Efficacy of an injectable formulation of eprinomectin against Psoroptes cuniculi, the ear mange mite in rabbits

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.

Mange in Rabbits: An Ectoparasitic Disease with a Zoonotic Potential

Mange in rabbits is a very important parasitic disease causing high losses. The disease is caused mainly by Sarcoptes scabiei, Psoroptes cuniculi, Cheyletiella parasitovorax, and Notoedres cati. Body mange and ear mange are the most common forms of this disease in rabbits. Animals can get mite infestation through direct contact with infected animals or contaminated fomites. This infestation is characterized by zoonotic nature and public health burden. The skin affection is characterized by pruritus, alopecia, severe cachexia, and sometimes death. Infestation is diagnosed mainly by skin scraping and microscopic examination. Control measures mainly depend on the use of different types of systemic and topical acaricides and the use of natural products and supportive elements. Vaccine is not commercially available and is still under investigation. Accordingly, this review article was designed to shed the light on the mange disease in rabbits in terms of mite's infestation and susceptibility, clinical manifestations, zoonosis, diagnosis, and control strategies.

Efficacy of Oral Sarolaner for the Treatment of Feline Otodectic Mange

Otodectes cynotis is a mite with a cosmopolitan distribution that is the primary agent for the development of otitis externa in feline species. The aim of this study was to evaluate the efficacy of the oral administration of sarolaner for the treatment of feline otodectic mange. We used 20 adult cats of both sexes that were naturally infested with O. cynotis. The mite infestation scoring was performed by video-otoscopy before treatment. The cats were randomized according to the infestation score and divided into two groups (treated and control). The treated group underwent oral administration of sarolaner in a single dose of 2–4 mg/kg. The evaluations were performed by video-otoscopy to evaluate the reduction of infestation score 2, 4, 6, 24 and 48 h and 7, 14, 21 and 28 days after medication. At the end of the study, the cats were sedated to enable the recovery of live and dead mites to determine efficacy. No adverse effects or laboratory changes were observed in these cats. Sarolaner showed 100% efficacy 48 h after treatment. Based on the results, a single oral dose of sarolaner was effective in controlling otodectic mange in naturally infested cats.

Comparing acaricidal and ovicidal activity of five terpenes from essential oils against Psoroptes cuniculi

Essential oils and their components represent an appealing alternative strategy against parasitic mites. The chemical complexity and variability of essential oils limit their use and additional work is required to analyze the efficacy and application rate of essential oils' individual components. In the present study, the activity of five terpenes (terpinen-4-ol, citral, linalool, eugenol, and geraniol) was evaluated against Psoroptes cuniculi motile stages and eggs collected from naturally infected rabbits. Eugenol presented the best acaricidal efficacy with a median lethal concentration (LC₅₀) value of less than 0.1% at 24 h, followed by geraniol (0.33%), linalool (0.38%), citral (0.46%), and terpinen-4-ol (0.66%). Geraniol and eugenol were able to kill all mites within 5 min at 1% concentration. The effective concentration to inhibit 50% (EC₅₀) of egg hatching was 0.65%, 0.66%, 0.85%, 1.47%, and 2.87% for eugenol, geraniol, citral, terpinen-4-ol, and linalool, respectively. In conclusion, eugenol, geraniol, citral, terpinen-4-ol, and linalool should be considered as promising agents for the development of botanical acaricides against Psoroptes cuniculi.

Efficacy of Ivermectin, Liquid Paraffin, and Carbaryl against Mange of Farmed Rabbits in Central Kenya

Mange is a common disease of rabbits globally, and knowledge of efficacy of drugs used in its treatment is critical for effective disease control. The current study evaluated the efficacy of three commonly used therapeutic agents in Kenya against mange. In a controlled laboratory trial, 20 adult rabbits were recruited for the study (16 of which were infested with mange, while 4 were mange-free). The 16 mange-infested rabbits were randomly allocated into 4 treatment groups each consisting of 4 rabbits, while 4 mange-free rabbits formed the negative control group. Treatments were administered as follows: group 1 (G1) received two ivermectin injections at an interval of 14 days, group 2 (G2) was treated with a combination of carbaryl and liquid paraffin applied every other day up to the end of the experiment, group 3 (G3) was treated with liquid paraffin droplets applied daily until the lesion cleared, while group 4 (G4, infected-untreated) received distilled water applied topically on their ears and group 5 (G5, uninfected-untreated negative control) was not treated with any preparation. The lesions were scored and sampled daily to check the viability of the mites. A field efficacy trial of the test compounds was performed using 105 mange-infested rabbits. The results revealed that all the test agents: ivermectin, liquid paraffin, carbaryl-water, and carbaryl-liquid paraffin combination were effective against mange, recording the lesion score of zero for psoroptic mange by day 21 in the laboratory and field trials. Lesion scores in the treated groups were significantly reduced (p < 0.05) at the termination of study compared with those of the positive control group in the laboratory trial. A point-biserial correlation revealed a strong association (r_pb = 0.79, p < 0.05) between the presence of viable mites and degree of psoroptic lesions in the field trial.

