Case Report Issue #1 2012

Richmond Location

Patient Signalment: “Ranger” – a 5 year old male, 38 kg, intact German shepherd used for breeding was referred with a 2 month history of left sided perianal fistula that was unresponsive to therapy.

Case Report:  Highest incidence of perianal fistulae are observed in middle-aged German shepherds. The cause for the development of these fistulae is unclear, but anatomic factors and a dysregulated immune response have been suspected. Food allergy has been incriminated in some cases. Thus, underlying food hypersensitivity should be identified and treated in these dogs.

Treatment Plan:

• Combination therapy was opted in order to achieve complete cure.
• Dietary change to exclusive Eukanuba FP Skin and coat response.
• Bilateral anal sacculectomy and perianal fistula En block resection by Dr Hutchinson at Boundary Bay Specialists.
• Antimicrobial therapy: Combination therapy with Metronidazole, Cefalexin and Sulfasalazine (see article attached).

Reference: Long term evaluation of canine perianal fistula disease treated with exclusive fish and potato diet and surgical excision. JAAHA 44:302-307 (2008).

Follow-up and Outcome:

• Day 12 post surgery – patient was doing well with no discharge or discomfort at the surgery site. Small fistula formed at surgery site that was self healing when kept on 3 drug antimicrobial therapy.
• Histopathological diagnosis – Perianal fistula with associated vasculitis and anorectal polyp, secondary to inflammation.
• 8 month follow-up since treatment – patient is doing well and has had no recurrence on the fish and potato diet.

Long-Term Evaluation of Canine Perianal Fistula Disease Treated With Exclusive Fish and Potato Diet and Surgical Excision

Abstract

“The records of 33 dogs that had perianal fistula disease treated with en blocsurgical excision and bilateral anal saculectomy, and that were perioperatively administered an exclusive white fish and potato diet, were reviewed to determine outcome. By 1 year after surgery, 87.9% of the dogs had complete or near-complete resolution of visible fistula disease, while only 20.7% continued to have mild intermittent clinical signs. Fecal incontinence was not reported in any dog. Overall, complications were considerably less in both severity and frequency when compared with previous reports.”

Journal of the American Animal Hospital Association November/December 2008 vol. 44 no. 6 302-307

The above study took thirty-three dogs with perianal fistula disease and used a combination of medical, dietary, and surgical treatments and evaluated these dogs after one year of surgery. The results showed that eighty-seven percent of the treated dogs had complete or near complete resolution of all symptoms. The medical therapy included preoperatively one to one hundred eighty days of cephalexin, metronidazole and sulfasalazine. These drugs were continued for thirty to sixty days postoperatively. The dogs were fed Eukenuba FP exclusively for the entire preoperative medication and continued for the duration of the study The surgery included anal sacculectomy and en bloc resection of all diseased tissue.

The diet may have two benefits. First of all, the diet may be helpful in some cases in avoiding potential allergens which may cause colitis. Secondly, the omega acids may decrease thomboxanes in the chronic phase of inflammation.

Serum pharmacokinetics of clindamycin hydrochloride in normal dogs when administered at two dosage regimens

Abstract

“The aim of this cross-over study was to compare clindamycin pharmacokinetics in the serum of clinically normal dogs when administered orally at two dosage regimens (5.5 mg/kg, twice daily, and 11 mg/kg, once daily), separated by a 1 week wash-out period. Serum samples were obtained from six clinically normal laboratory beagles before, 3, 6, 9 and 12 h after the first and fifth dose of clindamycin at 5.5 mg/kg, twice daily, and before, 3, 6, 9, 12, 18 and 24 h after the first and third dose at 11 mg/kg, once daily. Serum clindamycin concentrations were determined by reverse-phase liquid chromatography coupled with mass spectrometry. Results were analysed using Student’s paired t-test, at a 5% level of significance. Values of pharmacokinetic parameters that differed significantly between the two dosage regimens included the following: maximal concentration and area under the concentration–time curve were higher at 11 mg/kg, once daily, than at 5.5 mg/kg, twice daily; and, more importantly, the ratio of AUC_0–24 to the minimal inhibitory concentration (MIC) value of 0.5 μg/mL for a 24 h period (AUC_0–24/MIC) was higher when clindamycin was administered at 11 than at 5.5 mg/kg, at least during the first day of drug administration. Therefore, a better pharmacokinetic profile may be expected when clindamycin is administered at 11 mg/kg, once daily, for the treatment of canine pyoderma caused by Staphylococcus pseudintermedius.”

