A modified biopsy technique to improve histopathological evaluation of avian skin

Skin biopsies are a viable diagnostic tool in avian dermatology, however, the thinness of avian skin makes it difficult to prevent rolling and contraction of skin biopsy specimens during collection and fixation. The difficulty orienting such rolled samples during processing ultimately interferes with the establishment of a histopathological diagnosis. We describe a modified skin biopsy procedure for obtaining avian skin biopsy specimens. In this technique nontranslucent self-adhesive tape (Scotch tape) was attached to skin biopsy sites before obtaining skin biopsies using a standard skin biopsy punch instrument. A total of 23 skin biopsy specimens were obtained: 15 from nonfeathered skin of 12 normal Hispaniolan parrots, 3 from feathered skin of 2 normal birds and 5 from feathered skin of 3 psittacines presented for pathologic feather-picking. All 23 skin specimens consistently adhered to the tape during the biopsy procedure. The specimens were fixed in 10% neutral phosphate-buffered formalin. During processing, no curling or rolling of specimens occurred, and all specimens could be easily orientated for correct trimming and subsequent histopathological evaluation. The tape technique did not produce any appreciable artefacts. Remnants of the tape were microscopically evident above the stratum corneum assuring that none of the stratum corneum was lost during processing. Obtaining avian skin biopsy specimens using this modified tape technique is easy and ensures flat fixation of the skin biopsy specimens, which later allows trimming at right angles, and through the longitudinal diameter of feather follicles for accurate histopathologic evaluation.

Draining tracts and nodules in dogs and cats

Draining tracts and nodules in the dog and cat can present a diagnostic challenge to the veterinarian. A systematic approach and a complete list of differential diagnoses are needed to define the underlying disease, so that appropriate therapeutic management can be instituted and prognosis can be discussed with the owner. The purpose of this article is to review a complete list of differential diagnoses for draining tracts and nodules in the dog and cat, and discuss the appropriate diagnostic steps including cytology, biopsy and histopathology, culture and sensitivity, serology, and diagnostic imaging that are an important part of the work-up for draining tracts and nodules.

Strategy for preventing vertical transmisssion of HIV : Bombay experience

OBJECTIVE

To evaluate the efficacy of an interventional regime to reduce the perinatal mode of transmission of human immunodeficiency virus (HIV).

DESIGN

Prospective.

SETTING

Perinatal HIV clinic at a university affiliated maternity hospital.

SUBJECT & METHODS

After adequate counseling, consenting HIV positive women were offered perinatal intervention: (i) administration of 400 mg of zidovudine (AZT) per day for the last 6 weeks of the antenatal period; (ii) delivery by elective Caesarian section before rupture of membrances; (iii) oral AZT powder in the dose of 8 mg per kilogram daily to the infant for the first 6 weeks of life; and (iv) avoidance of breast milk. The infants were scheduled for regular follow-up for at least 18 months. A definitive diagnosis of infectivity in the infant was ascertained by two positive enzyme-linked immunosorbent assays (ELISA) at the age of 9 months and between 15 to 18 months.

RESULTS

Of the 107 mother-infant pairs enrolled, 22 infants were lost to follow-up, 15 were under 18 months of age at the time of this analysis and 2 infants died without a diagnosis. Of the remaining 68 infants followed up, 4 tested HIV positive at 18 months. Of the 229 women-infant pairs who did not receive perinatal intervention, 55 infants followed up to 15-18 months were found to be infected.

CONCLUSION

This interventional strategy significantly reduced the mother to child transmission of HIV. However, the results need to be substantiated by larger studies.

Endocrinopathies. Thyroid and adrenal disorders

This article focuses on common adrenal and thyroid diseases in the geriatric patient consisting of hypothyroidism in the dog, hyperthyroidism in the cat, and hyperadrenocorticism in the dog to include clinical signs, diagnosis, and management. A brief section on hyperadrenocorticism in the cat, thyroid tumors in the dog, and pheochromocytoma in the dog and cat are also included.