A single subcutaneous administration of a sustained-release ivermectin suspension eliminates Psoroptes cuniculi infection in a rabbit farm

BACKGROUND

Psoroptes cuniculi mites are the most common ear parasites infesting breeding female rabbits. The suffering rabbits show cutaneous signs of the infestation in the ears and are prone to secondary infections.

OBJECTIVES

This trial was conducted to eliminate P. cuniculi in farm rabbits with a sustained-release ivermectin-loaded solid dispersion suspension (IVM-SD) suspension, and studied the stability of the formulation.

ANIMALS

There were 986 breeding female Hyplus rabbits naturally infected with P. cuniculi.

METHODS

All rabbits infected with P. cuniculi were subcutaneously administered with a single dose of IVM-SD suspension at 2 mg/kg body weight. Twenty-seven rabbits with severe infections were observed daily and examined on days 0 and 14 to score the lesions and count mites in crusts.

RESULTS

Fourteen days after the treatment no live mites were detected, demonstrating 100% therapeutic efficacy. The mean lesion scores decreased from 4.33 to 0.11 in the left ears and from 4.22 to 0.22 in the right ears. No reinfection occurred within 60 days of treatment.

CONCLUSIONS

A single subcutaneous administration of the IVM-SD suspension at 2 mg/kg was effective in eliminating P. cuniculi infection in the rabbit farm.

Therapeutic use of Bacillus thuringiensis in the treatment of psoroptic mange in naturally infested New Zealand rabbits

Bacillus thuringiensis is a bacteria known for its bioinsecticidal toxins and it has been proposed as an alternative in the treatment of several parasites that infect domestic animals (helminths, ticks, mites). In this work, we evaluated the clinical efficiency of the Bacillus thuringiensis GP532 strain in the treatment of six rabbits naturally infested with the P. cuniculi mite. GP532 extract (10mg/ml) was applied by aspersion in both pinna, with a second application after seven days, and the therapeutic effect was measured in both qualitative and quantitative manner. GP532 application resulted in a decreased infestation rate, which was observed as early as 3days post-treatment. At day 14, a decrease from 4.66±0.61 to 0.50±0.10 in the left pinna and from 1.66±0.21 to 0.66±0.16 (P<0.05) in the right pinna was observed. This response was comparable to the commercial drug Ivermectin, which induced a decreased infestation rate from 4.00±0.51 to 0.16±0.10 in the left pinna and from 4.66±0.80 to 0.25±0.11 in the right pinna (P<0.05). At day 30 post-treatment, GP532 decreased the total infested area by 76.80±16.06%, whereas Ivermectin resulted in a 97.41±0.99% decrease. Neither treatment produced irritation or macroscopic lesions. Our results show that the B. thuringiensis GP532 strain has a therapeutic potential in the treatment of psoroptic mange in rabbits.

Efficacy of oral doramectin as treatment for Psoroptes ovis and Leporacarus gibbus in naturally infested rabbits

ABSTRACT: The present study evaluated the efficacy of a single oral dose of doramectin in the control of Psoroptes ovis and Leporacarus gibbus in naturally infested rabbits. Sixteen adult rabbits were selected and distributed in two experimental groups. The treated group received 200 μg/Kg of oral doramectin and the control group received the same volume of saline solution. The diagnosis of the mites was made with a stereoscopic microscope. Hairs from the dorsal part of the neck, lumbar right, lumbar left, ventral side of the tail and ventral abdomen were evaluated for L. gibbus, and ear wax evaluated for P. ovis. The evaluation of the efficiency and the clinical assessment of the lesions was made in days 0, +3, +7, +14, +21, +28, and +35 after treatment. An efficacy of 75% and 87,5% was observed for L. gibbus in days +3 and +7 after treatment, an efficacy of 100% was observed in days +14, + 21, +28 e +35. An efficacy of 100% for the control of P. ovis was observed following day +7. The clinical lesion score of the control group remained unaltered, except for one animal which conditions worsened during experimentation. In the treated group animals, regression of the lesions was observed following day +3, and on day +21 no signal of infestation by P. ovis was present. None of the animals from the treated group presented secondary collateral effects caused by the doramectin, which proved itself as an optimal alternative for mite control in naturally infested rabbits.

