2. ferret medicine.pdf

Ferret Medicine Marie Kubiak BVSc CertAVP(ZM) CertAqV DZooMed MRCVS RCVS Recognised Specialist in Zoo and Wildlife Medicine Learning objectives  Recognise common conditions  Describe appropriate diagnostics  Describe appropriate interventions. Describe appropriate preventative measures Ferre...

Ferret Medicine Marie Kubiak BVSc CertAVP(ZM) CertAqV DZooMed MRCVS RCVS Recognised Specialist in Zoo and Wildlife Medicine Learning objectives  Recognise common conditions  Describe appropriate diagnostics  Describe appropriate interventions. Describe appropriate preventative measures Ferrets  Domesticated variety of European polecat  0.7-1.5kg (females lighter than males)  Lifespan of 6-10yrs  Obligate carnivores  Tolerate handling and human contact well  Kept as pets  Used for hunting/pest control Common reasons for presentation  D+ & V+  Dental disease  Fight wounds  Insulinoma  Lymphoma  Adrenal disease  Cardiac disease  Persistent oestrous Diarrhoea and vomiting Typical diet • Dry ferret diet (35-40% protein) • Fresh carcass feeding Short simple GI tract (no caecum) Rapid transit time (~ 3 hours!) Causes of GI disease Infectious • Bacterial  Helicobacter mustelae  Campylobacter jejunae  Lawsonia intracellularis • Viral •  Coronavirus (ECE)  Canine distemper  Rotavirus Parasitic  Coccidia  Giardia  Cryptosporidium  Inflammatory • IBD  Neoplastic • Lymphoma  Traumatic • Foreign body  Stress/diet change  Idiopathic • Megaoesophagus Coronavirus • Epizootic catarrhal enteritis (ECE) • Ferret shows, rescue ferrets • Green slime disease! • Diagnosis: faecal PCR • Treatment: general supportive care • Beware systemic FIP-like form Helicobacter mustelae • Ulcerative gastritis • Anorexia, nausea, v+/d+, abdo pain, melaena • Recent stress • Diagnosis: Gastric biopsy and histopathology • Treatment: • Amoxicillin 20 mg/kg PO q 12 h • Metronidazole 20 mg/kg PO q 12 h • Bismuth subsalicylate 0.25 ml/kg PO q 4-6 h Adrenal Disease  Neutered ferrets  Middle aged  Aged 3 ½ to 4 ½ years peak time  Neutered >18 months previous  Indoor pets  Light >8hrs/day  No sex predilection Clinical Signs  Asymptomatic  Tail alopecia, comedones  Progressive bilateral flank alopecia  Easily epilated  May be pruritic (40%)  Vulval swelling  Dysuria with prostatomegaly  Aggression/sexual behaviour  Increased scent  Mammary gland enlargement  Petechiae Diagnosis  Clinical signs and signalment  Suggestive but not pathognomonic  Exclusion of other causes  Parasitic skin disease  Ovarian remnant  Further diagnostics needed to confirm adrenal cause  Hormone panel  Measurement of multiple sex hormones  Oestradiol  17-hydroxyprogesterone  Androstenedione www.lafebervet.com  Dehydroepiandrosterone sulfate  False negatives possible as only the three most common hormones are included in most panels Ultrasonography  Ultrasonography  Right adrenal gland:  Identify vena cava at the level of the right kidney  Adrenal gland adjacent to vena cava, where portal vein joins  Should be less than 10mm long and 4mm wide  Left adrenal gland:  Identify renal artery at level of cranial left kidney  Adrenal gland between aorta and renal artery  Should be less than 10.5mm long and 4mm wide  Common abnormalities:  Increased size  Rounded appearance  Altered echogenicity Normal left adrenal gland Elipsoid Within expected size parameters Besso, Juliette G., Amy S. Tidwell, and John M. Gliatto. "Retrospective review of the ultrasonographic features of adrenal lesions in 21 ferrets." Veterinary Radiology & Ultrasound 41.4 (2000): 345-352. Left adrenal hyperplasia Rounded Excessively wide (6.1mm) Right adrenal adenocarcinoma Enlarged (8.4mm wide) Impinging on vena cava Irregular echogenicity Besso, Juliette G., Amy S. Tidwell, and John M. Gliatto. "Retrospective review of the ultrasonographic features of adrenal lesions in 21 ferrets." Veterinary Radiology & Ultrasound 41.4 (2000): 345-352.  