Systemic diseases with cutaneous manifestations

The purpose of this article is to briefly discuss the following cutaneous manifestations of selected systemic diseases: poxvirus; feline leukemia virus (FeLV); feline immunodeficiency virus (FIV); herpesvirus; calcivirus; pseudorabies; plague; tularemia; toxoplasmosis; leishmania; hypothyroidism; hyperthyroidism; hyperadrenocorticism; diabetes mellitus; acromegaly; thallium poisoning; pancreatic disease; hypereosinophilic syndrome; mucopolysaccharidosis; and pansteatitis. Recognition of these cutaneous signs may help alert the clinician to the possibility of an internal disorder so that the appropriate diagnostic tests can be considered.

Ototoxicity assessment of a gentamicin sulfate otic preparation in dogs

Vestibulotoxic and ototoxic effects often are seen after long-term, high-dose systemic treatment with gentamicin, but toxic effects after topical use have not been reported in animals, to the authors' knowledge. Vestibular and auditory effects of twice daily otic gentamicin treatment for 21 days were evaluated in 10 dogs with intact tympanic membranes and in the same 10 dogs after experimental bilateral myringotomy. Each dog served as its own control; 7 drops of gentamicin sulfate (3 mg/ml in a buffered aqueous vehicle) were placed in 1 ear, and 7 drops of vehicle were placed in the opposite ear. Treatment and control ears were reversed after myringotomy. Vestibular function was evaluated daily by neurologic examination and behavioral assessment. Auditory function was evaluated twice weekly by determination of brain stem auditory evoked potentials. Gentamicin sulfate placed in the ear of clinically normal dogs with intact or ruptured tympanic membranes, in the quantities used in this study, did not induce detectable alteration of cochlear or vestibular function. Serum gentamicin concentration after 21 days of treatment was detectable in only 2 dogs and was an order of magnitude below documented toxic concentrations.

Ototoxicity

This article describes the pathophysiology of ototoxic agents and contains a list of potential ototoxic agents including a list of animal species in which the toxicity has been documented or research studies performed.

Ivermectin toxicosis in a kitten

A 4-month-old female kitten developed generalized ataxia, mild tremors, weakness, incoordination, and miosis after receiving an injection of ivermectin (0.3 mg/kg of body weight, SC) for treatment of ear mite infestation. The kitten became comatose within 12 hours, and despite supportive treatment, died 7 days after administration of ivermectin. Caution should be exercised when this drug is administered parenterally to kittens.

Babesiosis of companion animals and man

Babesiosis is caused by numerous organisms and is seen in a wide range of vertebrate hosts. The spectrum of disease is broad and ranges from asymptomatic carrier states to fulminant disease that results in rapid death. The importance of babesiosis in companion animals is well-recognized in parts of the world where virulent strains exist and where the diagnosis and treatment of both typical and atypical presentations is part of the everyday course of events for the small animal clinician. In parts of the world such as the United States where less virulent strains are found, diagnosis is more difficult. Diagnosis requires an astute eye examining the blood smear and a keen mind willing to "consider the zebras without forgetting the horses." Babesiosis is not uncommon in the United States; it is merely uncommonly diagnosed. The small animal clinician needs to be aware of the disease and its myriad possible presentations. A clearer understanding of the disease will lead to a truer picture of its importance not only in the United States but also worldwide.

Dermatologic aspects of tick bites and tick-transmitted diseases

Dermatologic manifestations of tick bites and tickborne disease are not commonly encountered. However, recognition of the signs and histopathologic conditions of tick bites can be important to the diagnosis and management of small animal diseases. Understanding the local nodular inflammatory reaction to a tick bite can allay the owner's fear that a newly recognized nodule may be a malignant growth. Additionally, recognition of tick bites and pathognomonic dermatologic changes may provide important evidence in making a diagnosis of tick-transmitted diseases.