Veterinary Dermatology (2011) Volume: 22, Issue: 5, Pages: 429-435

The above study indicated that eleven mg/kg every twenty four hours was at least as good or possibly better than five and a half mg/kg every twelve hours from a pharmacokinetic profile. There are clinical studies that indicate that pyoderma responds at least as well with the once a day treatment. Most studies indicate that Staphylococcus pseudintermedius has about a seventy-nine percent sensitivity to clindamycin. Our clinical impression and experience with clindamycin suggests the following; multiple uses of the drug in the same patient will often result in resistance developing. Vomiting or gastro-intestinal signs are rarely a problem as it is in cephalexin use. The use of clindamycin has not been associated with increased development of methicillin-resistant S. pseudintermedius (MRSP). A small number of our MRSP cases are sensitive to clindamycin as indicated by culture results. We have seen cases where the lower dosage of clindamycin does not work as well as the higher dosage.

Please note that we will be closed

Monday Dec 26,Tuesday Dec 27th and January 2nd.

We wish everybody and their furry friends a safe and happy holiday season.

We found this article posted in the Vet Practice News magazine we receive at our clinic and we thought it was interesting, so we wanted to share.  In a poll done with 485,000 insured pets to determine the top 10 medical conditions brought to their vet for the 2010 year, the top three for dogs were directly related to Animal Dermatology Specialty.  Of these 485,000 insured pets their owners have spent almost $43 million dollars in 2010 to treat those top 10 medical conditions. Just some food for thought when trying to decide on if you want to make an appointment with our Dermatology Specialist.  

Dr.Charach will be away for a family function April 8-10th and April 13th-17th for the Annual Animal Dermatology Conference. 

Please note we will NOT have a veterinarian on staff while he is away.

Best of Journal Club and Dermatology Rounds:

Lead by Dr.Mike Charach DVM, BSc, Dipl. ACVD

• Dr.Charach attended a 2 year Veterinary Dermatology Residency at the University of Florida 1990-1992, he became board certified in 1994. He has performed Allergy Skin testing on over 1000 dogs (Since 1987) over 40 horses, and using the Karl Storz Video Otoscopy for 3 years to treat and diagnose problems and diseases of the ear.

 Allergy testing & Successful Case Management (Dermatology Rounds)

Allergy skin testing helps diagnose and manage difficult allergy cases.

 Case 1: “Daisy” Referred from Ashcroft BC

 Exam & History

Daisy is a two year old spayed female Dalmatian with a one year history of severe non-seasonal pruritus. The pruritus is generalized but the two front legs are the worst. There is near complete alopecia of the two front legs from elbow to the paws.

 Testing

Intradermal allergy skin testing is negative with a moderate reaction to flea.

A negative skin test for atopy suggests food allergy as the next most likely diagnosis. An elimination food trial was initiated. Daisy was given three weeks of antibiotics for a mild pyoderma and Daisy was fed a vet commercial “Hypoallergenic diet” of duck and potato. After 6 weeks, there was no improvement in pruritus. Daisy was then fed a home cooked fish and potato diet. Daisy’s pruritus was 90-100% better after about 4 weeks. Daisy was then successfully switched to a commercial vet fish and potato diet. Three months later, Daisy is still 100% better and all the hair has grown back on the two front legs.

Discussion

Blood tests for environmental allergies are virtually 100% positive therefore not very specific. I would estimate about 40% of our skin test are negative with the exception of house dust/ house dust mite. These negative skin tests tend to rule out atopy and greatly implicate food allergies (AFR). We have seen many Elimination food trials (EFT) fail when using “Commercial hypoallergenic diets”. Homemade food trials remain the gold standard for diagnosing food allergies.