Adrenal enlargement:  Adrenal hyperplasia (56%)  Adrenocortical adenoma (16%)  Cystic/other change (2%)  Adenocarcinoma (26%)  All are presumed to be related and progressive changes Simone-Freilicher, Elisabeth. "Adrenal gland disease in ferrets." Veterinary Clinics of North America: Exotic Animal Practice 11.1 (2008): 125-137. Medical therapy  Mitotane/Trilostane  No effect on sex hormone production  Melatonin implants  Cosmetic effects at best  Androgen blockers/Oestradiol blockers  Can be used short-term to reverse severe clinical signs  GnRH agonists  Deslorelin  Lasts >18 months  Expensive  Easy to obtain Method of action  Pulsatile release of GnRH is overcome  Constant high level of GNRH leads to negative feedback  Lack of release of FSH and LH  Shutdown of adrenal stimulation  Ineffective if autonomous tumour has developed Prevention  Data indicates surgical neutering main factor  Removal of gonads prevents negative feedback on hypothalamic-pituitary axis  LH and FSH levels high  Adrenal receptors present  Adrenal hyperstimulation and exogenous sex hormone production results So why neuter?  Breeding control  Reduce aggression  Minimise ‘unpleasant’ scent  Prevent reproductive neoplasia/infections  Prevent oestrogen toxicity in unmated jills  Adrenal disease not seen widely in UK  Risk of oestrogen marrow suppression bigger risk Options 1) Surgical neuter  Introduces risk of adrenal disease  It is likely that some degree of hormonal alteration will occur  Not all neutered ferrets will develop clinical disease  Outdoor ferrets low-risk  Cost effective  Permanent and reliable method of preventing pregnancy and marrow suppression  Can use deslorelin should adrenal disease develop 2) Deslorelin implant to chemically neuter  Appears safe and effective  Not permanent  4.7mg: Recommended to replace every 12-18m  9.4mg: lasts 3-4 years  Expensive  NB used off licence in most cases  9.4mg licensed for chemical castration of male ferrets 3) Both neuter and use deslorelin implant  Spay prevents breeding and marrow suppression permanently  Deslorelin acts as concurrent preventative treatment for negative adrenal aspect of spay  Expensive combination for many owners  Need to replace implant in future 4) Using vasectomised hob  Sterile mating brings entire females out of season  Only one animal requires surgery  No need for medical intervention in any animal  Utilises physiological contraceptive  Hob can inflict bite injuries on females  False pregnancies common 5) “Jill jab”  Injected when signs of oestrus are seen  Requires vigilance by owner  Variable costs  Repeated consults  Single use vials raise costs  Potential for pyometra though rare  Delvosteron (0.5ml) - licenced  Not currently available   HCG (100iu) – off licence  Risk of reduced efficacy or anaphylaxis with repeat injections  Decision on protocol is owner’s responsibility  Offer options and suggest based on situation  Rescue centre: surgical neuter  Working ferrets: vasectomised hob  Pet ferrets: any of the options Insulinoma  Pancreatic islet B-cell neoplasm  Overproduction of insulin  Hypoglycaemia  Episodic lethargy and ataxia  Approximately 25% of ferret neoplasms  Genetic cause?  Excessive carbohydrate exposure?  Common in middle-aged ferrets ~4yrs of age www.medicine.uiowa.edu Diagnosis • Blood glucose <3.4mmol/l highly indicative • If not convincing then fast for 3-4hrs and retest  Ensure ongoing observation  Measurement of insulin ideal  Normal/high insulin in face of hypoglycaemia indicative  ALT and AST may be elevated due to hepatic lipidosis  Ultrasound scan of limited use  Microadenomas  Can use to assess for metastasis (liver, lymph nodes) First aid  Offering food often sufficient  Syrup on mucosa for inappetant patients  IV glucose in comatose patients  50% dextrose (0.25–2 mL) as slow bolus  Maintain on glucose saline  Fluid therapy  Ad lib food high protein, low carbohydrate food access Longer term care  Partial pancreatectomy  Methylene blue IV can enhance visualisation  Not been used clinically  Histopathology indicated as adenomas, carcinomas and hyperplasia