Acral Lick Dermatitis Research Articles

Enlarged clitoris in wild polar bears ( Ursus maritimus) can be misdiagnosed as pseudohermaphroditism

A 23-year-old female polar bear ( Ursus maritimus) killed in an Inuit hunt in East Greenland on July 9, 1999 had a significantly enlarged clitoris resembling, in size, form and colour, those of previously reported ‘pseudohermaphroditic’ polar bears from Svalbard. It has been suggested that an enzyme defect (21-hydroxylase deficiency), androgen producing tumour or high exposure to organochlorines during the foetal stage or early development could be the reason for the supposed pseudohermaphroditism observed for Svalbard bears. Except for the enlarged clitoris, all dimensions of the external and internal reproductive organs of the present were similar to a reference group of 23 normal adult female polar bears from East Greenland collected in 1999–2002. The aberrant bear was a female genotype, and macroscopic examination of her internal reproductive organs indicated that she was reproductively functional. A histological examination of the clitoral enlargement in the present East Greenland specimen allows a first-time histological evaluation of the earlier macroscopic field diagnosis from Svalbard. This examination revealed intense chronic ulcerative and perivascular clitoriditis similar to “acral lick dermatitis” frequently seen in domestic dogs (i.e., we did not find any signs of pseudohermaphroditic hyperplasia of clitoral tissue due to androgenic or antiestrogenic endocrine disruption). The levels of organohalogens and TEQ values were lower than concentration thresholds of toxicological risk. It is hence possible that the previously reported adult female polar bear pseudohermaphrodites from Svalbard are in fact misdiagnoses. Therefore, future studies examining pseudohermaphrodism in wildlife should consider that certain occurrences are natural events, e.g., enlarged clitoris in the present East Greenland polar bear. Furthermore, caution should be exercised in suggesting linkages of such inflammatory abnormalities with correlations to anthropogenic pollutant exposures.

Animal Models for Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a severely disabling psychiatric disorder that is characterised by the presence of obsessions and / or compulsions and affects approximately 2.5% of the general population. The underlying neurobiology is at present not well understood and treatment options for OCD are often of limited efficacy. There is therefore a real need to obtain more knowledge regarding the pathophysiology of OCD and to develop new anti-OCD medication. One way of achieving these aims is to generate animal models for OCD. Naturally occurring animal models of OCD such as acral-lick dermatitis in dogs represent possibly the best models in terms of symptomology, predictive validity and similarity of inducing conditions. Unfortunately, these advantages are offset by the associated high cost of obtaining a sample population. The alternative is to turn to laboratory-based models and these can be classified into behavioural (e.g. food restriction-induced wheel running leading to body weight loss), pharmacological (e.g. 5-HT agonist-induced loss of spontaneous alternation; chronic quinpirole-induced compulsive checking) and genetic (e.g. HoxB8 knock-out mice) subtypes. Each of the different models presents unique advantages and disadvantages. Of the 4 lab-based models examined, the first 3 have been interesting as OCD models because predictive validity has been demonstrated in each. However food restriction-induced wheel running does not correlate well on the similarity of symptoms with OCD, as body weight loss is more associated with anorexia nervosa. The 5-HT agonist model and chronic quinpirole model may be questioned on their inducing conditions; are 5-HT / dopamine dysfunction central in the pathology of OCD? Conversely, the knockout mouse model is exciting because the compulsive grooming phenotype elicited is similar to that observed in OCD. This behaviour appears to be due specifically to the knockdown of a gene that has so far not been implicated in the OCD story. However, no predictive validity has been demonstrated in this model at present. Finally, the review addresses future directions in OCD research and what possible new targets might exist. Keywords: obsessive compulsive disorder, animal models

Efficacy of clomipramine in the treatment of canine compulsive disorder

Objective To assess the efficacy of clomipramine for treatment of canine compulsive disorder (CCD). Design Randomized, placebo-controlled, double-blind, balanced AB-BA crossover clinical study Animals 51 dogs with CCD. Procedures Dogs were given clomipramine (3 mg/kg [1.3 mg/lb] of body weight, PO, q 12 h) for 4 weeks and placebo for 4 weeks. At the end of each treatment each owner rated the severity of their dog's behavior, using 2 validated rating scales. Statistical analysis was made by ordinal regression. Compliance, adverse effects, and the effectiveness of masking were also assessed. Each dog's behavior was reevaluated 1 to 2 years after completing the study. Results Behaviors included spinning (n = 17) and self-mutilation by licking (acral lick dermatitis, 12). Both rating scales demonstrated a treatment effect. Compliance was satisfactory, and masking was effective. Sedation and reduced appetite were reported more commonly when dogs were given clomipramine than when they were given placebo. Forty-five dogs available for follow-up evaluation still had their behaviors; 6 dogs were lost to follow-up evaluation. Clinical Implications Results suggest that clomipramine was effective in dogs with CCD and was not associated with serious adverse effects. However, treatment for 4 weeks was not curative. Behavior modification is likely to be necessary to manage CCD. (J Am Vet Med Assoc 1998;213:1760–1766)

