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Friday, April 30, 2010

Meet Dr. Jean-Yin Tan

Dr. Tan graduated from Cornell University in 2005. She went on to complete an internship at Mid-Atlantic Equine Medical Center in NJ and a large animal internal medicine residency at the University of Minnesota. She spent a year at UC Davis completing an Equine Primary Care fellowship and is now working in New Jersey. Dr. Tan has publications in journals including the American Journal of Veterinary Research and the Canadian Veterinary Journal and has spoken at various local conferences as well as ACVIM Forum. Her interests include neonatology, respiratory disease, and gastroenterology. She has experience with all large animals as well as horses!

Tuesday, April 20, 2010

Case Spotlight - Young Anemic Cat

“Teddy” – 1 and ½ year old MN DSH -
Cindy Stubbs, DVM, DACVIM (Small Animal Internal Medicine)

Owner reports lethargic, not as playful as normal, appetite decreased. PCR panel pending.
Cat one of three from a litter raised by owner. Littermates still in same household and are clinically normal with normal blood work. This pet reported to be quieter than the rest.

Never tested for FeLV/FIV. Was exposed to a FeLV positive cat in same house but separated.
No fever.
Inside only cat.
On Revolution for flea control. No history of exposure to fleas and ticks.

Pet looks fine on exam - normal weight and appearance. No overt abnormalities.

Blood work shows significant anemia with little to no regeneration. Path review still pending.

Anemia - suspect infectious disease as underlying cause (Feline Leukemia virus most likely), immune-disease also a consideration. Could have had an infectious disease that sparked an immune component to anemia.

(1) Check FeLV/FIV status on peripheral blood of this cat and other cats in the household.

(2) If negative, consider bone marrow aspirate or core biopsy. Perform CBC at time of bone marrow sampling so lab can compare. Perform Feline Leukemia IFA or PCR on the bone marrow sample (National Veterinary Labs recommended).

(3) Consider empirical treatment with doxycycline 5 mg/kg every 12 hours or 10 mg/kg once daily (follow with food or water to prevent esophageal issues) and/or prednisolone 5-10 mg/cat daily. Prednisolone preferred in feline patients as it is the active form of prednisone. Cats can make the conversion of prednisone to prednisolone in their liver but it is not reliable.

(4) Based on exam, pet has been anemic for some time and has adjusted to the anemia. A blood transfusion is not indicated at this time.

Follow Up
Follow-up telephone discussion: "Teddy" tested positive for both FeLV and FIV. The littermates were negative. Since the owner wishes to keep all the cats together, it will be important to stress the need for continued vaccination for FeLV and advise owner of the efficacy of the vaccines.

I recommend treatment for "Teddy" consist of doxycycline 10 mg/kg once daily for 3 weeks and possibly prednisolone 5 mg daily for 3 weeks. Reassess the PCV after that period of time to determine if there is a response to therapy. If the red blood cell count improves, the medications may have to be continued long term to maintain the PCV.

Pet should be handled as an immunosuppressed patient, with every cough or sneeze treated in a more aggressive manner. His long-term prognosis is quite guarded especially with the development of the apparent non-regenerative anemia. However, if the anemia does improve there is a chance he might do well for a longer period of time.

Anti-viral therapy has been met with questionable efficacy and I do not routinely recommend their use.

Meet Dr. Cindy Stubbs

Cynthia Stubbs, DVM, DACVIM - Small Animal Internal Medicine

Dr. Cindy Stubbs received her DVM from North Carolina State University in 1995. She then went on to complete a one-year rotating Internship in Small Animal Medicine and Surgery at Texas A&M University, followed by a Residency in Small Animal Medicine at Colorado State University (CSU). Her research interest was feline infectious diseases. In 1999, she received a Master's Degree in Clinical Sciences based on this research at CSU. Dr. Stubbs then worked for 2 years in a large, multi-doctor specialty hospital in Marietta, GA. From 2001-2008, Dr. Stubbs was the owner and internist for North Georgia Veterinary Specialty Care in Suwanee, GA. She currently provides internal medicine services at Triangle Veterinary Emergency Clinic in Durham, NC.

Her special interests in internal medicine include all things feline, especially infectious diseases. She speaks at local, state and national conferences about topics in feline medicine (systemic hypertension, diabetes mellitus, respiratory disease, renal disease, and geriatric care to name a few). She also enjoys working with canine patients, especially with their interesting endocrine concerns.

She currently lives in North Carilona with her husband, Paul Frank, their two young human children Jack and Lily, and their animal children (5 cats and 2 dogs). She enjoys reading and gardening in her "spare" time.

Meet Dr. Lisa Cellio

Lisa Cellio, DVM, Diplomate, ACVIM

Dr. Lisa Cellio is a Diplomate of the American College of Veterinary Internal Medicine. She completed her undergraduate education at the University of Notre Dame with a Bachelor’s Degree in biology in 1994. She then attended veterinary school at the Ohio State University College of Veterinary Medicine. She was awarded a Doctorate of Veterinary Medicine in 1998.

