Zoonotic Dermatoses of Exotic Companion Mammals

Integumentary disorders caused by zoonotic agents are very common in exotic companion mammals. This article provides an understanding of the main zoonotic dermatoses including parasitic, fungal, bacterial, and viral diseases to provide the most updated information on their epidemiology, diagnosis, reported clinical signs, and therapies.

Rabbit Dermatology

The majority of rabbit skin disease presentations can be divided into pruritus, alopecia, scaling, and nodules. Some disease will have more than one of these clinical signs. Ectoparasites, bacterial and fungal infections, and neoplasia account for most of the causes seen. Diagnostic tests include skin scraping and cytology, microbial culture, and biopsy. Therapy is dependent on cause. In addition to discussing the various causes and their treatments, important clinical care points are noted.

A rapid evidence assessment of the potential risk to the environment presented by active ingredients in the UK's most commonly sold companion animal parasiticides

A number of parasiticides are commercially available as companion animal treatments to protect against parasite infestation and are sold in large volumes. These treatments are not intended to enter the wider environment but may be washed off or excreted by treated animals and have ecotoxic impacts. A systematic literature review was conducted to identify the existing evidence for the toxicity of the six most used parasiticides in the UK: imidacloprid, fipronil, fluralaner, afoxolaner, selamectin, and flumethrin. A total of 17,207 published articles were screened, with 690 included in the final evidence synthesis. All parasiticides displayed higher toxicity towards invertebrates than vertebrates, enabling their use as companion animal treatments. Extensive evidence exists of ecotoxicity for imidacloprid and fipronil, but this focuses on exposure via agricultural use and is not representative of environmental exposure that results from use in companion animal treatments, especially in urban greenspace. Little to no evidence exists for the ecotoxicity of the remaining parasiticides. Despite heavy usage, there is currently insufficient evidence to understand the environmental risk posed by these veterinary treatments and further studies are urgently needed to quantify the levels and characterise the routes of environmental exposure, as well as identifying any resulting environmental harm.

Haematological response in the treatment of naturally acquired ectoparasite infestations in rabbits

The objective of this study was to determine changes in haematological values of topical administration of selamectin in rabbits with at least one species of naturally acquired ectoparasite infestation (<em>Sarcoptes scabiei</em> var. <em>cuniculi</em>, <em>Psoroptes cuniculi</em>, or <em>Cheyletiella</em> spp). Thirty-five rabbits were enrolled. They underwent physical examination and assessment of ectoparasite infestations on days 0, 14, 28, 56 and 86. Blood for haematology and serum biochemistry was collected on days 0, 14, 28 and 56. Selamectin was topically applied at a dose of 15 mg/kg onto the skin on days 0, 14 and 28, respectively. No ectoparasites or eggs were found in these rabbits from day 28 onwards by skin scraping and/or tape cytology. Haematology and serum biochemistry values were within normal limit throughout the study. However, the neutrophil to lymphocyte ratio significantly decreased post-treatment from 2.89 (0.90-5.47) on day 0 to 1.38 (0.56-3.09), and 1.44 (0.42-4.47) on days 14 and 56, respectively. There were no adverse drug reactions or treatment-related mortalities during the study. This study indicated that selamectin was effective and safe in the treatment and prevent re-infestation for at least 58 d post-treatment. Moreover, the neutrophil to lymphocyte ratio could be used for monitoring of inflammatory response in rabbits.

Efficacy of a dinotefuran, pyriproxyfen and permethrin combination product against Ctenocephalides felis felis (Bouché, 1835) (Siphonaptera: Pulicidae) on artificially infested rabbits

The aim of this study was to evaluate the efficacy of an insecticidal product in rabbits that combines the neonicotinoid dinotefuran with the pyrethroid permethrin plus the insect growth regulator pyriproxyfen. Adult New Zealand rabbits (n = 12) were infested with Ctenocephalides felis felis (50 males and 50 females per rabbit) at days -7, -2, +5, +12 and +19. The control group (n = 6) received no treatment and the treated group (n = 6) received the commercial formulation, indicated for use in dogs, which was applied topically on day 0. The animals were mechanically evaluated with combs (comb test), to assess pulicidal efficacy, on days -5, +2, +7, +14 and +21. All flea removals and counts were performed by region, following the order: head, ears, neck, forelegs, dorsum, abdomen, hind limbs and tail, in order to determine the preferred sites of parasitism by the C. felis felis flea in rabbits. The distribution of fleas prevailed in the head region (about 62%), followed by the neck and back (14 and 11%, respectively). The insecticidal efficacy was calculated using arithmetic means, showing effectiveness of 100% on days +2 and +7 and 82.2% and 81.6%, on days +14 and +21, respectively. Thus the present study has shown the combination to be a viable option in the treatment and control of rabbits infested by C. felis felis.

Advances in exotic mammal clinical therapeutics

It is important that veterinarians treating exotic companion mammals stay abreast of the latest developments relating to medications and drug delivery approaches for safety, efficacy and welfare issues. Sustained release formulations of commonly used drugs as well as newer routes for administration of therapeutic agents allow the veterinarian treating exotic companion mammals to reduce the stress associated with drug administration. Interactions can occur between vehicle and drugs when formulations are compounded, therefore research studies are warranted regarding potential problems associated with these formulations.

Pharmacokinetics of selamectin in helmeted guineafowl (Numida meleagris) after topical administration

Twenty-one healthy helmeted guineafowl (Numida meleagris) housed at the Oklahoma City Zoo were used to evaluate the pharmacokinetic parameters of topical selamectin. Birds were divided randomly into three groups of seven birds each. On day 1, all birds received one dose of 20 mg/kg selamectin topically. Based on the group number, blood was collected from each bird on three separate occasions over a 28-day period. Plasma using liquid chromatography with mass spectrometry was used to determine selamectin concentrations. Mean plasma terminal half-life and maximum plasma concentrations of selamectin were 5.8 days and 16.1 ng/ml, respectively, with maximum plasma levels reached at 3 days. No adverse effects were detected. Birds in this study did reach and maintain plasma levels reported as therapeutic in other species for 19 days. Based on these results, selamectin may be a valuable antiparasiticide in some avian species.

Ectoparasites in small exotic mammals

Ectoparasites inhabiting the skin are responsible for significant problems in small mammals, owing to ingestion of blood, lymph, sebaceous secretions, and scavenging skin debris, as well as a hypersensitivity reaction to parasite antigen resulting in severe pruritus and subsequent self-trauma-induced lesions. In general practice, the most common diagnosis in exotic pets is an unspecified mite infestation, but other ectoparasites such as lice, fleas, insects, or even helminths may cause dermatologic diseases. If treatment with topical insecticides is planned, the small mammal should be isolated for a few hours to enable drying and spreading of the product.