Veterinary Answers Logo

Veterinary Answers Logo

Monday, June 22, 2009

Hypomagnesemia in Acute Leptospirosis

I have seen this in my canine patients. Have you seen it as well?

Case report: severe, symptomatic hypomagnesemia in acute leptospirosis.

Spichler A, Athanazio DA, Furtado J, Seguro A, Vinetz JM.

We report a case of severe hypomagnesemia in non-oliguric acute renal failure caused by leptospirosis that required large doses of magnesium replacement during the acute phase of disease. Biochemical studies confirmed kidney-related magnesium wasting and the mechanisms of this defect are discussed. Magnesium imbalance with its attendant clinical complications occurs in leptospirosis and should be monitored and treated aggressively in cases of leptospirosis-induced non-oliguric acute kidney injury.

PMCID: PMC2637037
PMID: 19052304 [PubMed - indexed for MEDLINE]

Monday, June 15, 2009

Evanger's Dog and Cat Food Warning

FDA Suspends Temporary Emergency Permit for Evanger's

Recently the FDA and USDA announced suspension of a permit for Evanger's Dog and Cat Food Company.

In the statement the FDA reports that:

"Evanger's, operating in Wheeling, Illinois, deviated from the prescribed process, equipment, product shipment, and recordkeeping requirements in the production of the company's thermally processed low acid canned food (LACF) products. The deviations in their processes and documentation could result in under-processed pet foods, which can allow the survival and growth of Clostridium botulinum (C. botulinum), a bacterium that causes botulism in some animals as well as in humans."

A recall has not been announced. But please do keep in mind the possibility of Clotridium botulinum infection in cases presenting with flaccid paralysis who have ingested Evanger's canned foods.

What have our consultants been writing?

Christal Pollock, DVM, DABVP (Avian)

Carpenter JW, Pollock CG, Koch DE, Hunter RP. Single- and multiple-dose pharmacokinetics of marbofloxacin after oral administration to rabbits. Am J Vet Res. 2009 Apr;70(4):522-6. PubMed PMID: 19335109.

Pollock CG. West Nile virus in the Americas. J Avian Med Surg. 2008 Jun;22(2):151-7. PubMed PMID: 18689077.

Pollock C. Diagnosis and treatment of avian renal disease. Vet Clin North Am Exot Anim Pract. 2006 Jan;9(1):107-28. Review. PubMed PMID: 16407082.

Michael D. Willard, DVM, MS, DACVIM (Small Animal Internal Medicine)

Willard MD. Endoscopic diagnosis of diseases causing vomiting. Top Companion Anim Med. 2008 Nov;23(4):162-8. Review. PubMed PMID: 19081549.

Farnsworth CC, Herman JD, Osterstock JB, Porterpan BL, Willard MD, Hooper RN, Roussel AJ, Schmitz DG, Fogelberg K, Kochevar DT. Assessment of clinical reasoning skills in veterinary students prior to and after the clinical year of training. J Am Vet Med Assoc. 2008 Sep 15;233(6):879-82. PubMed PMID: 18795847.

Willard M. Therapeutic approach to chronic electrolyte disorders. Vet Clin North Am Small Anim Pract. 2008 May;38(3):535-41, x. Review. PubMed PMID: 18402879.

Chelsea Greenberg, DVM, DACVIM (Oncology)

Greene SN, Lucroy MD, Greenberg CB, Bonney PL, Knapp DW. Evaluation of cisplatin administered with piroxicam in dogs with transitional cell carcinoma of the urinary bladder. J Am Vet Med Assoc. 2007 Oct 1;231(7):1056-60. PubMed PMID: 17916030.

Greenberg CB, Boria PA, Borgatti-Jeffreys A, Raskin RE, Lucroy MD. Phase II clinical trial of combination chemotherapy with dexamethasone for lymphoma in dogs. J Am Anim Hosp Assoc. 2007 Jan-Feb;43(1):27-32. PubMed PMID: 17209082.

Neurology Case of the Month

This report is based on video evaluation and conversation with Dr. Smith regarding Fluffy Jones [regarding neurologic signs following ear cleaning].

The video evaluation is as follows: Mentation: BAR, Gait: mild vestibular quality ataxia, occasional stumbling to the right and/or left side, no evidence of UMN involvement or paresis, CN’s: Horner’s syndrome OD-rest NSF and no evidence of spontaneous nystagmus. Postural responses and reflexes were not evaluated. A mild right head tilt was also evident and occasional wide head excursions noted. The patient appears extremely alert and responsive and there does not seem to be evidence of central vestibular disease. However, she is currently on prednisone which may mask some clinical abnormalities.

Denervation hypersensitivity testing should be performed using phenylephrine OU. To confirm that the Horner’s syndrome is indeed a third order Horner’s (i.e. a post ganglionic lesion typically seen with otitis media), phenylephrine drops are used OU and any ocular changes monitored every few minutes. If resolution or near-resolution of the Horner’s occurs in less than 20 minutes, then the lesion is post-ganglionic and would support our presumption that we are dealing with ear disease. If it is between 20-40 minutes, a second order Horner’s must be considered, such as is seen with diseases of the mediastinum. If it takes greater than 40 minutes for resolution, then disease within the cervical spinal cord or midbrain must be considered (which is highly unlikely in this cat).

Since no ototoxic drugs were used to my knowledge, clinical signs likely have resulted from irritation to the sympathetic innervation in the middle ear as well as the vestibulocochlear nerve in the inner ear during the ear cleaning. If so, clinical signs will likely resolve over time but it may take months for the Horner’s syndrome to fully disappear. However, since there is no indication for prednisone in this cat and since prednisone may very well be masking a possible central vestibular disorder, re-evaluation after tapering prednisone is indicated including a full neurologic exam. If signs recur or other signs arise, MRI scanning of the head may be indicated.

Georgina Barone, DVM, DACVIM (Neurology)