Behavioural changes in dogs with acral lick dermatitis during a 2 month extension phase of fluoxetine treatment

Behavioural changes in dogs with acral lick dermatitis during a 2 month extension phase of fluoxetine treatment

Behavioural changes in dogs with acral lick dermatitis during a 2 month extension phase of fluoxetine treatment

Acral lick dermatitis (ALD) is a condition described in dogs that is believed to be an animal model of obsessive–compulsive disorder (OCD) in humans. In both conditions, serotonergic neural dysfunction is believed to be responsible for aberrant grooming behaviour. ALD is the first animal model proposed for a psychiatric condition. Serotonergic antidepressants are recommended as first line treatment in OCD. However, many patients have been discouraged from using these by reports of aggression and suicide-inducing effects of these drugs. This study examined behavioural effects of a 2 month extension phase of fluoxetine treatment in dogs previously diagnosed with ALD. A 2 month extension phase on fluoxetine 20 mg daily, immediately followed on a 6 week double blind, randomised, placebo-controlled trial of fluoxetine in 63 dogs with ALD, diagnosed for at least 6 months. The Dodman scales measured excitability, fearfulness, dominance and territorial aggression at the start and end of the 2 month extension phase. Excitability was rated in four settings, referred to as questions 1 to 4. Fifty-four dogs completed the extension phase. Three subjects were withdrawn with no reason given, one for vomiting on fluoxetine. At the end of the extension phase, the analysis of variance showed no significant difference between dogs who received placebo or fluoxetine during the original trial, for scores of fearfulness (p=0·127), dominance (p=0·274) or territorial aggression (p=0·172). Excitability also caused no significant difference on the four questions (p1=0·822, p2=0·607, p3=0·975, p4=0·820). After the extension phase, owners assessed dogs as being neither more aggressive nor anxious. Particularly, there was no difference in levels of dominance aggression (p=1). Using the paired t-test there was no statistically significant difference between scores obtained both at the end of the 6 week trial and the extension phase for fearfulness (p=0·128), dominance aggression (p=1·0), territorial aggression (p=0·422) and excitability (p1=0·487, p2=0·571, p3=0·711, p4=0·086). These results may serve to refute further the reports of the emergence of impulsive aggression in human subjects on fluoxetine treatment as no significant behavioural changes were noted in the dogs treated with fluoxetine for ALD. © 1998 John Wiley & Sons, Ltd.

Fluoxetine treatment of acral lick dermatitis in dogs: A placebo-controlled randomized double blind trial

The aim of the study was to assess the efficacy and tolerability of fluoxetine treatment of acral lick dermatitis (ALD) in dogs and to investigate ALD as an animal model of obsessive-compulsive disorder (OCD). Sixty-three dogs with ALD were treated with fluoxetine 20 mg daily, or placebo, for 6 weeks. In the fluoxetine group, owners rated both appearance of the lesion (t = 10.2, df = 29, P < 0.0001) and licking behavior (t = 10.2, df = 29, P < 0.0001) as significantly improved by the end of the trial. Veterinarian-rated pre- and post-treatment photographs showed statistically significant improvement in the fluoxetine group (mean = 2.55). There were no significant changes in the placebo group as rated by owners and veterinarians. These results demonstrate the efficacy of fluoxetine in the treatment of ALD and lend further support to ALD as an animal model of OCD.

Use of the selective serotonin reuptake inhibitor citalopram in a possible animal analogue of obsessive-compulsive disorder.

Canine acral lick dermatitis (ALD) has been suggested as an animal analogue of obsessive-compulsive disorder (OCD). A series of dogs with ALD or similar conditions were treated with citalopram, the most selective of the selective serotonin reuptake inhibitors. Six of nine (66.7%) dogs showed significant improvement. Given the apparent efficacy of citalopram in the treatment of OCD and related disorders, these data provide further evidence that ALD is a useful animal analogue of OCD.

Fluoxetine treatment of acral lick dermatitis in dogs: A placebo‐controlled randomized double blind trial

Fluoxetine treatment of acral lick dermatitis in dogs: A placebo‐controlled randomized double blind trial