 Homemade Elimination food trials and Rayne Clinical Nutrition.-

 A study about testing for food allergies in California was conducted by animal dermatologists. (Comparison of a commercial limited-antigen diet versus home-prepared diets in the diagnosis of canine adverse food reaction.  Vet Ther. 2002 Fall; 3(3):244-51 by T. Tapp, C. Griffin, W. Rosenkrantz, R.Muse, M.Boord)

  The abstract indicates the following:

•  Twenty four owners with dogs suspected of having food allergies were asked to prepare a homemade elimination food trial for 6-8 weeks. 
• After two weeks only fourteen of the original twenty four dogs (60%) were still willing to continue the home made food trial.  Ten (40%) owners were not willing to continue the home made food trial.
• Eight of the fourteen dogs continued homemade food trial showed significant improvement over the 6-8 weeks.
• These eight dogs were subsequently switched to a veterinary commercial hypoallergenic diet of fish and potatoes.
• Four of eight dogs did well on this dog food while the other four immediately became symptomatic.

Discussion:

If would appear two things can be surmised from this study.

1)      Elimination food trials utilizing homemade diets are better than commercial fish and potato “hypoallergenic” diet

2)      These dermatologists had around 40% non-compliance with conducting a homemade food trial

We offer the owners an option of home cooking for their pets or purchasing Rayne Clinical Nutrition diets, for their elimination food trial.  Rayne Clinical Nutrition is a local company that prepares home cooked single protein, single carbohydrate diets and delivers it to the clients.

 Case # 2: “Benson” Dr.Charachs own dog

Exam & History

Many years ago I owned a 2 year old Dalmatian named “Benson”. In May, “Benson” developed generalized pruritus and erythema of ears, axilla, abdomen, legs, and paws. “Benson” was allergy skin tested. There were severe reactions to five weed pollens (4+) and everything else was completely negative. “Benson” received allergen shots (ASIT) initially they were given once weekly (day 1, day 8, day 15) within three days after the third injection (day 15), “Benson’s” erythematous skin and pruritus was at least 90% resolved.  The injections were given every 2, 3, then 4 weeks. “Benson” was asymptomatic for the rest of the summer. No allergy shots were given in the winter and “Benson” remained asymptomatic. The next June, “Benson” started with the same symptoms. The pruritus responded completely to just two allergy injections three weeks apart. One more injection was required by the end of the summer (3 total). The third summer showed a mild return of symptoms, which again completely responded (100%) too just two injections of the weed allergens. After the third summer, “Benson” never had skin or ear problems again.

 Discussion

“Every Dermatologist should own a Dalmatian”

Summary

1)      Benson had a 100% response to allergy shots by day 18 of the ASIT after only 3 allergy shots

2)      First summer 8 allergy shots, winter 0.Second summer 3 allergy shots, winter 0. Third summer 2 allergy shots.  Allergies cured for the rest of his life

Q & A:

Why was this Dalmatian so successfully treated with ASIT?

Secret to Success:

1)      Early diagnosis and treatment leads to faster, more complete response to ASIT and produce higher “cure rates”.

2)      Early diagnosis and treatments contributes to fewer allergens having to be desensitized to and once again better cure rates.

3)      Early diagnosis and treatment also meant in “Benson’s” case not having to deal with secondary infections during immunotherapy.

Practical “Allergy Shots” made easier and faster-

Allergy Specific Immuno Therapy (ASIT): Utilizing Accelerated Single Bottle/Reduced number and Frequency of Injection in a Propylene Glycol Vehicle. (ASB/RN & FI/PGV)

How does allergy specific immunotherapy (ASIT) work?

Successful immunotherapy usually is associated with the following results:

• Increase Treg cells
• Increase IL 10
• Increase blocking antibodies

 Why is ASIT with propylene glycol superior to Aqueous based ASIT?

The addition of propylene glycol allows a slow release (depo effect) of allergens.

This slow release of allergens allows us to use a single full strength bottle.

We refer to A.S.I.T with propylene glycol as ASB/RN &F/PGV A.S.I.T.

(Accelerated Single Bottle/Reduced number & Frequency/Propylene Glycol Vehicle Allergy Specific Immuno Therapy)

We would like to inform our clients that Dr.Charach will not be available from

December 20th-December 30th.

He will return to regular hours January 3rd.

We wish everyone and their pets a Safe and Happy Holiday season!!!!!

We are very happy to announce that we have our very own Dermatology Resident. Dr. J. Bajwa will be starting August 9th 2010. Congratulations Dr.Bajwa, we look forward to working with him during this exciting part of his veterinary career.

Watch the recording of Dr.Charachs interview on the Global Morning News from May 12th 2010.

Dr.Charach goes into Global TV tomorrow morning to record a session with Lynn Colliar regarding pet allergies.   So watch the Global BC Morning News to see what he has to say on the topic.