Biology and Diseases of Rabbits

Beginning in 1931, an inbred rabbit colony was developed at the Phipps Institute for the Study, Treatment and Prevention of Tuberculosis at the University of Pennsylvania. This colony was used to study natural resistance to infection with tuberculosis (Robertson et al., 1966). Other inbred colonies or well-defined breeding colonies were also developed at the University of Illinois College of Medicine Center for Genetics, the Laboratories of the International Health Division of The Rockefeller Foundation, the University of Utrecht in the Netherlands, and Jackson Laboratories. These colonies were moved or closed in the years to follow. Since 1973, the U.S. Department of Agriculture has reported the total number of certain species of animals used by registered research facilities (1997). In 1973, 447,570 rabbits were used in research. There has been an overall decrease in numbers of rabbits used. This decreasing trend started in the mid-1990s. In 2010, 210,172 rabbits were used in research. Despite the overall drop in the number used in research, the rabbit is still a valuable model and tool for many disciplines.

Eficácia da ivermectina oral no controle de Psoroptes ovis e Leporacarus gibbus em coelhos naturalmente infestados

O objetivo do trabalho foi avaliar a eficácia da ivermectina administrada por via oral no controle de Psoroptes ovis e Leporacarus gibbus em coelhos naturalmente infestados. Foram selecionados 20 coelhos adultos, distribuídos na mesma proporção de ambos os sexos, em dois grupos experimentais, compondo dez animais por grupo. No grupo controle foi administrado o mesmo volume do tratamento de solução salina, enquanto o grupo tratado recebeu dose única de ivermectina oral (400 µg/Kg). O diagnóstico dos ácaros foi realizado com auxílio de microscópio estereoscópico após a devida coleta de material. Para P. ovis foi realizada através de coleta do cerúmen com auxílio de zaragatoas efetuadas nas orelhas e para por L. gibbus foi realizada coleta de pelos nas regiões do pescoço dorsal, lombar direita, lombar esquerda, cauda ventral e abdômen ventral. A avaliação da eficácia e a avaliação clínica das lesões, mensuradas em escores (grau 0 a 4) foi realizada nos dias 0, +3, +7, +14, +21, +28 e + 35, após o tratamento. Foi observada a eficácia de 100% no controle de P. ovis a partir do dia +7 e para L. gibbus a partir do dia +14, mantendo-se negativos até o final do período experimental. O escore da lesão das orelhas do grupo tratado regrediu a partir do dia +14 e no dia +21 todos os animais atingiram grau 0. No grupo controle, dois animais apresentaram aumento no escore da lesão das orelhas, um coelho apresentou aumento do escore de grau 1 para 2 e outro coelho de grau 3 para 4. Não foram observadas quaisquer reações adversas nos animais tratados. A ivermectina administrada por via oral em dose única foi eficaz no controle de P. ovis e L. gibbus em coelhos naturalmente infestados.

Dermatitis due to Mixed Demodex and Sarcoptes Mites in Dogs

In dogs, dermatitis due to mixed mite infestation is rare. During the five-year period of study, two dogs were identified suffering from dermatitis due to mixedDemodexandSarcoptesmites. Upon clinical examination dogs had primary and secondary skin lesions on face, around the ears, chin, neck, fore limbs and lateral abdomen. Microscopic examination of skin scrapings revealedDemodexandSarcoptesmites. Both dogs were treated with daily oral ivermectin at 100 to 400 μg/kg body weight as incremental doses, external application of amitraz and supportive treatments with topical antimicrobial shampoo. After completion of forty-two days of therapy, dogs were recovered from the dermatitis.