Dr. Cellio went on to further her veterinary education with a small animal rotating internship at Michigan Veterinary Specialists from 1998 to 1999. She spent the next three years as an emergency veterinarian in a busy emergency and referral institution. Dr. Cellio completed a three year residency program at Veterinary Specialty and Emergency Center in Overland Park, Kansas. In 2005, she became board-certified as a Diplomate to the American College of Veterinary Internal Medicine.

Dr. Cellio is married and has two young children. The family also includes two Cavalier King Charles Spaniels and one cat. Her hobbies include running, yoga and traveling.


By Lisa Cellio, DVM, Diplomate AVCIM (Small Animal Internal Medicine)

Histoplasmosis is a soil-borne dimorphic fungus that lives in warm moist and humid conditions. The causative agent is Histoplasma capsulatum and grows best in soil rich in nitrogen organic matter (such as areas with bird or bat excrement.) Histoplasmosis is endemic in temperate and subtropical regions and, in the United States. is most commonly found around the Ohio, Missouri, and Mississippi river valleys.

Infections occur after inhalation of the microconidia. In the body, the microconidia convert to the yeast phase in the lungs and reproduce by budding. The yeast are phagocytized by mononuclear cells. The incubation period is 12-16 days. Infections usually start in the lungs and spread to the lymph nodes and then other organs, including the gastrointestinal system, liver, spleen, bone marrow, adrenal glands, eyes, and, occasionally, the skin or CNS. Occasionally there is an occurrence of the gastrointestinal histoplasmosis without respiratory involvement suggesting the gastrointestinal tract may also be a primary source of infection.

Clinical signs vary with species. Cats have nonspecific signs because of disseminated disease. Dyspnea, tachypnea and abnormal respiratory sounds are common findings. Dogs more commonly have signs of inappetance, fever and weight loss. Signs may be limited to the respiratory tract but most have gastrointestinal involvement. Pointers, Weimaraners, and Brittany spaniels seem to be overrepresented.

Diagnosis is best made by the identification of small (2-4 um) organisms with halos seen on aspirates or impression smears. Occasionally these can also be found in circulating white blood cells or even in CSF. Organisms are most commonly found in the lung, lymph node or bone marrow aspirates in cats. In dogs, rectal scrapes, imprints of colonic biopsies or aspirates of the liver, lung, spleen or bone marrow are best. Histoplasmosis can be difficult to detect in biopsy specimens with hematoxylin and eosin stain. Special fungal stains should be used on biopsy specimens. Fungal isolation is not recommended because the organism is pathogenic. Serology is unreliable. The Histoplasmosis antigen test (Mira Vista) is gaining popularity. It can be used to support disease and is useful in monitoring for resolution with treatment.

Other abnormalities noted include a normocytic, normochromic, nonregenative anemia. Hypoalbuminemia occurs more commonly in cats. Occasionally, clotting times can be abnormal suggestive of microangiopathic hemolysis. Chest radiographs may reveal a linear or diffuse pulmonary interstitial pattern. Hilar lymphadenopathy is more common in dogs than in cats.

Itraconazole is the treatment of choice in both dogs and cats. Side effects include anorexia, vomiting and diarrhea, increased liver enzymes and a dose-dependent cutaneous vasculitis or dermatitis. Itraconazole should be continued 30 days past resolution of clinical signs and usually is a 4-6 month course. Histoplasma antigen can also be monitored. Pulmonary histoplasmosis in dogs can be self-limiting and may resolve without treatment. Itraconazole has poor penetration to the eyes and CNS but has led to resolution. Fluconazole has better penetration to the eye and CNS but is not as effective overall as itraconazole in the treatment of Histoplasmosis. It may also antagonize amphotercin B. Lipid complexed amphotercin B can be used alone or in combination with itraconazole for severe disease. It is helpful in animals that are anorexic or having gastrointestinal signs which may worsen on oral antifungal medications.

Corticosteriods often need to be used early in the course of treatment, although their use is controversial. They may help to decrease the inflammation associated with destruction of the fungus. They can also help to increase the appetite of cats or dogs with histoplasmosis. Initial response to therapy with itraconazole may take 7-14 days. Some animals may experience worsening in their respiratory signs in the first week of therapy. Bloodwork should be monitored approximately every month for changes in the liver enzymes while animals are on itraconazole. Increasing liver enzymes or persistent anorexia in animals undergoing treatment may lead to dosage adjustment or changing of the medication to a different antifungal agent. The prognosis for animals with Histoplasmosis is guarded to fair.

1. Greene, CE. Histoplasmosis, In: Greene, CE.ed. Infectious Disease of the Dog and Cat, 2nd ed. Philadelphia: WB Saunders; 1998, pp.577-583.
2. Sellon, RK, Legendre, AM. Systemic Fungal Infections, In: Bonagura, JD ed. Current Veterinary Therapy XIV. St. Louis: Saunders; 2009, pp.1265-1267