have different prognoses  Diet management  Low carbohydrate, high meat diet  Ad lib access to food  Diazoxide (5-15mg/kg bid)  Inhibits insulin secretion  Promotes gluconeogenesis and glycolysis  Inhibits glucose uptake  Prednisolone (0.25-2mg.kg bid)  Increases hepatic gluconeogenesis  Decreases peripheral tissue glucose uptake  Inhibits insulin binding to receptors  Controls symptoms while disease progresses  Can be used as primary or rescue therapy  Octreotide  Somatostatin analogue  Used for refractory cases in other species but of limited benefit in ferrets  Monitor blood glucose  Initially every 3-4 days  When stable q 2 months  Point measurement before medication administered  Owners can do at home  Survival of 12-24 months typical  Low rate of metastasis  Progressively refractive to medical management Lymphoma  Two distinct subtypes:  Juvenile lymphoma  Adult onset lymphoma  Transmissible and seen as ‘outbreaks’  ?viral aetiology  ?transplantable neoplastic cells  Predominantly T cell lymphoma Juvenile lymphoma  Aged <3yrs  Lymphoblastic  Organomegaly due to diffuse infiltration  Thymus enlargement common  Poorly responsive to treatment Adult onset lymphoma  More common  Aged >3yrs  Lymphocytic  Peripheral and abdominal lymph node enlargement  Clinically ‘well’ initially  Eventual infiltration into viscera  Progressive non-specific signs  Splenomegaly common in ‘normal’ and neoplastic cases Diagnosis  FNA of organ/lymph node  Incisional biopsy of viscera  Excisional biopsy of lymph node  Avoid mesenteric nodes due to interference with vasculature  Cytology of fluid Treatment  Prednisolone as sole therapy  Often gives remission for weeks to months  ?Resurgent lymphoma is resistant to further chemotherapy  Rapid deterioration following recurrence  Cheap, simple and non-invasive  Cyclophosphamide and vincristine poorly tolerated  Treatment limiting neutropaenia TUFTS protocol  Oral and S/C multidrug protocol 1. Prednisolone 2. L-asparaginase 3. Cyclophosphamide 4. Cytarabine 5. Methotrexate 6. Chlorambucil 7. Procarbazine  26 week treatment period with 19 visits  7 haematology samples  Promising results claimed Survival times  Mean survival 6 months (0.5-19 months)  T cell 5 months  B cell 8.4 months  On chemotherapy:  T cell 4.3 months  B cell 8.8 months  Other smaller studies suggest more positive benefits of chemotherapy Co-morbidity  Adrenal disease, insulinoma and lymphoma often seen in combination  ?Multiple Endocrine Neoplastic Syndrome  ?Chronic inflammatory process  ?Viral aetiology  ?Coincidence Adrenal disease Insulinoma  Ferrets living longer lives  Common diseases of elderly animals Lymphoma  Chronic conditions only detected on presentation Vaccination  Distemper is the only routine vaccine given to ferrets in the UK.  Range of recommendations  Full vs ½ or ¼ vial  Yearly, two yearly or even 6 yearly boosters  We give 1 full vial at 12 wks or older and boost every two years  High risk animals may be given an initial dose at 8wk and a second at 12 weeks. Vaccination  Some ferret owners will request vaccination for feline parvovirus.  Parvovirus in ferrets (Aleutian disease) is caused by a mink parvovirus.  There is no vaccine for aleutian disease in the UK.  No clinical evidence that vaccination with feline parvovirus is protective  Not currently advisable Parasite Control  Fleas  Cat flea (Ctenocephalides felis)  Routine control not commonly used unless persistent problems exist.  Frontline Combo and Advocate both licensed for use in ferrets  Ticks  Endoparasites Parasite Control  Fleas  Ticks  More of a problem in working ferrets  Frontline combo licensed  Endoparasites Parasite Control  Fleas  Ticks  Endoparasites  Not treated for routinely  No licensed drugs but doses are available: Drug Dose Use Fenbendazole 20mg/kg PO q24h x5d 50mg/kg PO q24h x30d Cestodes, nematodes Mesocestoides sp Piperazine 50-100mg/kg PO q14d Intestinal nematodes Praziquantel 5-10mg/kg PO, SC repeat in 10-14d Cestodes Thank You For Listening!