Eficácia acaricida de uma emulsão contendo 10% de óleo de nim (Azadirachta indica) no controle de Psoroptes ovis em coelhos naturalmente infestados

O objetivo do presente estudo foi avaliar a eficácia de uma emulsão contendo 10% de óleo de nim, Azadirachta indica, no controle de Psoroptes ovis em coelhos naturalmente infestados. Foram utilizados 12 coelhos separados aleatoriamente em dois grupos de seis animais cada. O grupo controle permaneceu sem tratamento, enquanto que o grupo tratado recebeu a formulação em teste, contendo 10% de Nim, borrifando ambos os condutos auditivos, uma vez ao dia, por sete dias consecutivos. Os animais foram avaliados diariamente para observação de possíveis efeitos adversos do produto. Nos dias +3, +7, +14,+21, +28 e +35 foi coletado material de todos os animais para avaliação da presença de ácaros vivos. Os coelhos do grupo controle apresentavam ácaros em ambos os condutos auditivos em todos os dias de observação. O grupo tratado apresentou eficácia de 41,7% no dia +3 e 100% a partir do dia +7 até o dia +35. O produto demonstrou ser eficaz no tratamento da sarna psoróptica em coelhos. Entretanto, todos os animais tratados apresentaram reações dermatológicas, tais como alopecia e hiperemia no local de aplicação do produto, variando de baixa a média severidade.

Plasma dispositions of ivermectin, doramectin and moxidectin following subcutaneous administration in rabbits

This study evaluated the comparative plasma dispositions of ivermectin (IVM), doramectin (DRM) and moxidectin (MXD) following subcutaneous administration in rabbits. Fifteen New Zealand white rabbits were allocated into three groups of five animals each. The animals in each group received IVM, DRM or MXD by subcutaneous injection at a single dose of 0.3 mg/kg. Blood samples were collected at various times between 1 h and 40 days after treatment and the plasma samples were analysed by high-performance liquid chromatography using fluorescence detection. Moxidectin was absorbed faster from the injection site and reached the peak plasma concentration ( Cmax) significantly earlier than IVM and DRM. There was no significant difference in Cmax values among the three molecules, whereas the area under the concentration–time curves of DRM (258.40 ng.d/mL) and IVM (191.62 ng.d/mL) was significantly higher than that of MXD (83.17 ng.d/mL). The mean plasma residence time and terminal half-life ( t1/2λ z) were longer for DRM (7.52 and 4.48 days, respectively) and MXD (8.97 and 8.16 days, respectively) compared with IVM (4.73 and 2.75 days, respectively). Considering the pharmacokinetic parameters for the parent molecules, the persistence of DRM and MXD are significantly longer than IVM and this may have a positive effect on their efficacy in rabbits following subcutaneous administration or utility relating to interdosing interval.

The acute effects of single-dose orally administered doramectin, eprinomectin and selamectin on natural infections of Syphacia muris in rats

This study was designed to determine the acute effects of a single-dose of orally administered doramectin, eprinomectin and selamectin on Syphacia muris infection in rats. Rats, naturally infected with S. muris, were divided into four groups: three different treatment groups (n=7) and one positive control (n=7). Cellophane tape preparations were obtained from the treated rats on day 0 pre-treatment and on days 2, 4 and 6 post-treatment. Syphacia sp. eggs were counted. Eprinomectin was found to be 100% effective in eliminating eggs on two post-treatment. However when egg counts on day 6 post-treatment were compared with pre-treatment egg counts, doramectin and selamectin were found to be 99.32 and 98.77% effective in eliminating eggs, respectively. On day 7 post-treatment, blood samples were obtained from all groups, and then the rats were necropsied. Doramectin, eprinomectin and selamectin were found to be 100% effective in eliminating adult S. muris, when compared with the positive control group.

Efficacy of selamectin in the treatment of cheyletiellosis in pet rabbits

Cheyletiellosis is a very common parasitic skin disorder of pet rabbits typically associated with pruritus and scaling. In this study, a total 23 rabbits with cheyletiellosis were treated with a single topical application of selamectin at a dose of 12 mg kg(-1). All rabbits were examined at 3 and 5 weeks after treatment. Five weeks after selamectin application, the scaling and pruritus had resolved in all 23 rabbits, and microscopic examination of epidermal debris collected by acetate tape and flea combing was all negative for mites and eggs. No side-effects were observed in any of the rabbits. This indicates that selamectin is an effective treatment for cheyletiellosis in rabbits.