In Search of Animal Models for Obsessive-Compulsive Disorder

AbstractAnimal models of obsessive-compulsive disorder may be derived naturally or generated experimentally. Either may be considered a full or partial model, depending on the extent of resemblance to human OCD. Although many models appear to be valid at first glance, complete models should demonstrate “compelling similarities” in all areas examined. Partial models may have only one or two OCD-like features; however, they still provide some opportunities for research. Criteria to consider when evaluating potential models are etiology, symptomatology, and use in indicating methods of therapy and prevention. Demonstration of common underlying physiological mechanisms, patterns of development and expression, and familial associations are some specific elements to consider when assessing the relevance of more complete models.Cognitive aspects of OCD are difficult, if not impossible, to explore in animals at present and may be quite different from what is found in humans. It is hard to imagine that animals experience ego-dystonicity; however, dogs with acral lick dermatitis (ALD) that have been scolded by their owners will resort to licking themselves when out of sight, implying that they know it is wrong. Because of the difficulty in evaluating an animal's internal state, some adopt the position that there is no complete animal model of OCD and that animal models are at best partial models. However, children who exhibit compulsive behaviors frequently do not experience accompanying obsessions. Even the expression of OCD in children—for example, licking and walking in geometric designs—resembles what is seen in animals.In the descriptions that follow, only directly comparable aspects of compulsive behavior in animals will be discussed. Naturally occurring models that appear to correspond most closely to full models may be useful in understanding the fundamental mechanisms underlying OCD and the OC spectrum, including genetics and neurobiology. Experimental models, which may be either full or partial models, could contribute similarly or provide limited but specific information in a targeted area of study, depending on the extent of their similarity to OCD.

O-10-3 - Fluoxetine treatment of acral lick dermatitis in dogs: A placebo controlled randomised double blind trial

O-10-3 - Fluoxetine treatment of acral lick dermatitis in dogs: A placebo controlled randomised double blind trial

Treatment of canine acral lick dermatitis by behavior modification using electronic stimulation.

Canine acral lick dermatitis is characterized by excessive licking on areas of one or more limbs, usually near the carpus or tarsus. In this prospective study, five dogs with acral lick dermatitis were treated with remote punishment utilizing precisely controlled, momentary shock from an electronic training collar. The problem resolved in four dogs. Resolution was defined as one month in which no shocks (i.e., no electronic shock collar worn) or Elizabethan collars were utilized and no licking had occurred sufficiently to recreate a gross skin lesion. Relapse during the follow-up period of six-to-12 months occurred in two dogs, but licking stopped after brief retraining periods.

Drug Treatment of Canine Acral Lick

Canine acral lick dermatitis is a naturally occurring disorder in which excessive licking of paws or flank can produce ulcers and infection that require medical treatment. Forty-two dogs with severe chronic canine acral lick dermatitis were treated in three double-blind crossover comparisons of clomipramine hydrochloride/desipramine hydrochloride, fluoxetine hydrochloride/fenfluramine hydrochloride, and sertraline hydrochloride/placebo. The serotonin uptake blocking drugs were clinically effective, while the other drugs were not. Based on phenomenology and pharmacological response, we propose canine acral lick dermatitis as an animal model of obsessive-compulsive disorder.

The neuroethological approach to obsessive-compulsive disorder

Advances in the neurobiology of obsessive-compulsive disorder (OCD) have raised the possibility that animal models in general and neuroethological models in particular may be useful in understanding and investigating this illness. One neuroethologically oriented model is that of canine acral lick dermatitis. In this report, we review the advantages and limitations of animal models of OCD. Preliminary data on the use of fluoxetine in the treatment of canine acral lick dermatitis are discussed.

Naltrexone for treatment of acral lick dermatitis in dogs

Summary Acral lick dermatitis (lick granuloma) was diagnosed in 11 dogs on the basis of history, physical examination, and histopathologic findings. A predilection for the left forelimb was noticed. All 11 dogs were given the narcotic antagonist naltrexone. Successful treatment (cessation of licking, reepithelialization of lesions) was seen in 7 dogs. All 7 dogs' lesions recurred when naltrexone was stopped, but reepithelialized in 5 dogs when the drug was readministered. Adverse effects (drowsiness, withdrawal from owner) were seen in 1 dog, but resolved within 48 hours of stopping the drug.

Canine lick granuloma treated with radiotherapy

ABSTRACTThirteen dogs with lick granuloma have been treated with X‐ray irradiation on two or more occasions. No case was cured, but treatment proved satisfactory in 11 cases for periods ranging from six months to three years. In two cases where treatment was unsuccessful lesions had been present for two years.

Transfer of free vascular cutaneous flaps by microvascular anastomosis. Results in six dogs.

Skin defects on the distal extremities of six dogs were reconstructed with free vascular cutaneous transfers by microvascular anastomosis. The donor flaps were based on the superficial cervical artery and vein. In five of the dogs, bone was exposed and skin was lost from half of the circumference of the limb. Two had infected fractures with sequestra and three had acute shearing injuries. The sixth dog had sensory denervation of the left antebrachium and a carpal acral lick granuloma. Before surgery, the patency of potential recipient vessels was confirmed with arteriography in five dogs and an ultrasonic doppler in one dog. Microvascular technique was used to reestablish circulation to the flaps after they were transferred to the recipient site. Total ischemic time of the flaps averaged 100 minutes. All flaps survived. Successful reconstruction of the cutaneous defects was achieved in these six cases.