystrophin-deficient muscular dystrophy.

This report describes a case of feline dystrophin-deficient muscular dystrophy (DDMD) with an atypical clinical presentation. A novel gene mutation is reported to be responsible for dystrophin-deficient hypertrophic muscular dystrophy. In an emergency setting, clinicians should be aware of muscular dystrophy in young cats and the importance of elevated creatine kinase (CK) activity. Muscular dystrophy is rare but can present both a diagnostic and therapeutic challenge in an emergency setting. Patients with muscular dystrophy have a progressive disease with no specific treatment and have an increased risk for death during their hospital stay.